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68K User`s Manual

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1. label EQU expression EQU defines a symbol and sets its value to that of the expression This operand may contain complex expressions but not forward references and once defined by an EQU statement or as a program label a symbol s value may not be changed IFxx expression IFDEF label IFP1 IFxx or IFDEF indicates the beginning of a sequence of assembler statements which may be logically conditionally in cluded or excluded from the input to the assembler The xx indicated above must be replaced by EQ GE GT LE LT or NE in order to indicate the condition expression xx zero for the inclusion of the assembler statements which are terminated by a corresponding ENDC ENDIF directive IFDEF includes the sequence of statements if the indicated label is defined IFP1 includes the sequence on the first pass of the assembler but excludes it on the second pass IFxx IFDEF and IFP1 state ments may be nested to 32 aggregate levels INCLUDE filename LIB filename USE filename INCLUDE LIB and USE provide the name of an auxiliary source file which is logically inserted into the current source file in place of the INCLUDE LIB or USE directive The file name must follow the conventions required by the host operating system LIST LIST allows the source listing to be produced unless it is suppressed by an option on the command line NOLIST NOLIST suppresses source listing production NOPAGE NOPAGE suppresses source list
2. Direc Curr lt FCB gt Dr Tr amp Recrd pointer No Sectr Numbr br ot Eoo qT tt toto ot to dt dt ot rF lt We mm ee en ee ee ee ee eee gt Sector buffer begins here B 1 SK DOS User s Manual APPENDIX C NON DISK FUNCTIONS This appendix lists the non disk function calls for SK DOS They are listed twice once in order by name and once by op code LISTED BY FUNCTION NAME NAME OP CODE CLASFY A02E DECIN A030 DEFEXT A024 EXECSD AO1F FINDEV A012 FLUSHT A044 FNPRNT A045 GETCH A029 GETDNT A03F GETNAM A023 GETNXT A02D HEXIN A02F ICNTRL A028 INLINE A02C INNOEC A02A INNOE1 A043 INTDIS A040 INTENA A041 LOADML A022 OCNTRL A032 OUT10D A039 OUT2H A03A OUT4H A03B OUTSD A038 OUT8H A03C PCRLF A034 PERROR A037 PNSTRN A036 PSTRNG A035 PUTCH A033 RENTER A025 RESIO A020 RESTRP A021 STATUS A02B STATU1 A042 TOUPPR A031 VPOINT A000 FUNCTION Classify alphanumeric characters Input decimal number Default extension Execute a SK DOS command Find device number from name Flush Type ahead buffer if any Print file directory name extension Get input character with echo Get date and time into Get file name into FCB Get next character from buffer Input hexadecimal number Input control see Chapter 14 Input into line buffer Get input character without echo with TA Get input character wi
3. Get input character without echo with TA Check keyboard for character with TA Input into line buffer Get next character from buffer Classify alphanumeric characters Input hexadecimal number Input decimal number Convert lower case to upper in D5 Output control see Chapter 14 Output character Print CR LF Print CR LF and string Print string Without CR LF Print error code Output 5 decimal digits Output 5 decimal digits Output 2 hex digits Output 4 hex digits Output 8 hex digits Get date and time Disable interrupts Re enable interrupts to previous status Check keyboard for character without TA Get input character without echo without TA Flush Type ahead buffer if any Print file directory name extension SK DOS User s Manual APPENDIX D DISK FUNCTIONS This appendix lists the disk function calls for SK DOS They are listed twice once in order by name and once by op code LISTED IN ORDER BY NAME NAME OP CODE DIROPN A00B DIREST A026 DISEEK A027 DSREAD A00D DSWRIT A00E FCLOSE A008 FCSCLS A009 FCSINI A01B FDELET A00F FDRIVE A01A FOPENR A005 FOPENU A007 FOPENW A006 FRBACK A015 FREAD A001 FRENAM A010 FREWIN A00A FRGET A016 FRPUT A017 FRRECD A014 FSKIP A011 FWRITE A002 SISOPN A00C SREAD A01C SWRITE A01D FUNCTION Open directory file Disk restore to track 0 Disk seek Read directory or system information sector Write directory or SIS entry Close f
4. Knowing that there are 252 data bytes in each sector we could thus locate any particular byte in a file after some fairly simple calculations For example to locate byte N in a file we could use the following two BASIC lines INT N 252 1 N INT N 252 252 4 Sector number Byte number N in these equations is assumed to start with O the 4 in the second equation is due to the fact that the first data byte in a sector is actually numbered 4 For example the 253rd byte in a file which would actually be numbered 252 would be byte number 4 the first byte in sector 0002 OTHER USEFUL ADDRESSES There are some additional addresses which will be of interest only to programmers who wish to customize SK DOS for their specific systems These are located at fixed offsets above COL DST see the SEQUENTIAL FILES part of this chapter for a description of how to find COLDST Warmstart COLDST 06 Warm Start SK DOS If you exit SK DOS to a ROM monitor or other debugging tool and wish to return you may do a jump to this Warmstart location Don t confuse this location with the WARMST trap described in Chapter 10 GETDAT COLDST 0C Get boot date At GETDAT there is a JMP instruction which points to the routine which asks you for the date when booting SK DOS If there is a clock calendar IC in your system you may replace this JMP with a call to your own routine which reads the date from this IC You must preserve all registers INT
5. ACAT 1 means drive 1 and so on In response to the ACAT 0 command SK DOS loads the ACAT COM program from the disk and executes it displaying a catalog of the disk in drive 0 To halt the listing just press the ESC or escape key Pressing ESC again will continue the catalog listing or pressing CR or RETURN will return to the SK DOS prompt Once the ACAT command 1s finished you may repeat the entire command by pressing control A The control A displays the entire previous command line ACAT 0 as if you had typed it again At this point you may simply perform that command by pressing CR or may backspace and change all or part of the line For example you may backspace to the 0 and replace it with a 1 assuming you have a drive 1 thereby changing the command to ACAT 1 Pressing the CR now would result in a catalog display of the disk in drive 1 Another way of repeating a command is by using the XEQ command XEQ tells SK DOS to execute the last program loaded by SK DOS In this case the last disk resident command loaded is ACAT so XEQ repeats the ACAT command There are two interesting points to note 1 Running ACAT again by typing XEQ is faster than typing ACAT again because typing ACAT loads the program from disk and then executes it whereas XEQ merely restarts the ACAT program without loading it again 2 Pressing control A repeats an entire previous com mand line including any arguments typed as part of that line for exam
6. For example to access the disk through the FCS to read text from a disk file the sequence of operations would be something like this 1 Set up a File Control Block with a DS instruction 2 Point the A4 register to the FCB and call the SK DOS FCS system to input a file name 3 Call SK DOS again to assign a default extension if needed 4 Call SK DOS a third time to open the file 5 Call SK DOS to read a byte from the file and process it 6 Repeat step 5 as long as needed then 7 Call SK DOS to close the file All of these operations use the FCB as a buffer both to hold the contents of an entire sector of data read from or written to the disk as well as to keep track of the file name and location and other pertinent data The FCB is discussed in the next Chapter SK DOS User s Manual 9 THE FILE CONTROL BLOCK The File Control Block or FCB for short is used for all communications between the File Control System FCS and user programs One FCB is required for each file that is opened by a program although that FCB can be reused again if a file is closed thereby releasing the FCB and another file is opened with the same FCB location The FCB is an area of memory 352 or 608 bytes long which must start on an even address Although only 352 byte FCBs are used at this time users should set aside 608 bytes for each FCB so as to be compatible with future versions of SK DOS SK DOS maintains several such FCBs for it
7. OPENNG DC BNE S LEA DC DC MOVE L MOVE B CMP B BEQ S MOVE L DC BNE S CMP B BEQ S MOVE B BRA S DC DC DC CMP B BNE S FOPENW OP ENNG PROMPT PC 4A4 PSTRNG INLINE LPOINT A0 43 A3 D4 23 D4 QUIT A0 A4 FWRITE ERROR 0D D4 NXATLIN A3 D4 NEXTL1 PERROR FCSCLS WARMST 3 FCBERR 44 ERROR IF FILE EXISTS DELETE IT LEA DC DC AND B CMP BNE S LEA DC DC AND B CMP B BNE S wo ASKDEL PC A4 PSTRNG GETCH SDF D5 59 D5 QUIT ASKSUR PC A4 PSTRNG GETCH SDF D5 59 D5 QUIT DELETE FILE IF OK WITH USER MOVE L A0 A4 CODE FOR DEFAULT GO DEFAULT IT OPEN FILE IF ERROR PRINT PERIOD PRINT IT INPUT A LINE POINT TO NEXT GET CHAR CHECK FOR YES SO GO QUIT POINT TO FCB GO OUTPUT CHAR ON ERROR END OF LINE YES START LINE GET CHAR AND REPEAT ALREADY EXISTS NO REAL ERROR ASK TO DELETE GET ANSWER CVT TO UPPER CASE Is IT YES QUIT IF NOT ASK IF HE S SURE GET ANSWER CVT TO UPPER CASE Is IT YES QUIT IF NOT POINT TO FCB SK DOS User s Manual 000070 AOOF DC FDELET DELETE THE FILE 000072 66C8 00003C BNE S ERROR ON ERROR 000074 609E 000014 BRA OPEN OPEN FILE AGAIN TEXT STRINGS 000076 2E PROMPT DC B re 000077 04 DC B 4 000078 5448 4154 2046 ASKDEL DC B THAT FILE ALREADY EXISTS DO YOU WISH TO DELETE IT OOOOAF 04 DC B 4 OOOOBO 4152 4520 594F ASKSUR DC B ARE YOU SURE YOU R
8. When it is encountered SK DOS immediately prints an error message and asks whether you wish to continue anyway If you answer Y then it will return error 1 to the calling program and continue any other answer will immediately abort the program close all files and return to SK DOS The one line explanations of errors are obtained from the ERRCODES SYS file and will only be obtained if this file is on the system disk otherwise only the error number will appear The ERRCODES SYS file also contains explanations for 68xxx exceptions If the processor hits an exception such as a bus error it will print error 1xx where xx is the CPU exception vector number followed by an explanation taken from the ERRCODES SYS file SK DOS User s Manual APPENDIX F DEFAULT EXTENSION CODES The following default extension codes are used by the DEFEXT routine O BIN Binary program file 1 TXT Text file 2 COM Command file 3 BAS Basic language file 4 SYS SK DOS system file 5 BAKBackup file 6 SCR Scratch temporary file 7 DAT Data file 8 BAC Basic compiled file F4 9 DIR 10 PRT 11 OUT 12 BAT 13 SRC 14 PIP Directory Printer file Output file Batch file Assembler source file Pipe NOTE Note that the default extension for commands is COM which is different from the CMD used in 6809 SK DOS This allows 6809 and 68K commands to coexist on the same disk without the danger of accidentally c
9. copying the contents of a large disk to two or more smaller ones The K option is VERY dangerous This command isn t really a copy rather it uses the directory compare routines to delete files from the source disk that appear on the destination This allows you to clear off extra copies of programs not needed on the source disk It operates very fast and will clear off a number of files faster than you can hit reset As with all danger ous options it is protected with an ARE YOU SURE prompt COPY K 1 0is most effective in killing files on drive 1 when they exist on drive 0 COPY KD 1 0 will kill the file on drive 1 when it is older than the file on drive 0 Use COPY KDL 1 0 to preview what files will be deleted The L option disables the file copy subroutine This is used to display a list of files that would have been copied if you hadn t used option L This can be used with other options to check disks for duplicate files newer dates bad files etc The M option is used to convert a SK DOS sequential file into arandom file This option is also used with R to recover a random file by track and sector NOTE this option is not used for normal file copying if the source file is random COPY will automatically make the destination file random The N option is used to copy the files on the source disk that are not already on the destination disk This can be used to add all new files to a backup disk The O option is a dummy character used
10. the file and reads and prints one character at a time The following listing shows how this is done THE LIST UTILITY The LIST program is one of the utilities supplied with SK DOS It is called with a command line which includes the name of the file to be listed after the word LIST as in LIST UTILITY FOR SK DOS 68K COPYRIGHT C 1986 BY PETER A STARK EQUATES TO SK DOS al THE FOLLOWING WOULD NORMALLY BE IN SKEQUATE TXT 00000001 FCBERR EQU 1 ERROR BYTE 0000A A024 DEFEXT EQU A024 DEFAULT EXTENSION 0000A008 FCLOSE EQU A008 CLOSE A FILE 0000A005 FOPENR EQU A005 OPEN FILE FOR READ 0000A001 FREAD EQU A001 READ NEXT BYTE 0000A023 GETNAM EQU A023 GET FILE NAME 00004034 PCRLF EQU SA034 PRINT CR LF 0000A037 PERROR EQU A037 PRINT ERROR MSG 0000A033 PUTCH EQU A033 OUTPUT NEXT CHAR 0000A01E WARMST EQU SA01E RETURN TO SK DOS 000000 ORG 0000 000000 6002 000004 LIST BRA S START GO TO START 000002 0100 VER DC W 0100 VERSION NUMBER START OF ACTUAL PROGRAM 000004 A034 START DC PCRLF START ON NEW LINE 000006 4201 CLR B D1 PREV CHAR WAS NONE 000008 204E MOVE L A6 A0 SAVE POINTER 00000A 284E MOVE L A6 A4 POINT TO USER FCB 00000C A023 DC GETNAM GET FILE SPEC 00000E 640C 00001C BCC S NAMEOK IF FILE NAME OK 000010 197C 0015 0001 MOVE B 21 FCBERR A4 ELSE IT S ERR 21 ERROR ROUTINE 000016 A037 ERROR DC PERROR PRINT ERROR CODE 000018 6142 00005C BSR S CLOSE CLOSE THE FILE 00001A AO1E DC WARMS
11. user FCB without interfering with SK DOS This can save the effort of having to declare memory for a separate FCB As mentioned earlier the USRFCB is 608 bytes long although at this time only 352 bytes are actually used The extra 256 bytes are left for future expansion LINBUF 608 A6 Line buffer 128 bytes The line buffer is a 128 byte buffer which is used by SK DOS for holding and processing commands It is however also accessible to user programs through the INLINE routine which enters text from the keyboard into the buffer and the GETNXT GETNAM and other routines which take data from the buffer In particular note that whenever a user program is called from the keyboard while in SK DOS any remaining text entered after the program name in the command line is still in the line buffer and may be recovered by the user program For example when the LIST program is called from the keyboard with a SK DOS LIST TEXT command when the LIST program begins the line buffer pointer LPOINT points to the first letter of the word TEXT The LIST program can access the name with several subroutines such as GETNAM This is a convenient way of getting and passing arguments to programs directly from the command line BACKSC 736 A6 Backspace character 08 DELETC 737 A6 Delete character 18 ENDLNC 738 A6 End of line character 3A ESCAPC 746 A6 Escape char 1B REPEAC 749 A6 Repeat character 01 These locatio
12. 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 1 10 1 11 1 12 1 13 1 14 1 A 1 B 1 C 1 D 1 E 1 F 1 G 1 H 1 I 1 SK DOS User s Manual 0 BEFORE STARTING In general it is important that you develop good habits when using any floppy disk system It is important that you make frequent backup disks since it is very easy to lose a file or even the data on an entire disk due to a slippery finger or careless mistake Since a Disk Operating System DOS is an extremely powerful program which allows you to access the disk on a most elementary basis exercising caution and making frequent back ups is especially important If possible you should make a backup of the SK DOS system disk before doing anything else If your SK DOS was supplied to you already configured for the disk controller and other hardware you now have then making such a backup is easy 1f your hardware is different from what SK DOS needs then it is not Assuming that your hardware is capable of running this version of SK DOS as is here is what to do to get a backup 1 Make sure the original SK DOS disk is write pro tected On a five inch disk you should place the write protect tab over the slot on one edge of the disk on an eight inch disk you should remove the write protect tab from the disk 2 Place the SK DOS disk into drive 0 close the door and boot it 3 After SK DOS is booted and you get the prompt use the FORMAT command to initialize a blank di
13. 80 but it may be set to any value between 50 and 132 however setting the output line width less than 64 will inhibit output formatting S S S S specifies the generation of the formatted and sorted symbol table listing at the end of the source listing on other than minimum systems TX tx Tx tx indicates type of object file to be produced O for S3 1 for S2 2 for 02 3 for 03 4 for 03 21 5 for 05 6 05 22 either 0 or 3 is usually the default option depending upon the system but minimum systems allow only 0 W w W w causes the assembler to ignore L W l and w suffixes on labels within expressions for compatibility with other compil ers ZXX ZXX ZXX ZXX sets max symbol length to xx bytes the default for minimum systems is 8 bytes and for other systems is 31 bytes source file specifies the main program source file name it must meet all requirements for a legal file name for the operating system under which the assembler is used ext represents an optional file extension by default this assem bler expects a source file name to have extension txt if none is specified object file specifies the name of the object file to be produced it will be suffixed as described above except for minimum systems If the assembler detects missing or invalid information specified on the command line it will output a prompt message indicating the correct format of the command line On o
14. CATALOG protected files will not appear in a catalog or directory listing although the commands supplied with SK DOS ignore this kind of protection b DELETE protected files cannot be deleted c WRITE protected files cannot be written over The PROTECT command is used to assign protection codes to a file To use PROTECT give the command PROTECT followed by the file name followed by one or more of the following codes C Catalog protect D Delete protect W Write protect X Cancel protection G 41 For example the command PROTECT SK DOS SYS WD would prevent SK DOS SYS from being deleted or written over PROTECT LIST COM XD would cancel whatever protection LIST COM currently has and instead substitute delete protection If protection codes contradict each other the rightmost codes take precedence For example the code CDWXC would assign catalog delete and write protection then cancel them all and instead provide only catalog protection SK DOS User s Manual RAMDISK RAMDISK RAMDISK allows you to set aside a fixed area of your RAM memory as a RAM disk also called a virtual disk The RAM disk is an area of RAM which is used exactly like a real or physical disk drive It has a drive number is accessed exactly the same as a real disk has a directory like a real disk and can store programs or data files like a real disk The main disadvan tage of aRAM disk as compared with a real disk is that t
15. CMFLAG 751 A6 752 A6 753 A6 754 757 A6 758 76 1 A6 762 765 A6 766 A6 167 A6 710 773 A6 TTA A6 716 779 A6 782 A6 784 787 A6 788 791 A6 792 A6 793 A6 MEMEND 796 799 A6 ECHOFL FNCASE 800 A6 801 A6 MAXDRV 802 A6 SEQNO ERRVEC DOSORG PLINES PWIDTH NULLWT SLINES PAUSEB 806 A6 834 A6 838 A6 3322 A6 3323 A6 3324 A6 3325 A6 3326 A6 OCOLUM 3328 A6 DEVIN DEVOUT DEVERR DEVTAB FCBPTR USRSPC ENVRON 3274 A6 3275 A6 3276 A6 3278 A6 4006 A6 4010 A6 4074 A6 User FCB 608 bytes Line buffer 128 bytes Backspace character 08 Delete character 18 End of line character 3A Backspace echo 08 System default directory Working default directory Escape char 1B System default drive Working default drive Repeat character 01 Current date month Current date day Current date year Last terminator Pointer to command table long word Pointer to line buffer long word Break Escape address long word Last character read from buffer Previous character read Offset load address long word Execution address flag ML execution address long word Error type File output addr vector long word File input addr vector long word Special I O Indicator Command flag Last usable memory addr long word Input echo flag File Name case flag Maximum drive number Sequence number Alternate ERRCODES SYS vector Absolute ORG of SK DOS
16. DOS from then on SK DOS User s Manual BEEP and NOBEEP BEEP and NOBEEP Assuming that your terminal supports the BELL character ASCII 07 the BEEP command will sound the bell or beep at each SK DOS prompt from then on This is a useful function if you like to walk away from your computer while it is doing a lengthy task Once the BEEP command is given the bell will sound until the computer is rebooted or until the NOBEEP command is used to cancel BEEP SK DOS User s Manual BUILD BUILD BUILD is used to generate a text file on the disk BUILD is not intended to replace a more general purpose editor instead BUILD might be used for testing or generating simple files The BUILD command line must include the name of the file to be generated This is usually done by including a file speci fication after the word BUILD as in this example BUILD TEXT The file specification defaults to a TXT extension unless specified otherwise and also assumes the current working drive G 6 While entering text with the BUILD command you may correct any line by backspacing and retyping a character Or while still in the middle of a line you may erase the entire line and start it over by hitting the control X key Once the line is entered by hitting the carriage return key however it is stored and cannot be changed In other words BUILD is not an editor The BUILD program ignores control characters and is limited to a
17. NO PRINT IT YES GET PREV SAVE CURRENT WAS PREV A CR YES SO SWALLOW IT SAVE CHARACTER READY FOR PRINTING AND PRINT IT WAS IT RETURN NO SO CONTINUE LINE FEED ALSO CONTINUE ADD POINT TO FCB CLOSE FILE RETURN Note also that the program is ORG ed at 0000 When loaded however it will be relocated upward by the current value especially how it checks for the end of file When the read routine detects an error the error code is fetched from byte 1 of the FCB and examined Ifitis an 8 end of file then the program simply finishes up If itis any other error then it goes to an error routine 00000001 000002F6 0000A024 0000A009 0000A00F 00004006 0000A002 00004029 0000A023 OOO0OA02C 0000A037 00004035 00004000 0000A01E BUILD UTILITY FOR SK DOS 68K COPYRIGHT C 1986 BY PETER A EQUATES TO SK DOS FCBERR EQU 1 LPOINT EQU 2F6 THE FOLLOWING WOULD NORMALLY DEFEXT EQU A024 FCSCLS EQU A009 FDELET EQU SAOOF FOPENW EQU SA006 FWRITE EQU A002 GETCH EQU A029 GETNAM EQU A023 INLINE EQU A02C PERROR EQU A037 PSTRNG EQU A035 VPOINT EQU A000 WARMST EQU SAOLE of OFFSET so that it resides in memory just above SK DOS THE BUILD UTILITY The following example shows how to open a file for writing and actually proceed to write into it STARK ERROR BYTE LINE BUFR PTR BE IN SKEQUATE TXT DEFAULT EXTENSION CLOSE ALL FILES DELETE A FILE OPEN FOR WRITE WRITE A BYTE
18. SK DOS User s Manual LIST LIST The LIST command will list the contents of a disk text file SK DOS LIST TEXT to the screen or printer l l would list the contents of the file called TEXT Since LIST is The LIST command in turn requires the name of a fileto intended for listing text files it assumes a TXT extension unless list It assumes that the required file name has been entered on told otherwise Hence LIST TEXT means the same as LIST the same line separated from the word LIST by either a comma TEXT TXT or a space For example G 32 SK DOS User s Manual LOCATE LOCATE LOCATE is used to identify the memory locations into which a binary file will load and to provide the transfer or starting address To use it type the command LOCATE followed by the name of the file desired as in SK DOS LOCATE FILE COM lt gt The file name defaults to a BIN extension if not supplied The above example shows an optional minus sign at the end of the command line This affects the displayed addresses as follows If the is omitted the default LOCATE will print the message ADDRESSES AS IF LOADED WITH CUR RENT OFFSET and display the actual addresses the file would use if loaded or executed with the current OFFSET These addresses consist of the addresses stored as part of the disk file plus the current value of OFFSET G 33 If the is present LOCATE will print the message AD DRESSES AS SAVED ON DISK W
19. SK DOS system calls which pass data and commands to and from device drivers without going through the normal GETCH and PUTCH calls For example when a user program calls ICNTRL with the instructions MOVE B 10 D4 DC ICNTRL the value of 10 is passed through SK DOS to the ICNTRL entry point of the appropriate driver The need for ICNTRL and OCNTRL is based on the need for consistency when SK DOS is implemented on a variety of very different computers Some of these use conventional termi nals but some such as the Atari or Amiga 68000 computers will have built in video and graphics interfaces Since each of these provides different output modes and screen display codes it is important to standardize input and output so that a given program may run on any of these and still provide a common output format All 68K SK DOS calls to GETCH and PUTCH as well as related calls such as PNSTRN or INLINE are sent to the specified driver routine through a portion of SK DOS called IOSEL or I O Selector As explained above the usual device assignments are 0 console both keyboard and screen 1 error device usually also the console 2 printer 3 6 user defined 7 the null device One function of ICNTRL and OCNTRL is to choose which driver is active at any time When you call ICNTRL or OC NTRL with the word FFFx in D4 this selects driver x for input or output respectively All following I O calls via PUTCH GETCH etc as
20. Within each sector the first two bytes are a link pointer and the next 14 bytes are empty filled with zeroes the remaining 240 bytes are split into ten groups of 24 with each set of 24 bytes being one file entry These bytes are used as follows Bytes 0 10 File name and extension Byte 11 File attribute Byte 12 File protection Bytes 13 14 Track and sector number of first sector Bytes 15 16 Track and sector number of last sector Bytes 17 18 File size in sectors Byte 19 Sequential random flag Byte 20 Time of file creation update Bytes 21 23 Month day year of file creation update The first character of the file name byte 0 is replaced by FF when a file is deleted but the remaining bytes are unaltered Hence the CAT command using its N option can display data on deleted files When the directory is first established all bytes in the empty directory are written as zeroes hence when SK DOS searches the directory for a file it stops searching when it gets to an entry whose first character is still 00 Although logically an SK DOS disk can hold one root directory and 26 or more subdirectories physically all of the files are listed in one master directory which is stored as a flat file as described above Within this directory files are coded as to which subdirectory A through Z they belong into by storing the directory code in bit 7 of bytes O through 7 of the directory entry As with all ASCII text in SK DOS file na
21. also the LINK command description G 24 SK DOS User s Manual FROMSDOS and TOMSDOS FROMSDOS and TOMSDOS These two commands are used for transferring text files between SK DOS 68K and IBM compatible PC s running MS PC DOS using the 180K disk format one side of a standard 360K disk To transfer a disk between an MS PC DOS system and a SK DOS system proceed as follows 1 First use the MS PC DOS FORMAT command to generate a special single sided transfer disk The command is FORMAT A 1 which assumes that the disk is in drive A It is important to start with a fresh newly formatted disk Then do one of the following 2a To transfer a text file from MS PC DOS to SK DOS simply copy it to this disk and then convert it to SK DOS format with FROMSDOS Note that only one file may be copied to this disk If you have more than one file you must use a fresh disk for each The syntax for using FROMSDOS is FROMSDOS lt MS PC DOS drive number gt lt SK DOS file spec gt For example to copy a file from an MS PC DOS disk in drive 1 to FILE TXT in drive 0 the command would be FROMSDOS 1 FILE The SK DOS file specification defaults to the working drive and a TXT extension unless specified otherwise so the file goes to O FILE TXT if drive 0 is the working drive G 25 2b To transfer a file from SK DOS to MS PC DOS take the disk formatted above to your PC system and run the follow ing Basic program using the PC s
22. appear to skip a number this is the number that would have been assigned to the copied file if it had not kept its old number 3 Since the sequence number is just a single byte the maximum number is 255 after which it returns to 0 SCAT arguments are the same as those for ACAT SK DOS User s Manual SK DOS09 SK DOS09 SK DOSO9 is 6809 SK DOS along with a 6809 CPU simulator which allows you to run 6809 SK DOS programs on your 68K computer This allows you to run programs which may not be available for the 68000 though at reduced speed To run SK DOSO9 simply type the command SK DOS SK DOSO9 As soon as the program runs you will be greeted by the familiar SK DOS signon except that this time it will be 6809 SK DOS that is running on your computer and the prompt will change to SK DO9 Since your 68K computer is essentially interpreting 6809 instructions you will notice a slight slowdown in operation On input and output such as listing a disk directory you will hardly notice a difference whereas on heavy computing there may be a significant slowdown depending on the program being run Even so you may want to do certain operations such as copying a disk in 68K mode since that will always be faster SK DOSO9 will run most 6809 software although there may be some programs which do not work This will generally include those which access I O hardware or other machine parameters directly bypassing DOS This includes for
23. brief summary of EDLIN commands SK DOS User s Manual FIND FIND FIND may be used to find specific occurrences of a string SK DOS FIND SKEQUATE END within a text file The syntax is will display the line number and text of every line which contains SK DOS FIND lt file spec gt lt search string gt the string END For example the command SK DOS User s Manual FORMAT FORMAT FORMAT is used to initialize a blank floppy disk and prepare it for use with SK DOS It completely erases a disk writes the System Information Sector on the disk initializes an empty directory and sets up the remainder of the disk as free space This section describes the FORMAT command in general terms the particular FORMAT command provided for your particular disk controller may be slightly different but the general operation will be the same Note also that there is a different format program called HDFORMAT for the hard drive To format a disk enter the command FORMAT followed by the drive number For example SK DOS FORMAT 1 would format the disk in logical drive 1 FORMAT will then ask for more information before it proceeds The questions it asks depend on the controller The 1772 or similar controllers With the Western Digital WD1772 or similar 1770 2790 etc controllers FORMAT will continue by asking HOW MANY TRACKS to which you may answer any number from 2 through 80 Be sure not to specify more tracks than your dr
24. character NULLWT 3324 80 DN A6 Null wait constant Some terminals or printers make errors if a carriage return or line feed character is immediately followed by printable characters In that case NULLWT may be used to insert a short delay It is normally initialized to 00 or no delay but may be changed by the user via the DOSPARAM command The wait delay depends on the CPU clock speed but is approximately equal to 0 01 second times the value of NULLWT SYSDIR 744 A6 System default directory WRKDIR 745 A6 Working default directory Both of these locations are initialized at 0 They are used as default directories SYSDIR is used as the default for loading any disk resident command while WRKDIR is used as a general default by the GETNAM routine whenever a directory is not specified as part of a file spec A value of O refers to the main or root directory while values of 41 through 5A refer to sub directories A through Z since these are the ASCII equivalents for the letters A Z SYSTDR 747 A6 System default drive WORKDR 748 A6 Working default drive Both of these locations are initialized at 0 They are used as default drive numbers SYSTDR is used as the default for loading any disk resident command while WORKDR is used as a general default by the GETNAM routine whenever a drive number is not specified as part of a file spec CMONTH 750 A6 Current date month CDAY 751 A6 Current date day CYEAR 752 A6 Curr
25. described above Then execute your Basic interpreter and load PICTEST BAS When it is executed PICTEST BAS will ask for the names of the two binary files to be compared If any differences are found between the two programs PICTEST BAS will print out the address where the difference was found Once such a list of addresses is found you should check these against a listing of the program being tested Some differ ences may be valid depending on your programming style others may be caused by errors such as perhaps forgetting to use BSR instead of JSR or forgetting to use PC after a variable name G 39 SK DOS User s Manual PROMPT PROMPT PROMPT allows you to change the system prompt from the PROMPT only changes the prompt currently in memory it normal SK DOS to any other string For example users who does not change the prompt string on the boot disk Hence the feel more at home with a shorter prompt such as perhaps three original SK DOS prompt will return the next time you boot the plus signs can change the prompt with the command system Moreover PROMPT may only be used once that is SK DOS PROMPT once PROMPT changes the current prompt it cannot change it again unless you reboot the system The new prompt may be up to 10 characters long and may E y 7 include any printable character G 40 SK DOS User s Manual PROTECT PROTECT Files may be assigned one or more kinds of protection codes as follows a
26. drive number corresponds to which drive select To properly set up a system therefore requires that you use the IS command in HUMBUG to tell the system which controller and drive select goes with which F number and then use the DRIVE command in SK DOS to tell it which F number goes with which logical drive number When you do the IS command HUMBUG will ask you which controller you want to boot from that controller will then have FO Since the 1772 can have up to four drives selecting it for booting will give it FO through F3 the 37C65 would then get F4 and F5 On the other hand if you select the 37C65 for booting it will get FO and F1 while the 1772 will get F2 through F5 The system will always boot from FO when you give the FD command so there must always be an FO drive Other than that you can skip drives so there could be an FO and an F5 perhaps Any time you want to know what the relationship is between F numbers and drive select numbers you can find out by using HUMBUG s IS command or by using DRIVE or IOSTAT in SK DOS 8 INCH FLOPPY DISK DRIVES It is unlikely that you will want to use 8 inch floppy drives but in case you do the WD37C65 controller can do it The drive may be connected through this conversion cable 34 pin cable 50 pin cable Function Track 44 76 36 38 40 42 44 46 14 Read data If you connect this adapter directly to the controller the 8 drive will be drive select 1
27. exam ple programs which require interrupts such as some text editors with type ahead buffers It also means that you cannot use a 6809 FORMAT program to format the disk you must use the 68K FORMAT instead Furthermore although you might be tempted to use the 6809 SK DOS s TTY command don t bother I O is handled by the 68K SK DOS and so use its DOSPARAM command instead There may be other programs which don t run as well programs which use some particular characteristic of the 6809 CPU which is difficult or impossible to simulate on the 68K CPU If you do run across some such example let us know and we will try to suggest some other approach While running SK DOSO9 the ESCape key works nor mally to temporarily pause output if you follow it with CR or RETURN or ENTER whichever it is called on your terminal you will return to either SK DOSO9 or in some cases to the application program running under SK DOSO09 G 48 Just as the MON command in normal SK DOS 68K brings you back out one level to the program which called it namely the monitor or boot ROM so MON in SK DOSO9 brings you out one level to the 68K SK DOS when you want to exit Finally a few technical details SK DOSO9 requires a minimum 128K system and devotes the entire second 64K of that system from 10000 to 1FFFF to simulating the 6809 environment Each location of that 64K pseudo memory cor responds to the equivalent location of a normal
28. first digit of codes above 99 must be replaced by its corresponding ASCII character For example code 100 is represented by 0 since the colon comes after the 9 in the ASCII code and thus the colon represents the digits 10 SK DOS User s Manual APPENDIX I ASM THE 68000 68010 ASSEMBLER by Edgar M Bud Pass Ph D Supplied with SK DOS 68K by arrange ment with and Copyright 1987 by Computer Systems Consultants Inc 1454 Latta Lane Conyers GA 30207 Telephone Number 404 483 4570 1717 Copyright Notice ASM the 68000 68010 Assembler and this appendix are copyrighted and should not be reproduced in any form except as described here without prior written consent of an officer of Computer Systems Consultants Inc The accompanying disk ette may be duplicated for backup purposes by the original license purchaser Protecting the software from unauthorized use will protect your access to new good software in the future Programs such as the ASM assembler would cost each user many hours or many thousands of dollars to develop individu ally They may be priced so low only because of the expected large volume of sales So let your friends pay for their software too Limited Warranty Statement Computer Systems Consultants Inc and its agents makes no express or implied warranties concerning the applicability of the ASM 68000 68010 assembler to a particular purpose Lia bility is limited to the original license cost T
29. for parking the heads of hard drives Winchester drives It is called simply with SK DOS PARK and takes its parameters from the data stored on the disk during formatting Parking the heads of a hard disk drive moves them to a section of the disk which is not used and prevents possible damage to the usable portion of the disk surface or to the data stored on it Parking the heads before moving a disk drive is generally regarded as desirable although there is some disagreement G 36 among users as to whether parking heads is necessary when just shutting the system off Nevertheless it is our opinion that devoting a part of the disk to a parking area and then always parking the heads in that area before shutting off the power is a sensible precaution despite the fact that it may slightly reduce the disk capacity The literature accompanying some drives specifies a park cylinder to be used if so then the choice is simple In other cases however the choice may not be so clear SK DOS User s Manual PDELETE PDELETE The PDELETE command is used to rapidly delete one or more files from a disk Its advantage over DELETE is that you need not type in individual file names since PDELETE will prompt you with the file names The syntax for using PDELETE is SK DOS PDELETE lt drive number amp directory gt lt op tional match list gt The first parameter must include a drive number and may also include a directory name If on
30. how much memory is installed in the system it then uses this information to set MEMEND MEMINI sets the highest address that SK DOS will try during that test This is essential in those systems which may not return a buss error if non exis tent addresses are accessed but can also be used to set aside an area of memory which SK DOS will never use SK DOS User s Manual SECTRD COLDST 20 Secondary sector read rou tine trap SECTRD normally contains 10 RTS instructions a total of 20 bytes which are called each time SK DOS calls the SREAD routine to read a sector A4 at this time points to the FCB being used for the read A user may substitute up to three alternate sector read routines by inserting JSR instructions which point to these other routines This allows the simple addition of a cache RAM disk or alternate disk controllers Such routines must preserve AO through A4 and DO through D4 When such JSR instructions are added they will normally go to a routine which analyzes the drive number in the specified FCB If the drive number is different from the one handled by this secondary disk read routine then it should perform an RTS to return to SK DOS if the drive number matches then the routine should perform the requested read remove from the stack the extra return address placed there by the added JSR and then RTS directly back to the calling program SECTWR COLDST 34 Secondary sector write rou tine trap SECTWR normally con
31. into the destination file but the SK DOS load routine uses only the last transfer address given SK DOS User s Manual BACKUP BACKUP The BACKUP command is used to make an exact backup of a disk This command requires two drives If BACKUP encounters an error on either the source disk or the destination disk it will display an error message but continue copying until it finishes the disk To call BACKUP enter the command BACKUP followed by the drive numbers of the source and destination drives as in SK DOS BACKUP 0O 1 This command would copy from drive 0 to drive 1 The two drive numbers must be entered and must be different Note carefully BACKUP copies from the first drive specified to the second drive Before BACKUP can be used you must format the destina tion disk with the FORMAT command Furthermore the des tination disk must have at least as many tracks and sectors as the source disk Ifithas fewer tracks or sectors then BACKUP will display an error message and stop After BACKUP is finished the destination disk will have the same apparent number of tracks and sectors as the source disk For example suppose you BACKUP a 35 track single density 5 1 4 disk ten sectors per track onto a 77 track double density double sided 8 disk The destination disk will have only 35 tracks and ten sectors per track In reality the remaining tracks and sectors will still be there but will be completely inaccessible to SK
32. is being done in reading or writing the current file Values of O through 127 9 2 00 through 7F indicate that space compression is being done and the actual value represents the number of spaces currently being compressed A value of 255 FF indicates that no space compression is being done SK DOS initializes this byte to 00 upon opening a file it is up to the user to change it to FF after opening the file but before reading or writing if space compression is not desired Byte No 60 Number of sectors per track This byte contains the number of sectors per track during random file operations See Chapter 13 for further information on random files Byte No 63 Reserved This byte is reserved for use by SK DOS Bytes No 64 67 Reserved These bytes are reserved for future expansion Bytes No 68 71 Next FCB pointer These four bytes point to the next FCB if any which was opened after this one or more exactly they point to the corre sponding bytes of the next FCB not to the beginning of that FCB This information is used by SK DOS to keep a list of all FCBs currently in use so that they can be closed if an FCSCLS operation is requested If this is the last FCB in the chain then these bytes contain zeroes Byte No 72 Physical Drive Number Using the DRIVE command SK DOS allows you to reas sign logical drive numbers to different physical drives this byte contains the physical drive number actually used by t
33. it may happen that the system will not properly work if the initial setup locations of the RAM accidentally contain information which fools SK DOS into thinking that you have this floppy disk controller If that happens use HUMBUG s FM command to zero out memory locations FFOBE8 through FFOBFF Normally this will not be a problem since it is very unlikely that these locations will contain just the right information to confuse SK DOS s disk drivers Chapter 14 gives further information on the disk drives and formats which are supported by this version of SK DOS 0 1 SK DOS User s Manual 1 INTRODUCTION The Disk Operating System or DOS for short is a program which acts as a file manager for a disk The DOS acts as a buffer between the disk hardware and the software which uses that disk Its primary function is to maintain a disk directory on each disk fetch program or data files from the disk as needed and store programs or data back on the disk SK DOS consists of three major parts 1 The Command Processor System or CPS which is the major interface to the user When SK DOS is active the CPS monitors the keyboard and waits for user commands At that time you can load and execute programs from the disk and do certain other functions In addition the CPS has a number of routines which can be used by other programs to simplify input and output for the terminal 2 The File Control System or FCS is the interface for pro
34. lt Y LIST READ ME then SK DOS will set up a 300K RAMdisk as drive 4 and then list the contents of the file READ ME TXT after it asks for the date just before it prints its first prompt 2 The lt Y in the previous example tells SK DOS to use the text from the Y PIP file as keyboard input As you recall the Y PIP file we supply on your system disk contains several dozen Y letters Since the RAMDISK command normally asks you for confirmation that you really want to set up the RAMdisk the lt Y tells SK DOS to use one of those Y letters as your answer rather than waiting for you to type ina Y 3 To save memory space as well as to allow some customization of messages the one line explanations printed with error messages are contained in a file called ERRCODES SYS Whenever PERROR prints out an error code it looks on the current system drive for the ERRCODES SYS file If that file is present then PERROR searches for the appropriate error number in that file and prints the text immediately following that number You may LIST ERRCODES SYS to see the file format and may make changes with any editor to suit your taste The ERRCODES SYS file contains error codes above 100 although SK DOS itself only uses error codes through 30 These higher codes are used for 68K exception vectors Each line of the file begins with a two character error code number in order to allow error codes through 240 to be represented with just two characters the
35. more complex editor program In keeping with its simplicity EDLIN has several limita tions It cannot handle a line longer than 79 characters and it is limited to working with text files which fit wholly into memory This may be a problem if you only have a few K of free memory but should not be a limitation in most 68K systems It does not provide a full screen display but limits you to working with one line at a time EDLIN is called with the command SK DOS EDLIN lt file spec gt where the lt file spec gt is the name of the file to be generated or modified If not specified the extension defaults to TXT If the file already exists it will be read into EDLIN s memory and can then be edited When you exit EDLIN will rename the old file to an extension of BAK deleting an old BAK file if it exists and rewrite the new file with the same name as the old EDLIN is a line editor That is it works on lines of text Each line of the file has a line number these numbers are dynamic in the sense that they automatically change as new lines are added or deleted Each time a line is printed out its current number is printed with a colon at the left as in 5 THIS LINE IS NOW LINE 5 OF THE FILE At any time you work on a so called current line which is your base of operations You can move up or down from that line but many operations can only be performed on this one current line EDLIN has two operating modes command mod
36. next instruction is invalid and will not be changed to a long branch For unsized instructions length modifiers are generally ignored Certain instructions ADD AND CMP EOR MOVE NEG OR and SUB have variations in their basic operation codes beyond length modification The following variations are normally handled by this assembler but may be coded explicitly as follows A address register operation ol immediate operation SK DOS User s Manual Other variations must be coded explicitly as the assembler has no manner in which to determine that they were desired as follows M memory operation Q quick immediate operation DAA extended carry operation For the MOVEM instruction if only one register is present in the register list it must appear as Dx Dx Ax Ax Dx Dx or Ax Ax The syntax of the MOVEM requires a register list not a register The BKPT MOVEC MOVEM and RTD instructions and the MOVE CCR and MOVE CCR variants of the MOVE instruction are invalid when the 68000 option m0 is chosen on the command line as these are all 68000 68010 instructions Error Messages Most error messages are self explanatory however all of them are briefly explained in the list below For minimum systems only error numbers are output by the assembler 19 Assembler error An internal error in the assembler has been detected probably caused by syntax errors in the statement 07 Bad 16 bit displacement The displ
37. on the controller if you connect it to the twisted end of anormal floppy connector then it will be drive select 0 on the controller SK DOS User s Manual APPENDIX A USER ACCESSIBLE VARIABLES SK DOS variables of interest to the machine language programmer are listed below They should be addressed using indexed addressing with A6 LISTED IN ORDER BY NAME NAME ADDRESSES FUNCTION BACKS BREAKA BSECHO CDAY CMFLAG 736 A6 762 765 A6 743 A6 751 A6 793 A6 CMONTH 750 A6 COMTAB CURRCH CYEAR DELETC DEVERR DEVIN DEVOUT DEVTAB DOSORG ECHOFL ENDLNC ENVRON ERRTYP ERRVEC ESCAPC EXECAD EXECFL FCBPTR FIADDR FNCASE FOADDR LASTRM LINBUF LPOINT 754 75 7 A6 766 A6 752 A6 737 A6 3276 A6 3274 A6 3275 A6 3278 A6 838 A6 800 A6 738 A6 4074 A6 782 A6 834 A6 746 A6 716 779 A6 TT4 A6 4006 A6 788 791 A6 801 A6 784 787 A6 753 A6 608 A6 758 761 A6 MAXDRV 802 A6 MEMEND 796 799 A6 NULLWT 3324 A6 OCOLUM 3328 A6 OFFSET PAUSEB PLINES PREVCH PWIDTH REPEAC SEQNO SLINES SPECIO SYSDIR SYSTDR USRFCB USRSPC 710 773 A6 3326 A6 3322 A6 767 A6 3323 A6 749 A6 806 A6 3325 A6 792 A6 744 A6 7A1 A6 0 A6 4010 A6 WORKDR 748 A6 WRKDIR 745 A6 Backspace character 08 Break Escape address long word Backspace echo 08 Current date day Command flag Current date month Pointer to command table lon
38. passed to or from a device driver and other device functions See Chapter 14 for a more complete explana tion FLUSHT A044 Flush Type ahead buffer if any This function flushes empties the keyboard typeahead buffer Gf implemented see Chapter 14 FNPRNT A045_ Print file name This function formats and prints the directory and file name but not drive number pointed to by A4 In memory the name should consist of 11 bytes 8 for the directory and name and 3 for the extension with no period between them In addition D4 B is used to specify whether to provide spaces for missing items If D4 B is zero then the name might be printed as just NAME EXT if D4 B is not zero then there would be two spaces before NAME leaving space for a possible directory name and four spaces between NAME and the period leaving space for an 8 character name Furthermore if the extension is missing zero in memory then using a non zero D4 B would leave three spaces after the period GROUP B DISK FUNCTIONS The following SK DOS functions involve reading or writ ing disks FCSINI A01B Initialize File Control System This function should not normally be used by user programs as it can result in corruption of the disk It totally initializes the system disk drivers are initialized all open files are forgotten and left open etc FCSCLS A009 Close all open files This routine allows user written programs to close all open files withou
39. record containing an optional 16 bit 2 byte xfer address and terminates a group of S1 records The number of bytes to follow is indicated as two hexadec imal digits If an address or value is to appear in this record it follows the length field just described it is represented in hexadecimal If data appears in the record it follows the starting address and is represented in hexadecimal The one s comple ment checksum of all of the items is indicated as two trailing hexadecimal digits ASM also produces the following object file types which are compatible with SK DOS comments default none none byte offset none none none xfer address xfer address def ault xfer address The naming of the object file produced by ASM is dependent upon the type of object file The following table provides the extensions 02 03 05 com 3 S2 68000 68010 Instruction Syntax The syntax of the assembler language accepted by this assembler is compatible with the standard language as im plemented by the Motorola 68000 68010 Resident Structured Assemblers Upper and lower case letters in instructions are not consid ered unique For those instructions with length modifiers the suffix w will usually be assumed if none is provided in the instruction field Branch instructions must be coded with s to indicate short branches or with 1 or without suffix to indicate long branch instructions A short branch to the
40. routine to flush typeahead buffer 68 79 Reserved for future use All of the above pointers and numbers are distinct for each device number The constants from PLINES down can be dis played or changed with the DOSPARAM command DEVIN DEVOUT AND DEVERR DEVIN DEVOUT and DEVERR are three bytes which indicate the current input output and error device number respectively Normally DEVIN and DEVOUT contain the num ber 0 indicating that they use device 0 while DEVERR contains the number 1 indicating that error messages from PERROR normally go to device 1 T O REDIRECTION FROM PROGRAMS Temporary I O redirection from the keyboard can only be done one way by using the gt and lt symbols on the command line Permanent redirection can be done by installing another driver I O redirection is done by programs in a totally different way since programs cannot install new drivers In general there are several methods available to programs for accessing different I O devices Moreover programs can access devices through file control blocks or can access files through device numbers 1 Normal console I O functions such as PUTCH GETCH PSTRNG INLINE OUTSD HEXIN and the like are all steered through DEVIN in the case of input functions or DE VOUT in the case of output functions Programs can change DEVIN or DEVOUT to different device numbers to use differ ent devices for these functions For example when a program wants to ou
41. space of a disk is reorganized with REDOFREE files can no longer be undeleted SK DOS User s Manual VERIFY VERIFY VERIFY is used to turn floppy disk verification on or off The correct syntax is VERIFY ON or VERIFY OFF Normally SK DOS defaults to verifying all sectors it writes to a floppy disk Disk operation however will be much faster if verification is turned off We feel that verification is desirable after all disks do occasionally make errors and therefore SK DOS normally has verification enabled unless you specifically turn it off There are however some major manufacturers who feel that verification is not necessary and whose systems default to verification off Although we do notrecommend turning verification off you may wish to do so for specific applications for example while using HTOF or while doing a backup These are cases where you can easily check the accuracy of the new disk by doing a CHECKSUM on it For example here is a way to do a very fast hard disk backup onto floppies by turning off verification G 56 1 Use VERIFY OFF to turn off verification 2 Enable the disk CACHE making sure it is large enough to contain the entire destination disk For example use a 750K cache for a 700K disk 3 FORMAT a fresh floppy disk once the empty cache is set up This reads the entire empty disk into the cache 4 COPY files to the destination disk using the A option of COPY to copy in alphab
42. the pointer SK DOS User s Manual UBASIC UBASIC UBASIC is not intended to replace a full featured Basic but does suffice for some applications It currently supports the following Basic operations FOR TO STEP RUN ON GOTO LIST ON GOSUB NEW PRINT STOP INPUT DIM READ GOSUB RESTORE RETURN POKE dec addr byte DOS GO TO INT IF GO TO TAB IF THEN ABS LET CHRS REM LOAD DATA SAVE NEXT LPRINT PEEK dec addr LLIST Decimal addresses in the above can be 0 through 16777215 but note that trying to PEEK or POKE a nonexistent address may lead to a BUS ERROR Although this Basic allows string constants as in PRINT HI it does not allow string variables such as A Only one statement per line is allowed the arithmetic is floating point G 54 BCD with nine significant digits and no exponentiation is allowed Variable names can be A through Z and AO through Z9 but array names can only be A through Z one or two dimensions of 1 through 255 are allowed but subscripts start with 1 not 0 LPRINT and LLIST are similar to Print and List respec tively but output to device 3 instead of the current output device DEVOUT usually 0 This Basic is a modification of the by now almost classical 4K Basic written by Robert H Uiterwyk for the first 6800 machines in the mid seventies The Basic 6800 version of the interpreter is in the public domain and the original Version 2 1 sou
43. the system does not contain a clock calendar chip then this number is written into the disk directory along with the date for the file if a clock calendar chip is interfaced to SK DOS then the sequence number is replaced by the time although it is still calculated and stored in SEQNO Since the sequence number is just a single byte it has a maximum value of 255 then it returns back to O and repeats its cycle ERRVEC 834 A6 Alternate ERRCODES SYS vector ERRVEC allows SK DOS to get its error messages from a file other than ERRCODES SYS If this long word contains 0 then the normal ERRCODES SYS file is used if it is non zero then it is assumed to hold a long word address pointing to an 11 character file specification containing the name and exten sion of another file to be used ERR VEC is initialized at O when SK DOS is booted but is not changed thereafter hence user programs should be careful to restore it when they are finished using other error files DOSORG 838 841 A6 Absolute ORG of SK DOS DOSORG contains the actual starting address of SK DOS in the current system This information is primarily for systems programmers as most users will have no need to know absolute memory addresses 11 3 OFFSET 770 773 A6 Offset load address long word OFFINI DOSORG 18 Initial OFFSET value long word The contents of OFFSET is added to the load address and transfer or execution address for all machine language pro grams loaded
44. therefore partition the disk into 2 to 4 partitions Would you like to partition the disk Y N In order to use the full 19 megabyte disk you must partition it into at least two partitions Each of these partitions becomes a separate logical drive and there is a maximum of four parti tions allowed per hard disk Even if a drive does not exceed 16 megabytes you may still partition it even though you do not need to in our particular example you must answer Y to the last question since the drive is just too big for one partition Assuming a Y answer HDFORMAT then asks How many partitions would you like SK DOS User s Manual Still assuming our previous example suppose you answer 3 to make three partitions Then the next series of messages is You will now partition the disk by Cyl inders Tracks The TOTAL number of us able cylinders on this drive is 615 The MAXIMUM number of cylinders al lowed in any one partition is 512 The MINIMUM number of cylinders al lowed in any one partition is 5 Decide how you would like to split up the TOTAL number of cylinders and enter the counts Cylinders for Partition HO 205 Cylinders for Partition H1 205 Cylinders for Partition H2 205 In this example we split the disk evenly by assigning 205 cylinders to each partition Although there is no need to make the partitions equal it may be convenient if you intend to use BACKUP to quickly copy one partition to another Assumin
45. they are written to the disk For example if the current OFFSET is 8000 then the file stored in the above example would contain addresses 1000 2000 and 1004 When loaded back into memory with GET however these addresses would be added back to OFFSET so that the file would go back into the same memory area it was saved from assuming OFFSET remained the same Option 2 cannot be used however if OFFSET is larger than any of the specified addresses in this case SAVE will print an error message and abort before finishing the file You should try saving a few files and then examining them with LOCATE to get a feeling for these two options SK DOS User s Manual SCAT amp SEQUENCE SCAT amp SEQUENCE SCAT is similar to CAT but differs in three ways 1 SCAT prints both the date of each file as well as its sequence number if one has been assigned to the file 2 The catalog listing is sorted by date and sequence number so that the most recent files appear first 3 SCAT does not allow all of the options used by the CAT command SCAT is designed for systems which do not have a clock IC installed If you do have a clock then you should read the description of the TCAT command which along with time stamping provides greater capabilities When a clock is not installed and interfaced with SK DOS as described under TCAT then SK DOS automatically assigns a sequence number to each file as it is written or updated Thi
46. to convert special key charac ters or sequences into a single byte which will be returned in D5 For example suppose a given terminal has a row of ten function keys which generate a two byte sequence such as ESCape followed by 30 for key FO and so on Using GETCH we would get back two separate characters a 1B for the ESCape and a 30 for the 0 The problem here is that we have no way of knowing whether this sequence came from function key FO or whether the user really typed an ESCape and then the digit 0 The command 0002 of ICNTRL would return the same two characters but with the parity bits intact if any ICNTRL command 0005 works a bit differently After it detects the ESCape code ICNTRL waits for approximately one half character time If it receives the 30 during that time then it assumes that the combination came from a single FO function key and returns a special code which signifies the FO key If the 30 is not received during that time then ICNTRL returns the ESCape first and then picks up the next character on the next pass The next character may also be returned by GETCH This description assumes a serial terminal keyboard computers with an integral keyboard may return a special func tion key code directly In order to generate the same special FO code with different terminals or computers the device driver has a translation table which converts any specific combination of one or more keys into an FO code wh
47. to turn off all default options if you do not want any options If used with any other option letters it has no effect The P option enables this prompt Prompt off P SK DOS S copy Y N You should respond with P if you want to continue copying without the promptor S to return to SK DOS or Y to copy this file N or any other character will skip to the next file This is useful for scanning through a disk copying only certain files Another use is skipping down to a certain file on a disk and copying all files after that The R option is used to read a file without using the directory If the directory of a disk has been destroyed but the user knows the file s starting address the file can be recovered Thecommand COPY R 1 2B 5 0 NEWFILE willread from drive 1 track 2B sector 5 until encountering an end of file or a record out of sequence The write file extension will default to SCR A second use for this option is to recover a deleted file the first sector of a deleted file can be found with the N option of CAT If the file has not been over written COPY can recover it Record sequence checking eliminates UNDELETE s restric tion that the file be the last file deleted Provision was made to start copying in the middle of a file This is a somewhat dangerous option since it allows the user to override the SK DOS File Control System The command must be typed as shown with three numbers and a file name Only a few other options ca
48. usually at the beginning of the line buffer and the command should end with a CR or ENDLIN character If the command line in turn executes a disk resident program then that program should end with a DC WARMST instruction to return to SK DOS SK DOS in turn knowing that the program was called from another user program will return control to the user program The user should be careful not to call a program which will overlay part of the calling program in memory STATUS A02B STATU1 A042 Check keyboard for character Check Keyboard for character by pass typeahead is routine allows a user program to check whether a character is being entered from the keyboard If no character is being entered the Z bit in the condition code register is set if a character is being entered then the Z bit is clear All other registers are preserved STATU1 is similar but bypasses typeahead if implemented see Chapter 14 INTDIS A040 Disable Interrupts This routine masks interrupts to level 7 thereby preventing the CPU from being interrupted by level O through 6 interrupts This SK DOS call is intended only for use by advanced pro grammers and then only in systems programs such as FOR MAT INTENA A041 Re Enable Interrupts This routine restores interrupts to the same status as existed before the last previous INTDIS call Make sure not to use INTENA unless it has been preceded by a INTDIS This SK DOS call is intended only for use
49. well as ICNTRL or OCNTRL are then vectored to that driver until you change the driver assignment with another call to ICNTRL or OCNTRL or changed DEVIN or DEVOUT On initial cold start 68K SK DOS initializes both input and output to FFFO so that the system defaults to SK DOS User s Manual using device 0 the console keyboard and screen Hence the casual user need not generally be concerned with ICNTRL or OCNTRL The second function of ICNTRL and OCNTRL is to pass special arguments to the selected device or input special key characters from the device The important requirement is that all SK DOS users agree on these arguments so that all drivers and all I O devices will respond in the same way regardless of which computer is being used The following sections describe this feature ICNTRL Assignments ICNTRL is used by placing a command code into D4 and doing a DC ICNTRL instruction The device driver may then return an argument in register D5 The current command codes are as follows 0000 Return number of current driver 0 7 in D5 0001 Return the name of current driver such as CONS in D5 Return a raw 8 bit character from the device Enable keyboard s function keys Disable keyboard s function keys 0005 Return a special character from the device FFFx Switch to driver x Additional other commands may be defined in the future Some device drivers will contain an input translation table and code which allows the driver
50. which will match against any character in a file was recently deleted and you have not written enough new files name Here is an example of an elaborate CAT command on the disk to reuse the deleted file s sectors CAT will display CAT AM 1 C AD TXT J M BAK a dash as the first character of the file name This option is i l l useful if you intend to use UNDELETE The A and M options specify an alphabetized maximum P This option will enable a paging subroutine toplaceblank listing of files in the C directory of drive 1 Only files satisfying lines on the top and bottom of the page This is handy when one of the following three criteria will be shown 1 any file listing a disk with a large number of files The printer width Whose name begins with AD 2 any file having a TXT exten equate is picked up and used to calculate the number of columns sion or 3 any file whose name begins with J whose third letter allowed for each form of the printed listing is an M and which have a BAK extension l l R The R option allows CAT to re start A prompt will The original CAT program and documentation were writ appear at the end of each CAT enter E to exit to SK DOS or ten by and provided through the courtesy of Bruno D Puglia and Leo E Taylor G 8 SK DOS User s Manual CHECKSUM CHECKSUM CHECKSUM is used to generate and display a sum of all the bytes on a disk The check sum is shown as an 8 digit hex number CHEC
51. 1 4 size and the most recent 3 1 2 size A still newer 2 size is likely to come into use in the next few years but is not common yet The data on a disk is written in circular tracks All 8 disks have 77 tracks while all 3 1 2 disks have 80 tracks Ancient 5 1 4 disks had 35 tracks but modern ones have either 40 or 80 tracks In the 5 1 4 case both kinds occupy slightly more than 3 4 of total width on the disk but in one case there are 40 wide tracks in the other there are 80 narrow tracks By making the tracks narrower and closer together the 80 track drive puts extra tracks into the position that would normally be between tracks on a 40 track drive Hence an 80 track drive can read a 40 track disk if it double steps that is if it skips over the in between areas between tracks The 80 track drive can also write a 40 track disk but there is a catch a 40 track drive may not be able to read it The reason is that the 80 track drive writes a narrower track which leaves some unrecorded space on each side Depending on the exact width and alignment of the track the 40 track drive may read so much of the garbage between tracks that it makes too many errors to be reliable The only way to tell is to try Disks also come in three densities SD or single density which is now quite obsolete DD or double density which is most common and HD or high density which has several variations and is the newest What is most confusing i
52. 6809 computer system For example the warm start location of 6809 SK DOS is CD03 while in SK DOSO9 it is located at 1CD03 The initial 1 is however totally transparent to 6809 software which simply addresses that location as CDO3 as it always has done since the address translation is done entirely by SK DOSO9 Just as in a true 6809 system though only the first 56K 1s actually used the last 8K which would normally be taken up by 6809 I O and monitor is empty and available RAM In addition SK DOSO9 also requires approximately 8K of user memory for its 6809 interpreter program This normally starts at the current value of OFFSET SK DOSO09 uses your normal 68K I O devices and can access all your 68K disk drives including RAM disk although you must make sure that your RAM disk memory does not conflict with the memory used by SK DOSO9 If it does then SK DOSO9 will print an error message when it is started indicating that there is not enough memory for it to function Since the disk formats for both 6809 and 68K SK DOS versions are identical 6809 and 68K files can coexist on the same disk You will note however that 68K command files have the extension COM whereas 6809 command files use the CMD extension Hence typing a common command such as CAT or DELETE will always call the correct program Inci dentally both SK DOSes will use the same ERRCODES SYS file since the error numbers are identical Further 6809 SK DOS ign
53. BPHY FCBDIT FCBDIS FCBCRN FCBDAT Sequential data pointer to next byte 4 through 255 Reserved for future use Random data pointer to next byte 4 through 255 Temporary name buffer 2 Column position for use by Basic Space compression indicator Number of sectors per track Temporary storage Reserved for future use Next FCB pointer Physical drive number Reserved for future use Directory track number Directory sector number Reserved for future use Current or desired sector number Reserved for future use Beginning of data area The names listed in the above table are those used in the SKEQUATE file it is convenient to use these names rather than numbers when referring to specific FCB bytes in user programs The chart below gives aconcise summary of this data Bytes marked with are reserved for future use O 1 2 31 41 5 6 7 8 9 Al BJ C DI EI F EriRW Dri I f fat xro Co liv lt File Name gt Ext tr Ir dele lib First Last Ra Ti Mo Da Ye Tr amp Tr amp Size jnd melntly Jar Sectri ISectri lomi Ihi f I Curre I I I t I I nt Tr lt Second File Name gt Ext amp Sec Temp name buffer 1 Se Ra I qP nP lt Delete File Name gt Ext Itr Itr Temp name buffer 2 Next open Ph
54. Basic or GWBasic it takes a minute or two 10 OPEN A TEXT TXT FOR OUTPUT AS 1 20 PRINT 1 GARBAGE 30 GOTO 20 This initializes the disk directory in a special way Now take the disk to your SK DOS system and run TOMSDOS to copy the desired file to the disk Only one file can be copied to this disk if you have more than one you must start with another formatted disk The syntax for using TOMSDOS is TOMSDOS lt SK DOS file spec gt lt MS PC DOS drive num ber gt For example TOMSDOS FILE 1 would copy 0 FILE TXT to the previously formatted MS PC DOS disk in drive 1 If you get a warning message make sure that you have specified the correct drive number for the MS DOS disk The disk can now be read on your MS PC DOS system If you wish to copy the file to another disk you must use the A option of MS PC DOS s COPY command For example to copy the file to a hard disk the command would be COPY A A TEXT TXAT C SK DOS User s Manual FTOH and HTOF FTOH and HTOF These two programs are used to do a floppy disk backup on systems which only have one floppy drive but which have either a hard disk or a large enough RAM disk to store the entire floppy disk contents FTOH is used to copy an entire floppy disk including boot sectors directory and even empty sectors to a disk file on a hard disk or RAM disk The syntax is SK DOS FTOH lt floppy drive number gt lt hard disk file spec gt HTOF is then used t
55. DFC SFC SR USP VBR Control register An Address register direct Dn Data register direct An Address register indirect An Address register indirect with postincrement An Address register indirect with predecrement expression An Address register indirect with displacement expression An Xn expression An Xn W expression An Xn L Address register indirect with index expression in ORG expression expression in ORG Address short or long expression in RORG expression in RORG expression PC Program counter with displacement expression PC Xn expression PC Xn W expression PC Xn L Program counter with displacement and index expression Immediate Comment Field The comment field consists of any text following the fields described above but preceding the terminating carriage return on the line It may contain characters with hex values from 20 thru 7E Directive Statement A directive statement consists of one to four fields as follows label directive operand com ment Label Field The label field of a directive follows the same rules provided above However a label may be used only with the directives indicated below Directive Field The directive field provides information for the assembler rather than instructions for the 68000 68010 processor This information includes such items as the base address of the program the establishment of symbol values the alloc
56. E followed by the logical drive number as in unchanged by pressing ENTER or may leave the date un SK DOS DISKNAME 2 changed by answering N to the question SK DOS User s Manual DOSPARAM DOSPARAM The DOSPARAM command can be used to display or change a number of DOS parameters To display the current DOS parameters use the command SK DOS DOSPARAM lt device number gt where the lt device number gt is optional and will default to 0 if not given DOSPARAM will then print out several system wide parameters as well as parameters for the specified device num ber as shown in the example below To use DOSPARAM to change one or more parameters type DOSPARAM followed by an optional device number followed by the two letter abbreviation for the parameter to be changed see below followed by an equals sign and then followed by the new value Several parameters can be changed in one command line as in SK DOS DOSPARAM 2 WD 64 BS 08 PS N The PAUSE value is either YES NO ON or OFF all other values are decimal except those identified with a See the chapter on User Accessible Variables for the ex planation of these parameters SK DOS PARAMETERS COMMON TO ENTIRE SYSTEM BS Backspace 08 Control H BE BS echo 08 Control H DL Delete 18 Control X EL Endline 3A TB Tab 00 none ES Escape 1B Control RP Repeat 01 Control A MD Max drive no 1 OF OFFSET 00005B00 ME MEME
57. EAD to sequentially read the sector starting with the first You may read as many bytes as there are in the file If executed after opening the file for update FREAD will start reading at the beginning of the file f Use FRRECD to extend the file g Use FCLOSE to close the file h The only way to write past the end of a sector into the next sector is to use FRRECD to position to the next sector See Chapter 13 for further information on random files FCLOSE A008 Close file This function closes a file currently opened for reading writing or updating No operation is performed on read files or on write files which were never written to other than remov ing them from the chain of file pointers When a write file is closed any data remaining in the data area of the FCB is written out to the disk and both the directory and the file sector map are updated to indicate the correct track and sector numbers of the last sector and the file size The system information sector SIS on track O sector 3 is also updated When a random file open for updating is closed the current sector is written out to disk if data has actually been written to it FREWIN A00A Rewind file This function can only be performed on a file which is open for reading and will result in Error 1 FCS function code error if attempted on a file open for writing The Rewind function is used to start reading a file from the very beginning and is equivalent t
58. EALLY WANT TO 0000D1 04 DC B 4 END BUILD Although it is not immediately obvious from the above examples all user written programs must be written in position independent code although see the description of the binary file format in Chapter 13 for possible exceptions To write position independent programs for 68xxx processors generally follow the following rules 1 Do not use JMP and JSR instructions use BRA and BSR instead In general there should be no JMPs or JSRs in your programs at all 2 Refer to variables within your program using PC rela tive addressing For example the instruction MOVE B NUM BER PC D4 would move the quantity NUMBER into D4 but the PC tells the assembler to use PC relative addressing Un fortunately the 68xxx does not allow PC relative addressing as a destination that is the instruction MOVE B D4 NUM BER PC is illegal Hence this instruction has to be replaced by a two instruction sequence such as LEA NUMBER PC A5 MOVE B D4 A5 While this adds an extra instruction every time you store to a local variable we suggest that you avoid the alternative shortcut of setting one address register to point to your data area and then doing all stores relative to that register Although this makes your program a bit shorter and faster it generates code which causes PICTEST to signal an error even though there is none PICTEST explained later in the manual is used to check a program
59. EVICES This chapter gives additional information on the entire in terrelated and inter twined subject of I O redirection device drivers printers communications and the like It supplements information given for the DEVICE command in Appendix G In particular it describes the differences between device names device numbers and device drivers Before continuing it is important to explain our use of the word device In SK DOS a device is any I O port other than a disk drive or RAMDISK This includes character oriented de vices such as the console terminals modems or printers For the sake of the discussion in this chapter we will differentiate between disks and devices even though many people would classify a disk as one type of device In fact SK DOS allows devices and disks to be treated in similar ways Nevertheless for our purposes it is easier to separate the concepts COMMAND LINE REDIRECTION In its simplest form I O redirection simply means sending output to a different place or accepting input from a different place than normal It can be accomplished directly from the command line by using the symbols gt and lt For example the command CAT normally displays a catalog of a disk on the screen On the other hand the command CAT gt CATFILE sends the catalog listing to adiskfile called CATFILE PIP rather than displaying it on the screen Furthermore the command CAT gt PRTR woul
60. FORMAT Finally some notes about how HDFORMAT works Most hard disks arrive from the factory with one or more defects on a brand new disk drive these will generally be carefully docu mented on a test printout enclosed with the drive Most such errors involve just a few bits on isolated tracks because most modern hard disk controllers use error correction they are able to correct such minor errors and therefore hide them As HDFORMAT verifies the disk however it writes and then reads each sector If the sector was not read correctly then it is obviously bad even when read correctly however HDFORMAT still checks whether a sector required error cor rection If so HDFORMAT tries to read that sector once more If it still requires error correction even though it may have been read correctly both times HDFORMAT still flags that sector as defective This will hopefully avoid future errors You may note that the number of free sectors displayed in a directory printout is always lower than the number calculated from the number of cylinders Part of this is due of course to the fact that the free sector printout does not include those in the directory and system information sector In addition HDFORMAT always formats the disk so that each track has the same number of sectors In some cases the partitions are such that HDFORMAT has to discard a few sectors so as to make the logical tracks all the same length The following information may h
61. GET CHAR GET FILE NAME INPUT TEXT LINE PRINT ERROR MSG CR LF AND STRING PT TO VAR AREA WARM START SK DOS User s Manual 000000 000000 000002 000004 000006 000008 00000A 00000C 00000E 000012 000014 000016 000018 00001C 00001E 000020 000024 000026 00002A 00002C 00002E 000030 000032 000036 000038 00003A 00003C 00003E 000040 000042 000048 00004A 00004E 000050 000052 000056 00005A 00005C 000060 000062 000064 000068 00006C OO006E 6002 0100 A000 204E 284E A023 652E 183C A024 A006 662A 49FA A035 A02C 2668 181B oco4 6712 2848 A002 660A Oc04 67E0 181B 60F2 A037 A009 AOLE OC2C 66F2 49FA A035 A029 0205 0CO5 66E2 49FA A035 A029 0205 ocos5 66D0 2848 000004 00003C 0001 000042 005C 000076 O2F6 0023 00003E 00003C 000D 000018 00002E 0003 0001 00003C 002C 000078 OODF 0059 O00003E 0052 0000B0 OODF 0059 00003E BUILD ORG BRA S DC W 0000 START 0100 ACTUAL START OF PROGRAM START DC MOVE L MOVE L DC BCS S VPOINT A6 A0 A6 A4 GETNAM ERROR VERSION GET POINTER SAVE POINTER POINT TO SYS FCB GET FILE SPEC ON ERROR IF NAME WAS OK DO DEFAULT EXTENSION MOVE B DC 1 D4 DEFEXT NOW OPEN FILE FOR WRITE OPEN NXATLIN NEXTL1 PROCESS ERRORS ERROR QUIT ERROR HANDLING ON OPENING FILE
62. IME COLDST 12 Add time to directory entry INTIME normally contains three RTS instructions Each time that SK DOS opens a file for writing it places the next sequence number for the file into D5 does a JSR to the INTIME trap with an immediate RTS because INTIME normally con tains six bytes of RTS and upon return stores the contents of D5 into byte 27 of the current FCB D5 normally contains the sequence number but a user may replace the RTS bytes with a jump into a user written routine which may replace the byte in D5 with a time of day byte One byte is not enough to indicate a precise time down to the minute but it can be used to represent time in tenths of hours resulting in 6 minute resolution A byte of 00 means no sequence number or time is present 01 is a time from 12 00 midnight to 12 05 a m 02 is 12 06 a m through 12 11 a m and so on User programs using INTIME must preserve all registers except for D5 OFFINI COLDST 18 Initial OFFSET value OFFINI generally points to an even location just above SK DOS on each cold start or warm start SK DOS reads OFFINI and then initializes OFFSET at the next even 256 byte address above OFFINI For example if OFFINI is 49EA then OFFSET will become 4A00 See the next section for a discus sion on how to use OFFINI OFFSET and MEMEND to reserve space for custom routines MEMINI COLDST 1C Initial MEMEND value When SK DOS is initially booted it does a memory sense to determine
63. ITHOUT OFFSET and will display the disk file addresses as they exist on the disk file without adding the current value of OFFSET This option describes the file but does not provide the information as to where the file would load in the current system Note that LOCATE s printout does not necessarily specify all of the memory used by a particular program since the program may use memory areas without actually loading any thing into them from disk When several binary programs are appended together they may contain more than one transfer address Although LO CATE will indicate them separately keep in mind that only the last transfer address will actually be used by SK DOS SK DOS User s Manual MAKEMPTY MAKEMPTY MAKEMPTY is acommand which generates an empty file Perhaps a bit of an explanation is in order SK DOS does not normally like empty files When a program asks SK DOS to open a file for writing but does not actually write anything into it SK DOS does not actually put the file on the disk In other words it will not generally create a real but empty file on the disk unless you reset the computer or remove a disk while a file is open for writing which is something you should never do Nevertheless there are times when an empty file would be useful for example to initialize a data file which is to be read G 34 by a Basic program updated with more data and then rewritten That is precisely what MAKEMPTY d
64. K program will calculate the amount of user memory left and abort if less than 16K would be left Otherwise it will display the amount left and ask whether to proceed If you do not answer with a Y it will abort without setting up the RAM disk Make sure not to allocate so much RAM to the RAM disk that not enough is left for other uses While RAMDISK is initializing it will print out a row of periods one for each track being initialized Note that the G 42 RAMDISK program checks for the existence of enough mem ory but does not check whether that memory is working cor rectly Once the RAM disk has been initialized it may be reas signed to a different drive number by again typing the RAMD ISK command followed by the new drive number but without a size Its size however cannot be changed Both the RAMDISK program as well as the extended disk memory contain flags which indicate the status of the RAM disk If you reboot SK DOS without powering down the system the newly booted SK DOS will not know about the RAM disk but the RAM disk contents in memory will be retained as long as it is not overwritten with other data If you immediately enter the RAMDISK command the RAMDISK program will reenable the RAM disk but will print the message RAM DISK WAS FORMATTED EARLIER rather than eras ing it and formatting it again Hence your data will be retained in the RAM disk still assuming of course that power has not been turned of
65. KSUM is used simply to verify that the content of a disk has not changed over some period of time Although it can be used with floppy or hard disks we find it most useful to use with the RAMDISK program Whenever we walk away from the computer for an extended length of time while the RAM disk is in use we run CHECKSUM on leaving and then again when we return This makes sure that the contents of the RAM have not accidentally changed perhaps due to a momentary power interruption while we were gone To use CHECKSUM simply follow it with the drive num ber as in SK DOS CHECKSUM 1 SK DOS User s Manual COMPARE COMPARE The COMPARE command requires two drives and does an which would compare the disks in drives 0 and 1 exact byte by byte comparison of two disks It is thus useful for If you want to check whether a single disk is readable you checking whether a disk has been backed up correctly although may also specify the same drive number for both disks as in the disk will be verified during BACKUP SK DOS COMPARE 0 0 To use COMPARE type the word COMPARE followed by the drive numbers of the two drives holding your disks as in SK DOS COMPARE 0 1 This mode reads a single disk twice and checks not only that it is readable but also that the same data is read both times G 10 SK DOS User s Manual COPY COPY COPY is used to copy files from disk to disk or from directory to directory It can copy just one fil
66. MAMMOND Here are short explanations of these options The A option will alphabetize the source directory before files are selected to be copied The C option will enable you to copy a file that is damaged by a CRC error or record sequence error This is a slightly dangerous option which should only be used if you don t have an alternate copy of a file The D option will find files that are on both disks and compare their creation dates and times or sequence numbers If the source file is newer it will be copied as a replacement for the older destination file The E option is used when you want to replace a file on the destination disk This option will suppress the prompt for whether you wish to delete the existing file It will often be used along with D to update a disk with newer versions of programs The F option changes copy s parameters from a match string list to a list of file numbers Follow the drive numbers with a list of file numbers for those files that you want to copy File SK DOS User s Manual numbers can be found with CAT A group of files can be specified as a starting and ending number separated by a dash The command COPY F 0 1 5 13 18 9 will copy file 5 files 13 through 18 and file 9 all to the root directory of drive 1 The from drive number always refers to all directories but you must append if you wish the files copied to the corre sponding directories of the to drive This option is useful for
67. MERS This chapter gives additional information for systems or advanced programmers It describes the disk format structure of files and information regarding customization DISK FORMAT A typical disk whether hard or floppy is divided into tracks each track is then divided into sectors The number of tracks and sectors on a disk depends on the type of disk and drive a 5 1 4 floppy disk might have as few as 35 tracks with 10 sectors per track or a Winchester hard disk might have as many as 256 tracks with 32 or more sectors per track In addition the disk drive might be able to use both sides of a disk or a Winchester disk might have multiple disks spinning on the same shaft As far as SK DOS is concerned the exact number of sides tracks and sectors is unimportant as long as there are at most 256 logical tracks numbered O through 255 per drive and 256 logical sectors numbered O through 255 per track For com patibility with 6809 SK DOS sector numbering begins with 1 for floppy disks The exact positioning of those sectors and tracks is con trolled by the disk drivers and FORMAT routine not by SK DOS itself On floppy disks the physical placement of these tracks and sectors on the disk would most likely agree with their logical numbering on hard disks they might physically be placed elsewhere on the disk Thatis why the previous paragraph uses the word logical in describing track and sector number a logical address i
68. ND SOOOBFFFF SK DOS PARAMETERS FOR DEVICE NUMBER 0 PL Print lines 0 SL Skip lines 0 WD Width 0 NL Null wait 0 PS Pause NO EF End of File 1A Control Z BR Baud rate 0 XF X OFF Char 00 none XN X ON Char 00 none SK DOS User s Manual DRIVE DRIVE DRIVE is used to reassign different logical drive numbers to the actual physical drives of your system or display the current drive assignment or write protect a drive For example since most users prefer to work with drive 0 as their main drive this allows them to use different physical drives as their drive 0 There are two ways of using DRIVE Just a plain SK DOS DRIVE will display the current assignment On the other hand the command may also be of the form SK DOS DRIVE Lx Ty P or U LD MD which would assign logical drive x to become Type y x and y can be numbers from O through 9 and T can be N for None F for Floppy H for Hard O for Other or R for RAM Disk There can only be one RAM disk Multiple assignments can be made on one line There are two options which can be specified as shown in brackets above First any assignment can be followed by the letter P to write protect that drive or U to un protect the drive Second the syntax LD MD would cause DRIVE to set the MAXDRYV variable equal to the last drive number currently in use if it is not already so set For example after the command SK DOS DRIVE L
69. Number of printed lines per page Page column width Null wait constant Number of skipped lines betw pages Output pause control byte Current output column Current input device 0 Current output device 0 Current error device 1 I O device descriptor table Pointer to first open FCB long word 64 bytes of free space for user pgms 1K of environment space SK DOS User s Manual APPENDIX B THE FILE CONTROL BLOCK FCB The first 96 bytes of an FCB numbered 0 through 95 for this discussion hold the following information NAME FCBERR FCBRW FCBDRV FCBNAM FCBEXT FCBATT FCBFTR FCBFSE FCBLTR FCBLSE FCBSIZ FCBRAN FCBTIM FCBMON FCBDAY FCBYR FCBCTR FCBCSE FCBNMB BYTE S 00 10 20 30 40 50 60 CONTENTS Reserved for future use Error code see Appendix E Read Write Update status Drive number 0 through 9 File name 8 bytes Extension 3 bytes File attributes Reserved for future use First track of file First sector of file Reserved for future use Last track of file Last sector of file Number of sectors in the file Random file indicator Time or sequence number Month of file creation 1 through 12 Day of file creation 1 through 31 Year of file creation last two digits Reserved for future use Current track number Current sector number Temporary name buffer 1 Reserved for future use FCBDPT FCBRIN FCBNMS FCBCOL FCBSCF FCBSPT FCBLST FC
70. O FO L1i HOP L2 N LD MD floppy drive 0 would become logical drive 0 hard drive 0 would become logical drive 1 and write protected and logical drive 2 would be disabled Furthermore MAXDRYV would be set to 1 assuming that there were no other active drives set via earlier DRIVE statements or by default One physical drive cannot be assigned two logical drive numbers if you attempt to do so DRIVE will print an error message and ignore the entire command With floppy drives the DRIVE command is essential if you have more than one floppy disk controller because it allows you to assign any physical floppy drive to any logical number It is also useful with hard disks for it allows a hard disk to be used as logical drive 0 this is especially useful when SK DOS is booted from a hard disk rather than a floppy It is also essential in systems where a hard disk is partitioned into two or more partitions it then allows any combination of disk partitions to be assigned logical drive numbers and also allows some of them to be write protected If you have a hard disk then see the HDFORMAT description for further information on hard disk partitions SK DOS User s Manual EDLIN EDLIN EDLIN is a simple line editor for generating or modifying text files It is not intended as a replacement for a full screen editor or word processing program rather it is designed to perform simple editing functions for users who do not have a
71. OS or else you may just have one or more files of driver source code which you will have to customize and assemble to fit your own hardware Device drivers must be installed with the DEVICE com mand For example the command DEVICE PARALLEL AT 2 AS PRTR would install a driver called PARALLEL DVR at device 2 and give it the name PRTR The DEVICE display would then say Normal Device Device Driver use number name Printer 2 PRTR PARALLEL DVR The DEVICE command can be used to change devices as often as desired you may also return back to a default driver by using the name DEFAULT instead of a file name as in DEVICE DEFAULT AT 2 AS CONS which would restore device 2 as the default device CONS Note that driver names default to DVR but DEFAULT has no default extension DEFAULT refers to the normal default driver whereas DEFAULT DVR would be needed in the command line if you had an actual DEFAULT DVR driver on a disk REMOTE CONSOLE OPERATION It is possible to operate SK DOS from a device other than the default console device For example if there is a serial device on the system and a driver for it then you may install that driver as devices 0 and 1 All normal console I O would then go to that device instead Note that it s necessary to install that driver at both number O and 1 so that error messages go to the new device The order of assigning device numbers also makes a difference if you assign number O first the
72. OUTSD A038 Output 5 decimal digits This routine outputs a decimal number of up to five digits Before entering the calling program should place into D4 the unsigned binary word to be printed and set D5 to zero if the number is to be printed without leading spaces or zeroes or to nonzero if the number is to be printed with leading spaces OUT10D A039 Output 10 decimal digits This routine outputs a decimal number of up to ten digits Before entering the calling program should place into D4 the unsigned binary long word to be printed and set D5 to zero if the number is to be printed without leading spaces or zeroes or to nonzero if the number is to be printed with leading spaces OUT2H A03A Output 2 hex digits This routine prints the two digit hexadecimal number that is in the right most byte of D4 on entry OUT4H A03B Output 4 hex digits This routine prints the four digit hexadecimal number that is in the right most word of D4 on entry OUT8H A03C Output 8 hex digits This routine prints the eight digit hexadecimal number that is in D4 on entry PERROR A037 Print error code When an error is encountered by the FCS while using an FCB user programs should do a call to this routine to print the error code PERROR should be entered with A4 pointing to the beginning of the FCB and the error code in byte 1 of the FCB The error codes are listed in Appendix E The error code is printed as a number in addition if the system disk c
73. QUATE TXT which provides a series of EQUates which define the exact numeric code for each function Hence only the function name given in the following descriptions need be remembered This file may be included as a library file in any user programs you write with the instruction LIB SKEQUATE Once so defined the names in the SKEQUATE file can be used in the DC line as in DC FREAD Each of the functions listed in this chapter always preserves registers DO through D4 and AO through A4 and generally never preserves registers D5 through D7 and A5 through A6 Arguments passed to SK DOS are generally passed in D4 or A4 as applicable and arguments passed back to the user pro gram are generally in D5 or A5 as appropriate In addition all of the following functions always return with A6 pointing to the SK DOS user accessible variable area see Chapter 11 and VPOINT for a fuller explanation The functions listed in this chapter are divided into two groups 10 1 A Functions which do not involve reading or writing to the disk B Functions which do involve writing or reading disks GROUP A NON DISK FUNCTIONS The following SK DOS functions do not directly involve disk operations COLDST Cold start COLDST is the only function which is not called through an Axxx trap Instead it is the entry point that is used when SK DOS is first loaded from disk and executed Entering at COLDST erases all pointers and completely initializes
74. S This character is returned in D5 and also placed in the CURRCH location in SK DOS the previous character which was in CURRCH is placed into PREVCH so that user programs have access to the last two characters taken from the line buffer This routine automatically calls CLASFY so that the carry bit can be used to indicate whether the current character is alphanumeric or not If the line buffer contains a string of spaces then GETNXT will return only one space GETNXT will continue fetching charac ters until it gets to the end of the line at which time it will continue to output the end of line 0D CR or ENDLIN if it is called again and will also set the carry bit to indicate a non alphanumeric character This routine uses the LPOINT 10 2 pointer to keep track of the next character to be taken from the buffer This pointer is normally set to the beginning of the buffer after a line is input from the keyboard with INLINE and is incremented by one each time a character is fetched from the buffer so that it always points to the next character to be fetched At the end of a line it always points to the CR character RESIO A020 Reset I O pointers RESIO resets I O vectors to their initial states For example if output is vectored to a disk file a call to RESIO returns output to the terminal In general RESIO resets console I O vectors to their normal conditions RESIO is called during WARMST so that SK DOS always returns to a known s
75. S User s Manual TCAT TCAT TCAT is similar to CAT but differs in three ways 1 TCAT prints both the date of each file as well as the time if one has been assigned to the file 2 The catalog listing is sorted by date and time so that the most recent files appear first 3 TCAT does not allow all of the options used by the regular CAT command Although TCAT is provided primarily for those users who have aclock calendar installed it is also useful to others because of its ability to sort directory entries by date to display the latest files first Here are a few examples of how to use TCAT TCAT prints a catalog of the default directory of the work disk TCAT 5 prints a catalog of the root directory of drive 5 TCAT 5 FS prints a catalog of all files on drive 5 which have names beginning with FS TCAT 5 A FS prints a catalog of all files on drive 5 subdirectory A which have names beginning with FS TCAT 5 FS prints a catalog of all files in all subdirectories on drive 5 which have names beginning with FS G 51 TCAT 5 FS T COM prints a catalog of all files on drive 5 which have file names beginning with FS and also have extensions beginning with T and of all files on drive 5 which have the extension COM TCAT 5 F S T COM prints a catalog of all files on drive 5 which have file names beginning with F S where stands for any character and also have extensions beginning with T AND of all files on
76. SK DOS to the beginning User programs should not use this entry point especially when files are open as entering at COLDST causes SK DOS to forget all its open files This can corrupt the contents of a disk or its directory Nevertheless COLDST may be useful in special applications Keep in mind however that the precise address of COLDST depends on the particular sys tem SK DOS is run on You may determine the appropriate address for your system by using the LOCATE command with the option to determine the load address of SK DOS SYS COLDST should be entered with a JMP instruction WARMST A01E Warm start WARMST is the re entry point to be used by user programs Re entering at WARMST closes all open files and thus helps to insure the integrity of the directory SK DOS then prints its prompt and looks for a command to be processed by the Com mand Processor System RENTER A025 Re enter SK DOS This routine re enters the SK DOS command processor system at the point where it processes a command line Itis used when it is desired to continue processing the remainder of a command line such as after the O or P commands VPOINT A000 Point to SK DOS variable area This routine returns the address of the SK DOS variable area in A6 Indexed addressing via A6 may then be used to access those variables in SK DOS of interest to user programs VPOINT may not be needed in most programs since all SK DOS function calls also return this ad
77. SK DOS User s Manual Sk pos 68K User s Manual by Peter A Stark Copyright 1986 1990 by Peter A Stark and licensed to Star K Software Systems Corp P O Box 209 Mt Kisco NY 10549 914 241 0287 All rights reserved SK DOS User s Manual Copyright 1986 1990 by Peter A Stark All Star K computer programs are licensed on an as is basis without warranty Star K Software Systems Corp shall have no liability or responsibility to customer or any other person or entity with respect to any liability loss or damage caused or alleged to be caused directly or indirectly by computer equipment or programs sold by Star K including but not limited to any interruption of service loss of business or anticipatory profits or consequential damages resulting from the use or operation of such computer or computer programs Good data processing procedure dictates that the user test the program run and test sample sets of data and run the system in parallel with the system previously in use for a period of time adequate to insure that results of operation of the computer or program are satisfactory SOFTWARE LICENSE A Star K Software Systems Corp grants to customer a non exclusive paid up license to use on customer s computer the Star K computer software received Title to the media on which the software is recorded cassette and or disk or stored ROM is transferred to customer but not title to the software B I
78. T RETURN TO SK DOS FILE SPEC WAS OK DEFAULT TO TXT 00001C 183C 0001 NAMEOK MOVE B 1 D4 DEFAULT EXT 000020 A024 DC DEFEXT DEFAULT TO TXT NOW ACTUALLY OPEN THE FILE 000022 A005 DC FOPENR 000024 66F0 000016 BNE S ERROR MAIN LOOP TO READ AND PRINT EACH CHARACTER 000026 2848 MAIN MOVE L A0 A4 POINT TO SYS FCB 000028 A001 DC FREAD GO READ NEXT CHAR OPEN FOR READ IF NOT ZERO 12 1 SK DOS User s Manual 00002A 00002C 000032 000034 000036 000038 00003C 000035 000040 000042 000046 000048 00004A 00004C 00004E 000052 000054 000058 00005A 00005C 00005E 000060 The above example shows a variety of techniques Note 670C 0C2C 66E2 6126 AOE oco5 660A 1c01 1205 oco6 67DE 1205 1805 A033 0c04 66D2 183C A033 60CA 2848 A008 4E75 000038 0008 0001 000016 00005C OOOA 000048 000D 000026 000D 000026 000A 000026 BEQ S CHAROK GO ON IF NO ERROR IF THERE WAS AN ERROR SEE IF END OF FILE CMP B 8 FCBERR A4 BNE S ERROR BSR S CLOSE DC WARMST CONTINUE IF CHARACTER IS OK CHAROK CMP B 0A D5 BNE S PRNTIT MOVE B D1 D6 MOVE B D5 D1 CMP B 0D D6 BEQ S MAIN PRNTIT MOVE B D5 D1 MOVE B D5 D4 DC PUTCH CMP B S50D D4 BNE S MAIN MOVE B 0A D4 DC PUTCH BRA S MAIN CLOSE SUBROUTINE CLOSE MOVE L A0 A4 DC FCLOSE RTS END LIST END OF FILE NOT END OF FILE CLOSE ON EOF RETURN TO SK DOS IS IT LINE FEED
79. Table The device descriptor table provides information on cur rently installed devices more information is found in Chapter 14 BAUDRT 3329 80 DN A6 Baud Rate 100 This byte specifies the baud rate for serial devices and is not used for others BAUDRT indicates the baud rate divided by 100 for example a baud rate of 110 is shown as 01 If no baud rate is specified the driver may use its own default value EOFILC 3330 80 DN A6 End Of File Character When adevice rather than a file is used for input during input redirection EOFILC defines which character will generate error 8 end of file The default is 1 A which is control Z XOFFC 3331 80 DN A6 X Off Character XONC 3332 80 DN A6 X On Character These two bytes specify whether a serial port uses the X On X Off protocol and which characters it uses When these characters are O the default then no X On X Off is used When they are set to other values usually 13 or control S for X Off and 11 or control Q for X On then the port will immediately stop all output upon receipt of an X Off and will only resume upon receipt of an X On Note that this 1s different from using ESCape to halt and resume output since ESC only works for device 0 SK DOS User s Manual 12 PROGRAMMING EXAMPLES This section shows several examples of how to use SK DOS in writing programs which access the disk SK DOS LIST TEXT The program reads the file name from the line buffer opens
80. This same drive also has a logical drive number which may be different from the physical number This assignment is handled by the DRIVE command which may assign any of the ten logical drive numbers to any physical drive The file spec uses ogical drive numbers not physical drive numbers 2 Floppy disks usually have only a root directory most people use subdirectories only to split a large hard disk into smaller more easily manageable sections Each subdirectory might then be used for a specific type of file Incidentally if you change the variable FNCASE to allow both upper and lower case file specs you can then have a total of 52 subdirectories on a disk called A through Z and a through z 3 1 3 There are several file names which are reserved for SK DOS s own internal use These fall into two categories a The names DIR GET GETX MON RESET SAVE TRACE and XEQ are used for internal memory resident commands While these names may also be used for file names any command files bearing these names will not be called since SK DOS will use its internal commands instead b The names CONS PRTR and NULL and possibly a few others of your own choosing apply to I O devices rather than files These names can also be used for file names but in certain cases SK DOS will interpret them as applying to adevice rather than a file 4 While files can have any valid extension by convention certain kinds of files tend to hav
81. acement value is less than 32768 or greater than 32767 25 Bad 16 bit displacement range The displacement value is less than 32768 or greater than 32767 11 Bad 16 bit extension The extension value is less than 32768 or greater than 32767 02 Bad 3 bit value The quick immediate data value is not in the range 1 to 8 or the specified breakpoint number is invalid 03 Bad 32 bit field specifier The bit field value specifies a bit outside of a long word 31 Bad 4 bit value The specified vector number is invalid 08 Bad 8 bit displacement The displacement value is less than 128 or greater than 127 26 Bad 8 bit displacement range The displacement value is less than 128 or greater than 255 12 Bad 8 bit extension The extension value is less than 128 or greater than 255 15 Bad 8 bit field specifier The bit field value specifies a bit outside of a byte 22 Bad 8 bit operand The operand value is less than 128 or greater than 255 O1 Bad address displacement The displacement is out of range for the effective address type 06 Bad count operand The immediate shift count is less than 1 or greater than 8 10 Bad destination effective address The destination effec tive address type is invalid for this type of instruction 09 Bad destination indexed address The indexed destina tion effective address type is invalid for this type of instruction 13 Bad effective address The effective address type is i
82. alled in the system and then stores the address of the last memory location in MEMEND OFFSET and MEMEND together therefore define the lower and upper limits respectively of free user memory User programs can check these locations to determine how much user memory is available or can change the contents to set aside memory for themselves ECHOFL 800 A6 Input echo flag This location tells the character input routine whether to echo output to the output port A non zero value initialized to FF at warm start enables echo INCASE 801 A6 File Name case flag This location determines whether lower case file names are allowed either as disk resident command names or as file names processed by the GETNAM function The default value is 60 which allows only upper case names and lower case names are automatically converted to upper case Lower case names will be allowed if FNCASE is changed to FF MAXDRV 802 A6 Maximum drive number This location is used to define the maximum drive number on the system It is initialized to 03 and the maximum number it may have is 09 SK DOS will return a drive number error whenever a drive number is specified in a file spec which exceeds the value of MAXDRYV If your system has more than four drives then MAXDRV should be increased correspond ingly when the appropriate disk drivers are installed SEQNO 806 A6 Sequence Number This byte holds the sequence number assigned to each file written If
83. alling the wrong one SK DOS User s Manual APPENDIX G SK DOS COMMAND SUMMARY This Appendix describes the commands currently supplied with SK DOS From time to time however we may add other commands which may not be described here Most commands will provide you with information on their proper usage if you type the command name a space and a question mark as in BUILD This Appendix describes the following commands Disk resident commands ACAT FIND APPEND FORMAT BACKUP FROMSDOS BEEP FTOH BUILD HDFORMAT CACHE HELP CAT HTOF CHECKSUM LINK COMPARE LIST PROMPT PROTECT RAMDISK REDOFREE RENAME SCAT SEQUENCE SK DOSO09 STEPRATE COPY LOCATE SYSTEM DAMON MAKEMPTY TCAT DELETE NOBEEP TOMSDOS DEVICE PARK TRACENAB DIFF PDELETE UBASIC DISKNAME PEEK UNDELETE DOSPARAM POKE VERIFY DRIVE VERSION EDLIN WORK Memory resident commands DIR MON TRACE GET RESET XEQ GETX SAVE Other supplied programs PICTEST S1TOCOM SK DOS User s Manual ACAT ACAT The ACAT command displays a fully alphabetized catalog listing of a disk or a directory It is similar to CAT except that it does not support all of the options that CAT does To use ACAT type the word ACAT followed by an op tional drive number and directory specifier which defaults to the work drive if not entered You may follow this with a match list additional information if you want only certain files listed The general format is to enter ACAT
84. ally assumed except for branch instructions for which a 1 suffix is assumed The w suffix default also applies to most direc tives except for ORG and RORG for which a 1 suffix is assumed The suffix s is used to indicate short branch instructions This assembler will not change short branches to long branches or vice versa and a short branch to the next instruction will not be changed to a long branch but will be noted as an illegal instruction This assembler will not automatically change add subtract or move instructions to their equivalent quick immediate form Although this would produce faster and smaller object code it may also produce undesirable results in some cases The pro grammer is thus responsible for coding the best form of a desired operation Operand Field The operand field contains zero or more parameters of the instruction If multiple sub fields are present they must be separated by a comma Only the MOVEM instruction allows more than two operands but the register list of that instruction must be separated with slashes and hyphens even if only one register is used Many instructions such as MOVE have two operands which are designated as source and destination sub fields from left to right The DB types of declarative may also contain multiple sub fields This assembler supports the standard Motorola notation for the 68000 68010 effective addressing modes They are summa rized below CCR
85. amples in case you need to write your own SERIAL and PARALLEL are simple drivers for a serial port using a 68681 DUART and a parallel port using a 68230 PI T or 6821 PIA respectively ADM 3A is an expanded serial driver which shows how ICNTRL and OCNTRL functions are im plemented with translation tables NOTE To preserve consistency between different im plementations of SK DOS users writing device drivers which implement ICNTRL and or OCNTRL are urged to adhere to the codes listed above In order to correlate your work with that of others please contact Star K Software Systems Corp before making any extensions to these codes KEYBOARD TYPEAHEAD BUFFER Some SK DOS implementations depending on the BIOS or device drivers may implement a keyboard typeahead buffer hence there are three DOS calls STATU1 INNOEI and FLUSHT specifically dealing with the operation of such a buffer If a typeahead buffer is not implemented then STATU1 and INNOE1 behave exactly the same as STATUS and IN NOEC respectively while FLUSHT does nothing If a typeahead buffer is implemented then either the BIOS or the device driver or both may contain a buffer area which holds incoming characters from the keyboard or other device This buffer which is typically 64 bytes but may be larger or smaller acts as a FIFO or first in first out memory As charac ters come in they go into one end of the buffer as SK DOS or a user program needs them they come
86. arting addresses must be placed some where in memory and identified to SK DOS The following is an example of such a table CMDTAB DC B DIR Command name DC B 0 delimiter to signal end of name DC L DIR Starting address of com mand DC B GET Command name DC B 0 delimiter to signal end of name DC L GET Starting address of com mand DC B 0 End of table flag Finally to tell SK DOS where this table is located its starting address i e the address of the first DC B must be placed as a long word into location COMTAB The astute reader may note that depending on the length of the command name the assembler may insert an extra empty byte between the DC B command name delimiter and the DC L which holds its address so as to make sure that the DC L starts on an even address This is irrelevant to SK DOS TRACING PROGRAMS If you have a ROM system monitor such as HUMBUG which supports tracing programs you may use SK DOS s TRACE command to enter a program in the trace mode TRACE has three asterisks so that you will not accidentally type in the command when you don t mean to TRACE is generally used just before you load in and execute a new program being tested It sets the trace bit in the user status register so that SK DOS enters the new program in the trace mode The 68xxx CPU will then execute the first instruction and trap to the ROM monitor generally to display a register dump You may then use t
87. arts over The Control A key re displays the entire previous line in the line buffer from the current cursor position to the previous end of line carriage return and can be used to repeat all or any part of a previous line PSTRNG A035 Print CR LF and string PSTRNG is used to output an entire string of text to the terminal The string is preceded by a carriage return and line feed meaning that the text begins on a new line on the screen On entry A4 should point to the first character to be printed and the string should end with an 04 byte to denote end of data PNSTRN A036 Print string WITHOUT CR LF PNSTRN is used to output an entire string of text to the terminal Unlike PSTRNG however it is not preceded by a carriage return and line feed On entry A4 should point to the first character to be printed and the string should end with an 04 byte to denote end of data CLASFY A02E Classify alphanumeric characters This routine is used to classify characters in D4 If the character is a letter or digit then the C carry bit of the condition code register is cleared otherwise it is set PCRLF A034 Print CR LF This routine prints a carriage return line feed that is it forces the cursor to the next line so that subsequent input or output will occur at the beginning of a new line GETNXT A02D Get next character from buffer This routine is used to get the next character from the 128 byte input buffer used by SK DO
88. ated or may be joined together the or symbol must be used to start each group of options B b B b inhibits the construction of the output object file which is produced by default this file normally has the same file name as the main program source file except that it has suffix mxt formatted as S records or com formatted as binary records the details of which are described later in this manual F f F f inhibits the generation of word alignment bytes generated when directives which cause odd alignment are followed by directives requiring even alignment H xxx hxxx Hxxx hxxx sets listing pagination mode and sets page length to decimal Xxx which may not be less than 24 or greater than 130 L l L l inhibits the generation of the formatted source listing the source listing may be redirected to disk or printer with command line parameters as supported by the operating system vertically formatted and paginated listings may be created with the H option SK DOS User s Manual Mx mx Mx mx indicates type of processor for which code is to be generated O for 68000 1 for 68010 2 for 68020 3 for 68030 1 2 and 3 cause the same actions OX 0x Ox 0X specifies name of object file to be produced it will be suffixed as described above except for minimum systems PXXX PXXX PXXxx pxxx sets width of formatted output lines to decimal xxx the default is
89. ation of storage the specification of additional source files to be read by the assembler etc A list of the directives implemented by this assembler is provided later in this manual Lower case and upper case letters in the directive field are not considered unique Operand Field The operand field consists of zero or more sub fields Mul tiple sub fields are separated with commas Comment Field The comment field consists of any text following the fields described above and preceding the terminating carriage return The comment field may be composed of characters with ASCII hex values from 20 thru 7E and tab characters Comment Statement A line which starts with an asterisk is ignored by the assem bler except for being optionally listed along with the remainder SK DOS User s Manual of the program A comment statement may be composed of characters with ASCII hex values from 20 thru 7E and tab characters A comment statement may be labelled since the asterisk appears to the assembler in this case to be in the instruction field Directives label DC operand operand label DC B operand operand label DC L operand operand label DC W operand operand label FCB operand operand label FCC operand operand label FDB operand operand DC specifies the assignment of one or more values into successive words bytes or long words The suff
90. ations The difference between GET and GETX has to do with error checking As GET loads a binary file it checks the loading address of every byte It will not allow a byte to be loaded below the current value of OFFSET or above the current value of MEMEND if any such invalid address is found GET prints an error message and aborts loading GETX on the other hand does no such checking In general you should therefore always use GET rather than GETX GETX should be reserved only for special and well thought out purposes SK DOS User s Manual HDFORMAT HDFORMAT HDFORMAT lets you format a hard disk for use with SK DOS as opposed to FORMAT which is strictly for floppy disks This command will work slightly differently for different systems and you may have received an addendum which de scribes any such differences for your system configuration The following describes the command as used with the WD1002 controller HDFORMAT is called with the simple command line SK DOS HDFORMAT and then proceeds to ask for the information it needs to properly format the hard disk It s important to answer these correctly and so we will discuss these questions and their answers at length The first question is Which drive A or B In most instances only one drive is present and so the choice is A The WD1002 HDO controller used on some computers allows three hard drives which it calls drives 0 1 and 2 but SK DOS supports
91. between pages These constants may be changed with the DOSPARAM command PAUSEB 3326 80 DN A6 Output pause control byte If PAUSEB is non zero and PLINES is non zero then terminal output will pause after each PLINES lines and resume when the escape key is pressed on the keyboard PAUSEB is normally initialized at FF thereby enabling the pause but since PLINES defaults to 0 no pause actually takes place PWIDTH 3323 80 DN A6 Page column width This byte is used to control the page width of output to the terminal or printer When output goes to the right of the PWIDTH column on the terminal or printer SK DOS will issue a carriage return line feed at the next space character PWIDTH may be set with the DOSPARAM command SK DOS normally initializes PWIDTH to 0 which disables it To use PWIDTH you should set it to a value approximately 10 less than the actual screen or paper width so as to leave room for any long words at the end of the current line PWIDTH works in conjunction with the OCOLUM and SPECIO variables described below SK DOS User s Manual SPECIO 792 A6 Special I O Indicator When SPECIO is nonzero the PWIDTH value is ignored SPECIO is initialized to zero at warm start and by RESIO OCOLUM 3328 80 DN A6 Current output column This byte indicates the current output column on the terminal or printer It is used with the PWIDTH variable and reset to 0 at the start of every line or by printing any control
92. but cannot format the double stepping formats labelled with above The PT68K 4 however also has a Western Digital WD37C65 controller which can also handle several types of high density drives of the type commonly used on PC clones It can also easily handle an 8 drive The high density drives come in two types One commonly called a 1 2 meg HD drive uses 5 1 4 disks but rotates at 360 rpm instead of 300 rpm By using 80 tracks and a data rate the same as 8 disks it squeezes almost 1 2 megabytes of data on the disk The second usually called a 1 44 meg disk uses 3 1 2 disks but rotates at 300 rpm and uses the same data rate as the 1 2 meg drive Because it rotates slower it has a capacity 20 higher than the 1 2 meg drive Both of these high density drives can read and write the lower density disks as well but SK DOS does not implement single density for them Hence the WD37C65 controller can handle the following combinations ce ae aa 1 2meg HD wn un w J SK DOS User s Manual T a E Jid ot 40 1 44 meg ka 80 HD e l D T E MEPER E As before this controller can read and write all formats listed above but cannot format those shown with a The last format indicated with a is a special format using 128 byte sectors developed for a specific customer and not very useful for general use Since the 1772 controller can only handle two kinds of drives which really only differ by the n
93. by advanced program mers and then only in systems programs such as FORMAT FINDEV A012 Find device from name This function converts a device name such as CONS for console to a device number plus 10 For example to find out whether PRTR has been installed as a printer driver place the name PRTR followed by seven 00 bytes to erase the remaining name and extension bytes into the file name bytes of an FCB and call FINDEV If PRTR is not installed then SK DOS will return error 4 not found if 1t is installed then SK DOS will place the device number plus 10 into the logical drive number byte For example if PRTR is device 2 then FINDEV will return 12 in byte 3 of the FCB GETDNT A03F Get date and time If the system contains aclock calendar IC then this function returns the current date and time in D5 and D6 as shown below D5 WWMMDDYY year in hexadecimal day in hex month in hex 7774 day of week 00 none 0l Sunday 02 Monday SK DOS User s Manual D6 OOHHMMSS seconds in hex minutes in hex hours 24 hr time always zero If no clock calendar IC is available then the day of week byte of D5 and all of D6 are zero and only the date month day year is returned obtained from the date typed in by the user upon booting ICNTRL A028 Input Control OCNTRL A032 Output Control These two functions permit device driver selection special characters to be
94. ch different computer In some cases the BIOS is provided either by Star K or by a hardware manufacturer in other cases you may have purchased a more generic version of SK DOS and will have to provide your own BIOS if your hardware is different from those systems currently supported Depending on the version SK DOS with all its hardware dependent routines occupies approximately 24K to 32K of RAM The exact location of SK DOS varies from system to system but in most systems it begins at 1000 Once booted however it is not necessary to know exactly where SK DOS is located in your memory since SK DOS 1s called by application programs through exception vectors Hence this manual de scribes the FCS and CPS portions of SK DOS from the point of view Of a user or applications programmer BIOS information needed only by systems programmers implementing SK DOS on a new system is provided in a separate optional Configu ration Manual SK DOS User s Manual 5 THE COMMAND PROCESSOR SYSTEM When SK DOS is first loaded and started it responds with the SK DOS prompt and waits for acommand to be processed At this point you may enter either a Memory Resident Com mand a Disk Resident Command or a Batch Command De pending on the command sometimes several commands may be entered on one line separated by colons Commands may consist of more than one part and may be up to 127 characters long if necessary The various parts of ac
95. command line This option will allow you to change disks and Atits simplest invoking the CAT command can be as simple do aCAT withoutre entering the data on the command line The as typing the word CAT or it can be followed by a number of user can select CAT options to control the type of information parameters A more complex command might be in the form listed in the disk file CAT lt how gt lt where gt lt what gt S The S option will enable the sector size of files to be All of these parameters are optional any of them can be displayed used but if you use more than one then they must be in the order The typical CAT display will look like the following shown above how where what All parame ters are entered on the command line If you forget what to do the CAT help list can be displayed by entering a command of CAT Drive 2 Dir A Disk SOURCE 4 Created 31 May 82 File Name Type Begin End Size Date 2 COPY99 TXT 29 03 11 0F 128 21 Jun 82 lt How gt Options 12 RANDOM SYS R 01 01 01 03 3 3 Nov 81 The so called how options consist of one or more option letters preceded by a sign and Files 21 Biggest 206 Total 131 1029 Free 111 should follow after the word CAT as in The top line of this display provides the drive number CAT SDF1 directory disk name disk number and disk creation date The available options are A separate line describes each file and provides its number A Alpha Alphabetize ou
96. criptions include typical error codes that may be generated on specific operations In addition most of the operations may also result in disk read or write errors due to hardware problems In all cases if no error occurs then the FCS returns with the Z bit of the condition code register set If an error does occur then the Z bit is cleared and byte 1 of the FCB as well as location ERRTYP contains the code for the error that occurred Error codes are listed in Appendix E FREAD A001 Read the next byte from file FWRITE A002 Write the next byte to the file Most FCS read or write operations are sequential these functions are used to read or write the next sequential byte or character in the file During a read the next byte from the file is read from the sector currently in the FCB using the data pointer in byte 49 and returned in D5 while during a write the character in D4 is written to the file Since the file is read or written on the disk an entire sector at a time this function actually buffers the data through the sector buffer bytes 96 of the FCB Hence no actual disk read or write will generally occur for most FREAD or FWRITE O calls When an actual disk read or write is required SK DOS will handle that automatically without user intervention FOPENR A005 Open a file for read This function opens a file for reading Before calling the FCS the calling program must insert the drive number name and extension of the des
97. ction set such as the 68020 and 68030 only those instructions common to the 68010 and to the superset processor may be generated directly by the 68010 assembler For those processors with instruction sets which are subsets of the 68010 instruction set such as the 68000 and 68008 only those instructions common to the 68010 and to the subset processor may be correctly generated by the 68010 as sembler those instructions not in the subset will be treated as invalid instructions by the subset processor The m0 option may be specified on the command line to inhibit the incorrect gener ation of code for subset processors This assembler provides an absolute assembler capability and produces object code directly without the use of a link ed itor It supports conditional assembly the use of complex arith metic expressions and the inclusion of auxiliary source files It optionally produces a formatted listing of the program being assembled On other than minimum systems its output includes a sorted cross reference of the symbols declared and used in the program and English error messages as appropriate A macro pre processor is available Invocation of The ASM Assembler The ASM assembler is invoked with a command line for matted as follows ASM options source file ext ob ject file in which the following symbols are used options represents optional assembler options as de scribed below multiple options may be separ
98. cts all codes b NUM LOCK codes are not affected by SHIFT or CONTROL c CONTROL is not affected by SHIFT 9 Codes for unshifted PRT SCRN and up down left and right arrows were changed from to their current values in SK DOS version 2 4 OCNTRL Assignments OCNTRL is the opposite of ICNTRL it is used to send special arguments to an output device and its driver Its main purpose is to allow a program to drive a variety of output devices in a common way without having to be concerned with the particular type of output device being used Interfacing to a variety of output devices is again done via a translation table For example when a program places the code 0002 into D4 and then calls OCNTRL the driver uses the translation table to convert the 0001 into whatever character or sequence of characters is needed to erase the screen on the current output device OCNTRL expects a 16 bit word as an argument and de pending on the exact I O device will recognize the following 0000 Return number of current driver 0 7 in DS 0001 Return name of current driver e g CONS in D5 0002 Erase screen 0003 Home cursor 0004 Cursor up 0006 Cursor right 0007 Bell may also use 07 in data stream 0008 Cursor left may also use 08 in data stream 0009 Horizontal tab 000A Line feed may use 0A in data cursor down OOOB Clear current line 000C Erase screen amp home cursor form feed on printer 000D Carriage return may also us
99. d with INLINE LPOINT points to the first character in the buffer Each time another character is obtained from the buffer LPOINT is incre mented so that it points to the next byte When the pointer gets to the CR code at the end of the line it then remains pointing to the CR When an entire name or number is fetched from the buffer such as by GETNAM then at the end of the routine LPOINT points to the first character past the delimiter such as a space or comma or to the delimiter itself if CR BREAKA 762 765 A6 Break Escape address long word As indicated earlier terminal output can be interrupted by pressing the ESC key at which time SK DOS waits for a second character If the next character is again an ESC then output resumes if the second character is a carriage return 0D character then SK DOS aborts the program This return is handled through the return address in BREAKA which is ini tialized to point to WARMST User programs may also use BREAKA to return to SK DOS in that way More commonly user programs may store a different address in BREAKA to force a return elsewhere when the return key is pressed CURRCH 766 A6 Last character read from buffer PREVCH 767 A6 Previous character read As characters are fetched from the line buffer by SK DOS routines such as GETNXT these two locations hold the latest character fetched CURRCH and the previous character fetched PREVCH EXECKFL 774 A6 Execution addres
100. d send the catalog listing to the printer if a PRTR printer driver is installed otherwise it will go to a disk file called PRTR PIP You can also force output to a PRTR file even when a PRTR device is installed simply by including the extension Input redirection is handled with the lt symbol For example the command BUILD FILE is generally used to input text from the keyboard into FILE The command BUILD FILE lt ANOTHER would also send text to FILE but would take the text from another file called ANOTHER PIP Alternatively if there is a device called COM1 on the system then BUILD FILE lt COM1 would take the text from this input device Think of lt and gt as being arrows The gt in gt FILE points to FILE so data goes to FILE whereas lt FILE points away from FILE so data comes from FILE Note also that file names used in redirection default to PIP extensions which stands for pipe though this can easily be changed by specifying a different extension 14 1 DEVICE NAMES AND DEFAULTS In the above examples PRTR and COM1 were device names as opposed to file names Device names are similar to file names but a must have exactly four characters and b are not allowed any extensions Whenever you use a device name SK DOS checks whether such a device exists If it does then it uses the device If not then it uses the same name as a file name That s why in the above example gt PRTR
101. ddress is a number between 0000 and FFFF During loading SK DOS adds the current value of OFFSET to load addresses specified in the file unless the option is used in the command line 03 is similar to 02 in that it also marks the beginning of data to be loaded into memory but it is followed by a four byte load address and a two byte count It is therefore used for memory addresses above FFFF or for loading data longer than 255 bytes although such data is often split into a number of shorter 02 segments As with the 02 segment SK DOS adds the current value of OFFSET to load addresses specified in the file unless the option is used in the command line 16 marks the beginning of a two byte transfer address that is the address where the file just loaded should be executed The current value of OFFSET is added to the address specified in the file 17 marks the beginning of a four byte transfer address used if the transfer address is above FFFF The current value of OFFSET is added to the address specified in the file 04 05 18 and 19 are similar to 02 03 16 and 17 respectively except that the current value of OFFSET is NOT added to the specified address in the file Note however that load addresses are still checked against OFFSET and MEMEND limits unless the GETX command is used see the descriptions of GET and GETX later in this manual These four codes are provided for special applications and should no
102. direct access to the disk read routine The user program must provide the drive number in byte 3 of the FCB and the track and sector numbers in bytes 34 35 Upon exit the data from the desired sector begins at byte 96 of the FCB If an error is encountered the Z bit of the condition code register is cleared and byte 1 of the FCB contains one of the following error codes error 9 disk read error error 14 disk seek error or error 16 drive not ready SWRITE A01D Write a single sector This operation provides direct access to the disk write rou tine The user program must provide the drive number in byte 3 of the FCB the track and sector numbers in bytes 34 35 and the 10 6 data to be written beginning at byte 96 of the FCB If an error 1s encountered the Z bit of the condition code register is cleared and byte 1 of the FCB contains one of the following error codes error 10 disk write error error 11 write protected disk error 14 disk seek error error 16 drive not ready or error 29 disk verify error FDRIVE A01A Find next drive number This function is used to find the next available drive number On entry you must place either the number FF or a valid drive number into byte 3 the drive number byte of the FCB The FCS will then return with the next available drive number The FCS will start with the next higher drive number since FF is equivalent to 1 entering with this value will start with drive 0 Searchin
103. dress in A6 The variables which may be accessed are listed in Chapter 11 GETCH A029 Get input character with echo GETCH is used to get an input character from the keyboard it returns with the character in D5 All valid keyboard character codes can be input but the parity bit bit 7 is changed to a O for all input The character is echoed to the output INNOEC A02A INNOE1 A043 Get input character without echo Get input character without echo bypass typeahead SK DOS User s Manual INNOEC is just like GETCH but characters are not echoed to the output and the parity bit is not cleared Thus INNOEC can be used for 8 bit input whereas GETCH only reads 7 bits INNOE1 is similar but bypasses typeahead if implemented on the system see Chapter 14 PUTCH A033 Output character PUTCH is used to output a character from D4 to the output terminal INLINE A02C Input into line buffer SK DOS maintains a 128 byte line buffer which it uses to parse commands to its own Command Processor System The INLINE routine is used to enter an entire line of text from the keyboard into this line buffer and may also be used by user programs A line is normally ended with a CR character 0D which is placed at the end of the entered text Hence the maxi mum text line which can be entered into the 128 byte buffer is 127 bytes long This routine permits erasing errors with the backspace key The Control X key erases an entire line and st
104. drive 5 which have the extension COM The possible options for TCAT are the same as for ACAT and SCAT Try TCAT on the SK DOS disk to see what it does If your system has a clock calendar IC but your version of SK DOS does not already have time stamping implemented information on adding time stamping is provided in the 68K SK DOS Configuration Manual SK DOS s COPY command carries the old date and time along with the file Hence copies of your files will have the same date and time as the original The time code is based on a 24 hour clock and is given in tenths of an hour ranging from 00 to 239 For example a code of 123 means 12 3 hours or 3 10 of an hour 18 minutes past noon The TCAT program would display this as 12 18 If the time code is 00 which is the case for files without a time then TCAT will omit the time printout SK DOS User s Manual TIME TIME If your system has aclock calendar IC then the TIME utility may be supplied with your SK DOS It allows you to read and set this clock The command SK DOS TIME is used to display the current time in the format DAY MM DD YY HH MM SS AM The command SK DOS TIME S is used when you want to set the clock Simply answer the questions asked to set the clock making sure to use two digit numbers as requested SK DOS User s Manual TRACE and TRACENAB TRACE and TRACENAB TRACE is a memory resident command which allows you to enter a user progra
105. e 0D in data stream 000E Mask output of character in D5 OOOF Permit output of character in D5 0010 Return size of text screen in D5 D6 0011 Move cursor to position D5 D6 0012 Return cursor position in D5 D6 0013 Return character under cursor in D5 0014 Clear to end of line 0015 Clear to end of screen 0016 Erase screen 0017 Home cursor 0018 Insert line before current line 0019 Delete current line and close up SK DOS User s Manual 0020 Switch to normal print normal intensity 0021 Switch to condensed print 0022 Switch to expanded print 0023 Switch to double strike bold double intensity 0024 Switch to enhanced print mode 0025 Switch to italics 0026 Switch to character spacing in D5 0027 Switch to line spacing in D5 0040 Switch to graphics mode in D5 0041 Switch to text mode 0042 Choose color in D5 0043 Draw to position D5 D6 FFFx Switch to driver x Additional other codes may be defined in the future Arguments 0000 0001 and FFFx and 0002 for ICNTRL are handled internally by SK DOS all other argu ments are passed directly to the ICNTRL or OCNTRL section of the appropriate driver except for the default console driver in the BIOS which simply ignores the control codes CUSTOM DEVICE DRIVERS The SK DOS system disk includes source code for three device drivers called SERIAL TXT PARALLEL TXT and ADM 3A TXT These drivers demonstrate the exact format of a device driver and should be used as ex
106. e Otherwise the instruction field would be misinterpreted as the label field Labels are composed of characters of which all are signifi cant up to the default number of 8 for minimum systems or 31 for other systems Only the first eight characters are displayed on the formatted listing The first character of a label must be a letter or period and the remaining characters must be letters periods digits under lines and dollars Lower case and upper case letters are consid ered unique Label definitions starting at other than the left margin must end with a colon however the colon is not consid ered to be a part of the label name No alignment is normally forced before or after a label s value is set However alignment may be forced before a label definition by instructions and by certain types of declaratives if the label is coded on the same line as the instruction or declara tive In order to ensure label alignment in cases such as labels not coded on the same line as an instruction an DS 0 or EVEN directives may be inserted on the line before a label definition or a label may also be coded on the line with one of these directives The following symbols may not be used as labels since to do so would create ambiguous register references AO thru A7 CCR DO thru D7 DFC PC SFC SP SR USP VBR a0 thru a7 cer dO thru d7 dfc pc sfc sp sr usp vbr These represent the following 68000 68010 registers AO th
107. e a bB 62 0062 42 0042 02 0002 A SK DOS User s Manual No Lock Shift OA 0127 32 003 N 0327 32 0032 Lock 62 0304 0206 cere Lock Lock 71 0320 Up 0B 0125 0325 Arrow Grey 2D 002D 032D 2D 002D Minus Arrow 5 0327 Arrow Plus 0322 Arrow kaji Arrow NOTES 1 All codes in columns 1 through 4 are hex numbers 2 The notation AA BBCC means that the code AA is gener ated using the normal character input routine INCHS8 in HUM BUG GETCH INNOEC or ICNTRL function 0002 in 33 0033 30 0030 2E 002E 0324 032A 032B 33 0033 30 0030 2E 002E 14 5 SK DOS and BBCC is generated using ICNTRL in HUM BUG or ICNTRL function 0005 inSK DOS 3 If BB is 00 then CC is the standard ASCII code for that key and is equal to AA With some exceptions BB codes of 01 stand for unshifted characters 02 stand for shifted characters 03 stand for control characters and 04 stand for characters which do not fit any of the above groups 4 or means that no key code is generated for that key 5 Items labelled are not affected by the NUM LOCK key their key codes are indicated in the other three columns at all limes 6 CAPS LOCK affects only the alpha keys A Z For these keys it reverses the meanings of columns 1 and 2 7 The ALTernate key adds 80 or 0080 to all codes shown 8 The precedence is a ALT affe
108. e a group of files an entire directory or an entire disk It can also retrieve deleted files although UNDELETE is generally easier to use alpha betize while copying and more In its simplest form the COPY command is used by entering the word COPY the file spec of the file to be copied and the file spec of the destination For example COPY 0 PROG TXT 1 NEWPROG ABC would copy PROG TXT from drive 0 to a new file called NEWPROG ABC on drive 1 But there are many other possible ways of calling COPY Although there are some exceptions the most common form of a COPY command looks like this COPY lt how gt lt from where gt lt to where gt lt since date gt lt match list gt We will leave the how and since date for later and begin with the from where The lt from where gt parameter This item describes where the file s will come from It may be a a plain drive number such as O or 2 in which case the current default directory is assumed except when the F option is used see later b a drive number and directory such as 1 A or 2 where the asterisk would mean all directories or c a file name and extension possibly preceded by a drive number and directory If such a specific file spec is supplied then a match list would not be used An extension is always required in this case as this option must narrow down the copy function to a specific file If a drive and directory are not supplied then the curren
109. e and insert line mode In command mode its prompt is a sign often followed by the current line number in insert mode its prompt is an sign The command mode supports one character editing com mands such as P for Print or I for Insert Such commands can be preceded by a line number if you wish to change to a different current line For example the command 10P would tell EDLIN to go to line 10 and then print it Do not insert a space between a command letter and any of the arguments before or after it The following EDLIN commands can be used C Change a string on current line The letter C is followed by a delimiter the old string the same delimiter the new string and the same delimiter Any character can serve as the delimiter For example the command 10C Hence Thus would go to line 10 and then change G 22 Hence to Thus The command may optionally be followed by an asterisk as in 10C Hence Thus which makes the command a global command changing all occurrences of Hence to Thus from the current line down to the end of the file D Delete the current line This command deletes the current line and renumbers all of the following lines F Find a string below current line The letter Fis followed by a delimiter the string to be found and the same delimiter asin F this string The com mand may optionally be followed by an asterisk as in F this string which makes the command a global command it will t
110. e instead replaced by the TAB character 09 followed by a byte representing a space count between 2 and 127 inclusive Strings of spaces of length greater than 127 are broken up into smaller pieces each of length 127 or less SK DOS User s Manual No special character is used to denote the end of text although the last line of text will generally end with a CR Any space remaining in the last sector of a text file is filled with NULL 00 bytes When SK DOS reads a space compressed file it does not return any NULL characters to the calling program hence it will generate an end of file error immediately after the last character of the text Text files may consist of any characters except for NULL 00 and TAB 09 Binary File Format SK DOS binary files are non space compressed files which contain binary data along with additional information which specifies where in memory that data is to be loaded and or executed A typical binary file will generally consist of several seg ments each of which begins with an identification byte which describes what the segment consists of There are ten such identification bytes 02 marks the beginning of a relatively short segment con taining binary data to be loaded into memory The 02 is followed by a two byte load address a one byte count which specifies how many bytes are to be loaded and anumber of bytes equal to the count The count is a number between 1 and 255 and the load a
111. e specified extensions These extensions are listed in Appendix F Most programs and com mands default to specific extensions unless another extension is specified For example the EDLIN command is used to edit text files and always assumes that its text files use a TXT extension if none is given The GET command on the other hand is always used to load binary files into memory and so it automatically assumes a BIN extension if none is given You may provide an extension when you use these commands but it is usually not necessary Unlike default extensions which are built into commands and programs default drive numbers and directories can be specified by the user by using the SYSTEM and WORK com mands When SK DOS is first booted it defaults everything to the root directory of drive 0 You may keep these defaults but specify different drive numbers or directory names just when you need them or you may set up a default drive or directory different from the root directory of drive 0 which will then automatically be chosen for most commands unless you specify otherwise Here is a simple example Suppose you wish to use the LIST COM command to display a file called FILE TXT Let s assume that LIST is in directory C of drive 0 while FILE TXT is in directory X of drive 3 One way to do this would be to give the command SK DOS 0 C LIST COM 3 X FILE TXT But since SK DOS automatically defaults to COM exten sions for commands w
112. e updating SK DOS checks the byte prior to reading or writing to make sure that the file is open for the appropriate operation The values of this byte for an open file are as follows 1 open for sequential reading 2 open for sequential writing 3 open for updating but no changes have been made to current sector 83 open for updating and changes have been made to current sector this is hexadecimal 83 Byte No 3 Logical drive number 0 through 9 This byte contains the number of the drive being used for this file control block The drive number will normally be a number from O through 9 but when opening a file for reading or writing it may also be specified as FF in which case SK DOS will search your drives beginning with drive 0 for a drive where the requested operation can be completed Then it will place the correct drive number into this byte and open the 9 1 file Since many disk drivers do not provide a way of determin ing whether a5 floppy disk is ready or not SK DOS may hang up if there is no disk in a drive being searched although the DRIVE command can be used to define non existent drive numbers See also Chapter 13 for I O redirection and its use with the logical drive number Bytes No 4 11 File name 8 bytes These eight bytes contain the name of the file being used with this FCB The first character of the name always in byte 4 must be a letter and the remaining ones may be either letters di
113. elp you to determine the proper settings for your drive it was obtained from a Western Digital spec sheet and we have not personally checked its accuracy 300 Seagate ST4096 819 6 2 2 613 1024 8 102 Seagate251__ 819 bes ae 918 15 Miniscribe3650_ 809 6 12383 Miniscribe 3053 1024 Miniscribe 8425 SK DOS User s Manual HELP HELP HELP is simple program which merely reminds you how to get help with other SK DOS commands simply type their name a space and a question mark G 30 SK DOS User s Manual LINK LINK LINK is one of the commands used to generate a bootable SK DOS system disk on some systems It tells the super boot program where to find the SK DOS program on the disk Here is a short explanation of why LINK is needed To start SK DOS you usually use a monitor command In systems which contain HUMBUG or another customized monitor this command may boot SK DOS directly In simpler systems however this monitor command may only be capable of reading one sector from a disk In that case it loads a super boot program from track O sector 1 of the disk into memory The super boot program then reads the rest of SK DOS and executes it Since SK DOS could be anywhere on the disk the super boot needs a quick way of finding it This is accomplished by using LINK to store the disk address of SK DOS directly into the super boot program itself LINK is only necessary when
114. emory to disk For example the command SAVE PROGRAM 9000 A000 9004 would save a file called PROGRAM from memory locations 9000 through A000 and assign a transfer starting address of 9004 All addresses are hexadecimal the file name extension defaults to BIN if not given and the transfer address is omitted if not given Once called the SAVE command asks the following ques tion SAVE OPTIONS 1 USE ABOVE ADDRESSES IGNORING OFF SET OR 2 SUBTRACT OFFSET FROM ABOVE AD DRESSES CHOOSE 1 OR 2 These options affect only the addresses stored on the disk as part of the file not the address of the memory area saved to disk as follows Option 1 Use Above Addresses The addresses specified 9000 A000 and 9004 in the above example are stored on the disk as the load and transfer addresses In other words the G 46 addresses saved as part of the file correspond exactly with the area of memory saved to disk In general however if this file is subsequently loaded back into memory it will usually go back into a different location since most loading is done by adding the current value of OFFSET to the addresses actually stored as part of the disk file If you desire to load this file back into exactly the same memory locations it came from you must use the minus option of GET Option 2 Subtract OFFSET From Above Addresses In this case the current value of OFFSET is subtracted from the specified addresses before
115. ence GETCH INNOEC and INNOE1 will all wait for a character to be typed if none exists when they are called Hence we need a way of checking whether there is a character there STATUS is therefore used to test whether there is any character in the typeahead buffer whereas STATU1 tests whether a last char acter exists Note when there is a single character in the buffer it becomes both the first and last character and STATUS and STATU1 will both return a true when tested If the character is obtained with GETCH or INNOEC then both STATUS and STATUI1 will go false But if it is obtained with INNOE1 STATU1 will go false but STATUS will still be true indi cating that it is still in the buffer as well Finally FLUSHT is a function which empties the entire buffer so that both STATUS and STATUI1 return false FLUSHT should always be used after INNOE1 returns a break or ESCape character and may also be used when you want to make sure that some left over character in the buffer does not provide an undesired answer as when asking a Y or N question The following example shows how these DOS calls are used inside UBASIC to check for a control C or ESCape Although checking for ESCape is normally done by SK DOS internal routines note that here UBASIC does its own checking This is needed since it would otherwise remove the ESCape from the buffer before SK DOS has a chance to check it Each time UBASIC outputs a cha
116. ent date year The above three locations hold the month day and year entered from the keyboard when SK DOS is first cold started This date is used by SK DOS when writing files on the disk and may also be accessed or changed by user programs All three bytes are binary numbers and CYEAR contains only the last two digits of the year for example in 1990 the registers contain 90 or a hexadecimal 5A LASTRM 753 A6 Last terminator This byte contains the last terminator encountered by the GETNXT routine from the line input buffer COMTAB 754 757 A6 Pointer to command table long word SK DOS contains several memory resident commands such as XEQ and GET users may add additional memory res ident commands and let SK DOS know about them via COM TAB by putting into COMTAB a pointer to a table which lists the added commands This table is searched by SK DOS after its own command table but before it looks for disk resident commands Each entry in the user command table should consist of a the command name of up to eight letters with no exten sion b a zero byte to signal the end of the name and c a four byte address pointing to the command program An extra zero byte at the very end signals the end of the table The command should end with either an RTS or DC WARMST LPOINT 758 761 A6 Pointer to line buffer long word LPOINT points to the next character to be obtained from the line buffer When the buffer is first fille
117. er s Manual APPENDIX E SK DOS ERROR CODES SK DOS uses the following error codes in addition user programs may use other error codes which are documented in their respective manuals CODE MEANING 1 FCS operation code error 2 File already open or in use 3 File already exists 4 File does not exist 5 Directory Error 7 Disk is full 8 Input past end of file 9 Disk read error 10 Disk write error 11 Disk is write protected 12 Protected file 13 Error in closing file 14 Disk seek error 15 Invalid drive number 16 Drive not ready 18 This FCS operation not permitted on this file 19 Random file operation not allowed 20 Disk I O error 21 Illegal or missing file name or extension 22 Can t Close error 23 Random file map overflow 24 Specified random sector number is invalid 25 Random sector number does not match file contents 26 SK DOS command syntax error 28 Missing transfer address 29 Disk has been switched while file was open 30 File not open Internally SK DOS errors are represented by one byte numbers which are generally placed into byte 1 the second byte of a file control block by the File Control System User programs should test for these by their numbers Error messages are generally printed out by using the PER ROR routine which prints out the error number usually fol lowed by a one line explanation of the error Error 1 FCS operation code error is treated a bit differently from the others
118. er the file creation time encoded as a one byte number or a sequence number Se quence numbers are sequential numbers beginning with 1 when the system 1s first booted Sequence numbers indicate the order in which files are written on any particular day See INTIME in Chapter 13 for further information Byte No 28 Month of file creation 1 through 12 Byte No 29 Day of file creation 1 through 31 Byte No 30 Year of file creation last two digits SK DOS User s Manual These three bytes hold the date when the file was created All three bytes are in binary but only the last two decimal digits of the year are stored That is in 1984 byte 30 stores a decimal 84 or a hexadecimal 54 Byte No 31 Reserved This byte is reserved for use by SK DOS Bytes No 32 33 Reserved These bytes are reserved for future expansion Byte No 34 Current track number Byte No 35 Current sector number These two bytes contain the track and sector number of the sector currently in the FCB If the file is being read then they indicate where the data currently in the FCB came from if the file is being written then they indicate where this data will go Bytes No 36 46 Temporary name buffer 1 These eleven bytes are used to temporarily hold a file name and extension while the file is being renamed or deleted Byte No 47 Reserved This byte is reserved for use by SK DOS Byte No 48 Reserved This byte 1s reserved for future expansi
119. er the secondary disk drivers are ready when SK DOS is searching for the next ready drive At that time A4 points to an FCB which contains the drive number and the drive number is also in D5 The called routine should return a zero condition if the requested drive is ready or non zero if it is not ready The program must preserve AO through A4 and DO through D5 SECFL1 COLDST 84 Secondary Flag 1 SECFL2 COLDST 8A Secondary Flag 2 SECFL3 COLDST 90 Secondary Flag 3 13 4 These are three six byte areas which may be used by sec ondary drivers as general purpose flags TRPFLG COLDST C0O Trap Initialization Flag TRPFLG determines whether SK DOS will initialize only the Line 1010 trap if TRPFLG 0 or all the traps if TRPFLG is non zero each time that RESTRP is called This decision is largely based on the type of system and should not normally be changed by the user If TRPFLG is zero then traps such as bus error etc will be handled by the monitor if TRPFLG is non zero then traps will be handled by SK DOS RESERVING MEMORY WITH OFFSET AND MEMEND Since OFFSET and MEMEND point to the beginning and end respectively of free user memory they can be used to set aside memory for other programs which should co exist with SK DOS without interfering with it When SK DOS is initially booted it is loaded with initial values of OFFINI and MEMINI It first checks memory starting with OFFINI up through the value of MEMINI looking
120. es not change the other SK DOS User s Manual 4 SK DOS OVERVIEW The SK DOS package consists of essentially two parts 1 The SK DOS program itself 2 Asetof disk resident commands such as CAT and LIST The disk resident commands are described later this section deals with the SK DOS program itself The SK DOS program in turn consists of three parts 1 The File Control System or FCS for short which maintains the disk directory and in general is responsible for managing the disk contents The FCS has various routines which may be called by other programs some of these routines actually handle the disk and its files while other routines may handle peripheral functions such as printing out strings or converting numbers to and from decimal These routines are used by the FCS but they are documented in this manual and may also be used by application programs 2 The Command Processor System or CPS for short which acts as an interface between a user and the FCS When SK DOS is first loaded and executed the CPS prints the SK DOS prompt and awaits further instructions These instruc tions may or may not involve the FCS 3 The Basic Input Output System BIOS which adapts SK DOS to run on a particular hardware system The BIOS 4 1 contains the software which interfaces with the keyboard dis play printer and disk drives The FCS and CPS parts of SK DOS are the same on all systems the BIOS portion must be tailored for ea
121. etic order 5 Once the disk is full use CHECKSUM on the destination disk Since the data is still in the cache you are actually checksuming the data in RAM not the data on the disk 6 Use CACHE lt drive number gt to flush the data from the cache and CHECKSUM the disk again The new checksum which uses data actually read off the disk must match the checksum in step 5 7 If there is more to backup from the hard disk flush the cache again and go back to step 3 This time however give COPY appropriate arguments so it continues backing up files from where it stopped the previous time SK DOS User s Manual VERSION VERSION VERSION is used to determine the version number of a binary file if that file has a version number included All SK DOS utilities and most other programs begin with the sequence of instructions START BRA S START1 DC W 0102 START1 actual program begins here so that the third and fourth bytes of the program are the version number 0102 in the above example which is printed as 1 2 VERSION can be used to check that version code To use it type the command VERSION followed by the name of the file as in SK DOS VERSION COPY If not entered the file name defaults to a COM extension G 57 SK DOS User s Manual XEQ XEQ XEQ is a memory resident command used to execute a suppose the command CAT 0 is used to display a catalog of a program previously loaded by SK DOS using the execution di
122. executed If no memory resident command exists by that name SK DOS will try to find the command on the disk and execute it Disk resident commands are program files which have a COM extension If no such COM file is found SK DOS makes one more try to find a Batch File A batch file is a text file having a BAT extension which itself contains one or more other memory or disk resident commands which should also be executed For example suppose a batch file called TWODIR BAT has the following two text lines DIR QO DIR 1 Entering the command TWODIR would then display the disk directories of both drives O and 1 If a command is given which is none of the above then SK DOS will print a file not found error message Note that a BAT file should never have the same name as a COM file since SK DOS will find and execute the COM file first and never execute the BAT file at all SK DOS User s Manual 6 MEMORY RESIDENT COMMANDS SK DOS recognizes a number of Memory Resident Com mands These are commands which are integral parts of SK DOS and are in memory at all times They are therefore called by their names and do not get either an extension or drive number Memory resident commands include the following more detailed descriptions are provided in Appendix G DIR Display the contents directory of a disk GET Load a binary file from disk into memory GETX Load a binary file from disk into memory MON Exit SK DOS a
123. f in the meantime or that the RAM disk memory has not been overwritten with other data If you do wish to actually erase all data on the RAM disk insert the word NEW into the command as in SK DOS RAMDISK NEW x which will totally erase the RAM disk and then reformat it as drive x RAMDISK changes both the OFFSET and MEMEND pointers The RAMDISK program itself is loaded beginning at the current value of OFFSET and then OFFSET and OFFINI are changed to point above the program so that subsequent programs are loaded above the RAMDISK program The virtual disk memory itself into which RAM disk data is stored is placed at the top of user memory just under the initial value of MEMEND and MEMEND is then reset to point just under it This has a bearing on what happens if SK DOS is exited and rebooted while a RAM disk exists After rebooting the RAMDISK program will no longer exist in memory but the RAM disk data should still exist at the top of memory below the current value of MEMEND As long as no program is run which uses more than 16K of RAM this data will continue to exist and the RAMDISK can be reinstated by another RAMD ISK command without data being lost SK DOS User s Manual REDOFREE REDOFREE REDOFREE is used to rearrange the sequence of the free sectors of a disk so they go in order from the outside of the disk toward the inside The sectors are in this sequence on a fresh disk but gradually become disordered as a dis
124. for a memory address which fails to store a memory pattern stored into it or which generates a bus error Once such an address is found SK DOS stores into MEMEND the top address of the last 4K block of memory found to be working This value of MEMEND then remains there unless changed by user programs SK DOS does not itself change it at any time although pro grams such as RAMDISK may Following the above at every warm start SK DOS sets OFFSET to the next even 256 byte boundary above the current OFFINI Since OFFINI at boot up normally points just above SK DOS and its drivers OFFSET is thus initialized to the next 256 byte boundary above SK DOS PROCESSOR STATE AND STACK USE Since user programs call SK DOS with traps SK DOS obviously runs in supervisor state User programs utilities and application programs however run in user state The system stack pointer is initialized at COLDST with the user stack pointer initialized at COLDST 0200 For example if COLDST is at 1000 then the user stack will go from 0E00 down while the system DOS stack will go from 1000 down The system stack will never extend down as far as the user stack so data on the user stack is preserved during DOS calls Between them OFFSET through OFFINI and MEMEND through MEMINI therefore delimit the current user memory User programs and SK DOS utilities can subsequently change these values to reserve memory for themselves A pro gram which wants
125. from disk by SK DOS unless LASTRM contains the ASCII code for a minus sign Programs are thus loaded into the address specified in the disk file only if OFFSET is 0 or if LASTRM contains a minus sign Normally OFFSET points just above SK DOS so that all user programs are loaded into free memory above SK DOS Such programs can be executed as long as they are written to be position independent OFFSET and MEMEND together therefore define the lower and upper limits respectively of free user memory Since user programs may change OFFSET as they run to load another program into memory above themselves for exam ple SK DOS resets OFFSET to the value stored in OFFINI each time it does a warm start it actually sets OFFSET to the next 256 byte boundary above OFFINI to make OFFSET a more convenient number OFFSET is thus only a temporary value valid for the duration of any given program OFFINI is more permanent DEVIN 3274 A6 Current Input device DEVOUT 3275 A6 Current Output device DEVERR 3276 A6 Current Error device These three bytes specify the devices currently being used for input output and error displays They default to device 0 for input and output and device 1 for the error device all of which are normally the default CONS console device User programs can change DEVIN and DEVOUT to go to different devices but DEVERR should usually remain so that error messages still go to the console DEVTAB 3278 A6 Device Descriptor
126. g no further errors the next message will be READY TO FORMAT HARD DRIVE ARE YOU SURE YOU WANT TO GO AHEAD which should be answered with Y There are a number of self explanatory error messages which may come up during the above procedure For example selecting a partition size that is too small or too large or selecting partition sizes which do not add up to the total number of cylinders on the disk will give an error message and allow you to re enter the data Once formatting starts HDFORMAT will print out status information so you can see what it is doing If the disk has defective sectors their locations will be displayed and they will be deleted from the free space on the disk A relatively large number of defective sectors can be tolerated on a disk without a problem except that logical track 0 sectors 0 3 and 5 must always be good on every partition errors in any of these will cause an immediate Fatal Error message and HDFORMAT will quit If this occurs in partition 0 of a disk then the hard disk is not usable If it occurs in another partition however then it will generally be possible to move these defective sectors to some other track by partitioning the disk differently and then reformat the disk without problem Different disk partitions can be assigned different logical drive numbers with the DRIVE command Partitions are called HO through H7 as follows Drive A has HO through H3 Drive B has H4 through H7 HD
127. g will continue up until the current value of MAXDRV if no ready drive is found the FCS will return error 16 drive not ready in byte 1 of the FCB and also set the carry bit otherwise the carry bit is cleared DIREST A026 Disk Restore This function does a restore on the drive pointed to by the drive number in the current FCB that is the head on the current drive is retracted to track 0 This function is only implemented for the floppy disk and is used specifically by the FORMAT routine it should not be used by any other programs DISEEK A027 Disk Seek This function causes the drive indicated in the current FCB to seek 1 e move the head to the current track number given in the FCB No checking is actually done other than checking that the drive number is valid This function is only implemented for the floppy disk and is used specifically by the FORMAT routine it should not be used by any other programs SK DOS User s Manual 11 USER ACCESSIBLE VARIABLES Many of the SK DOS variables are of use to a programmer writing programs to run under SK DOS These variables are of two types 1 User variables which are often needed by application programs running under SK DOS These are described in this Chapter 2 System variables which are generally needed only by systems programmers implementing SK DOS on anew system or modifying major operating parameters A few of these are described in Chapter 13 but most such var
128. g word Last character read from buffer Current date year Delete character 18 Current error device 1 Current input device 0 Current output device 0 I O device descriptor table Absolute ORG of SK DOS Input echo flag End of line character 3A 1K of environment space Error type Alternate ERRCODES SYS vector Escape char 1B ML execution address long word Execution address flag Pointer to 1st open FCB long word File input addr vector long word File Name case flag File output addr vector long word Last terminator Line buffer 128 bytes Pointer to line buffer long word Maximum drive number Last usable memory addr long word Null wait constant Current output column Offset load address long word Output pause control byte Number of printed lines per page Previous character read Page column width Repeat character 01 Sequence number Number of skipped lines betw pages Special I O Indicator System default directory System default drive User FCB 608 bytes 64 bytes of free space for user pgms Working default drive Working default directory A 1 LISTED IN ORDER BY ADDRESS ADDRESSES FUNCTION USRFCB LINBUF BACKSC DELETC ENDLNC BSECHO SYSDIR WRKDIR ESCAPC SYSTDR m en a m oo e a a 747 A6 WORKDR 748 A6 REPEAC 749 A6 CMONTH 750 A6 CDAY CYEAR LASTRM COMTAB LPOINT BREAKA CURRCH PREVCH OFFSET EXECFL EXECAD ERRTYP FOADDR FIADDR SPECIO
129. gits hyphens or underlines If the name is shorter than 8 characters then the remaining bytes must be filled with zeroes Bytes No 12 14 Extension 3 bytes These three bytes contain the extension that goes with the name in bytes 4 through 11 The extension obeys the same rules as the name described above Byte No 15 File attributes This byte defines the type of user access permitted to this file The bits are used as follows Bits 0 3 reserved for future use leave at 0 Bit 4 will not be listed by CAT utility Bit 5 Reading not permitted Bit 6 Deletion not permitted Bit 7 Writing not permitted Bytes No 16 17 Reserved These bytes are reserved for future expansion Byte No 18 First track of file Byte No 19 First sector of file These two bytes point to the first sector of the file Bytes No 20 21 Reserved These bytes are reserved for future expansion Byte No 22 Last track of file Byte No 23 Last sector of file These two bytes point to the last sector of the file Bytes No 24 25 Number of sectors in the file These two bytes indicate the size of the file in sectors Byte No 26 Random file indicator This byte indicates whether the current file is a sequential file or a random file A zero in this byte indicates a sequential file a nonzero indicates a random file See Chapter 13 for further information on random files Byte No 27 Time or sequence number This byte normally contains eith
130. grams running under SK DOS The FCS does the actual work of managing the contents of the disk It has various routines which can be called by user programs for managing the disk contents 3 Memory and disk resident commands provide addi tional functions which work in conjunction with the CPS and FCS to provide an easy way of maintaining the disk In addition to the various commands supplied with SK DOS there are other programs available from other vendors which are designed to also work with SK DOS Furthermore SK DOS 68K floppy disks are compatible with those used by 1 1 6809 SK DOS and Flex a trademark of Technical Systems Consultants so text and data files may be brought over from 6809 systems and used on your 68K system as well The interface between SK DOS and user programs is sim ilar to that standardized over a number of years on earlier 6809 systems and is fully documented in this manual Since a DOS must be customized to run on a particular system Star K Software Systems Corporation in conjunction with manufacturers who license SK DOS provides several different versions Depending on the hardware configuration you specified with your order you may already have received a version which is customized for your hardware or you may have received a generic version which must still be adapted to your particular hardware In general you will have one of the follow ing two files on your disk SK DOS SYS is a bootable versi
131. happen because CACHE will think you are still using the old disk and will read and write data as if the old disk was still in the drive Any data written to the new disk will go in the locations it would have gone on the old disk We have recently modified CACHE so that it checks the identification on a disk before all accesses to the directory this somewhat slows down oepration but does prevent many disk accidents Note that CACHE only saves data for floppy disks it does not store data for the RAM disk since that would just duplicate data already in RAM or a hard disk since hard disks are generally almost as fast as the cache memory Hence the memory assigned to CACHE 1s used only for floppy disk data The CACHE program can be used in addition to RAMDISK but if both are used together then the RAMdisk must be set up first The reason for this requirement is that this allows the RAMdisk memory to be above the cache memory If SK DOS is subsequently rebooted there is a greater chance of the RAMd isk data being preserved since it is in higher memory The cache memory on the other hand is always erased when rebooting This also serves to explain why the cache memory size can be changed while RAMdisk memory size cannot Although CACHE can use anywhere from 32K to 1024K i e one megabyte of memory the actual size chosen depends on the application If you merely intend to use a floppy disk for a few files then 32K or 64K might be suff
132. he RAM disk becomes erased when power is turned off or if there is a power outage Hence any important data on a RAM disk should be copied to a real disk before power is turned off and perhaps at frequent intervals between RAM disk is enabled with the command SK DOS RAMDISK lt drive number gt lt RAM disk size gt where the lt drive number gt may be any number from 0 through 9 which then becomes the drive number of the RAM disk If the drive number coincides with that of a real disk drive then the real drive becomes inactive and the RAM disk takes its place A drive number must be supplied If the RAMDISK drive number is larger than any other existing drive the value of MAXDRYV will automatically be changed to reflect the RAM disk drive number Since most systems will not have the maxi mum number of ten drives allowed by SK DOS it will usually be possible to place the RAM disk above other real drive numbers the lt RAM disk size gt is the size in increments of 4K of the memory to be devoted to the RAM disk with a minimum of 8K If the amount entered is not a multiple of 4K then the next lower 4K multiple will be used It can be entered either as just a plain number such as 16 or followed by the K as in 16K When RAMDISK is first called a size must be specified but no size need be entered if the RAMDISK command is used to reassign the drive number of an existing RAM disk When initializing a new RAM disk the RAMDIS
133. he facilities of the monitor to trace further insert breakpoints or do other debugging When using TRACE with HUMBUG you must first execute the TRACENAB command which tells HUMBUG that 13 5 you will be using TRACE and initializes one of its memory locations In a few instances that may not work the easiest solution is then to exit SK DOS with the MON command type the HUMBUG command ST 1000 to execute one harmless trace instruction and then return to SK DOS with the RD command This sets the HUMBUG registers properly SYSTEM INFORMATION SECTOR FORMAT The System Information Sector SIS contains the following data all unused bytes are 00 Bytes 16 26 Disk name and extension Bytes 27 28 Disk number Bytes 29 30 Track and sector number of first free sector Bytes 31 32 Track and sector number of last free sector Bytes 33 34 Number of free sectors Bytes 35 37 Month day and year of disk creation Byte 38 Number of logical tracks on the disk 1 Byte 39 Number of logical sectors per track DIRECTORY STRUCTURE The directory of a disk occupies track 0 of every disk beginning at sector 5 and extending to the end of the track This area of a disk is reserved for the directory when the disk is initially formatted but SK DOS will extend the directory one sector at a time if additional space is needed Like any other file the directory is a linked chain if additional sectors are needed they may be anywhere on the disk
134. he hard ware in reading or writing a sector or file Byte No 73 Reserved These bytes are reserved for future expansion Byte No 74 Directory track number Byte No 75 Directory sector number These two bytes point to the location in the directory where the current file is listed The directory begins on track O sector 5 but may extend to other tracks if track 0 is filled Bytes No 76 77 Reserved These bytes are reserved for future expansion Bytes Nos 78 79 Current or desired sector number This byte indicates the position of the current sector within the file In sequential files the first sector of a file is sector number 1 and so on In random files the first two sectors which contain the file map are number 0 and sector 1 is the first data sector of the file See Chapter 13 for further information on random files Bytes No 80 95 Reserved These bytes are reserved for future expansion Byte No 96 Beginning of data area The 256 bytes starting at byte 96 contain the data for an entire disk sector Use of a 608 byte FCB leaves another 256 bytes at the end of this data area thereby allowing for future expansion to 512 byte sectors SK DOS User s Manual 10 SK DOS FUNCTIONS SK DOS has a large number of subroutines and functions which can be called from user programs Some of these are actual part of the File Control System others are simply routines which the FCS itself uses and which are useful to the t
135. hen display every line from the current line down to the end of the file containing the specified string G Go to a line The G command is used to go to a new current line It is followed by one of the following line number as in G20 the letter T to go to the top of the file or the letter B as in GB to go to the bottom I Insert a new line after the current line Use the I command to insert one or more new lines after the current line by typing in an I and a carriage return or enter The prompt will now switch to an sign and you can enter one or more new lines To switch from enter mode back to command mode type a sign at the beginning of a new line P Print The P command prints one or more lines beginning at the current line It may be followed by one of several arguments as in these examples P Prints the current line P5 Prints 5 lines beginning with the current line P 5 Prints from the current line down to line number 5 P Prints from the current line to the bottom of the file Q Quit without saving The Q command exits back to SK DOS without saving any texton the disk and is used primarily if you wish to abandon all the work you have edited S Save and then exit to SK DOS The S command saves the current text to the disk and then returns to SK DOS If as explained above EDLIN is modifying an existing file then itrenames the old file to BAK before saving the new text Print a help message Prints a
136. hile LIST defaults to TXT extensions for text files the command could have been shortened to SK DOS 0 C LIST 3 X FILE If you expect to use a lotof commands from drive 0 directory C and perhaps a lot of text files from drive 3 directory X then you could specify those as default values with SK DOS SYSTEM 0 C SK DOS WORK 3 X These two commands would tell SK DOS to use 0 and C for loading its system commands and to use 3 and X as the work drive and directory Once you do this then the command to list the file would simply be SK DOS LIST FILE Subdirectories are generally used to organize the contents of a hard disk For example you might put all assembler source SK DOS User s Manual files into the A subdirectory put your Basic programs into B put C programs into C and so on Although it wastes space it is possible to put separate copies of a file into more than one directory For example to place a copy of the above 3 X FILE TXT into subdirectory Y you could simply use the COPY command as follows SK DOS COPY 3 X FILE TXT 3 Y FILE TXT 3 2 To move a file from one directory into another you use the RENAME command Thus the command SK DOS RENAME 3 X FILE TXT 3 Y FILE TAT leaves only one file on the disk but moves it from X to Y This is different from the COPY command which would leave two copies of the same file on the disk one in X and another in Y Note that in this case changing one copy do
137. his warranty is presented expressly in lieu of all other warranties expressed or implied including those of merchantability and fitness for use and of all other obligations on the part of Computer Systems Consultants Inc and its agents Problems and Improvements Users are encouraged to submit problems and to suggest or to provide improvements for the ASM assembler Such input will be processed on a best effort basis Computer Systems Consultants reserves the right to make program corrections or improvements on an individual or wholesale basis as required The company is under no obligation to provide corrections or improvements to all users of ASM In the case of specific situations requiring extensions to ASM or major assistance in its use consulting is available on a pre arranged for fee basis Introduction This assembler is used to convert 68000 68010 assembler language mnemonics and expressions to 68000 68010 machine language The syntax of the assembler language which it ac cepts is compatible with the standard language as implemented in the Motorola 68000 and 68010 Resident Structured Assem blers In order to be somewhat more compatible it accepts several directives implemented only by the TSC 68000 Assem bler It may also be used to produce machine language for any of the other processors in the 680xx family although with some limitations For those processors with instruction sets which are supersets of the 68010 instru
138. iables are described in the optional Configuration Manual not in this Users Manual The precise location of User variables may change between various versions of SK DOS Any call to an SK DOS function however returns in A6 a pointer to the beginning of this variable area In particular the call to VPOINT see Chapter 10 specif ically exists to return the address of this variable area in A6 Each of the locations described below can be referenced using indexed addressing with reference to A6 This may be done either by referring to the numeric offset given in the descriptions below or by using the SKEQUATE file on your SK DOS disk as a library file in your assembly language programs as follows LIB SKEQUATE You may then refer to variables by their symbolic name For example the following two lines are equivalent LEA 0O A6 A4 LEA USRFCB A6 A4 include as library Uses absolute offset Uses offset defined in SKEQUATE NOTE In the following the abbreviation DN stands for Device Number and is used for those variables whose addresses are different for different devices For example PLINES is listed as 3322 80 DN A6 For device number 0 the address is 3322 A6 for device it is 3322 80 1 A6 or 3402 A6 and so on USRFCB 0 A6 User FCB 608 bytes This area is an FCB which is used by SK DOS for its own internal operations This is done in such a way however that other programs which require an FCB can also use this
139. ich would be common to all systems The supplied ADM 3A driver shows how this is done When ICNTRL command 0005 receives a regular ASCII character it simply returns it as a single byte in D5 with bits 8 15 of D5 equal to 0 But a special keyboard character is identified by making bits 8 15 non zero in other words special characters are represented by the words 0100 and higher The following table shows the key codes for an implementa tion using a PC compatible keyboard 0002 0003 0004 14 4 1B 001B 3 Num Lock x Key 1 2 2 3 4 3 33 0033 23 0023 0433 5 O 4 6 7 10 043 11 12 _ 2D 002D 5F 005F 1F 001F 043 14 Back 08 0008 08 0008 7F 007F 09 0009 021 F 6 51 0051 W 57 0057 E 45 0045 52 0052 54 0054 59 0059 55 0055 49 0049 4F 004F 50 0050 5B 005B 5D 005 D 0D 000D 0D 000 000D jae E 6 1 4 O J Nn Q ge 1 tT Y u U il 4 25 6 4 4 R C eturn l br TO Tho Tho DO FY FRO PO IN TR FR m m W ito CO IO Om IN Nn o ar ee ontro aA S n 7 8 OD 9 l S x l 46 0046 F a jen Q 0 30 3 3 33 34 35 36 37 39 3 3B 003B 3A 003A 043B_ 40 gt 27 0027 22 0022 0427 i 60 0060_ ED 43 _ scwosc 7c 007c 1c 001C 7A 007A xX cC V n a le ar
140. icient If on the other hand you intend to do extensive processing with one disk then the size should be about 20 larger than the size of the floppy disk since CACHE needs some extra memory for its data storage and for elbow room If you have several floppy drives then the cache memory should be large enough to accommodate all of the expected floppy disk operations on all drives When you intend to use a single floppy for extensive oper ations you can greatly speed up processing by reading the entire floppy into the cache at the beginning assuming that the cache memory is large enough to hold the disk s contents This is easily done by doing a CHECKSUM on the disk which reads the entire disk and coincidentally stores itin the cache memory Once this is done SK DOS will no longer need to read that disk at all it will only access the disk for writing Note that CACHE only stores floppy data in fact it goes by the physical drive number rather than the logical drive number Hence if you use the DRIVE command to reassign a drive s logical drive number but don t swap diskettes in the drive CACHE will follow the diskette to its new logical drive number FInally once again make sure to flush the cache whenever you change a floppy disk SK DOS User s Manual CAT CAT CAT is used to display the contents catalog of a disk or hit any other key to do another CAT as originally listed on the directory
141. ile Close all open files Initialize File Control System Delete a file Find next drive number Open a file for read Open a file for update Open a file for write Backup to previous sector Read the next byte from file Rename a file Rewind file Read a random byte Write a random byte Select a specified random sector Skip current sector Write the next byte to the file Open system information sector Read a single sector Write a single sector D 1 LISTED IN ORDER BY OP CODE FREAD A001 FWRITE A002 FOPENR A005 FOPENW A006 FOPENU A007 FCLOSE A008 FCSCLS A009 FREWIN A00A DIROPN A00B SISOPN A00C DSREAD A00D DSWRIT A00E FDELET A00F FRENAM A010 FSKIP A011 FRRECD A014 FRBACK A015 FRGET A016 FRPUT A017 FDRIVE A01A FCSINI A01B SREAD A0I1C SWRITE A01D DIREST A026 DISEEK A027 OP CODE FUNCTION Read the next byte from file Write the next byte to the file Open a file for read Open a file for write Open a file for update Close file Close all open files Rewind file Open directory file Open system information sector Read directory or system information sector Write directory or SIS entry Delete a file Rename a file Skip current sector Select a specified random sector Backup to previous sector Read a random byte Write a random byte Find next drive number Initialize File Control System Read a single sector Write a single sector Disk restore to track 0 Disk seek SK DOS Us
142. incomplete The most common error message is DATE BAD This occurs when the user does not enter a valid date when SK DOS is booted or by failure of a hardware clock when used for setting the SK DOS date COPY will check the date on all files when it reads the disk directory and report any dates outside a reason able range This reduces the chance that a bad date will be passed on to the new file There are two alternatives when the BAD DATE message appears You can answer Y indicating that you approve of bad dates or answer N and not copy the file After returning to SK DOS you can re enter COPY using option SK DOS User s Manual COPY U which will assign the current SK DOS date to the file or use unused sector If the disk is protected or not ready the program the DATE command to set the file date to the day the file was will exit immediately l made The original COPY program and documentation were writ In order to check that the destination disk exists and is not ten by and provided through the courtesy of Bruno D Puglia write protected COPY reads the SIS track O sector 3 of the and Leo E Taylor destination disk and then duplicates it on sector 4 which is an G 13 SK DOS User s Manual DAMON DAMON DAMON is a trouble shooting program which displays the display of its number on the screen Moreover once activated drive track and sector number of each sector being written or the only way to turn it off is to reboot the sy
143. ing pagination ORG expression ORG L expression ORG W expression ORG specifies the starting absolute memory base of the program counter ORG and ORG L specify long absolute ad dresses representing the full range of the address space ORG W specifies short absolute addresses restricted to the address ranges 00000000 00007FFF and FFFF8000 FFFFFFFF PAGE PAGE causes the next line on the source listing to appear on the next page RORG expression RORG L expression RORG W expression RORG specifies the starting absolute memory base of the program counter and the generation of program counter rela tive effective addresses RORG and RORG L specify long ab solute addresses representing the full range of the address space RORG W specifies short absolute addresses restricted to the address ranges 00000000 00007FFF and FFFF8000 FFFFFFFF RPT expression RPT specifies the number of times the next line in the same source file will be repeated The next line is always included at least once even if the value of the expression is zero label SET expression label expression SET defines or redefines a symbol and sets its value to that of the expression This operand may contain complex expres SK DOS User s Manual sions but not complex forward references and this symbol s value may be changed only by another SET or directive SPC SPC places a blank line in the source listing TTL title NAM title TTL a
144. ired file into bytes 3 through 14 of the FCB The FCS will take care of initializing all other parts of the FCB If the requested file is not on the disk the FCS will return error code 4 file does not exist When the FCS is finished opening the file it prepares the file for sequential reading next and assumes that space compression will be used FOPENW A006 Open a file for write This function opens a file for writing Before calling the FCS the calling program must insert the drive number name and extension of the desired file into bytes 3 through 14 of the FCB The FCS will take care of initializing all other parts of the FCB If the specified disk already has a file with the specified name the FCS will return error code 3 file already exists This function opens a sequential file but it may be changed to a random file by storing a non zero number into byte 26 of the FCB after opening the file but before writing any data into it See Chapter 13 for further information on random files FOPENU A007 Open a file for update This function opens a random file for reading or updating Once the file is open you may do one of the following SK DOS User s Manual a Use FRRECD to position to a particular sector of the file b Use FRBACK to backup to the preceding sector c Use FRGET to read a particular byte from the currently selected sector d Use FRPUT to write a particular byte to the currently selected sector e Use FR
145. ives can handle You will normally answer 35 or 40 but formatting fewer tracks is often convenient when you wish to save time and don t need as much space on the disk If your disk controller supports double sided or double density operation the next questions will be SINGLE OR DOUBLE SIDED SINGLE OR DOUBLE DENSITY SINGLE OR DOUBLE DENSITY TRACK 0 Answer with an S or D as appropriate The track 0 question will only be asked if you had specified double density for the disk itself You should specify a single density track O only if you intend to be compatible with 6809 versions of SK DOS the standard SK DOS 68K format is double density including a double density track 0 Although SK DOS can read and write single density disks note that a boot disk i e a disk which will be used for booting SK DOS must be double density throughout You will next be prompted ENTER DISK NAME ENTER DISK NUMBER The disk name must conform to standard file name rules and may have an extension and the number may go from 0 through 65535 IMPORTANT NOTE Although a disk name and number are not required to use a disk you should get in the habit of putting a distinctive name and number on every disk because SK DOS periodically checks them to make sure you have not switched a disk while a file is open on it Giving every disk the same or no name and number will defeat this file protection method While formatting the disk FORMAT will le
146. ix G SK DOS User s Manual 8 THE FILE CONTROL SYSTEM FCS The FCS is the heart of SK DOS since it is responsible for reading writing and locating files on the disk Although the FCS system is working it is invisible when you run some of the disk resident commands such as BUILD or LIST It is however heavily used by all programs which run under SK DOS The following explanation will assume that you have the knowledge and need to examine the operation of SK DOS on this detailed level When reading a file the FCS looks up the file location in the system portion of the disk track number 0 on the disk and then goes to read it When writing a file to the disk the FCS uses the system track to assign space to the file when the file is written the FCS updates the system track so that the file can later be found Fortunately though this process is rather complex in any disk system the user need not be concerned with how itis done or where on the disk a given file is located The SK DOS FCS does all this automatically the user need only give the FCS a file name anda command as to what to do This is done by setting up a File Control Block or FCB for each file that is to be opened a given program may use as many FCBs as desired The FCB 8 1 contains the file spec assorted flags and variables which are used by the FCS to keep track of the file and also the data read from or about to be written to a single sector on the disk
147. ixes are inter preted as described above for instruction suffixes A DC B directive not followed immediately by another DC B directive will normally have a filler byte inserted if necessary to force word alignment FCB and FCC are equivalent to DC B and FDB is equivalent to DC W Strings must be enclosed in single or double quote symbols label DS expression label DS B expression label DS L expression label DS W expression label EVEN label RMB expression label SPACE expression DS indicates the reservation of aspecified number of words bytes or long words usually without placing values into the locations No word alignment is forced after any DS directive although word alignment is forced before DS DS L DS W and EVEN directives RMB is equivalent to DS B and EVEN is equivalent to DS 0 SPACE is equivalent to DS B except that the contents of the locations are initialized to binary zeroes END label END indicates the logical end of the assembler language unit although not necessarily the end of the program as the assembler will continue to process input until it finds physical end of file Although the END statement may not be labelled an optional label may appear as an operand indicating the starting address of the program and will be placed into the output object file as the transfer address ENDC ENDIF ENDC and ENDIF indicate the end of the range of an IFxx or IFDEF declarative
148. k is used because each time that a file is deleted its sectors are added to the end of the free space The space from deleted files is thus scattered around the disk with the result that the free space also wanders all around the disk The syntax for using REDOFREE is SK DOS REDOFREE lt drive number gt D REDOFREE then prints anumber of basic parameters about the disk reads all the sectors in the free space sorts them into numeric order and finally rewrites the sector linkages to place them into numeric order After each of these steps REDOFREE asks whether to proceed so you may stop it at any point REDOFREE provides the option of printing a listing of free sector segments both before and after they are sorted If the listing is selected each line may be followed by one of two marks G 43 1 Before the segments are sorted a caret mark indicates that the current segment points backward and thus the free chain goes backward This will be corrected after sorting 2 After the segments are sorted a comma indicates that the current segment is contiguous to the next and that these two segments will be combined into one 1f the free space is relinked The optional D argument in the calling line activates one other option in REDOFREE Ifyou enter the D then the program will print out the starting track and sector number of all deleted files it finds in the free chain these are identified by the sequence number 0001 as well a
149. le SLTOCOM CMD is a 6809 version intended for systems programmers who may be using a 6809 system for software development The syntax for using S1TOCOM is SK DOS S1TOCOM lt file name gt where the file name is the name of the binary S1 file to convert The input file defaults to a BIN extension while the output file will have the same name but with a COM extension If a COM file already exists S1TOCOM will delete it without any prompt after it is finished S1TOCOM will delete the input file again without any prompt G 45 ef If the optional sign does not follow the file name then the loading and transfer addresses in the output file will be exactly the same as those in the input file If the sign is entered then the current value of OFFSET will be subtracted from the addresses given in the input file The option is primarily for programmers who wish to convert a non position independent file to SK DOS operation and have assembled that file to lie in a memory location known to be available But note that this option can lead to great problems if the value of OFFSET at the time the conversion to binary is done is not the same as the value when the converted program is executed It would be much safer to use SITOCOM without the option and then use the option of GET followed by XEQ to execute the final program SK DOS User s Manual SAVE SAVE This memory resident command saves binary data from m
150. lled or is not specified at all The directory name and its slash may not always appear if it is missing then SK DOS uses either the system or work drive default directory FILENAME in the above example is aone to eight character long word which usually is chosen to identify the contents of the file It must begin with a letter and the remaining characters may be either letters numbers hyphens asterisks stars or the underscore The file name is the only absolutely required part of the file spec in every instance EXT in the above example is a one to three character abbreviation which usually identifies the type of file It is sepa rated from the name by a period and may also be followed by another period and the drive number Like file names exten sions must begin with a letter and the remaining characters may be either letters numbers hyphens asterisks stars or the underscore Extensions are not always required if they are obvi ous since SK DOS programs default to certain extensions for certain commands Each of the four parts of the file spec needs some further clarifying details 1 SK DOS differentiates between physical drive numbers and logical drive numbers The physical drive number is the wired in number determined by the hardware controller and the actual disk drive For example a given floppy drive may have its DSO drive select 0 jumper installed which gives that drive the physical number of drive 0
151. lt where gt lt what gt where the lt where gt can be either a drive number such as 0 or 1 or a drive number and directory letter such as 1 C an asterisk may be used in place of adirectory letter to scan all directories on the disk The lt what gt in the above example is a match list specifying which files are to be listed The following examples show some possibilities ACAT catalogs all files on the current work drive and its default directory ACAT 1 catalogs all files on drive 1 ACAT 1 TX catalogs all files on drive 1 whose file names begins with the letters TX ACAT COM catalogs all files with COM extensions ACAT TX COM catalogs all files whose file name begins with TX AND which also have COM extensions ACAT TX E COM catalogs all files whose file name be gins with TX E where stands for any character AND which also have COM extensions ACAT TX COM catalogs all files whose name begins TX and also all files which have COM extensions ACAT 2 C TX COM catalogs all files whose name begins TX and also all files which have COM extensions but only on drive 2 directory C ACAT 2 TX catalogs all files whose name begins TX in all directories of drive 2 Note how a is a wild card character which stands for any character in the middle of a file spec and stands for any directory when used in a drive directory specifier Note also that when a drive number is not specified ACAT defaults to the default work dri
152. ly adrive number is specified then the current default directory of that drive is used if both a drive number and directory are specified such as 1 D then only the files in that directory may be deleted An asterisk used as G 37 the directory as in 1 would refer to all directories of the specified drive The match list works like that of CAT COPY or TCAT If not given then PDELETE will prompt with the names of all the files on the specified disk or directory one at a time If given then only files which match the match list will be prompted For example the command SK DOS PDELETE 1 TX CMD would prompt with the names of all files whose names begin with TX or which have CMD extensions In each case you will be asked whether to delete and can answer Y yes N no or Q quit SK DOS User s Manual PEEK and POKE PEEK and POKE The PEEK and POKE commands are similar to the same commands of Basic These commands can be used to make minor modifications to SK DOS or other programs To use PEEK give the command PEEK followed by a hexadecimal address The contents of that address will be printed out To use POKE enter the command POKE followed by the hexadecimal address of the location to be poked and the hexa decimal number to be poked into that location The POKE G 38 command will print out both the old and the new contents as a check When PEEKing or POKEing non existent memory loca tions yo
153. m with the CPU in trace mode so that the program can be debugged This mode requires a monitor ROM such as HUMBUG which supports the trace mode The TRACE command which has three asterisks as part of the name to avoid the possibility of its being called acciden tally is used just before the command which loads and executes the program being debugged For example to debug a program called NEWPROG CMD the commands would be SK DOS TRACE SK DOS NEWPROG The TRACENAB command is needed only when tracing with HUMBUG and no previous tracing has been done since turning on the power When HUMBUG traces a program it saves the contents of the 68xxx processor s trace trap places its G 53 own trap address into the trap and then goes to a user program after returning it replaces the original address in the trap When tracing is begun with SK DOS s TRACE command rather than via HUMBUG HUMBUG s trace routines are entered in the middle and hence HUMBUG does not have achance to save the previous contents of the trap location It therefore restores the wrong value into the trap location TRACENAB corrects that problem in most cases The correct syntax is SK DOS TRACENAB HUMBUG If TRACENAB does not work properly such as may happen if you use an old version of TRACENAB you can get around it by using MON to return to HUMBUG doing a harmless single step with ST 1000 and then returning to SK DOS with RD This will also fix
154. maximum line length of 127 characters To end entering text type a character at the beginning of anew line SK DOS User s Manual CACHE CACHE The CACHE command is used to set up a disk cache that is a memory area which stores data read from or written to a floppy disk When SK DOS tries to subsequently read that data again it reads it from the cache memory rather than reading it from the physical disk itself This significantly speeds up disk operations There are three ways of calling the CACHE command SK DOS CACHE NEW lt memory size in K gt sets up anew cache memory of the specified size For example the command CACHE NEW 320K would set up a 320K cache memory area The specified cache memory can range from 32K to 1024K actually 1 megabyte in size Another way of calling CACHE is with SK DOS CACHE lt drive number gt which erases flushes all data from the cache which corre sponds to the specified logical drive number Finally the command SK DOS CACHE STATUS displays a status report of the cache memory including the memory size the number of sectors it can store the number of sectors currently empty and the actual number of sectors cur rently stored for each floppy drive IMPORTANT WARNING Since CACHE has no way of knowing when you insert a new disk into a drive it is essential that you manually flush the cache each time you swap disks IF YOU DO NOT DO SO YOU MAY CORRUPT THE NEW DISK This will
155. mbers For example issuing a DRIVE command which says DRIVE LO F1 tells SK DOS that logical drive O should be physical floppy drive 1 c Drive Select numbers The drive select number is the number that the controller thinks the drive is For example a floppy drive has a set of three or four jumpers often labelled DSO through DS2 or DS3 which identify a particular drive to the controller Typically the first drive on the controller is DSO the second is DS1 and so on But there is a problem here changing a drive select number requires that you move these tiny jumpers on the drive Some 14 8 manufacturers such as IBM and Tandy don t want their cus tomers messing with these jumpers and instead do the drive selection in the drive cable Tandy used to do it by removing pins from the drive connector IBM does it by twisting part of the cable In IBM s case both floppy drives are jumpered as DS1 but the cable makes one into DSO and the other into DS1 Because IBM style cables are so cheap that is the approach we use with the WD37C65 controller As long as a computer had only one floppy controller then the F number was the same as the drive select Thus floppy drive FO was DSO on its controller But now that we can have two controllers as the PT68K 4 has both a WD1772 and a WD37C65 we can have two DSO drives one on each controller It is HUMBUG s Initial Setup IS command which tells HUM BUG and SK DOS which physical
156. me gt is a four character name such as CONS See gaenen Dueson Gee td or PRTR which will be assigned to the device Terminal CONS Default driver the lt device number gt is a number from 0 to 7 that will be Error device CONS Default driver assigned to the driver Printer CONS Default ariver Additional information on DEVICE usage may be found in Default driver Chapter 14 CONS Default driver CONS Default driver CONS Default driver NULL Default driver NAHU PW DHF O Q O Z N Null device G 16 SK DOS User s Manual DIFF DIFF DIFF is used to compare the contents of two text files and print out any differences between them The correct syntax for using DIFF is SK DOS DIFF lt file spec 1 gt lt file spec 2 gt where the file specs are of the two files being compared DIFF compares the two files on a line by line basis so two files having the same text but formatted into different lines will be shown as different Each time DIFF finds lines which are different it displays them and continues until it finds two lines which again match DIFF has several characteristics which should be noted If the two lines are of different lengths then DIFF will stop at the end of the shorter file and print out the message No further similarities found So as to avoid resynchronizing on blank lines it ignores them When looking forward for another pair of matching lines it stops after 50 lines Hence if there are more than 50 consec
157. mes are stored as 7 bit ASCII characters with the left most eighth or parity bit normally a0 Bit 7 of bytes 0 7 the eight bytes of the file name would therefore normally be zeroes Instead they are now used SK DOS User s Manual to hold the directory code letter For example here are some sample file name bytes File TEXT in the root directory 54 45 58 54 00 00 00 00 lt ASCII for TEXT O 00 0 0 0 0 O lt parity bits 00 means root File TEXT in directory U 54 C5 58 D4 00 80 00 80 lt ASCII for TEXT O 1 01 0 1 0 1 lt parity bits 55 means U While at first glance this seems like an awkward way of coding subdirectories in practice just a few extra instructions are required to process these parity bits SK DOS routines 13 6 GETNAM and FNPRNT do the processing automatically for input and output of file specifications The advantages on the other hand greatly outweigh the disadvantages the directory structure is totally compatible with earlier versions of SK DOS same routines which differentiate between file names also dif erentiate between directory names without any extra program ming or time it becomes easy to move a file from one directory to another without rewriting it the directory remains a manage able size and for most situations the entire directory for an entire disk is still contained in just one track thereby minimizing disk access time SK DOS User s Manual 14 I O REDIRECTION AND I O D
158. more digits in the range 0 to 7 ASCII constants start and end with single or double quote symbols and contain characters with hex values 20 thru 7E quote symbols within the constants matching the delimiters are represented by two adjacent quote symbols the number of characters in ASCII constants within expressions is restricted to four except in DC and equivalent types of directives Operators used in expressions may include the following in decreasing order of priority unary minuses left right logical shifts lt lt and gt gt logical and or amp and multiplication and division and addition and subtraction and Object File Formats One of the object file types produced by this assembler follows the format of the standard Motorola S records file The format of each type of S record is described below The record type field is an S and a digit interpreted as follows S1 indicates a record containing data starting at the value in the 16 bit 2 byte address field I 5 S2 indicates a record containing data starting at the value in the 24 bit 3 byte address field S3 indicates a record containing data starting at the value in the 32 bit 4 byte address field S7 indicates a record containing an optional 32 bit 4 byte xfer address and terminates a group of S3 records S8 indicates a record containing an optional 24 bit 3 byte xfer address and terminates a group of S2 records S9 indicates a
159. n additional 80 bytes for the default CONS driver The CONS information is copied into the rest of DEVTAB during booting the DEVICE command then modifies the contents of DEVTAB when it installs other drivers Each device number has an 80 byte device descriptor within the table These bytes contain the following Bytes Description 00 03 Logical name such as CONS or PRTR 04 07 Pointer to first address of the driver 0000 if in BIOS 08 11 Length of the driver in bytes 0000 if in BIOS 12 15 Pointer to driver initialization routine 16 19 Pointer to input status check routine in driver 20 23 Pointer to get input character with echo routine 24 27 Pointer to get input character without echo routine 28 31 Pointer to input channel control routine for ICNTRL 32 35 Pointer to output status check routine 36 39 Pointer to output character routine 40 43 Pointer to output chan control routine for OCNTRL 44 Print lines PLINES constant 45 Page width constant PWIDTH 46 Null wait constant NULLWT 47 Skip lines constant SLINES 48 Pause flag PAUSEB 49 Line counter counts lines per page 50 Column counter OCOLUM 51 Serial device baud rate BAUDRT 52 End of file character EOFILC 53 X Off character XOFFC 54 X On character CONC 55 Reserved for future use 56 59 Pointer to input status check routine bypass typeahead 60 63 Pointer to get input char w o echo routine bypass typeahead SK DOS User s Manual 64 67 Pointer to
160. n a file although you should call DEFEXT to put in a default extension just in case DEFEXT will not add an extension ifit detects that a device exists with the specified name Then call FOPENR or 14 3 FOPENW to open the file for reading or writing If the specified driver does not exist SK DOS will open the file normally that s why it is good to have a default extension If it does exist then SK DOS will use the device for subsequent reads or writes instead of a file Note that the device can only be used sequen tially random file operations will not work and may give undesired results SK DOS accesses devices through an FCB by substituting fake drive numbers Normally only drive numbers 0 through 9 are valid disk drive numbers when you open an FCB to a device SK DOS uses drive numbers 10 through 17 to refer to devices 0 through 7 respectively If you know the name of a device but not its number then it is easiest to open the file with that name If you already know the number then it is not even necessary to open the file just set up an FCB put in a drive number equal to 10 plus the desired device number and use FREAD or FWRITE to read or write 6 Before doing any of the above a program may check whether a given driver is installed by using FINDEV 7 GETNAM recognizes device names and substitutes the device number plus 10 when the specified device is installed ICNTRL and OCNTRL ICNTRL and OCNTRL are two
161. n be used with R See M if the original file was random The S option is used to copy only files generated on or after the date specified in the since date parameter For example the command COPY S O 1 6 28 88 would copy all those G 12 COPY files dated June 28th 1988 or later Since no directory is speci fied only files in the root directory would be copied in this case The S option can however also be combined with several other COPY command features to make more complex commands The S option can not be combined with the F copy by file number option since the F option will take precedence The F and S options are often used for backing up a hard disk to floppy disks F is used for a complete backup to copy groups of files at atime to separate floppy disks S is useful in making incremental backups of just those files which have been changed or newly generated in the last few days The T option is used only for those systems that store data files on track zero COPY normally prevents a file from linking to track zero Some hard disk systems include track zero as part of their free sector chain in that case COPY will switch to the T option automatically The U option is used when you want the destination file to have the present SK DOS date rather than the date of the source file being copied This may be useful if you know the source file has an erroneous date The W option loads COPY but then waits for any key to be pre
162. n consideration of this license customer shall not reproduce copies of Star K software except to reproduce the number of copies required for use on customer s computer and shall include the copyright notice on all copies of software reproduced in whole or in part C The provisions of this software license paragraphs A B and C shall also be applicable to third parties purchasing such software from customer Wherever used in this manual SK DOS and HUMBUG are registered trademarks of Star K Software Systems Corp Some earlier versions of 6809 SK DOS are also known as STAR DOS This is revision 1 16 of the manual last revised on October 29 1990 SK DOS User s Manual Oo On AN BR WN KF CO p O i Oar eh Ss CONTENTS BEFORE STARTING INTRODUCTION FOR THE IMPATIENT FILE SPECIFICATIONS SK DOS OVERVIEW THE COMMAND PROCESSOR SYSTEM CPS MEMORY RESIDENT COMMANDS DISK RESIDENT COMMANDS THE FILE CONTROL SYSTEM FCS THE FILE CONTROL BLOCK SK DOS FUNCTIONS USER ACCESSIBLE VARIABLES PROGRAMMING EXAMPLES INFORMATION FOR ADVANCED PROGRAMMERS YO REDIRECTION AND I O DEVICES APPENDICES USER ACCESSIBLE VARIABLES THE FILE CONTROL BLOCK FCB NON DISK FUNCTIONS DISK FUNCTIONS SK DOS ERROR CODES DEFAULT EXTENSION CODES SK DOS COMMAND SUMMARY ADDENDA AND OTHER INFORMATION ASM THE 68000 68010 ASSEMBLER USER REGISTRATION AND UPDATE POLICY ili 0 1 1
163. n you will have to use the remote keyboard to assign number 1 as the console keyboard will no longer be active 14 2 NOTE The remainder of this chapter will probably only be of interest to advanced programmers DRIVER MEMORY ASSIGNMENT When a new driver is loaded from disk DEVICE checks to see whether the driver is smaller than the driver currently in stalled under that device number If so then the new driver simply overlays the current driver If not then the new driver has new memory assigned to it just above the current value of OFFSET and then OFFSET and OFFINI are moved up above the new driver The default CONS and NULL drivers have zero size and so will never be overlaid If the same driver is used under various device numbers several copies of the driver will exist in memory at the same time one for each device number This is important to remember for several reasons First it means that new drivers can only be installed from the keyboard or from a BAT file not from another program because memory may not be available for the new driver while another program is running Second it means that each copy of a driver maintains its own variables such as PLINES see below even when it applies to the same hardware device DEVICE DESCRIPTOR TABLE Information on device assignments is stored in the Device Descriptor Table called DEVTAB This table consists of 640 bytes 80 bytes for each of the 8 device numbers plus a
164. nd NAM specify the title to be placed at the top of each page in the source listing when pagination is active Arithmetic Expressions Expressions consist of combinations of symbols constants operators and parentheses Symbols must normally be defined before being used in complex arithmetic expression evaluations All arithmetic and logical operations are performed using 32 bit two s complement integer arithmetic division is truncated and overflows are normally lost Expressions may be forced into 16 bit mode by enclosing them with W or by masking them with Sffff Symbols used in expressions include the following program labels symbols defined with DC DS EQU SET directives numeric constants gt the program counter Program labels and symbols are composed of one to 31 characters starting with a letter or period as described earlier in this manual Constants may be expressed in decimal hexadecimal bi nary octal or ASCII and are constructed as follows Decimal constants are composed of one or more digits optionally followed by D or d Hexadecimal constants start with a dollar symbol or end with H or h and are composed of one or more digits or letters restricted to the ranges a thru f and A thru F Binary constants start with a percent symbol or end with B or b and are composed of one or more digits O and 1 Octal constants start with an at symbol or end with O or o and are composed of one or
165. nd of drive are For the 360K 40 track drive you can format the following 1 A 40 track double density disk 2 A 40 track single density disk 3 A 40 track double density disk track 0 single density For the 720K 80 track drive you can format the following 1 An 80 track double density disk 2 A 40 track double density disk double stepping 3 A 40 track single density disk double stepping For the 1 1 megabyte drive you can format the following 1 An 80 track high density disk 2 An 80 track double density disk 3 A 40 track double density disk double stepping For the 1 4 megabyte drive you can format the following 1 An 80 track high density disk 2 An 80 track double density disk For the 8 inch 77 track drive you can format the following 1 A 77 track double density disk 2 A 77 track single density disk 3 A 77 track single density disk 128 byte sectors The last format is a very special format developed for one of our customers and you will probably never use it You must choose one of the alternates given by typing 1n its number FORMAT will then ask for the number of tracks since users often format fewer than the maximum number of tracks if they need less space and wish to save time Formatting with the 37C65 controller provides more options for higher density disks but fewer for low density disks For example it does not allow any single side formatting and does not provide as many single density options See
166. nd return to a ROM monitor RESET Exit SK DOS and return to a ROM monitor SAVE Save contents of memory to a binary disk file TRACE Allow command tracing see TRACENAB in Ap pendix G XEQ Execute the last file loaded from disk There are some differences between GET and GETX and between MON and RESET GET and GETX both load a binary file from disk into memory but GET checks the loading addresses and will return an error message if the file would load outside the normal 6 1 user accessible memory as defined by two variables called OFFSET and MEMEND GETX does not check such loading addresses MON and RESET both exit SK DOS and return to a ROM monitor but in some systems MON will re enter the monitor without doing a complete system initialization whereas RESET will completely initialize the system This distinction is import ant because RESET will initialize all exception vectors to the ROM monitor s values whereas MON may not In some sys tems RESET may not be operational Although DIR will display the contents of a disk you may prefer to use some of the other disk resident commands such as CAT ACAT SCAT or TCAT which provide more informa tion than DIR Although strictly speaking Control A is not a command this may be a convenient place to discuss it Pressing a control A while typing any command will repeat the remaining portion of any previous command display it on the screen and ready it for execution The c
167. nd set the carry LOADML A022 Load open machine language file This routine is used to load a machine language file into memory at its normal load address which is equal to the address listed in the file plus the OFFSET address except that the OFFSET address is not added if LASTRM contains a minus sign LOADML is normally used by the memory resident GET command to fetch programs prior to execution Prior to entering LOADML the user program should use the USRFCB user FCB to open the file to be loaded The file is then loaded and its transfer address is stored in the EXECAD location If there is no transfer then XFERFL is set to 0 else it is non zero Any transfer address found is stored in the EXECAD location Errors such as error 4 file not found cause an immediate return to the calling program with a non zero condition and the FCB indicat ing the error read errors once a file is found immediately abort the program close all files and return to SK DOS warm start DEFEXT A024 Default extension This routine is used to enter a default extension into an FCB if the file specification already in the FCB does not contain one Before entering the user program should point A4 to the begin SK DOS User s Manual ning of the FCB and should place into D4 a numeric code which indicates which default is desired The codes are as follows O BIN 3 BAS 6 SCR 9 DIR 12 BAT L TXT 4 SYS 7 DAT 10 PRT 13 SRC 2 COM 5 BAK 8 BAC 11 OUT 14 PIP
168. ng one or two digits for the month and day and two digits for the year as in 9 26 82 and hit the ENTER key If your system has a calendar clock and it has been set to the correct date and time SK DOS may take its date from the clock instead of asking you to enter it You will now get the prompt SK DOS SK DOS is now running and awaiting your further com mand You are looking at just the tip of SK DOS the part which is visible to the user There is much more to SK DOS than this but this is the only part which you can see and experiment with without doing a bit more reading You can now type in a variety of commands Some com mands will be immediately recognized by SK DOS and acted upon these are called memory resident commands Others are not recognized and so SK DOS will try to find them on the disk these are called disk resident commands To try a memory resident command type the word XEQ and hit ENTER XEQ tells SK DOS to execute the last program loaded in by SK DOS Of course we haven t yet used SK DOS to load anything and so we get an error message which reads 2 1 ERROR 28 MISSING TRANSFER ADDRESS SK DOS error codes are explained in Appendix E in this case there is no transfer address so SK DOS does not know what to execute Let us next execute a disk resident command ACAT 0 The ACAT command prints an alphabetized catalog of the disk or current directory ACAT or ACAT 0 means drive 0
169. ng the heads land when power is shut off The drive instructions specify that the parking area is on cylinder 656 Winchester drives also use write precompensation to re duce write errors Precompensation is only needed on inner tracks and different drives need it on different tracks Many drives start precompensation on track 128 but you should consult the drive manual for the correct number to enter Using this information the next four questions and their answers for this sample drive would be Number of cylinders Tracks Side to use on drive 615 Which cylinder should the drive be parked on 656 Which cylinder to start precompensa tion 128 How many heads on the drive 4 There are 32 sectors per track side The park cylinder is not actually used by HDFORMAT instead it is saved and used by the PARK command Even when a specific parking area is not suggested by the disk manufacturer we recommend that you reserve some cylinders for that purpose and subtract that number of cylinders from the total capacity of the drive In some cases you may want to use only part of a hard disk for SK DOS leaving the remainder for some other DOS In that case simply specify either a smaller number of heads or a smaller number of cylinders For example you could specify 309 cylinders which would leave the other 306 for use by the other DOS SK DOS next asks Enter the required code for drive step rate The step rate dete
170. ns contain the backspace character 08 or control H delete character 18 or control X end of line character 3A or colon escape 1B and repeat 01 or control A respectively These locations are used by SK DOS in console input routines and can be changed by user programs or the DOSPARAM command The DELETC character may be used to delete an entire line and return to the beginning while the ENDLNC character normally acolon 1s accepted much the same as a carriage return OD as an end of command delimiter The ENDLNC character however can also be used to separate multiple commands on one line The ESCAPC character is used to halt output to the terminal Output may be restarted with another ESCAPC or else may be aborted with a carriage return not ENDLNC The REPEAC character normally 01 or Control A 1s used to repeat the last used console command PLINES 3322 80 DN A6 Number of printed lines per page SLINES 3325 80 DN A6 Number of skipped lines be tween pages These two locations are initialized by SK DOS at 0 which disables them If PLINES is non zero then output to the terminal will stop after PLINES continuous lines of output skip SLINES blank lines and then continue A typical application is to make PLINES equal to a decimal 56 and make SLINES equal to a decimal 10 for paged output to a printer Printed output would then have 56 continuous lines of print and 10 skipped lines which step over the perforation
171. nvalid for this type of instruction 14 Bad expression format The expression 1s badly formed or contains a space 27 Bad expression range The address expression has a value outside the short addressing range 18 Bad instruction field The item in the instruction field cannot be recognized 20 Bad label usage The directive statement may not be labelled xx Bad library file The indicated library file could not be found 21 Bad multiple destination The operand specifies registers not allowed in a multiple destination list xx Bad object file The indicated object file could not be created 16 Bad operand 1 for instruction type The first operand is improper for this instruction 04 Bad operand 1 format The first operand has been coded incorrectly 17 Bad operand 2 for instruction type The second operand is improper for this instruction O5 Bad operand 2 format The second operand has been coded incorrectly 23 Bad operand format The instruction operand field is badly formed or contains an unintended space or other illegal character xx Bad source file The indicated source file could not be found xx Library file nest error The indicated library file could not be included as the nest level is too deep usually 3 for minimum systems and 12 for others 24 Phasing error The non redefinable symbol has been found to have a different value on the second pass as it had on the first pass of the as
172. o bytes 3 through 14 of the FCB and the new name and extension into bytes 52 62 of the FCB temporary name buffer 2 If there is an error the Z bit is cleared and the FCS returns one of the following codes in byte 1 of the FCB error 4 old file does not exist or error 3 new file name already exists FSKIP A011 Skip current sector This function skips the current sector and goes to the next sector of the current file When a file is being read the FCS simply skips the remaining data in the current sector and pre pares to read the next sector On writing the FCS fills the remainder of the current sector with zeroes writes it out to the disk and prepares to write into the next sector if however the FCS is already pointing to a new sector but has not yet written into it then this function is ignored FRRECD A014 Select a specified random sector This function allows you to select a specified random sector of arandom file This function can only be used after an existing random file is opened for update with FOPENU To use this function code place the two byte sector number of the desired sector into bytes 78 and 79 of the FCB and and then call the FCS If the desired sector number is 0 then the first sector of the file map will be read if the desired sector number is larger than the current size of the file the file will be extended so that the desired sector is the last sector in the file and all new sectors will be filled wi
173. o closing the file and then immediately opening it for reading again DIROPN A00B Open directory file This function prepares the current FCB to read directory entries with DSREAD Before using this function the calling program should place the drive number into byte 3 of the FCB no other initialization is required This function does not actu ally do any reading but merely prepares the FCB for a subse quentread with DSREAD Itis primarily used by the FCS itself and will not usually be used by user programs SISOPN A00C Open system information sector This function prepares the current FCB to read the SIS with DSREAD Before using this function the calling program should place the drive number into byte 3 of the FCB no other initialization is required This function does not actually do any reading but merely prepares the FCB for a subsequent read with DSREAD It is primarily used by the FCS itself and will not usually be used by user programs DSREAD A00D Read directory or system informa tion sector This function must be preceded by either DIROPN open directory or SISOPN open system information sector and reads the first or next entry in the directory or SIS respectively into the first 96 bytes of the FCB it also reads the entire sector into the sector buffer area of the FCB When used on the SIS only one read should be performed since only one entry exists 10 5 in the SIS when used on the directory up to
174. o do the opposite copy the disk contents from the hard disk or RAM disk file to the floppy disk The syntax is SK DOS ber gt In both cases only a floppy drive number is specified as the entire disk is copied but a hard disk or RAM disk file name is needed since the floppy disk contents occupies only a single file on the hard disk or RAM disk HTOF lt hard disk file spec gt lt floppy drive num SK DOS User s Manual GET amp GETX GET amp GETX GET and GETX are memory resident commands used to load a binary file into memory The word GET or GETX is followed by the file name of the file to be loaded An extension of BIN is assumed and the current work drive is used unless specified otherwise For example the command GET CAT BIN or just GET CAT would load a binary program called CAT BIN from drive O and place it in memory GET and GETX usually add the current value of OFFSET see Chapter 11 to both the load address and execution address of the program loaded Most often this will result in the program being loaded into memory directly above SK DOS itself For special uses the addition of OFFSET can be defeated by a specifying the full name and extension of the file to be loaded and b immediately following it by a minus sign without a space between the extension and the minus Note however that this is not normally done and may create some problems read the discussion of the SAVE to see the im plic
175. oes To use MAKEMPTY follow the command witha file name as in SK DOS MAKEMPTY DATAFILE This command would create an empty file called DATAF ILE DAT on your working drive since a default extension of DAT is assumed unless specified otherwise The resulting empty file contains all zeroes which is inter preted by Basic as well as text editors as truly empty an attempt to read this file will result in an immediate end of file indication SK DOS User s Manual MON and RESET MON and RESET MON and RESET are used to exit SK DOS and return back to the system monitor if there is one in your computer system Both of these are memory resident commands Not all systems have both MON and RESET sometimes only one or the other may be available The difference between them has to do with their treatment of exception vectors traps When running SK DOS always resets the line 1010 exception vector of the 68xxx CPU to its own value In addition depending on the state of TRPFLG SK DOS may also reset all G 35 of the other exception vectors as well If both MON and RESET exist on a system then MON will return to the monitor at a point where the ROM monitor will leave the exception vectors as they were set up by SK DOS RESET will return to the monitor at a point where the monitor will do a complete reset including reinitializing all of the exception vectors SK DOS User s Manual PARK PARK The PARK command is used
176. ommand may be separated by either spaces or commas and the command should be followed by a RETURN which may be labelled ENTER or CR on some keyboards Commands typed into the command processor and other input which may be entered in user programs are stored in a line buffer called LINBUF If you type acontrol A character while inputting acommand or other input into the line buffer SK DOS will add the remaining contents of the line buffer to the input you have just typed and display it on your terminal This is useful for repeating a command in its entirety or repeating just parts of it For example suppose you have just completed the com mand COPY O NAME1 TXT 1 NAME2 OLD and then upon completion of that command you type a control A SK DOS will display the entire previous line again and position the cursor after the D in OLD If you then press the RETURN key you will perform the command again Alterna tively youmay backspace and change any part of the command For example if you backspaced to the beginning of NAME2 and typed in a new name such as NAME3 then the line would read 5 1 COPY O NAME1 TXT 1 NAME3 At this point you could either press RETURN and execute the line as is or again press control A the latter would complete the line by adding the OLD at the end Whenever you enter a command line SK DOS will first check whether you have typed the name of a memory resident command If so the command is immediately
177. on Byte No 49 Sequential data pointer to next byte 4 through 255 On all sequential read or write operations this byte points to the next byte to be read or written into the sector buffer portion of the FCB The pointer is a 4 for the first byte or 255 for the last byte SK DOS changes this byte automatically users will not normally touch it Byte No 50 Reserved This byte is reserved for future expansion Byte No 51 Random data pointer to next byte 4 through 255 On all random read or write operations this byte points to the next byte to be read or written into the sector buffer portion of the FCB The pointer is a 4 for the first byte or 255 for the last byte Unlike the sequential data pointer byte 49 this byte is not changed by SK DOS but is to be set by user programs instead See Chapter 13 for further information on random files Bytes No 52 62 Temporary name buffer 2 These eleven bytes hold the new name and extension of a file being renamed The new name should be stored into these bytes prior to calling the rename function of the FCS using the same rules as apply to bytes 4 through 11 above These bytes overlap with some of the bytes below but there is no conflict as they are used at different times Byte No 58 Column Counter for Basic This byte is used only by Basic to keep track of the current output column Byte No 59 Space compression indicator This byte indicates whether space compression
178. on which is started with the appropriate boot command of your monitor and which is already configured for your hardware SK DOS COR is a generic version which lacks all console terminal and disk driver interfacing In order to run this version you will have to provide your own interface routines An SK DOS Configuration Manual available from Star K Soft ware Systems Corp describes the process of configuring SK DOS for other hardware systems and shows sample inter facing routines which can be used as a guide SK DOS User s Manual 2 FOR THE IMPATIENT If you re anything like us you want to try out anew program even before reading the manual just to make sure it works This 1s difficult to do with something as powerful as a DOS but just to show you a bit of what SK DOS can do this section shows you how to bring the system up and run it This is only possible at this time if you have received a version of SK DOS which is already configured for your specific hardware After you finish trying it out we suggest you put itaway and go back to reading this manual To start make sure that your disk is write protected and place it into drive 0 Read Section O for information regarding how to boot SK DOS on your system The computer will load the program and respond with WELCOME TO SK DOS 68K C 1986 1990 BY PETER A STARK STAR K SOFTWARE SYSTEMS CORP ENTER TODAY S DATE MM DD YY Respond with the date usi
179. only drives 1 and 2 To avoid confusion with drive numbers under SK DOS we therefore call these two drives A and B instead of 1 and2 SK DOS does not allow what the WD 1002 HDO calls drive 0 because the WD 1002 HDO switches to this drive number upon powering up and not putting an actual drive on this port avoids the possibility of the disk being corrupted when powering up or down The next four questions have to do with the size and config uration of the disk which requires some explanation first Hard Winchester drives typically contain several platters which rotate on a common shaft Each platter has two sides with a head on each side to read and write data The heads are all mounted on acommon assembly so they move in and out together At any one time each head is positioned over a circular track on its surface All of those tracks together make up a cylinder The data on each track is divided into sectors with typically thirty two 256 byte sectors per track the number of sectors per cylinder is then equal to the number per track times the number of tracks per cylinder For example a MiniScribe 3425 drive has two platters with four heads There are 615 tracks on each platter so there are 615 cylinders and 32 sectors on each track Beyond the 615th track however this drive has additional tracks which though not good for storing data are specially set up as a parking area an area designed for letti
180. ontains the file ERRCODES SYS SK DOS will read a one line text de scription from this file and print it alongside the numeric code to explain the error s meaning TOUPPR 4031 Convert lower case to upper in D5 Converts a lower case character in D5 into upper case Primarily for use right after GETCH or GETNXT if only upper case letters are desired HEXIN A02F Input hexadecimal number This routine inputs a hexadecimal number from the line buffer and places it in D5 Before entering the calling program should make sure that LPOINT points to the first digit of the number to be input at the end LPOINT will be left pointing as described earlier for GETNAM On output D6 is non zero if a number was actually found and the carry bit is set if an invalid character was found in the number It is possible for both D6 and the carry to be zero if HEXIN encounters a delimiter such as a space comma CR or ENDLIN immediately on entry If a number is not found the number returned is zero if the number is greater than FFFFFFFF then only the last eight hex digits are returned DECIN A030 Input decimal number This routine is similar to HEXIN but inputs a decimal number rather than a hexadecimal one EXECSD A01F Execute a SK DOS command This entry point allows a user written program to call SK DOS as a subroutine and have it execute a command line placed into the line buffer On entry A4 should point to the beginning of the command
181. ontrol A is a powerful feature but it can also be misused if entered past the end of the last previous command SK DOS User s Manual 7 DISK RESIDENT COMMANDS SK DOS is supplied with a variety of disk resident com mands which are described in Appendix G In addition it is relatively easy to write your own command files and store them on the disk for later execution Disk resident commands are supplied as binary machine language files with COM extensions They are executed simply by typing their names For example the CAT COM command may be executed just by typing CAT after the SK DOS prompt This is equivalent to typing the sequence SK DOS GET CAT COM SK DOS XEQ since any unknown word other than one recognized by SK DOS as a memory resident command is interpreted as 7 1 calling a disk command and executing it A COM extension is assumed and the program is automatically executed as soon as it is loaded Since SK DOS automatically searches the disk for com mands it is possible for users to write their own Disk Resident Commands Arguments to be used by the command can be entered on the same line as the command name and then processed by the command with the aid of SK DOS routines such as NEXTCH get the next character from the Line Buffer The listing of the LIST command later in this manual will show how additional commands can be written The disk resident commands supplied with SK DOS are described in Append
182. ores BAT files Finally Sk DOSO9 can only access root directories 1 e unnamed directories of drives since multiple directories were not available on 6809 SK DOS systems SK DOS User s Manual STEPRATE STEPRATE The STEPRATE command is used to set the speed at which SK DOS commands disk drives to step from track to track Depending on your disk controller and disk drivers this com mand may not exist or may be slightly different For 5 1 4 disk drives the allowable step rates are 6 12 20 or 30 milliseconds ms per step with most floppy disk control lers or 2 3 12 or 20 ms with the Western Digital 1772 controller The step rate is specified after the word STEPRATE as in SK DOS STEPRATE 30 Each time STEPRATE is called it responds by displaying the new step rate setting if no step rate is specified in the command or an invalid number is specified then the step rate remains the same and the current value is displayed G 49 For those users more at ease with programming floppy disk controllers the values 0 through 3 which are the values actually given to the floppy disk controller may also be specified as follows the actual numbers depend on thecontroller used 0 6ms 1 12ms 2 20 ms 3 30 ms Smaller step rates will produce faster operation but you should be careful not to specify a value smaller than your disk drives can handle since that may lead to errors If in doubt it is better to e
183. out the other end of the buffer Think of the FIFO as a pipe characters go in one end and come out the other in the exact same order as they went in In this way characters that came in while the system is doing other tasks are held until they are needed This allows you to type ahead of the computer for example giving it commands before they are needed When typeahead is implemented normal input via GETCH INNOEC or INLINE for example goes through the buffer Hence normal programs need not even know whether such a buffer exists or not Occasionally however it is useful to be able to bypass the buffer when immediate response to an ESCape or control C is needed for example or even to be able to empty the buffer such as when asking OK to delete Y or N and you wish to make sure that a previously entered Y does not get used as an answer This is where the three typeahead operations come in Let us discuss them one by one When typeahead is implemented GETCH and INNOEC input the first character in the buffer 1 e the character that has been in the buffer the longest whereas INNOE 1 inputs the last character the most recent one INNOE1 should therefore be used if you are checking for control C or ESCape in which case you want to bypass any characters preceding it and act on it immediately Note that using INNOE1 to get the last character does not remove it from the buffer it is still there and still in its correct sequ
184. ple the 0 in ACAT Ois the argument and specifies the drive number XEQ restarts a program but does not supply any arguments these must be entered after the XEQ as in XEQ 0 It is now time to return to reading the rest of this manual so type the memory resident command MON This command exits SK DOS and returns to the monitor assuming that your computer has one SK DOS User s Manual 3 FILE SPECIFICATIONS The term File Specification or just file spec refers to the four items required to completely specify a file on a disk the drive number a directory name the file name and an extension The file spec usually looks something like this 0 A FILENAME EXT In this example 0 is the drive number It is separated from the rest of the file spec by a period and is usually a number between 0 and 9 inclusive The drive number and its period may not always appear if it is missing then SK DOS uses one of two default values which may both be the same it uses the system drive default value when loading commands from a drive and it uses the work drive default value for most everything else The drive number may either precede the rest of the file spec as above or may follow it A is the directory name An SK DOS disk has a main directory sometimes called a root directory and may have up to 26 smaller directories called subdirectories The subdirector ies are called A through Z while the root directory is either ca
185. r 5 CONS Default driver 6 CONS Default driver Null device 7 NULL Default driver This tells us that devices 0 through 6 are currently the CONS console default driver while device 7 is the NULL default SK DOS User s Manual driver Furthermore it also tells us that device 0 is normally the terminal which is used to control SK DOS device 1 is the error device where most error messages go device 2 is usually the printer although right now printer output would go to the console instead and device 7 is usually the null device As you can see at this point CONS has several device numbers That means that output sent to any one of those numbers would really go to the console The assignments shown in the above tables can be changed at any time by using the DEVICE command DEVICE is most often used to substitute a disk resident device driver for one of the default drivers DEVICE DRIVERS In most systems there will be just one console but there could be several printers Moreover a printer could require either a serial interface or a parallel interface Hence the software to drive a printer as well as other devices must be changeable so it can fit the hardware This is done by using disk resident programs to interface with other devices These programs are called device drivers and usually have a DVR extension on the disk Depending on your system you may already have one or more such drivers supplied with your SK D
186. r 12 CAT will display the month as BAD F This option will list the actual directory number M The M option will provide information on track sector lt Where gt Parameter The where parameter specifies which disk or directory to display This parameter can be either a plain drive number such as 1 or a drive number period directory letter and a slash as in 1 C An asterisk can be used to mean all directories as in 1 It is not possible to enter a directory without a drive number preceding it If no where information is entered then the default work drive and directory are chosen if only a drive number is entered then the root directory of that drive is chosen data and the protect file code information The M option turns lt What gt Parameters on the D F and S options plus routines needed for the header The what parameter specifies a match list which is com track and sector and protect codes pared against the files in the directory and only those files N This option will display deleted file entries that exist in matching the match list are displayed The match list can con the directory The actual file may not exist on the disk itmay tain one or more file names and or extensions or portions of have been overwritten when it was part of the list of free sectors names and extensions The asterisk is a wild card character You cannot assume a deleted file is intact unless you know it in a match list
187. racter or each time it finishes interpreting the current statement it calls the following BREAK routine BREAK DC STATS1 Check last char BEQ S BREAK1 exit if not there DC INNOE1L else get last char is it control C BEQ S CNTRLC Yes go process it CMP B ESCAPC A6 D5 is it ESC BEQ S ESCAP Yes go process it BREAK1 RTS Neither so exit CNTRLC DC FLUSHT on control C flush BRA L READY and to READY prompt ESCAP DC FLUSHT On ESCape flush ESCAP1 DC INNOEC Then get next char CMP B ESCAPC A6 D5 is it ESCape BEQ S BREAK1 Yes RTS to continue BREAKO CMP B 3 D5 SK DOS User s Manual CMP B S0D D5 is it CR BEQ L READY Yes go to READY BRA S ESCAP1 No wait for char Note how the typeahead buffer is flushed only after either the control C or ESCape is identified any other character is left in the buffer DISK DRIVES AND CONTROLLERS This manual has most recently been updated to cover addi tional features of the PT68K 4 computer Since this computer system has different floppy disk controllers from previous ver sions this chapter describes a few features which you should know In particular itis helpful to understand the kinds of floppy drives and disks that are supported Don t let the depth of the following discussion turn you off we give a lot more detail than you need right now so you can come back later and appreciate the fine details Floppy disks come in three sizes the very old 8 inch size the newer 5
188. rce code is available in the book Best of Interface Age Volume 1 Software in BASIC published in 1979 by dilithium Press P O Box 92 Forest Grove OR 97116 We greatly recommend this book for further information about this inter preter Basic error messages are printed in the form ERROR 2 2 IN LINE xxxx A description of the error replaces the periods and the line number identifies the location of the error in the program If no line number is given the error occurred in a command or direct execution statement SK DOS User s Manual UNDELETE UNDELETE UNDELETE is used to restore files which have been acci dentally deleted UNDELETE can only undelete one file at a time the last file deleted but it can be used again to undelete the file before that and so on The syntax for using this command is SK DOS UNDELETE lt drive number file name extension gt where the drive number and file name are required but the extension defaults to SCR if not given If you do not know the correct name of the file assign some dummy name undelete the G 55 file and then examine it to see what to rename 1t to In any case undeleted files should be examined to check that they are the desired file Depending on the size of the file and the size of the free space the file may exist in the free space for a long time or it may be written over quite soon Hence files should be undeleted as soon as possible In any case once the free
189. rmines how fast the drive will move the heads from one track to the next In the buffered mode the controller tells the drive to move as fast as it can and simply waits until the head movement is finished in other modes stepping signals are sent at fixed intervals from 0 5 to 7 5 milliseconds apart until the drive is at the requested cylinder Almost all modern disk drives permit buffered stepping in that case enter a code of 0 for an HDO controller and a code of 5 for a WX1 WX2 GEN or similar IBM XT type controller For older disk drives you will have to consult your disk drive manual to determine its capabilities and then consult the disk controller manual for an appropriate code to enter HDFORMAT will now use the data you have entered and compute the total capacity of the disk as specified If you have entered asmaller number of heads or cylinders because you wish to reserve part of the disk for use by another DOS then only the usable part of the disk will be used in this calculation For the above example HDFORMAT would print out Total disk capacity is 19680 K which is a bit over 19 megabytes Because of the structure of SK DOS each logical drive is at this time limited to a maximum of 16 megabytes so the above example shows that this particular Winchester drive has more capacity than SK DOS can handle as a single drive It will therefore print out the message THIS EXCEEDS THE MAXIMUM LOGICAL DRIVE CAPACITY you must
190. rogram at a time when OFFSET has not yet been defined it contains absolute loading and transfer addresses rather than relative ones Hence you can determine the absolute address where your SK DOS is loaded into memory by examining the SK DOS SYS or SK DOS COR file with the LOCATE command using the option so the OFFSET is not added by LOCATE Since COL DST is located at the very beginning of SK DOS this method is also used to find the address of COLDST in your system Note that segments do not contain any kind of checksum it is assumed that any disk errors will be caught by CRC or other error checking in the disk hardware or drivers As in text files the last segment of a binary file is generally followed by NULLs so as to fill out the last sector of a file RANDOM FILES The directory for each file only gives the track and sector numbers of the first and last sector of the file it does not contain any information as to which other sectors the file uses Since the sectors of a file need not necessarily be consecutive on the disk they could lie anywhere on the disk if the disk has been much used and its free space is not all in one place the file itself contains information linking one sector to the next This is done by the first two bytes in each sector which contain the track and sector number of the next sector in the file In a sequential file we normally start reading or writing at the beginning of a file and then continue th
191. rough A7 32 bit address registers AO through A7 CCR 8 bit condition code register SR bits 0 7 DO through D7 32 bit data registers DO through D7 DFC Destination Function Code register PC 32 bit program counter SFC Source function code register SP 32 bit stack pointer same as A7 SR 16 bit status register USP 32 bit user stack pointer SK DOS User s Manual VBR Vector base register Instruction Field The instruction field contains the 68000 68010 assembler instruction or directive It will normally always be present but if it is omitted the operand and comment fields must also be deleted If the instruction field consists only of an asterisk a comment field may follow the instruction field Lines contain ing labels only are allowed as are totally blank lines The program counter is always aligned to an even address before a 68000 68010 assembler instruction An instruction name contains no more than seven characters with upper case and lower case non unique The complete set of 68000 68010 assembler language instructions is described in the Motorola 68000 and 68010 Resident Structured Assembler manuals The set of directives accepted by this assembler is described later in this Appendix Those 68000 68010 instructions which require data size specification may be suffixed with length modifiers These include b for 8 bits w for 16 bits and 1 for 32 bits If no data length modifier is specified a w suffix is norm
192. rough the file following these two byte links until we get to the end As pointed out earlier the third and fourth bytes of a data sector contain a two byte four hex digit sector count which numbers the sectors of a file For example the first data sector of a file has the number 0001 the second is numbered 0002 and the seventh would be numbered 0007 Don t confuse these numbers with the physical location of the sector on the disk which is sometimes called the sector s disk address and which consists of a track number and a sector number The sector count could be used to make sure we read the sectors of a file in the right order but in practice is almost never used with sequential files Though we have used the term sector count above in the rest of this discussion we will simply call it the sector number Some people also call it the record number but this is a bit confusing since the word record can also be applied to a part of a sector Although sequential files are most common we often need random or direct access files These are files which allow us to read or write data in the middle of a file without necessarily reading or writing all the data before it For example at some point we might need to read data located in sector 0007 followed SK DOS User s Manual by sector 0104 followed by sector 0025 and so on This is accomplished by the random file capabilities of SK DOS In order to allow us to rapidly locate a pa
193. rr on the conservative side SK DOS User s Manual SYSTEM and WORK SYSTEM and WORK The SYSTEM and WORK commands are used to specify the system and working drives and directories When SK DOS is first booted the root directory of drive O becomes the default system and working drive that is all programs will be loaded from this system drive directory and all files being worked on will be loaded from this working drive directory The default drive and directory selection can be changed with these two commands For example the command SK DOS SYSTEM 1 would make drive 1 the default system drive while SK DOS WORK 8 C would make drive 8 directory C the default working drive and directory Entering the SYSTEM or WORK command without a valid drive number following causes the current drive and directory to be displayed Entering a drive number without a directory name switches to the root directory of that drive it is not possible to enter a directory without a drive number to go with it In addition the system drive not the work drive can also be specified as SYSTEM ALL Inthis case SK DOS willsearch the root directories of all drives in numeric order starting with drive 0 until it finds the requested file If SYSTEM ALL is used it is important to make sure that MAXDRYV is properly set so that SK DOS does not try to search drives which do not exist Use the DOSPARAM command to inspect or change MAX DRV G 50 SK DO
194. rticular sector number in a file without reading all the sectors before it SK DOS provides for a special random file format which con tains an extra two sectors These two sectors which are always at the very beginning of a random file contain a file map of the file which maps out the placement of the file on the disk and helps us to find a specific sector These two sectors always have a sector number of 0000 Thus the very first data sector of any file is always sector number 0001 but in a sequential file this is the first actual sector of a file whereas in a random file it is actually the third sector If you try to do a sequential read of a random file SK DOS skips the first two sectors and so you will never know they are there Few application programs actually need random files but if they do they will take care of generating and manipulating them automatically through SK DOS Nevertheless here is informa tion on how this is done There is only one way to generate a random file 1 Open a file for writing with FOPENW 2 After opening but before writing anything to it change byte 26 of the FCB to a non zero number 3 Now write sequentially to the file using FWRITE 4 When done close the file with FCLOSE SK DOS will automatically put a two sector file map at the beginning of the file and will update it as data is written to the file Note that the file map is customized for the particular placement of the file sec
195. s flag This location 1s non zero when location EXECAD contains a valid execution address for a machine language program and is zero when such a valid execution address does not exist If a command such as XEQ is executed when there is no valid address then SK DOS will print error 28 missing transfer address EXECAD 776 779 A6 ML execution address long word These four bytes hold the transfer address obtained when a machine language file is loaded from the disk including the value of OFFSET if used This location is also used by the XEQ command to execute the last loaded program ERRTYP 782 A6 Error type This byte contains the number of the last error detected by the File Control System FOADDR_ 784 787 A6 File output address vector FIADDR 788 791 A6 File input address vector These two addresses are used for redirection of standard output or input respectively If they are zero no redirection is done If redirection is desired then one or both of the above vectors may contain the address of an FCB currently open for writing or reading respectively SK DOS User s Manual CMFLAG 793 A6 Command flag This location indicates whether the Command Processor System is processing a keyboard command when 0 or a com mand passed to it from a user program when non zero MEMEND 796 799 A6 Last usable memory address long word When SK DOS is initially booted it does a memory test to determine how much memory is inst
196. s internal use One of these 1s called the User FCB or USRFCB It is available for use by other programs Although it is used by SK DOS this is done in a way which does not preventits use by those programs which also require a FCB The FCB consists of 352 or 608 bytes Of these the first 96 bytes are used for storage of various file parameters while the remaining 256 or 512 bytes hold the data for one sector of disk data During a disk read operation these bytes hold the contents of the last sector previously read during a write oper ation these bytes generally hold the contents of the next sector to be written Not all of the first 96 bytes are used the following descrip tions cover those bytes that are used in SK DOS Byte No 0 Reserved This byte is reserved for future expansion Byte No 1 Error code see Appendix E After the FCS is finished doing an FCB operation it returns to the user program If no error is found then the Z bit in the condition code register is a 1 and the content of this byte is irrelevant But if an error is found then the Z bit is a O and this byte contains an error code The status of the Z bit should be tested directly after returning from SK DOS with a BNE to error routine or BEQ to normal continuation instruction The content of this error byte is also stored in ERRTYP Byte No 2 Read Write Update status This byte indicates whether the file is open for reading writing or random fil
197. s number starts with 1 when the system is booted and increments by 1 each time a new file is written When your disk contains a number of files all having the same date the sequence number tells you what order the files were written in The SCAT command then prints the catalog but sorted by date and sequence number so that the most recent file appears on top Obviously if your system has a clock then using time stamping and TCAT provides the actual time rather than just a sequence number but the sequence number is a good second G 47 best if no clock is available It has three characteristics you should keep in mind 1 Each time the system is powered up the sequence number starts with 1 In other words if you turn off the power and then restart the sequence number will return back to 1 To avoid having multiple files with the same date and sequence number you may want to get in the habit of manually updating the sequence number if you restart the system so that it continues with the next higher number The SEQUENCE command is used for this purpose For example to change the number to 7 use the command SK DOS SEQUENCE 7 Typing just SEQUENCE without anumber will print out the current sequence number 2 The sequence number is incremented by 1 for every file written or updated This includes files being copied even though copied files are not assigned a new number In other words each time you copy a file the sequence will
198. s that some very old SK DOS systems use single density on their outermost track but DD elsewhere Finally all modern floppy disks are DS or double sided only the very oldest drives are still SS or single sided With all of these abbreviations it is easy to see why we need this short introduction to the topic One more complication the tracks are divided up into smaller sections called sectors In SK DOS each sector has 256 bytes although other systems use 128 512 or even more bytes per sector The number of sectors that can be crammed into a track depends on how fast the disk turns and on how closely the bits are crammed together in time Most disks turn at 300 rpm which is 5 revolutions per second while 8 and some high density disks turn at 360 rpm or 6 revolutions per second Now on to specifics Most SK DOS systems use a version of the Western Digital 17xx or 27xx FDC floppy disk control ler chip In particular both the PT68K 2 and PT68K 4 use the WD1772 controller which supports SD or DD disks but not 14 7 HD or high density disks SS or DS and either 3 1 2 or 5 1 2 disks These controllers could also support 8 disks but are usually not wired up to do so This controller can therefore typically handle the following situations Drive Sides Type 5 1 4 40tr 40 Dens A s 360K Un yn UN yn Yn Yn The 1772 controller can read and write all of the above formats
199. s the length of these files You can use this to search the free space for old deleted files which can then be copied out to another disk by using the R option of COPY For example on a hard disk this often lets you recover files days or even weeks later But note that the sequence numbers are overwritten when you reorganize the free space with REDOFREE Hence you cannot find files which were deleted before the last time you ran REDOFREE This free space is marked as uncommitted free space when you use the D option SK DOS User s Manual RENAME RENAME RENAME is used to rename a disk file To use this com Optional drive numbers and or directory names may be mand enter the word RENAME followed by the old name and supplied for one or both files as in the new name as in RENAME 1 F OLDNAME TXT 1 A NEWNAME TXT RENAME OLDNAME TXT NEWNAME ABC If not supplied for the old file the drive and directory names No quotes are needed but the extension must be supplied default to the current work drive and directory If not supplied for both names for the new file they are the same as the old file G 44 SK DOS User s Manual S1TOCOM SITOCOM S1TOCOM is a program which converts a binary file in Motorola 1 S9 format into a binary file in SK DOS format It is used to convert the output of some 68000 assemblers into a format which can be loaded and executed by SK DOS S1TOCOM is supplied in two forms S1TOCOM COM is the 68K version whi
200. s where SK DOS thinks the sector is located the physical address is the actual location on the disk where the disk drivers place it Depending on the system SK DOS floppy disks may be either single or double density and single or double sided In addition double density disks may have either a single or double density directory track As long as disks are used only on a single system the particular floppy disk format is not important Standard SK DOS 68K disks will generally be double density throughout and may be single or double sided Disks intended to be interchanged with 6809 SK DOS systems how ever should be formatted and used in single density single sided format since 6809 SK DOS requires that track 0 always be in single density Each sector of an SK DOS disk contains 256 bytes of data Of these 256 bytes the first four are used for system information and the remaining 252 bytes are usable for file data SK DOS uses a linked chain disk format That is the sec tors used in files as well as sectors which are in the so called free chain are linked to each other much like the links in a chain Each sector contains atwo byte pointer which points to the next sector in that chain unless it is 0 which indicates the end of that chain This pointer occupies the first two bytes of every sector In addition the sector also has a number which occupies the third and fourth byte and which counts the sectors within a file Th
201. sembler This is often due to conditional assembly including different text on the two passes or due to other syntax errors in the assembly text 28 Redefined symbol The symbol defined in other than a SET statement has been redefined 30 Symbol table overflow The table which contains the program labels has been filled to capacity Attempt to reduce its size with the Zxx command line option reduce the number of labels used in the program reduce their lengths or divide the program into smaller parts 29 Undefined symbol The symbol is used in an expression or in a context which does not allow forward references or is not defined in the program SK DOS User s Manual USER REGISTRATION AND UPDATE POLICY In order to register as an authorized user of this product and to receive updates if any are required please 1 Fill out and return the Registration Form below to Star K Software Systems Corporation P O Box 209 Mt Kisco N Y 10549 2 Enclose a self addressed stamped envelope with the name and version of this product written in the lower left corner we will keep the envelope on file and use it to notify you of any updates that may be necessary 3 Note that registration of your purchase is extremely important We at Star K stand behind our products and make great efforts to let our customers know of updates and extensions to their programs But to make this work we ask that they send in their registration forms and en
202. sk in drive 1 See Appendix G for instructions on using FORMAT Format the disk in double density including track 0 4 Once a new disk is formatted use the BACKUP command to copy the SK DOS system disk onto the blank disk See Appendix G for instructions on BACKUP 5 Make several such backup disks and put the original SK DOS disk away into a safe place In any case it might be a good idea to read this entire manual before proceeding PLEASE NOTE Several years of work and effort have gone into writing and improving SK DOS It pains us to see this work taken lightly by individuals who give away or Sell bootleg copies of this software or this manual Please don t do it This manual describes the latest additions to SK DOS to adapt it to the WD37C65 floppy disk controller used in the PT68K 4 computer In order to boot SK DOS from a floppy disk on this com puter you must first do an Initial Setup using HUMBUG s IS command to specify what kind of disk drive s you are using If your computer has a battery backed up static RAM the initial setup configuration will be saved until you change it otherwise you will have to enter it each time you turn on the computer If you use the PT68K 4 you should therefore make sure you have a HUMBUG version 2 0 or later which has the IS command If you are using this new version of SK DOS on an older computer such as the PT68K 2 which does not have a WD37C65 controller or recent HUMBUG
203. sk in drive 1 the command XEQ 1 would then repeat CAT address loaded with the file from the disk as modified by but would give it the argument 1 to specify drive 1 OFFSET Note that XEQ can only be used to repeat disk resident If the program requires arguments as part of the calling line programs not memory resident programs these arguments can be placed after the XEQ For example G 58 SK DOS User s Manual APPENDIX H ADDENDA AND OTHER INFORMATION My favorite law which I affectionately call Stark s First Law of Computerdom says A program without bugs must be so simple that it probably wasn t worth writing in the first place It is quite likely that somewhere within SK DOS lie one or more bugs which have yet to be discovered If you find one please let us know and we will exterminate it at once In any case be sure to follow the instructions on the User Registration page to be sure that we can contact you with updates if required This Appendix provides additional information about SK DOS which does not seem to fit any other section as well as addenda or corrections to the manual which are discovered after the remainder of the manual is printed 1 When SK DOS is first booted it looks on the boot disk for a text file called STARTUP BAT This batch file may have one or more commands which will be immediately executed as if they had come from the keyboard For example if this file contains the text RAMDISK 4 300K
204. ssed before continuing This allows you to switch disks before actually copying Note that the same effect can be achieved by using GET to load COPY switching disks and then using XEQ plus appropriate arguments to execute it The Z option is somewhat dangerous It is used to delete the file from the source disk after it is copied Essentially the file is moved from one disk to the other Option letters are often used in combinations here are some examples of popular combinations DN Updates the destination with all files from the source that are not on the destination or have an older date on the destination EZ Moves file P COM from source to destination no matter what KD Kill the file on drive 1 when it is older than the file on drive 0 LNA Alphabetically lists those files on the source that are not on the destination The lt Since date gt parameter This parameter is used only with the S option and specifies the date used for copying only files dated on or after this date will actually be copied The month day and year must appear in that order and may be separated by hyphens or slashes as in 6 28 88 or 6 28 88 Note that the date must appear after the to where parameter but before the match list if used General Comments It is important to realize that if you get an error while writing a file to the destination disk the new file may be defective The file may appear in the directory but usually it is
205. stem Hence it is a read by SK DOS and the address of the current File Control specialty program to be used only when needed to debug a Block You might use it whenever you want to follow SK DOS program disk accesses to see what it is doing DAMON substantially slows down the operation of the disk system since each sector read or written is accompanied by a G 14 SK DOS User s Manual DELETE DELETE DELETE is used to delete a disk file from a disk You may delete several files with one DELETE command To delete a file enter the command DELETE followed by by specifying more than one file name The maximum length of the file name as in the entire DELETE command however is limited to 128 char DELETE TEXT TXT acters The extension is required The command defaults to the default directory on the work drive G 15 SK DOS User s Manual DEVICE DEVICE DEVICE is used to display or install device drivers To display the current device assignments simply type the com To install a new driver use the format mand DEVICE lt driver name gt AS lt device name gt AT lt Device num SK DOS DEVICE ber gt and you will get a display similar to the following where l l eee the lt driver name gt is the name of a device driver file with The current I O device assignments are a default extension of DSK or alternatively the word DE Normal Device Device Driver FAULT for the default console driver use number name the lt device na
206. t actually knowing which they are If FCSCLS detects an error then it prints error 13 error in closing file clears the Z bit in the condition code register and returns with A5 pointing to the FCB which was being closed when the error was detected When FCSCLS detects an error it does not close the remaining files hence its routine use to close files is not encouraged Instead users should close each file separately NOTE Each of the following Group B functions requires that the calling program must point A4 to the FCB to be operated on and then do a call to the appropriate function specified below If the operation is finished without error then FCS returns with the Z bit set If an error is detected then the Z bit is Cleared and the error code is in byte 1 of the FCB If no error 10 4 is detected this byte is not necessarily 0 and should not be tested unless the Z bit indicates an error The normal call to these functions is thus LEA A4 Point to the File Control Block DC lt function gt Call FCS to perform operation BNE ERROR Go process error if detected Note that it is required that A4 point to the beginning of the FCB when FCS is called Since the contents of AO through A4 and DO through D4 are preserved upon return from the FCS so A4 will still be pointing to the FCB upon return If the FCS is called with an unimplemented operation code the FCS will print out an error message and return to SK DOS The following des
207. t default will be used The lt to where gt parameter This item describes where the file s will be copied to It may be any one of the three formats described under lt from where gt above If the where information is incomplete then the drive and directory will come from the default work values and the file name will be taken from the from list For example if the command is COPY 0 A FILE2 TXT 2 then the file will be copied to the default directory on drive 2 and will still be called FILE2 TXT Any other directory would have to be specifically called out If the to directory is specified as then the file will be copied to the same directory as it was on the source disk The lt match list gt parameter In those cases where the from parameter does not provide enough data to specify a specific file the match list can be used to narrow down the field to a specific file or group of files This list is essentially a list of one or more file names and or exten sions or portions thereof COPY will copy only those files which match the match list If for example the match list consists of the word UN then any file whose name begins with UN will be copied if it consists of TXT then any file with a TXT extension will be copied If the match listitem is UN TXT then files must both have aname G 11 beginning with UN and also must have a TXT extension An asterisk can be used as a wild card character inside a name or ex
208. t normally be used as they may cause the system to crash in future multi task ing versions of SK DOS OF and 10 are special codes used for programs which are not written in the normal position independent code PIC They are used to allow SK DOS to modify an address while loading a position dependent program The 0F is to be followed by a single word address relative to OFFSET and the 10 is to be followed by a single long word address relative to OFFSET which specifies the address of a long word address which is to be modified by adding the current value of OFFSET to it For example suppose the current value of OFFSET is 5000 and the 13 2 disk file contains the sequence 0F 12 34 or the sequence 10 00 00 12 34 Either of these two segments tells SK DOS to add 5000 to the contents of address 6234 which is presumed to have been previously loaded This code would normally be used only with assemblers or compilers which generate non position independent code With one exception all of the loading and transfer addresses referred to above are merely relative addresses they are added to the current value of OFFSET see Chapter 11 when used For example if OFFSET currently has a value of 5000 and a file has a loading address of 1000 and a transfer address of 1004 then it will actually be loaded into memory at 6000 and executed starting at 6004 The exception is SK DOS itself Since SK DOS is loaded by the bootstrap p
209. t you know its progress and may display messages if errors are encountered Most of FORMAT s time is spent checking each sector written to make sure it is readable Unreadable sectors are removed from the chain of free sectors and at the end of the formatting process FORMAT displays the number of good free sectors available on the disk Any number of defective sectors can be thus bypassed but formatting will be aborted if an error is discovered in several crucial sectors of track O sectors 1 2 3 or 5 You may also specify an optional interleave factor on the command line as in SK DOS FORMAT 1 5 which would establish an interleave of 5 Allowable values are from 1 to 9 for single density 1 to 17 for double density if no interleave is specified a default value of 3 is chosen Changing the interleave constant may speed up some operations but slow down others the value of 3 seems a good compromise for most uses See also the LINK command description The 37C65 controller The 37C65 controller can handle many more drive and disk combinations than the 1772 so itis more specific in the choices it offers When you use this controller FORMAT first checks the drive description information you entered with HUMBUG s IS command to see which type of drive you have Depending on the drive it will then give you a choice of two or three different kinds of disks you can format with that drive The available choices for each ki
210. tains 10 RTS instructions a total of 20 bytes which are called each time SK DOS executes the SWRITE routine to write a sector A4 at this time points to the FCB being used for the write A user may substitute up to three alternate sector write routines by inserting JSR instructions which point to these other routines This allows the simple addition of acache RAM disk or alternate disk controllers The program must preserve AO through A4 and DO through D4 SECCOL COLDST 48 Secondary cold start initial ization SECCOL normally contains 10 RTS instructions a total of 20 bytes which are called during cold start This area would normally be used for initializing any drivers used with SECTRD or SECTWR A user may call up to three initialization routines by inserting JSR instructions which point to these other routines j The program must preserve AO through A4 and DO through D4 SECWAR COLDST 5C Secondary warm start ini tialization SECWAR normally contains 1O RTS instructions a total of 20 bytes which are called during warm start This area would normally be used for initializing any drivers used with SECTRD or SECTWR A user may call up to three initialization routines by inserting JSR instructions which point to these other routines The program must preserve AO through A4 and DO through D4 SECCHK COLDST 70 Secondary disk ready check SECCHK normally contains 10 RTS instructions a total of 20 bytes which are called to check wheth
211. tate upon return from a user program RESTRP A021 Reset trap vectors RESTRP resets the 68K processor s trap vectors to those initially used by SK DOS at boot see TRPFLG for further information RESTRP is called during WARMST so that SK DOS always returns to a known state upon return from a user program GETNAM A023 Get file name into FCB This routine is used to take a file specification from the input buffer and place it into the appropriate bytes of an FCB At entry A4 should point to the FCB to be filled and the LPOINT line buffer pointer should point to the beginning of the file specifi cation in the line buffer As the file specification is parsed the drive number will be placed into the drive number location of the FCB unless no drive number is specified in which case the working drive will be used The directory name file name and the extension if present will also be placed into the FCB if the directory name is missing it will be replaced by the default directory and a missing name or extension will be replaced by zeroes If the file specification has no errors then the carry will be cleared else it will be set The file specification in the line buffer may end with a space comma CR or ENDLIN character if a space or comma then LPOINT will point to the next character after it if aCR or ENDLIN then LPOINT will point to the CR or ENDLIN character Errors will place error code 21 illegal file name into the FCB a
212. ten reads can be performed on any one sector since there are ten directory entries per sector Upon the eleventh read DSREAD will automatically read the next sector of the directory Error 8 input past end of file will be returned at the end of the directory Note that all entries are read even deleted entries indicated by a FF as the first character of the file name or unused entries indicated by a 00 as the first character DSWRIT A00E Write directory or SIS entry This function writes a directory or SIS entry from the first 96 bytes of an FCB back into its appropriate position in the sector buffer and then writes the sector buffer back to the disk Because of the need to properly set up a number of pointers this function should only be used after DSREAD which in turn should only be used after DIROPN or SISOPN FDELET A00F Delete a file This function deletes a file name from the directory and returns its used sectors to the chain of free sectors maintained in the System Information Sector track O sector 3 Before using this function the calling program must place the drive number file name and file extension of the desired file into bytes 3 through 14 of the FCB It returns error 4 if the file name is not found along with the Z bit of the condition code register cleared FRENAM A010 Rename a file This function renames an existing file before calling the FCS the user s program must place the old file specification int
213. tension as in U D which would match with any name such as UAD or UBD or even U8D As mentioned earlier the match list is optional if absent then any file satisfying the lt from where gt parameter will be copied For example COPY 0 1 PROG TXT would copy PROG TXT and all other files whose name begins with the letters PROG and which have TXT extensions from drive 0 to drive 1 COPY 0 1 D A B BIN wouldcopy all files whose names begin with A or B or which have a BIN extension from drive 0 to directory 1 D The lt how gt parameter The lt how gt parameter describes how the copy is to be done and allows a variety of variations on the basic COPY command It is specified by including one or more option letters between the word COPY and the lt from where gt parameter which must always begin with a drive number so COPY can tell where the option letters end and the lt from where gt parameter begins The following option letters are allowed copy in Alphabetical order allow Corrupt files to be copied copy files with newer Date delete Existing destination file copy by File number alpha not allowed Kill duplicate file on source List files without copying Make random file copy files Not on destination turn Off defaults Prompt before copying file Recover from track sector copy Since a specified date Track zero protection override Use current SK DOS date Wait for disk change Zap source file after copying NSEZCHrYV AVOZZ
214. th zeroes See Chapter 13 for further information on random files FRBACK A015 Backup to previous sector This function allows you to backup to the previous random sector of arandom file Read the description of FRRECD as this function is similar You cannot backup from sector 1 the first data sector of the file back to sector O the first file map sector and any attempt to do so will generate error 24 invalid sector SK DOS User s Manual number See Chapter 13 for further information on random files FRGET A016 Read a random byte This function allows you to read a specified random byte from a random file currently opened for update To select the byte place its number a value from 4 to 256 into byte 51 of the FCB Note that there are only 252 data bytes per sector and they are numbered from 4 through 256 The byte will then be read from the currently selected sector See Chapter 13 for further information on random files FRPUT A017 Write a random byte This function allows you to write a specified random byte to a random file currently opened for updating To select the byte place its number a value from 4 to 256 into byte 51 of the FCB Note that there are only 252 data bytes per sector and they are numbered from 4 through 256 The byte will then be written to the currently selected sector See Chapter 13 for further information on random files SREAD A01C Read a single sector This function provides
215. the SIS into this sector to verify that the diskis available for writing Sector 5 begins the directory which extends to the last sector of track 0 Each directory entry requires 24 bytes so there is room for 10 entries in each sector with 16 bytes empty For example on a 5 14 single density single sided disk there are 10 sectors in track 0 Hence there are six sectors in the directory numbered from 5 to 10 for a total of 60 directory entries The six sectors are linked through the first two bytes in each sector and the last sector has a pointer of 00 00 When the directory is filled up however SK DOS will take a sector from the free chain and add it to the directory so that the directory can be expanded to make room for more entries although this may greatly slow down the operation of the system if the added directory sector is on one of the inner tracks of the disk since the disk head will have to step in and out each time it accesses the directory SEQUENTIAL FILES Most SK DOS files are of the sequential type as opposed to random files discussed next Sequential files are intended to be read in order from beginning to end Such files generally are of two types text or binary Text File Format SK DOS text files consist simply of ASCII text usually separated into lines of text by CR 0D characters LF charac ters 0A are not included Most text files use space compres sion where two or more consecutive spaces ar
216. ther than minimum systems this prompt provides summary information on valid command lines Assembler Syntax The input to this assembler is one text file containing a number of lines formatted according to the requirements of the 68000 68010 assembler language Because of the ability of this assembler to include auxiliary text files source text libraries may be readily established and used Whatever the source the lines may be automatically formatted to separate the label instruction and operand fields whenever the output line is specified to be at least 64 characters in width 2 The statements acceptable to this assembler are free field one statement per line Intermediate fields are separated by at least one space or tab and each line is terminated by a carriage return There are three types of statements in the assembler lan guage as follows instruction directive comment Each of these statement types is discussed below Instruction Statement An instruction statement consists of zero to four fields as follows label ment instruction operand com Label Field The label field is optional It is normally used to provide a symbolic name for the address of the machine code generated by the following assembler instruction However labels may also be used as parts of arithmetic expressions to assist in the process of assembling the program If the label field is omitted it must be represented by a spac
217. thout echo bypass TA Disable interrupts Re enable interrupts to previous status Load open machine language file Output control see Chapter 14 Output 5 decimal digits Output 2 hex digits Output 4 hex digits Output 5 decimal digits Output 8 hex digits Print CR LF Print error code Print string Without CR LF Print CR LF and string Output character Re enter SK DOS Reset I O pointers Reset trap vectors Check keyboard for character with TA Check keyboard for character bypass TA Convert lower case to upper in D5 Point to SK DOS variable area WARMST AOLE Warm start C 1 LISTED IN ORDER BY OP CODE VPOINT A000 FINDEV A012 WARMST A01E EXECSD AOIF RESIO A020 RESTRP A021 LOADML A022 GETNAM A023 DEFEXT A024 RENTER A025 ICNTRL A028 GETCH A029 INNOEC A02A STATUS A02B INLINE A02C GETNXT A02D CLASFY A02E HEXIN A02F DECIN A030 TOUPPR A031 OCNTRL A032 PUTCH A033 PCRLF A034 PSTRNG A035 PNSTRN A036 PERROR A037 OUTSD A038 OUT10D A039 OUT2H A03A OUT4H A03B OUT8H A03C GETDNT A03F INTDIS A040 INTENA A041 STATU1 A042 INNOE1 A043 FLUSHT A044 FNPRNT A045 OP CODE FUNCTION Point to SK DOS variable area Find device number from name Warm start Execute a SK DOS command Reset I O pointers Reset trap vectors Load open machine language file Get file name into FCB Default extension Re enter SK DOS Input control see Chapter 14 Get input character with echo
218. to make sure it is position independent NOTE to non assembly language users The assembly language examples in this chapter are in tended only as guides for those users who intend to write their own assembly language programs If you wish to try them out proceed as follows 1 Type the command EDLIN SAMPLE to edit a sample file 2 When EDLIN returns with a prompt give it the I command to start inserting text 3 Enter the LIST program the first program in this chapter Examine the listing to note that the first line of the program begins with an asterisk type in only the material to the right of that column For example begin the first line with LIST begin the 7th line with FCBERR EQU 4 When you finish typing in the program enter a at the beginning of a new line and then use the S command to exit EDLIN 5 Give the command ASM SAM PLE to assemble the sample from assembly language to machine language You will now see that the assembler added all of the machine language code which you did not type in 6 Assuming there are no errors correct the program if there are then give the command SAMPLE SAMPLE The computer will then use the SAMPLE COM file generated by the assembler to print out the SAMPLE TXT file you typed SAMPLE COM does exactly the same thing as the LIST command supplied with SK DOS except that it does not have the help feature SK DOS User s Manual 13 INFORMATION FOR ADVANCED PROGRAM
219. to reserve permanent memory for itself such as a RAM disk can be loaded into memory at OFFSET and then point OFFINI above itself or can move itself to the top of memory and then point MEMEND just below itself Either way its memory will then be protected permanently since SK DOS does not itself move these boundaries It is also possible to reserve memory just temporarily for example a program might be needed only for a while Such a program can then be loaded into low memory and OFFSET adjusted to point to an even address above the program OFFSET will then remain at this value only until the next warm start at SK DOS User s Manual which time it will go back to the previous value as determined by OFFINI Note that OFFSET must always be even USER INSTALLED MEMORY RESI DENT COMMANDS Users may add their own memory resident commands to the list normally contained within SK DOS The program code for such commands may be left in memory and protected from SK DOS in one of several ways 1 The program can be placed at the bottom of user memory and then OFFINI set to point above the program s top memory address or 2 The program can be placed at the top of user memory and then MEMEND set to point just below the program s bottom address or 3 The program can be placed into some other memory area which SK DOS does not use and does not know about To add the command to SK DOS s command list a table of command names and st
220. tors on the disk If you copy a file from one disk to another the two file map sectors will be different since the copy will most likely be in a different place on the disk But you need not concern yourself with this since SK DOS does this automatically Once the file is written it can be read or updated the data in it can be modified or lengthened But random files are usually made oversize to begin with so there is room for adding more data at a later time without increasing the file size later The file can be read sequentially just like any sequential file If it is opened with FOPENR and then read with FREAD it will look like any sequential file since SK DOS will automat ically skip the file map sectors and read only the data sectors Things are a bit more complex and interesting if the file is opened for updating We now have anumber of options which are listed in the description of the Open for Update operation FOPENU The most important concept is that by use of FRRECD we can locate any sector number that is a sector with a desired sector count in the file in a short time For example we can tell SK DOS to read sector number 0104 of a file Given a sector number SK DOS will look it up in the file map calculate the exact location of that sector and then go directly to it Once we have located the specific sector we can specify an exact byte of that sector and either read it with FRGET or write it with FRPUT
221. tput by Ist letter within the disk directory sectors the name and extension begin D Date Display file Date ning and ending tracks and sectors size and creation date F File No Display File number Random files are identified by the letter R to the right of the M Maximum Full listing with all options extension The three SK DOS protect codes are indicated by N Non existent Display Deleted files with letters although the catalog protect bit is not honored by CAT P Paging Paging with printer column width C catalog protect D delete protect W write protect R Repeat Repeat CAT as listed on command line The last line indicates the total number of files on the disk S Size Display file Size in sectors the size of the biggest file on the disk the total size of the CAT normally defaults to the M or Maximum option when displayed files as compared with the total size of all files on that none is specified Entering any option letter on the command disk and the number of free sectors line will turn that option on but all others are turned OFF Hence you must enter ALL options you want if you enter any at all The following gives more information on specific options A This option will group the listing by the first letter rather than provide a fully alphabetized list such as provided by ACAT When the A option is used you cannot use any match strings D This option will display the file s creation date If the month is zero or ove
222. tput to a printer it can change DEVOUT from 0 to 2 assuming that a PRTR or similar driver is installed If not then output will still go to the console It is also possible to input from one device but output to another by changing DEVIN and DEVOUT accordingly 2 An indirect way of changing DEVIN and DEVOUT is through ICNTRL and OCNTRL calls FFFx see the next section 3 PERROR output is done via DEVERR and programs can change this byte to steer error output to different devices 4 All of the above can also be sent to a disk file or input from a disk file by opening the appropriate file and placing the FCB address into FIADDR for input or FOADDR for output and then setting DEVIN or DEVOUT to device number 8 Note that physical I O devices are only numbered 0 through 7 number 8 applies only to disk files If the file is not open or if SK DOS encounters an error while using the file it will print an error message reset the device number to 0 and continue using device 0 for input or output You may then use the EOFILC usually control Z to indicate an end of file on input 5 Conversely an FCB can be used to access an I O device simply by using the four letter device name when opening the file Just be careful not to try to input from an output device such as a printer The process would go like this First place a four letter device name into the name bytes of the FCB Do not use an extension or SK DOS will assume you mea
223. u may get undesirable results On some systems which do not generate bus errors the system may totally die If the hardware properly generates bus errors then you will get an error message either from SK DOS if TRPFLG is non zero so that SK DOS handles all exceptions or from the monitor Gf TRPFLG is zero so exceptions are handled by the monitor SK DOS User s Manual PICTEST BAS PICTEST BAS PICTEST BAS is a Basic program which helps to check that an assembly language program written for use with SK DOS is indeed relocatable The version supplied is specifically written for use with RBASIC or with TSC XBASIC on 6809 systems or with SK DOSO09 but can be easily modified for use with other Basic interpreters Although it is somewhat difficult to test an assembly lan guage source file for position independent relocatable coding it is easy to test the machine language object code The trick is to simply assemble the same program twice once with an ORG of 0000 and once with a different ORG such as 1000 If the program is truly relocatable then the two object codes should be exactly identical although certain programming techniques may result in slight differences Then it is only necessary to compare the two object files for differences PICTEST BAS does this job by reading the Motorola S1 type files output by an assembler Before using PICTEST BAS assemble the program to be tested with two different ORG statements as
224. umber of tracks the software and hardware can fairly well differentiate between the different kinds of disks without your having to tell it The only place where you must specify what kind of disk you want is during formatting when you must answer several questions as to the number of sides and tracks and the density The 37C65 controller on the other hand can handle five different kinds of drives and twenty different kinds of disks It can generally figure out what kinds of disks you are using as long as you tell it what kind of drives you have You must do this in HUMBUG before you boot by using HUMBUG s IS command to do an Initial Setup DRIVE NUMBERS D Sect Trk ens 1120K 3 577 5 720 K 2 1 1 3 2 N Nn 8 8 8 4 15 6 13 2 SK DOS users are sometimes confused by the variety of numbers used to identify the various disk drives Disk drives are identified by three different sets of numbers a Logical Drive Numbers Logical drive numbers are what you use in normal operation when you refer to your main drive as drive 0 or set up your RAMdisk as drive 4 The DRIVE command refers to these by L numbers For example if you have a hard drive and one floppy drive you might set up the hard drive as drive 0 called LO by DRIVE and the floppy as drive 1 or L1 b Physical drive numbers This is what the file control block calls PHYDRYV or what DRIVE calls F and H nu
225. us the sector format looks like this Bytes 1 and 2 pointer to next sector Bytes 3 and 4 sector counter Bytes 5 through 256 252 bytes of data 13 1 Some sectors have a slightly different format and may omit the pointer or sector counter All the tracks on a disk can be used for storing data and program files except for track 0 The sectors on this track have special uses as follows Sector 1 on track O holds the super boot program This is a program which is loaded by the boot program in the system ROM monitor and which in turn loads the rest of SK DOS into memory This sector has 256 bytes of data as the first four bytes of the sector are used for regular data storage rather than being used as pointer and sector count bytes On some systems the boot procedure may be different and so this sector may not be needed on those systems Sector 2 is often empty It has been set aside as an extension of sector 1 in case more than 256 bytes are needed for booting Sector 3 is the System Information Sector or SIS It contains the disk name and number the date when the disk was formatted the number of tracks and sectors on the disk and three pieces of information about the free sector chain on the disk the track and sector numbers of the first sector in the chain the track and sector numbers of the last sector in the chain and the total number of sectors in the chain Sector 4 is usually empty although the COPY utility places a copy of
226. utive different lines in the two files DIFF may not be able to resynchronize at the very end of the dissimilar texts SK DOS User s Manual DIR DIR DIR is used to display the contents directory or catalog of an entire disk including all its subdirectories DIR is not as useful and does not provide as much informa tion as some of the other catalog utilities such as ACAT CAT SCAT or TCAT It is however memory resident so it can be used without having a system disk with another cat utility installed in a drive Except for an optional drive number DIR accepts no other options or match list arguments In addition to providing a list of files on adisk DIR provides one additional piece of information which the other programs do not provide a list of subdirectories used on the disk This is done in the form of a display like this Subdirectories used lt ABCDE UVWXYZ gt Only those letters which are used as subdirectories appear The symbols lt and gt appear only in those cases where sub directories exist with ASCII codes either below A or above Z Such names are normally illegal but may still exist if written by programs G 18 SK DOS User s Manual DISKNAME DISKNAME The DISKNAME command is used to change the name DISKNAME will then print out the current values and allow number or date of a disk Simply type the command DIS you to enter new values You may leave the old name or number KNAM
227. ve and its default subdirectory if a drive number is specified without a directory code even if the drive number happens to be the same as the current work drive then ACAT will search the root directory SK DOS User s Manual APPEND APPEND The APPEND command is used to combine several source files together to make a single large destination file For example it can combine a number of text files together into a large file or can combine several machine language programs into one large program APPEND writes a new destination file with the original source files left unchanged To use this command type the word APPEND followed by the names of the source files to be combined followed by the name of the resulting destination file For example the com mand SK DOS APPEND PROG1 BIN PROG2 BIN 2 PROG3 BIN 1 PROG COM G 3 would combine PROGI BIN PROG2 BIN and2 PROG3 BIN in that order into a new file called PROG COM on drive 1 All of the source files must exist and the destination file must not exist Although files of any type may be appended usually all the files will be of the same type The extension of the first source file defaults to TXT if not specified otherwise and the exten sions of all succeeding files source and destination default to the same extension as the first file When machine language program files having transfer ad dresses are appended the transfer addresses are carried forward
228. velopes We do not maintain a separate mailing list and will not notify our customers unless we have this material on file 4 When we receive your registration you also become eligible to download software updates from the Star K BBS at 914 241 3307 USER REGISTRATION FORM Purchaser Name Address Product Being Registered SK DOS 68K Serial No Purchase Date Purchased from Computer Model Comments
229. went to a printer if such a device existed but to a disk file otherwise When SK DOS is initially booted it has just two devices these are called the default devices CONS is the console keyboard and screen It is used for normal input and output NULL is a null device which is used when you want to do a function but want no output whatsoever For example the command ASM PROG gt NULL would assemble a file but provide absolutely no output not even assembler error messages Even though it starts with just two devices SK DOS can have up to eight The others must however be specifically installed either by a command from the keyboard or by commands included in a STARTUP BAT file by reading in device drivers from a disk If you wish you can substitute other devices instead of the default ones as well DEVICE NUMBERS In addition to having names devices also have device num bers When using I O redirection you will always refer to them by name programs on the other hand may refer to them by either name or number The DEVICE command lets you see and change the correspondence between device names and num bers If you execute the DEVICE command just after booting up SK DOS you will get a display like this Normal Device Device Driver use number name Terminal 0 CONS Default driver Error device 1 CONS Default driver Printer 2 CONS Default driver 3 CONS Default driver 4 CONS Default drive
230. you want to generate a bootable system disk data disks which do not contain a copy of SK DOS and which will never be booted do not need LINK There are three basic ways of generating a bootable system disk 1 Use BACKUP to do a mirror image copy of an existing bootable system disk onto another formatted disk Since BACKUP does an exact copy of a disk the resulting disk will G 31 be exactly like the original and will also be bootable But if the original disk has unneeded files or defects so will the new disk 2 Use HTOF to restore a disk image previously stored with FTOH of a bootable disk onto a floppy disk 3 Use FORMAT to initialize a blank disk then use COPY to copy SK DOS to it and then use LINK to give its address to the super boot program In this way it is possible to copy only needed files to the new disk Use of COPY instead of BACKUP also compacts the disk and rearranges the files to make disk access faster To link a disk enter the command LINK followed by the SK DOS file name For example SK DOS LINK 1 SK DOS SYS would tell the super boot in drive 1 where to find the file SK DOS SYS You must enter the extension The drive num ber is optional and will default to the working drive if omitted Incidentally self contained programs those which use the monitor but not SK DOS itself can also be linked to the super boot In that case they will be loaded and executed directly upon booting the system
231. ypical programmer This chapter documents these routines and shows how they are used All of these routines are accessed through the excep tion vectors of the 68xxx processor 68xxx processors have a number of traps which trap un defined or illegal operations and cause a return to a supervisor or operating system via a set of exception vectors in low mem ory A full description of this system is beyond the scope of this manual and we suggest you get the Motorola literature for your processor or one of the many textbooks on 68xxx programming for more information One of the undefined or illegal 68K operations which causes a trap is any machine language instruction beginning with A Motorola literature refers to these as Line 1010 instructions Whenever any such instruction is encountered the 68K CPU does a trap via one of its exception vectors to SK DOS Thus SK DOS uses these instructions within user programs to call functions within SK DOS Within SK DOS the second byte of each such instruction is used to select a particular function to be performed For example the instruction A001 is used to read a byte from a file A002 writes a byte and so on A user program calls such a function with the instruction DC SAOxx where the xx is simply replaced by the number of the function desired To avoid the necessity of remembering the numeric code for each particular function the SK DOS disk includes a file called SKE

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