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Hisoft Pascal - The Sharp MZ

1. Pn is equivalent to BEGIN WRITE GPD WRITE P 2 s WRITE Pm END The write parameters PI P2 Pn can have one af the following forms lt e gt or lt em gt or lt e min gt or lt ezmsH gt where e m andn are expressions and H is a literal constant We have 5 cases to examine 138 is of type integer and either lt e gt or lt e m gt is used The value of the integer expression e is converted to a character string with a trailing space The length of the string can be increased with leading spaces by the use of m which specifies the total number of characters to be output If m is not sufficient for e to be written or m is not present then e is written out in full with a trailing space and m is ignored Note that if m is specified to be the length of e without the trailing space then no trailing space will be output 21e is of type integer and the form lt e m H gt is used In this case e is output in hexadecimal If m 1 or m 2 then the value e MOD 16 m is output in a width of exactly m characters If m 3 or m 4 then the full value of e is output in hexadecimal in a width of 4 characters If m gt 4 then leading spaces are inserted before the full hexadecimal value of e as necessary Leading zeroes will be inserted where applicable Examples WRITE OZ2S m H m i outputs 1 m 2 outputs 1 m 3 outputs 0401 m 4 outputs 0401 m 5 outputs 0401 Sle is of type real The forms lt e gt lt e m gt or
2. FILEs are not implemented although variables may be stored on tape ARECORD type may not have a VARIANT part PROCEDURES and FUNCTIONS are not valid as parameters Many extra functions and procedures are included to reflect the changing environment in which compilers are used among these are POKE PEEK TIN TOLIT and ADDR The compiler occupies approximately 12K of storage while the runtimes take up roughly 4 and the editor uses 2k Thus typically the total size of the package is roughly 19K leaving the rest of your computer s memory for the Pascal source and object programs Hisoft Pascal recognises various control codes entered from the keyboard mostly within the editor Of course different systems can have very different keyboard designs and thus wil have different ways of reaching control codes In this manual the control characters used will be referred to as ENTER CC CH CI CP CS and CX The Implementation Note for your system which may be found at the back of this manual will tell you the corresponding keys for your system Whenever HP is waiting for a line of input the control characters can be used as follows ENTER is used to terminate the line EC returns to the editor CH deletes the last character typed CI move to the next TAB position CP directs output to the printer if available or if output was going to the printer then it returns to the screen cx deletes the whole line typed so far The metho
3. expected Y expected Wrong type expected Factor expected Constant expected This identifier 15 not a constant THEN expected DO expected TO or DOWUNTO expected C expected Cannot write this type of expression OF expected expected expected PROGRAM expected Variable expected since parameter is a variable parameter BEGIN expected Variable expected in call to READ Cannot compare expressions of this type Should be either type INTEGER or type REAL Cannot read this type of variable This identifier is not a type Exponent expected in real number Scalar expression not numeric expected Null strings not allowed use CHR O C expected Y expected Array index type must be scalar expected Yor expected in ARRAY declaration Lowerbound greater than upperbound Set too large more than 256 possible elements Function result must be type identifier or 1 expected in set e or or Y expected in set Type of parameter must be a type identifier Null set cannot he the first factor in a non assionment statement Scalar including real expected Scalar not including real expected Sets incompatible Z and cannot be used to compare sets FORWARD LABEL CONST VAR TYPE or BEGIN expected 47 2 S 4 S 6 75 B 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 29 26 27 28 29 30
4. x 4 00 54 5 CLD E IXH LD D CDG 2 D 5 3 3 CALL 4385 DI 2 END This procedure traps a frequency of zero which it converts into a period of silence For non zero frequencies the frequency and length of the note are approximately converted to the values required by the SPECTRUM ROM routine and this is then called via BEEPER PROCEDURE BEEP Frequency f INTEGER Length REAL VAR I INTEGER BEGIN TF Frequency 0 THEN FIR 11421 TO ENTIER 120802Lerqth DO ELSE BEEPER ENTIER FrequencyzLength ENTIER 437500 Frequency 34 125 FUR Ii 1 TO 151 DO short delay between notes END Example of the use of BEEP PEEP 262 0 5 BEEP 8 103 sounds middle C for 0 5 seconds followed by a one second silence 2 Graphics Three graphics procedures are given the First plots a given X Y co ordinate whilst the second and third are used to draw lines from the current plotting position to a new position which is defined relative to the current plot position and which then becomes the current piot position Both PLOT and LINE take a BOOLEAN variable ON which if TRUE will cause any point ta be plotted regardless of the state of the pixel in that plot position or if FALSE will cause any pixel already present at the plot position to he flipped ive if on it becomes aff and vice versa This effect is identical to that caused by the SPECTRUM OVER command CA procedure that mirrors the BASIC PLOT command Simp
5. Procedure NEW see Section 2 A dynamic variable unlike a static variable which has memory space allocated for it throughout the block in which it is declared cannot be referenced directly through an identifier since it does not have an identifier instead a pointer variable is used This pointer variable which is a static variable contains the address of the dynamic variable and the dynamic variable itself is accessed by including a after the pointer variable Examples of the use of pointer types can be studied in Appendix 7 There are some restrictions on the use of pointers within Hisoft Pascal These are as follows Pointers to types that have not been declared are not allowed This does not prevent the construction of linked list structures since type definitions may contain pointers to themselves e g TYPE item RECORD value INTEGER next item END link item Pointers to pointers are not allowed Pointers to the same type are regarded as equivalent e g VAR first links current item The variables first and current are equivalent i e structural equivalence is used and may be assigned to each other or compared The predefined constant NIL is supported and when this is assigned to a pointer variable then the pointer variable is deemed to contain no address 1 7 4 RECORDs The implementation of RECORDs structured variables composed of a fixed number of constituents called fields within Hisoft Pascal
6. S d This command allows you to change the delimiter which is taken as separating the arguments in the command line On entry to the editor the comma is taken as the delimiter this may be changed by the use of the S command to the first character of the specified string d Remember that once you have defined a new delimiter it must be used even within the S command until another one is specified Note that the separator may not be a space Command V The V command takes no arguments and displays the current default values of the line range and the two strings The line range is shown first followed by the two strings which may be empty Remember that certain editor command e g D and N do not use these defaults but must have values specified on the command line Command X This simply displays the end address of the compiler in hexadecimal This information will be useful when making a back up copy of the compiler since to make a back up copy you should save code from the start of the compiler up to the end of the compiler See your Implementation Note for more details 4 3 An Example of the use of the Editor Let us assume that you have typed in the following program using 110 10 10 PROGRAM BUBBLESORT 20 CONST 30 Size 2000 40 VAR 50 Numbers ARRAY 1 51 223 OF INTEGER 50 I Temp INTEGER 70 BEGIN 80 FOR I 1 TO Size DO NumbertIJ RANDOM 90 REPEAT 100 FOR I 1 TO Size DO 110 Noswaps
7. The sub commands are space increment the text pointer by one i e point to the next character in the line You cannot step beyond the end of the line DELETE or BACKSPACE decrement the text pointer by one to point at the previous character in the line You cannot step backwards beyond the first character in the line CI control function step the text pointer forwards to the next tab position but not beyond the end of the line SENTER gt end the edit of this line keeping all the changes made Q quit the edit of this line i e leave the edit ignoring all the changes made and leaving the line as it was before the edit was initiated R reload the edit buffer from the text i e forget all changes made on this line and restore the line as it was originally L list the rest of the line being edited i e the remainder of the line beyond the current pointer position You remain in the Edit mode with the pointer re positioned at the start of the line K kill delete the character at the current pointer position Z2 delete all the characters from and including the current pointer position to the end of the line F find the next occurrence of the find string previously defined within a command line see the F command above This sub command will automatically exit the edit on the current line keeping the changes if it does not find another occurrence of the find s
8. lt e m n gt may be used The value of e is converted to a character string representing a real number The format of the representation is determined by n If n is not present then the number is output in scientific notation with a mantissa and an exponent 1f the number is negative then a minus sign 15 output prior ta the mantissa otherwise a space is output The number is always output to at least one decimal place up to a maximum of 5 decimal places and the exponent is always signed either with a plus or minus sign This means that the minimum width of the scientific representation 1s B characters if the field width m s less than 8 then the full width of 12 characters will always be output If m 8 then one or more decimal places will be output up to a maximum of 5 decimal places m 12 Y For m gt 12 leading spaces are inserted before the number Examples WRITE 1 23E 10 m m 7 gives 1 23000E 10 m 8 gives 1 2E 10 m 9 gives 1 25E 10 m 10 gives 1 220E 10 m 11 gives 1 2 00E 10 m 12 gives 1 23000E 10 m 13 gives _ 1 23090E 10 If the form e m n is used then a fixed point representation of the number e will be written with n specifying the number of decimal places to be output No leading spaces will be output unless the field width m is sufficiently large 1 n is zero then e is output as an integer f e is too large to be output in the specified field width then it is output in scientific format with a fi
9. you could use the following PROGRAM A BEGIN je WRITE CHR 16 Cto turn the printer OND WRITELN CHRI2 C2 1 D0 0 100 100 _ WRITE CHR 16 turn the printer OFF END NS An extra command has been addad to the Hisoft Pascal editor for the SHARP M1700 this is the W command which works like the P command except that it dumps a block of text to tape in a Form which is suitable for later inclusion via the compiler option F Note that you cannot include text that has been written to tape using P if you want to include text then the text must have been written to tape using the W command Using the T command from the editor will elie the text and then save the object code to tape as described in Section 4 2 5 of this manual This will overwrite the compiler and should only be done when the program is Fully de hugged and ready for use To load this object code inta a clean MZ700 then you should use the MZ700 monitor s L command type L lt CR gt and press PLAY on the tape deck The object code will be loaded and axecuted hit any key at the end of the execution ta return to the monitor Use 71200 followed by cR to execute the abject code again If at any time you wish to return to the 0 monitor From within the Pascal then use the B command and then hit any key To re enter the Pascal from the monitor use ec for a cold start destroying any text or 71221 for a warm start
10. CH 1 via the DEL key 1 CI via CTRL I 2 GPE via CTRL P i NSN via CTRL X say cs via the SHIFT and BREAK key held down n together 1 Entry from the keyboard is as normal s producing upper case letters unless the SHIFT key is held down However if CTRL K is pressed while in editor mode then this action will be reversed hitting keys will produce the SHIFTed character on that key while holding SHIFT and the key down together will produce the unSHIFTed character apote t that tas an exits Hit Sm again to return to the normal mode of entryi Im SO ES In addition ta the comprehensive iis 2 Functions described in Section 4 of the XM OS Manual user s of Hisoft Pascal on the SHARP MZ700 have access to a simple screen editing scheme this works as follows If while in the main editor command Joop i e with a gt sign at the left hand edge you press any pf the cursor movement keys then the cursor will move as directed and you will be placed in screen editing mode In this mode you may overtype any text on the screen using INST and DEL to open up or close down a screen line as required Then when you press the CR key the line with the cursor in it will be transmitted to the Hisoft Pascal editar and control returned from the screen editor to the Hisoft Pascal line editor You should note that you must ensure that all Screen editing takes place within a single line on the screen and that since
11. SPACE The 7X SPECTRUM keyword entry scheme is not supported we see this as a positive advantage instead all text must be inserted using the normal alphanumeric keys Using SYMBOL SHIFT and any key except I will always reach the ASCII symbol associated with that key and not the keyword e g SYMBOL SHIFT T gives gt and SYMBOL SHIFT G gives You must not use the single symbols lt and gt j instead these should be entered as a combination of the symbols lt gt and The editor comes up in upper case mode this may be toggled in the normal way using CAPS SHIFT and 2 You have control over the temporary attributes of the various character positions on the screen through the use of the standard control codes eg WRITE CHR 17 CHRI4 will make the paper green but you cannot change the permanent attributes If while using these contro codes an invalid sequence is detected then the message System Call error will be displayed and the execution 71 aborted Note that certain CHR codes are interpreted by Hisoft Pascal e g CHR 8 is taken as DELETE and thus these codes cannot be passed directly to the Spectrum ROM use the SPOUT procedure see below if you want to write CHR codes without interpretation by Hisoft Pascal When dumping text or object code to tape you must he careful to have the tape recorder in RECORD made before beginning the dump If you have used the T ranslate command to save the object code
12. and V can be of any type except SET See Section 2 3 5 5 above for a discussion 30 of the use of integers to represent memory addresses Examples POKEQGR6000 A places 41 at location 4000 POKE 16294 2 6E3 places OO OR 9079 hex at location 0900 2 3 5 8 TOUT NAME START SIZE TOUT is the procedure which is used to save variables on tape The first parameter is of type ARKAY 1 8J OF CHAR and is the name of the file to be saved SIZE bytes ot memory are dumped starting at the address START Both these parameters are of type INTEGER E g to save the variable V to tape under the name VAR use TOUTC VAR y ADDR Y SIZE Y The use of actual memory addresses gives the user far more flexiblity than just the ability to save arrays For example if a system has a memory mapped screen entire screenfuls may be saved directly See Appendix 4 for an example of the use of TOUT 2 3 5 9 TIN NAME START This procedure is used to load from tape variables etc that have been saved using TOUT NAME is of type ARRAYI 1 8 of CHAR and START is of type INTEGER The tape is searched for a file called NAME which is then loaded at memory address START The number of bytes to load is taken from the tape saved on the tape by TOUT E g to load the variable saved in the example in Section 2 3 5 8 above use TINCVAR ADDROZ See Appendix 4 for an example of the use of TIN 2 3 5 10 QUT P C This procedure is used to direct
13. and runtimes on tape then ta load the program simply enter LOAD CODE from within BASIC To execute the program enter RANDOMIZE USR 24608 from within BASIC From within ZX BASIC you can re enter the HP4TM editar in one of two ways enter RANDOMIZE USR 24503 ta perform a warm start ive preserving the Pascal program or RANDOMIZE USR 24593 to doa cold start re initialising the Pascal and clearing any existing Pascal text The ZX Printer is supported via the use of the compiler P option see Section 3 2 of the Programmer s Manual and via CHR 15 in a WRITE or WRITELN statement Note that as a result you cannot use CHR 16 within a WRITE LN statement to specify the INK colour instead you can use CHR 15 to set the INK Most parallel printer interfaces are supported by Hisoft Pascal since printer output is always directed through stream 3 specifically the Kempston and Morex interfaces work well Any return ta BASIC from within Pascal will cause execution to pause hit any key to accomplish the return to BASIC This pause has been added to allow runtime error messages etc to remain on the screen the return to BASIC clears the screen An extra command has been added to the Hisoft Pascal editor for the ZX Spectrum this is the W command which works like the P command except that it dumps a block of text to tape in a form which is suitable For later inclusion via the compiler option F Note that you cannot include tex
14. error will be generated and if a decimal point is present without a subsequent digit then a Number expected error will be given Feals like integers may be read immediately see 1 and 2 above 25 2 3 1 5 READLN READLN VI V2 Vn 1s equivalent to BEGIN READ V1 V2 Vn READLN END READLN simply reads in a new buffer from the keyboard while typing in the buffer you may use the various control functions detailed in Section 0 0 Thus EOLN becomes FALSE after the execution of READLN unless the next line is blank READLN may be used to skip the blank line which 15 present at the beginning of the execution af the object cade i e 1t has the effect of reading in a new buffer This will be useful if you wish to read a component of type character at the beginning of a program but it is not necessary if you are reading an integer or a real since end of line markers are skipped or if you are reading characters from subsequent lines 2 5 2 Input Functians 2 3 2 1 EDL N The function EDLN is a Boolean function which returns the value TRUE if the next char to be read would be an end of line character CHR 13 Otherwise the function returns the value FALSE 2 3 2 2 INCH The function INCH causes the keyboard of the computer to be scanned and if a key has been pressed returns the character represented by the key pressed If no key has been pressed then CHR G is returned The function therefore returns a result o
15. for another line Use CC to exit i fica Program to jist lines ot Shows use of pointers records 58 PROGRAM ReverseLine TYPE elem RECORD next elem ch CHAR END link elem VAR prev cur heap link BEGIN REFEAT MARK heap prev NIL WHILE NOT EOLN DO BEGIN NEWtcur READ cur ch 1 cur next prevs orev cur END Write out the line backwards by set up backwards 7 cur previ WHILE cur lt gt NIL DO BEGIN WRITE cur ch 3 curs cur next END WRITELN RELEASE heap READLN UNTIL FALSE END lc 50 40 Zo amp 0 70 8o 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 290 260 270 280 290 ioo BLO 320 320 540 35 360 S70 380 A90 400 of a number input from the Frooram to show the use of recursion 117 2u 30 PROGRAM FACTOR 1 usina recursion and 2 using an iterative method RFAC invoked N times lt Simple Loop O M XINT CHAR FOSINT algorithm This program calculates the factorial keyboard TYPE FOSINT VAR METHOD NUMBER Recursive FUNCTION RFAC N FOSINT INTEGER F PDSINT N RFAC N 1 13 IN VAR BEG IF N gt 1 THEN F ELBE P RFAC F END Iterative solution gt FUNCTION IFAC N POSINT INTEGER POSINT 2 TON DOF FRI Give method I or R and number ys VAR I F BEGIN E is FAC F F FOR I I
16. is as Standard Pascal except that the variant part of the field list is not supported Two RECORD types are only treated as equivalent if their declaration stems from the same occurrence of the reserved word RECORD see Section 1 7 1 above The WITH statement may be used to access the different fields within a record in a more compact form 11 RECORD declarations and WITH statements do not open a new scope This means that you should not use the same field identifiers in two different record declarations or use the same name as a variable and a field identifier See Appendix 7 for an example af the use of WITH and RECORDs in general 12 128 FIELD LIST fe isentirier PD type Ee xm Used in conjunction with RECORDs see Section 1 7 4 above and Appendix 7 for an example 1 7 VARIABLE variable identifier field identifier Two kinds of variables are supported within Hisoft Pascal static and dynamic variables Static variables are explicitly declared through VAR and memory is allocated for them during the entire execution of the block in which they were declared Dynamic variables however are created dynamically during program execution by the procedure NEW They are not declared explicitly and cannot be referenced by an identifier They are referenced indirectly by a static variable of type pointer which contains the address of the dynamic variable See Section 1 7 2 and Section 2 for more details of
17. normally present any difficulties however should the user wish ta compare such numbers the use of I ensures that the results of the comparison will be correct The equivalent situation may arise with real arithmetic in which case an overflow error will be issued if the arguments differ by more than approximately 3 4E38 this cannot be avoided 36 If I then no check for the result of the above comparisons is made DEFAULT I Option P If the P option is used the device to which the compilation listing is sent is changed i e if the video screen was being used the printer is used and vice versa Note that this option is not followed by a or DEFAULT The video screen is used Option F This option letter must be followed by a space and then an eight character filename If the filename has less than eight characters it should be padded with spaces The presence of this option causes inclusion of Pascal source text from the specified file from the end of the current line useful if the programmer wishes to build up a library of much used procedures and functions on tape and then include them in particular programs The program should be saved using the built in editor s P command On most systems the list option L should be used otherwise the compiler will not compile fast enough Example F MATRIX include the text from a tape file MATRIX When writing very large programs there may not be en
18. of bytes occupied by the array is n s e g an ARRAY 1 10 OF INTEGER requires 10 2 20 bytes an ARRAYC2 12 1 10 OF CHAR has 11 10 110 elements and so requires 110 bytes A 3 1 5 Sets Sets are stored as bit strings and so if the base type has n elements then the number of bytes used is n 1 DIV B 1 Examples a SET OF CHAR requires 256 1 DIV 8 1 32 bytes a SET OF blue green yellow requires 3 1 DIV 8 1 1byte A 3 1 6 Pointers Pointers occupy 2 bytes which contain the address in Intel format i e low byte first of the variable to which they point A 3 2 Variable Storage at Runtime There are 3 cases where the user needs information on how variables are stored at runtime a Global variables declared in the main program block b Local variables declared in an inner block c Parameters and passed to nd from procedures and returned values functions These individual cases are discussed below and an example of how to use this information may be found in Appendix 4 Global variables Global variables are allocated from the top of the runtime stack downwards e g if the runtime stack is at 4BOOO and the main program variables are VAR i INTEGER ch CHAR x REAL then i which occupies 2 bytes see the previous section will be stored at locations BOOO 2 and 8BOOO 1 i e at AFFE and AFFF ch i byte will be stored at location AFFE L i e at AFFD x 4 bytes w
19. of characters defined by the string has been read or EDLN TRUE If the string is not filled by the read i e if end of line is reached before the whole string has been assigned then the end of the string is filled with null CHR O characters this enables the programmer tc evaluate the length of the string that was read The note concerning in 13 above also applies here 1 Vis of type integer In this case a series of characters which represent an integer as defined in Section 1 3 is read All preceding blanks and end of line markers are skipped this means that integers may be read immediately cf the note in 1 above 1 the integer read has an absolute value greater than MAXINT 32767 then the runtime error Number too large will be issued and execution terminated If the first character read after spaces and end of line characters have been skipped is not a digit or a sign or then the runtime error Number expected will be reported and the program aborted 41 V is of type real Here a series of characters representing a real number according to the syntax of Section 1 3 will be read All leading spaces and end of line markers are skipped and as for integers above the first character afterwards must be a digit or e sign I4 the number read is too large or too small see Section 1 3 then an verflow error will be reported if E is present without a following sign or digit then Exponent expected
20. over an end of line marker then before the read operation is terminated a new line of text will be read into the buffer from the keyboard While ceading in this line all the various control codes detailed in Section 0 0 will be recognised Now READ V 1 V2 V is equivalent to BEGIN READ VD READ V25 READ Vn END where Vi V2 etc may be of type character string integer or real The statement READ V has different effects depending on the type of V There are 4 cases to consider 11V is of type character In this case READ Y simply reads a character from the input buffer and assigns it V If the text window on the buffer is 24 positioned on a line marker a CHR 01Z character then the function EOLN will return the value TRUE and a new line of text is read in from the keyboard When a read operation is subsequently performed then the text window will be positioned at the start of the new line Important note Note that EDLN is TRUE at the start of the program This means that if the first READ is of type character then a CHR 3 value will be returned followed by the reading in of a new line from the keyboard a subsequent read of type character will return the first character from this new line assuming it is not blank See also the procedure READLN below 2 V is of type string string of characters may be read using READ and in this case a series of characters will be read until the number
21. pointer by one You remain in the change sub mode until you press ENTER whence you are taken back to the Edit mode with the pointer positioned after the last character you changed DELETE or BACKSPACE within this sub mode simply decrements the pointer by one i e moves it left while CI has no effect 4 2 4 Tape Commands Text may be saved to tape or loaded from tape using the commands P and 6 Command P n ms The line range defined by n lt x lt m is saved to tape in Hisoft Pascal format under the filename specified by the string s Remember that these arguments may have been set by a previous command Before entering this command make sure that your tape recorder is switched on and in RECORD mode While the text is being saved the message Busy is displayed Command G amp The tape is searched for a file in Hisoft Pascal tape format and with a filename of s While the search is taking place the message Searching will be displayed If a valid Hisoft Pascal tape file is found but has the wrong filename then the message Found followed by the filename that was found on the tape is displayed and the search continued Once the correct filename is found then Found will appear on the list device and the file will be loaded into memory 1f an error is detected during the load then an error message is displayed and the load aborted If this happens you must rewind the tape press PLAY and type 6 again If
22. preserving text 70 HISOFT PASCAL 4TM 1 5 IMPLEMENTATION NOTE 48K ZX SPECTRUM Loading HPATM From Tape Unpack the cassette tape from its case and load it into your cassette recorder with Side A uppermost On your SPECTRUM make sure that you are in Keyword Entry Mode and then enter LOAD press J and then twice Now press PLAY on the tape recorder first a small BASIC loader will be loaded this will execute automatically and proceed to load the HPATM code If a tape error is detected then stop the tape rewind to the start press NEW on the A key on the SPECTRUM and then enter LOAD again If you still get a tape loading error then try adjusting the volume on your tape recorder if errore persist please return the tape to Hisoft and we will replace it Once the HP4TM code has been loaded it will execute automatically and the message Top of RAM will be displayed now consult Section 0 0 of this manual for details of how to proceed Implementation on the SPECTRUM The 2X SPECTRUM is a rather unusual computer and to a certain extent the implementation of Hisoft Pascal reflects this The various control codes discussed in the Programmer s Manual are reached as follows on the SPECTRUM RETURN via the ENTER key cc via CAPS SHIFT and 1 CH DELETE i e CAPS SHIFT and 0 CI via CAPS SHIFT and 8 CP via CAPS SHIFT and 3 enabling L isting of text to printer Cx via CAPS SHIFT and 5 65 via CAPS SHIFT and
23. same type of data She He could do this by VAR A B ARRAYUA C 1 DF INTEGER and now the user can freely assign A to R and vice versa since only one TYPE record has been created Although on the surface this name equivalence approach may seem a little complicated in general 1 leads to fewer pragramming errors since it requires more initial thought from the programmer 20 SECTION 2 PREDEFINED IDENTIFIERS 2 1 CONSTANTS The largest integer available i e 32767 MAXINT TRUE FALSE The constants of type Boolean 2 2 TYFES See Section 1 3 See Section 1 3 The full extended ASCII character set of 256 elements TRUE FALSE This type is used in logical operations including the results of comparisons INTEGER REAL CHAR BOOLEAN 2 3 PROCEDURES AND FUNCTIONS 2 3 1 Input and Output Procedures 2 3 1 1 WRITE The procedure WRITE is used to output data to the screen or printer 3 When the expression to be written is simply of type character then WRITE e passes the B bit value represented by the value of the expression e to the screen or printer as appropriate Note CHR G CTRL H gives a destructive backspace on the screen CHROU2 CTRL L clears the screen or gives a new page on the printer CHR 3 CTRL M performs a carriage return and line feed CHR 6 CTRL F will normally direct output to the printer if the screen is in use or vice versa Generally though WRITE F1 P2
24. the Pascal wil take a while to load roughly 5 minutes Once the Pascal has been loaded it will be executed automatically displaying the Top of RAM message now refer to Section 0 of this manual for further details Implementation on the NewBrain The implementation of Hisoft Pascal on the NewBrain is a fairly standard one with one or two exceptions We shall consider the keyboard video tape and printer separately Keyboard Stream 1 is opened as a KBWIO device 5 stream while stream 2 is assigned as a KBIIO device 4 stream by Hisaft Pascal These streams are used for all input within Hisoft Pascal this means that the NewBrain screen editor is not supported for input The standard contro codes given in Section 0 of this manual are reached as follows on the NewBrain keyboard RETURN is NEW LINE on the NewBrain cc is CTRL C hold CONTROL and C down together CH is the cursor left character lt CI is CTRL I CP used within a program as CHR 14 see below Cx is CTRL X CS reached via the STOP key CTRL A is used to flip CAPS LOCK on and off initially pressing the keys A Z give you the capital letters on the keys as does SHIFT A Z s Use CTRL A once and you are put in a mode where hitting A Z without SHIFT gives you lower case a z while using SHIFT as well gives the capital letters Use CTRL A to return to capitals only mode etc 61 Note that the use
25. the use of dynamic variables and Appendix 7 for an example When specifying elements of multi dimensional arrays the programmer is not forced to use the same form of index specification in the refecence as was used in the declaration e g if variable a is declared as ARRAY 1 10 OF ARRAYLLI 101 OF INTEGER then either a 11 1 or a 1 1 may be used to access element 1 1 of the array 13 FACTOR unsigned constant variahl B function identifie e o3 expression fig t eres rn See EXPRESSION in Section 1 13 and FUNCTIONs in Section 3 for more details 1 11 TERM The lowerbound of a set is always zero and the set size is always the maximum of the base type of the set Thus a SET OF CHAR always occupies 32 bytes a possible 254 elements one bit for each element Similarly a SET OF 0 10 is equivalent to SET OF 0 255 1 12 SIMPLE EXPRESSION 14 The same comments made in Section 1 11 concerning sets apply to simple expressions 1 13 EXPRESSION simple expressior 6900666 When using IN the set attributes are the full range of the type of the simple expression with the exception of integer arguments for which the attributes are taken as if 0 255 had been encountered The above syntax applies when comparing strings of the same length pointers and all scalar types Sets may be compared using gt lt lt gt or Pointers may only be compared using a
26. to the ASCII value of X Examples CHR 49 returns 1 CHR C71 returns T 27 2 3 4 Arithmetic Functions In all the functions within this sub section the parameter X must be of type real or integer 2 3 4 1 ABS X Returns the absolute value of X e g ABS 4 5 gives 4 5 The result is of the same type as X 2 3 4 2 SGR X Returns the value X X i e the square af X The result is of the same type as X 2 5 4 5 SART X Returns the square root of X the returned value is always of type real Maths Call Error is generated if the argument X is negative 2 3 4 4 FRAC X Returns the fractional part of X FRAC X X ENTIER X As with ENTIER this function is useful for writing many fast mathematical routines Examples FRAC 3 returns 0 5 FRAC 12 56 returns 0 44 2 3 4 5 SIN X Returns the sine of X where X is in radians The result is always of type real 2 5 4 6 COSO0 Returns the cosine of X where X is in radians The result is of type real 2 5 4 7 TANX Returns the tangent of X where X is in radians The result is always of type real 28 2 5 4 8 ARCTAN X Returns the angle in radians whose tangent is equal to the number X The result is of type real 2 3 4 9 EXP X Returns the value e X where e 2 71828 The result is always of type real 2 3 4 10 LNOO Returns the natural logarithm i e to the base e of X The result is of type real If X lt O then a Maths Cal
27. various runtime error messages may be generated see Appendix 1 You may suspend a run by using CS subsequently use CC to abort the run or any other key to resume the run SECTION 1 SYNTAX AND SEMANTICS This section details the syntax and the semantics of Hisoft Pascal unless otherwise stated the implementation is as specified in the Pascal User Manual and Report Second Edition Jensen Wirth 1 1 IDENTIFIER Only the first 10 characters of an identifier are treated as significant Identifiers may contain lower or upper case letters Lower case is not converted to upper case so that the identifiers HELLO HEL1o and hello are all different Reserved words and predefined identifiers may only be entered in upper case 1 2 UNSIGNED INTEGER 1 3 UNSIGNED NUMBER unsigned integer Integers have an absolute value less than or equal to 32767 in Hisoft Pascal Larger whole numbers are treated as reals The mantissa of reals is 23 bits in length The accuracy attained using reals is therefore about 7 significant figures Note that accuracy is lost if the result of a 7 calculation is much less than the absolute values of its arguments e g 2 00002 2 does not yield 0 00002 This is due to the inaccuracy involved in representing decimal fractions as binary fractions It does not occur when integers cf moderate size are represented as reals e g 200002 200000 2 exactly The largest real available is 5 4558 while the sma
28. 3 22 33 34 Sa 36 7s 38 35 40 41 42 41 44 45 46 47 48 49 50 51 Hexadecimal digit expected 52 Cannot POKE sets S5 Array too large gt 64K 54 END or 5 expected in RECORD definition 55 Field identifier expected S6 Variable expected after WITH 57 Variable in WITH must be af RECORD type S8 Field identifier has not had asociated WITH statement 59 Unsigned integer expected after LABEL 60 Unsigned integer expected after GOTO 61 This label is at the wrong level 62 Undeclared label 63 The parameter of SIZE should be a variable 64 Can only use equality tests for pointers 67 The only write parameter for integers with two 5 is e m H 68 Strings may not contain end of line characters 69 The parameter of NEW MARK or RELEASE should be a variable of pointer type 70 The parameter of ADDR should be a variable 0 1 2 Runtime Error Messages When a runtime error is detected then one of the following messages will be displayed followed by at PC XXXX where XXXX is the memory location at which the error occurred Often the source of the error will be obvious if not consult the compilation listing to see where in the program the error occurred using XXXX to cross reference Occasionally this does not give the correct result 1 Halt 2 verflow 3 Out of RAM 4 by zero also generated by DIV S Index too low 5 Index too high 7 Maths C
29. 80B RETURN via the CR or ENT key cc via the BREAK key SHIFT and CTRL on the MZ80K and MZ 0A CH via the DEL key giving a destructive backspace CI via the cursor right key CP see below For printer handling cx via the cursor left key CS identical to CC i e the BREAK key The M2Z80K and M280A computers do not support the true ASCII character set in that the lowercase letters are not reached via codes 97 61 to 122 47A inclusive Hisoft Pascal assumes a true ASCII character set and thus must incorporate a conversion routine For the lowercase characters on these computers The result of this is that while using Hisoft Pascal the lowercase letters are reached via the standard ASCII codes 451 to 47A and the SHARP graphics chararters that normally exist at these codes are reached via the SHARP codes of the lowercase letter which is replacing the particular graphic The MZ80B uses true ASCII character set and the above does not apply to it 65 Note that on all SHARP computers you must not use any characters with a code greater than 7F directly within the Pascal text since such a character would be interpreted as a compacted Reserved Word You may of course WRITE codes greater than 7F using CHR e g NRITE CHR 132 One result of the above restriction is that the 3 form of comment is nat supported you should use and instead The repeat key facility of the MZ80A and MZ80B is not available under Hisoft Pascal si
30. E 8 TATA VHT pt 263 deer TAE 6 dst ai CONTENTS PAGE SECTION 0 PRELIMINARIES 1 0 0 Getting Started 1 0 1 Scope of this Manual 4 0 2 Compiling and Running 5 SECTION 1 SYNTAX and SEMANTICS 7 bel IDENTIFIER 7 A UNSIGNED INTEGER 7 1 3 UNSIGNED NUMBER 7 1 4 UNSIGNED CONSTANT 8 1 5 CONSTANT 9 1 6 SIMPLE TYPE 9 1 7 TYPE 10 T4 ARRAYs and SETs 10 12 52 POINTERS 11 1 7 4 RECORDs 11 1 8 FIELD LIST 13 1 9 VARIABLE 13 1 11 TERM 14 1 12 SIMPLE EXPRESSION 14 1 13 EXPRESSION 15 1 14 PARAMETER LIST 15 1 15 STATEMENT 15 1 16 BLOCK 18 1 17 PROGRAM 19 1 18 Strong TYPEing 19 SECTION 2 PREDEFINED IDENTIFIERS 21 21 CONSTANTS 21 2 2 TYPES 21 2 3 PROCEDURES and FUNCTIONS 21 2 3 1 Input and Output Procedures 21 eal ey WRITE 21 2 3 1 2 WRITELN 24 2 3 1 3 PAGE 24 2431 4 READ 24 2 3 1 5 READLN 26 2 3 2 Input Functions 26 2 3 2 41 EOLN 26 2434252 INCH 26 26 26 27 27 27 27 28 28 28 28 28 28 28 28 29 29 29 29 29 29 30 30 30 30 30 31 31 31 32 32 32 32 32 32 32 33 33 35 35 35 Transfer Functions TRUNC X ROUND X ENTIER X ORD X CHR X Arithmetic Functions ABS X SQR X SQRT X FRAC X SIN X COS X TAN X ARCTAN X EXP X LN X Further Predefined Procedures NEW p MARK v1 RELEASE v1 INLINE C1 C2 C3 3 USER V HALT POKE X V TOUT NAME START SIZE TIN NAME START OUT P C Further Predefined Functions RANDOM SUCC X P
31. END N BEGI REPEAT WRITE READLN READ METHOD NUMEER IF METHOD R RFAC NUMBER IFAC NUMBER THEN WRITELN NUMBER ELSE WRITELN NUMBER UNTIL NUMBER 0 59 END 40 50 60 7 80 90 100 110 20 130 140 150 140 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 230 340 350 360 370 380 390 400 410 420 430 440 450 460 470 HISOFT PASCAL IMPLEMENTATION NOTE NEWBRAIN Loading from Tape Turn on your NewBrain connect your tape recorder load the supplied Hisoft Pascal cassette into your tape recorder press PLAY on the recorder and type LOAD on the computers After a while the filename HPAT NewBrain Loader should appear on the screen If this does not happen or if you should subsequently experience difficulty in loading from the tape then stop the tape rewind it to the beginning press STOP on the NewBrain followed by NEW and LOAD again If you repeatedly experience problems then please return the tape to Hisoft for replacement After the Loader has been loaded into the computer the tape will stop and the cursor will appear on the screen now type RUN and the message HP4T Loader c Hisoft 1983 will appear on the screen and the tape will start again the main code of the compiler package is now being loaded Owing to the buffering of the tape data and the relative slowness of the tape interface
32. FE 2 start POKE IBUFE 22 execute USER 421 14251 on the MZ80B write the headers USER 424 13282 on the MZ80B write the datax BD Executing the above program will dump the compiler runtimes and editor to tape use the SHARP monitor LOAD command to reload the package which will autostart with a cold start to the editor To re enter Hisoft Pascal from within the SHARP monitor execute 21218 or 123E on an MZ80B for a cold start and 1221 41241 on an MZSOB For a warm start preserving the text The standard SHARP printer interface routine is included in Hisaft Pascal for the MZ80K and M2Z80A this is accessed via the F option as detailed in Section 3 of this manual or via WRITE CHR 15 which toggles the printer on and off 66 For the MZ80B a parallel printer routine is included within Hisoft Pascal this is suitable for driving an EPSON printer and is accessed in the standard way i e via the P option or through WRITE CHR 15 An extra command is included within the editor for the SHARP computers this is the W command which works like the P command except that it dumps a block of text to tape in a Form which is suitable for inclusion via the compiler option F at a later stage Note that you cannot include text which has been written to tape using the P command if you want to include text then the text must have been saved on tape via the W command We hope that the
33. ISOFT PASCAL PROGRAMS The following programs should be studied carefully if you are in any doubt as to how to program in Hisoft Pascal tFroaram to illustrate the tise of TIN and TOUT The program constructs a very simple telephone directory on tape and then reads it back You should write any searching required FF GFA GM TAFE CONST Size z10 i TYPE Entry RECORD Name ARRAY C1 10 OF CHAR Number ARRAY C1 10 OF CHAR END VAR Directory ARRAY 1 Sizel OF Entry 1 INTEGER EEGIN tSet up the directory 7 FOR I 1 TO Size DO BEGIN WITH DirectorytIJ DO BEGIN WRITE Name please READLN READ Name WRITELN WRITE Number please READLN READ Number WRITELN END END To dump the directory to tape use TOUT Director ADDR Directory SIZE Directory Now to read the array back do the following TINt Director ADDR Directory And now you can process the directory as vou wish 2 END 57 IN reverse order HARE and RULE SE 3 f Ureate linked i st structurel fall pointers to elem do this many times fassign top of heap to heap points to no varaible yet create a new dynamic record tand assign its field to ane character from file this field s pointer adresses previous rcecord scanning the records NIL is first WRITE this field i e character Address previous field Release dynamic variable space Wait
34. RCRCO 5 340 1410 RIGHT 40 1420 END 1430 END 2 SPIRALS 1 PROGRAM SPIRALS 2 VAR 1350 PROCEDURE SPIRALS L ATREAL 1370 BEGIN 1390 POL 1390 RIGHT A 1400 SPIRALS L 1 A 1410 END 1420 BEGIN 1430 TURTLE 1440 SPIRALS 9 95 Cor 9 90 or 9 121 ved 1456 END 3 FLOWER 1 PROGRAM FLOWER 2 WR 1350 PROCEDURE PETAL STREAL j 1371 BEGIN 1380 ARCR S 68 13398 LETU20 1404 ARCR S 68 141 LEFT 12 1128 END 1438 PROCEDURE FLOWER SIREAL 1440 VAR ITINTEGER 1458 BEGIN 1448 FOR 1 21 TO 6 0 1578 BEDIN 1488 PETAL S 1498 RIGHT 6 1500 END 1518 END 1520 BEGIN TURTLE 1533 127 001 1548 LEFT 98 gt PDC 1550 RIGHT 68 PETAL OI2 1560 LEFT 68 PETAL 1 2 3 1570 SETHD 98 FWD A0 1580 FLOMER CE A 1570 END For further extended study of Turtle Graphics we highly recommend the excellent if expensive book Turtle Geometry by Harold Abelson and Andrea di Sessa published by MIT Press 79 HISOFT PASCAL 91 be felle Dackerousgau aud ee tuct fore BFC POKE A3FB CHR 3 ee Neder befel le TOUT QR WR ARC SIE SE C yr ed e CONST fma 6 5 Debt be fel Le MMO Q i Me CG Q Aiue H alle Lope e Let lk go Me AQ fus gt Whe bep auf OD
35. RED X ODD X ADDR V PEEK X T SIZE V INP P COMMENTS and COMPILER OPTIONS Comments Compiler Options 2 3 4 1 2 3 4 2 2 3 4 3 2 3 4 4 2 3 4 5 2 3 4 6 27 2 3 4 8 2 3 4 9 2 3 4 10 RO PSEREN B9 e 3 3 23 3 3 34 Pe 03 2 3 5 8 2 3 5 9 2 3 5 10 2 3 6 3 1 3 2 SECTION 39 39 40 40 40 4 43 44 44 45 47 47 48 49 49 49 49 51 51 51 51 51 53 53 533 54 57 61 81 THE INTEGRAL EDITOR Introduction to the Editor The Editor Commands Text Insertion Text Listing Text Editing Tape Commands Compiling and Running from the Editor Other Commands An Example of the Use of the Editor ERRORS Error numbers generated by the compiler Runtime Error Messages RESERVED WORDS and PREDEFINED IDENTIFIERS Reserved Words Special Symbols Predefined Identifiers DATA REPRESENTATION and STORAGE Data Representation Integers Characters Booleans and other Scalars Reals Records and Arrays Sets Pointers Variable Storage at Runtime SOME EXAMPLE HISOFT PASCAL PROGRAMS IMPLEMENTATION NOTES ETC SECTION 4 4 1 4 2 APPENDIX 1 A 1 1 A 1 2 APPENDIX 2 A 2 1 A 2 2 A 2 3 APPENDIX 3 3 1 APPENDIX 4 on BIBLIOGRAPHY SECTION O PRELIMINARIES 0 0 Getting Started Congratulations You are now the owner of an almost complete implementation of the Standard Pascal programming language Hisoft Pascal is a very powerful tool that ena
36. RIES IMPLEMENTATION NOTE Loading the Compiler from Tape Unpack the supplied cassette and load it into your tape recorder with the label marked Verison 5 MZ 7 64K facing upwards Now from within the monitor program of the M1700 press the L key and then the CR key and then press PLAY on your tape recorder After a while the message LOADING HP4T15MZ2 7 should appear on the screen if this does not happen or if you experience any further tape loading problems then please return the tape to your dealer for replacement After roughly two and a half minutes the package will have loaded into the computer and it will then auto execute and produce the message Top of RAM now refer to Section 0 of the Hisoft Pascal Programmer s manual for details of how to answer this and subsequent configuration questions Note that in most cases simply pressing CR in answer to these questions will suffice Implementation on the SHARP 742700 series The implementation of Hisoft Pascal on the SHARP M1700 series is fairly straightforward and more Powerful than most other implementations The full 64K RAM of the computer is utilised by paging the extra memory in and put as necessary this gives a total of roughly 40K for user programs The various control codes discussed and used in this manual are reached as follows on the M1700 RETURN Via the CR Ley on the MZ700 cc z via CTRL C i hold the CTRL key and the letter C key down together
37. TRUE 120 IF NumbertI3J gt Numbert1 13 THEN 130 EEGIN 140 Temp NumbertI1 150 NumbertI12J Numbert1 123 160 NumbertI 12J Temps 170 Noswaps FALSE 180 END 190 UNTIL Noswapss 200 FOR I 1 TO Size DO WUWRITE NumbertI21 4 17 END This program has a number of errors which are as follows Line 10 Missing semi colon Line 30 Not really an error but say we want a size of 100 Line 100 Size should be Size l Line 110 This should be at line 95 instead Line 190 Noswapss should be Noswaps Also the variable Numbers has been declared but all references are to Number Finally the BOOLEAN variable Noswaps has not been declared To put all this right we can proceed as follows F50 200 Number Numbera and then use the sub command S repeatedly E10 then the sequence X ENTER lt ENTER gt ESO then K C 1 lt ENTER gt lt ENTER gt F100 100 8ize Size 1 followed by the sub command S M110 93 110 followed by ENTER E190 then X DELETE lt ENTER gt lt ENTER gt 65 Noswaps BOOLEAN N10 10 to renumber in steps af 10 You are strongly recommended to work through the above example actually using the editor 46 APPENDIX 1 ERRORS A 1 1 Error numbers generated by the compiler 1 Number too large Semi colon or END expected Undeclared identifier Identifier expected Use not in a constant declaration expected This identifier cannot begin a statement
38. above information will enable you to make the most of Hisoft Pascal on your SHARP computer Please do not hesitate to contact us if you experience any difficulties we can only put your problems right if you tell us about them PARALLEL PRINTER DRIVER FOR HISOFT PASCAL UNDER SHARP MZ80K AND M180A The following gives details of incorporating a parallel printer driver routine into Hisoft Pascal on the SHARP M280K and MZ80A computers The driver routine assumes that a standard SHARP extension card using ports FE and FF for the printer has been fitted and that the printer being driven is compatible with the EPSON MX80 series of printers To incorporate the routine proceed as follows 1 Load Hisoft Pascal into your machine and enter the editor 2 Enter the following Pascal program using the I command PROGRAM Enterhex CONST Max 50j VAR I INTEGER A f ARRAYE1 Max DF CHAR FUNCTION Hex CHAR READICH Ti 0RD CH IF CH IN 0 9 TIEN I 1 48 ELSE IF CH IN L A F J THEN I 1 5 ELSE IF CH IN 2 f 2 THEN 121 87 ELSE 1120 1 1 1 END Hext OR BO z BEGIN FOR 1 21 TO Max DO AI Hex FOR 11 1 TO Max DO 9 POKE 1273 1 ACTI POKECH 253 0 POKE 1257 CHRD POKE 1284 CHR 1Z END Remember to use the hash symbol SHIFT 3 and not tne sign when specifying hexadecimal numbers within Hisoft Pascal programs on the SHARP computers Having typed in the above program compile and run i
39. all Error B Number too large 9 Number expected 10 Line too long 11 Exponent expected Runtime errors result in the program execution being halted 48 APPENDIX 2 RESERVED WORDS AND PREDEFINED IDENTIFIERS A 2 1 Reserved Words AND ARRAY BEGIN CASE CONSI iv DO DOWNTO ELSE END FORWARD FUNCTION GOTO IF IN LABEL HOD NIL NOT OF OR PACKED PROCEDURE PROGRAM RECORD REPEAT SET CHEN TU FYFE UNTIL VAR WHILE WITH A 2 2 Special Symbols The following symbols are used by Hisoft Pascal and have a reserved meaning u vg ee v 2 A 2 3 Predefined Identifiers The following entities may be thought of a declared in a block surrounding the whole program and they are therefore available throughout the program unless re defined by the programmer within an inner block For further information see Section 2 CONST MAXINT 32767 TYPE BOOLEAN FALSE TRUE e CHAR The expanded ASCII character set INTEGER MAXINT MAXINT REAL lt A subset of the real numbers See Section 1 3 5 PROCEDURE WRITE WRITELN READ READLN PAGE HALT USER POKE INLINE OUT NEW MARK RELEASE TIN TOUT FUNCTION ABS SOR ODD RANDOM ORD SUCC PRED INCH EOLN PEEK CHR SQRT ENTIER ROUND TRUNC FRAC SIN COS TAN ARCTAN EXP LN ADDR SIZE INP 49 APPENDIX DATA REPRESENTATION AND STORAGE Data Representation 3 1 The following discussion details how data is represented internally b
40. bles you to build highly structured and easy to understand programs However as with any computer language it is going to take you some time to get used to using Hisoft Pascal We strongly recommend that you adopt the following procedure when using this package for the first time read the rest of this Section very carefully trying out the example programs until you understand how they are created compiled and executed read the Implementation Note for your computer these are found at the back of the manual and are colour coded and then read it again now read the editor section of this manual Section 4 and try out the example at the end of the Section go through the above steps until you feel comfortable using the editor and compiling running 3 Pascal program 1f you come to a complete halt in understanding what is happening leave the computer and do something else for a while and then return and start from scratch it is easy to get confused when operating in a new environment if you are convinced that your problems are not of your own making then please do not hesitate to contact Hisoft our staff are always willing to answer any genuine questions regarding our products Now read on Hisoft Pascal HP is a fast easy to use and powerful version of the Pascal language as specified in the Pascal User Manual and Report Jensen Wirth Second Edition Omissions from this specification are as follows
41. comment starts with a U character or the character pair Unless the next character is a all characters are ignored until the next Y character or character pair If a was found then the compiler looks for a series of compiler options see below after which characters are skipped until a Y or is found 7 2 Compiler Options Compiler options are included in the program between comment brackets and are the first option in the list is prefaced by a dollar symbol Example C A to turn keyboard and array checks OFF The following options are available Option L Controls the listing of the program text and object code address by the compiler If L then a full listing is given 1f L then lines are only listed when an error is detected DEFAULT L Option O Controls whether certain overflow checks are made Integer multiply and divide and all realarithmetic operations are always checked for over flow If 0 then checks are made on integer addition and subtraction If O then the above checks are not made DEFAULT 0 Option C Controls whether or not keyboard checks are made during object code program execution If C then if CC is pressed then execution will return to with a HALT message see Section 2 5 5 6 This check is made at the beginning of all loops procedures and functions Thus the user may use this facility to detect which loop etc is not terminating correctly during t
42. d of loading Hisoft Pascal into your computer varies depending on your machine your Implementation Note gives details in general typing LOAD will suffice but please check your Implementation Note first When the compiler has been successfully loaded it will execute automatically and produce the message Top of RAM You should respond to this by either entering a positive decimal number up to 65536 followed by ENTER or by hitting ENTER Note that we refer to the ENTER key here on some systems this is the CR or NEWLINE or RETURN key 0 If you enter a number then this is taken to represent the highest RAM location 1 otherwise the first non RAM location is automatically computed The compiler s stack is set to this value and thus you can reserve high memory locations perhaps for extensions to the compiler by deliberately giving a value less than the true top of RAM In the ZX Spectrum version of Hisoft Pascal the true top of RAM is taken to be the start of the user defined graphics area UDG in the Sinclair manual You will now be prompted with Top of RAM for T Here you can enter a decimal number or default to the Top of RAM value previously specified What you enter will be taken as the stack when the resultant object code is executed after using the editor T command See Section 4 for details You will need to define a runtime stack different from the top of RAM if for example you have written extensions to the ru
43. e as described above For the examples given below all you have to do here is press the ENTER CR NEWLINE etc key for each of the 5 questions TOF OF RAM TOP OF RAM FOR T and TABLE SIZE Now the Pascal s editor will be in charge letting vou know that it s there by the gt prompt Let s type the following 110 10 lt ENTER gt you should now be prompted with the number 10 this is a line number and what you subsequently type will be entered into the Pascal textfile at line 10 typing ENTER will terminate the line and then you will be prompted with line number 20 and so on You can continue to enter text like this with the line numbers being generated automatically for you until you enter the special CC code see your Implementation Note On the ZX Spectrum CC is CAPS SHIFT 1 So type the following program remembering that you do not need to type in the line numbers 1 PROGRAM HELLO TO CGIN 20 WRITELNC HELLO WORLD 47 END SO Cr Remember CC is a special abort code CAPS SHIFT 1 on the Spectrum Right to compile this program type C ENTER You should see a listing of you program appear with some extra numbers at the front this is a compiler listing If the program compiles correctly the message Run will appear answer Y to this question and the program will run and print out HELLO WORLD and return to the editor You can now run the program again by R ENTER If your program did not c
44. e direction by A degrees LEFT AREAL this is identical to TURN and is provided simply for convenience and compatibility with RIGHT ARCR RIREAL A INTEGER the turtle moves through an arc af a circle whose size is set by R The length of the arc is determined by A the angle turned through subtended at the centre of the circle in a clockwise direction Typically R may be set to 0 5 TURTLE this procedure simply sets the initial state of the turtle it is placed in the middle of the screen facing EAST heading of 0 on a blue backgound paper and leaving a yellow trail Remember that the state of the turtle is not initially defined so that this procedure is often used at the beginning of a program This concludes the list of facilities available with Hisoft Pascal TURTLE although simple in implementation and use you will find that Turtle Graphics are capable af prducing very complex designs at high speed To give you a taste of this we present some example programs below Remember that you must have Hisoft Pascal loaded before entering the programs Example Programs In all the example programs given below we assume that you have already loaded Hisoft Pascal and used G TURTLE to load the Turtle Graphics package which starts at line 10 and finishes at line 1350 Now proceed with the examples 1 CIRCLES 1 PROGRAM CIRCLES 2 VAR TITINTERER 1344 BEGIN 1378 TURTLE 1380 FOR 12 1 TO 9 DO 1390 BEGIN 1400 A
45. eld width of m see above Examples WRITE 1E 2 6 2 gives 120 00 WRITE GE2 8 2 gives 100 00 WRITE 23 455 6 1 gives 23 5 WRITE 23 455 4 2 gives 2 34550E 01 WRITEC2ZS 455 4 0 gives 23 41e is of type character or type string Either e or lt e m gt may be used and the character or string of characters will be output in a minimum field width of 1 for characters or the length of the string for string types Leading spaces are insertedif m is sufficiently large Sle is of type Boolean Either e or e m gt may be used and TRUE or FALSE will be output depending on the Boolean value of e using a minimum field width 4 or 5respectively s D 2 3 1 2 WRITELN WRITELN outputs gives a newline This is equivalent to WRITE CHR 13 Note that a linefeed is inciuded WRITELN P1 P2 P3 is equivalent to BEGIN WRITE P1 P2 PS WRITELN END 2 5 1 3 PAGE The procedure PAGE is equivalent to WRITE CHR 12 and causes the video screen to be cleared oc the printer to advance to the top of 3 new page 2 3 1 4 READ The procedure READ is used to access data from the keyboard It does this through a buffer held within the runtimes this buffer 15 initially empty except for an end of line marker We can consider that any accesses to this buffer take place through a text window over the buffer through which we can see one character at a time If this text window is positioned
46. ers in the computer Weil firstly we reserve 4 bytes of storage for each real in the following format data 23 22 0 7 0 bit H L E D register sign the sign of the mantissa 1 negative 0 positive normalised mantissa the mantissa normalised to the form 1 xxxxxx with the top bit bit 22 always 1 except when representing zero HL 0 DE 0 exponent the exponent in binary 25 complement form Thus 2 o 1600000 OOOOOOOO OOOOOO000 0060001 40 00 HOO 8O1 1 D 1000000 OOOOOO0O00 OOOCOOQOGO OGQOQOOQOCQO 40 00 00 00 12 5 11 1100100 G0000000 OOOO00000 00000011 HEG 00 00 03 O 1 0 211001160 01100110 011001190 11111100 HAG 455 445 RFC 32 So remembering that HL and DE are used to hold real numbers then we would have to load the registers in the following way to represent each of the above numbers 2 LD HL 4000 LD DE 010 1 LD HL 4000 LD DE 0000 12 5 L D HL E400 LD DE 0300 0 1 LD HL 6666 LD DE FC44 The last example shows why calculations involving binary fractions can be inaccurate 0 1 cannot be accurately represented as a binary fraction to a finite number of decimal places N B Reals are stored in memory in the order ED LH A 3 1 4 Records and Arrays Records use the same amount of storage as the total of their components Arrays if n number of elements in the array and s size of each element then the number
47. f type character Note that you should always disable keyboard checks when using INCH i e always specify compiler option C 2 3 2 Transfer Functions 2 3 3 1 TRUNCOO The parameter X must be of type real or integer and the value returned by TRUNC is the greatest integer less than or equal to X if X is positive or the least integer greater than or equal to X if X is negative Examples TRUNC 1 5 returns 1 TRUNCU 9 returns 1 26 2 3 3 2 ROUND X X must be of type real or integer and the function returns the nearest integer to X according to standard rounding rules Examples ROUND 6 5 returns 6 ROUND 11 7 returns 12 ROUND 6 51 returns 7 ROUND 23 5 returns 24 2 3 3 3 ENTIER X X must be of type real or integer ENTIER returns the greatest integer less than or equal to X for all X Examples ENTIER 4 5 returns 7 ENTIER 11 7 returns 11 Note ENTIER is not a Standard Pascal function but is the equivalent of BASIC s INT It is useful when writing fast routines for many mathematical applications 2 3 3 4 DRD OO X may be of any scalar type except real The value returned is an integer representing the ordinal number of the value of X within the set defining the type of X If X is of type integer then ORD OO gt X this should normally be avoided Examples ORDCa returns 7 DRD C amp returns 64 2 3 3 5 CHR X X must be of type integer CHR returns a character value corresponding
48. he debugging process It should certainly be disabled if you wish the object program to run quickly If C then the above check is not made DEFAULT C Option S Controls whether or not stack shecks are made If 5 then at the beginning of each pracedure and function call a check is made to see if the stack will probably overflow in this block If the runtime stack overflows the dynamic variable heap or the program then the message Out of RAM at PC XXXX is displayed and execution aborted Naturally this is not foolproof if a procedure has a large amount of stack usage within itself then the program may crash Alternatively if a function contains very little stack usage while utilising recursion then it is possible for the function to be halted unnecessarily If S then no stack checks are per formed DEFAULT 5 Option A Controls whether checks are made to ensure that array indices are within the bounds specified in the array s declaration If A and an array index is too high or too low then the message Index too high or Index too low will be displayed and the program execution halted If A then no such checks are made DEFAULT A Option I When using 16 bit 2 s complement integer arithmetic overflow occurs when performing a gt lt gt or lt operation if the arguments differ by more than MAXINT 32747 If this occurs then the result of the comparison will be incorrect This will not
49. he following format C N1 N2 S1 52 followed by ENTER where C is the command to be executed see Section 4 2 below Ni is a number in the range 1 32767 inclusive N2 isa number in the range 1 32767 inclusive Si is a string of characters with a maximum length of 20 52 is a string of characters with a maximum length of 20 The comma is used to separate the various arguments although this can be changed see the S command and spaces are ignored except within the strings None of the arguments are mandatory although some of the commands e g the D elete command will not proceed without N1 and N2 being specified The editor remembers the previous numbers and strings that you entered and uses these farmer values where applicable if you do not specify a particular argument within the command line The values of N1 and N2 are initially set to 10 and the strings are initially empty 1 you enter an illegal command line such as F 1 100 HELLO then the line will be ignored and the message Pardon displayed you should then retype the line correctly e g F1 100 HELLO This error message will also be displayed if the length of S2 exceeds 20 1f the length of 51 is greater than 20 then any excess characters are ignored Commands may be entered in upper or lower case While entering a command line all the relevant control functions described in Section 0 0 may be used e g CX to delete to the beginning of the line T
50. he following sub section details the various commands available within the editor note that wherever an argument is enclosed by the symbols lt gt then that argument must be present for the command to proceed 4 2 The Editor Commands 4 2 1 Text Insertion Text may be inserted into the textfile either by typing a line number a space and then the required text or by use of the Tl command Note that if you type a line number followed by ENTER i e without any text then that line will be deleted from the text if it exists Whenever text is being entered then the control functions CX delete to the beginning of the line CI go to the next tab position CC return to the command loop and CP toggle the printer may be employed The DELETE tor BACKSPACE key will produce a destructive backspace but not beyond the beginning of the text line Text 1s entered into an internal buffer within Hisoft Pascal and 1f this buffer should become full then you will be prevented from entering any more text you must then use DELETE or CX to free space in the buffer Command I nym Use of this command gains entry to the automatic insert modes you are prompted with line numbers starting at n and incrementing in steps of m You enter the required text after the displayed line number using the various control codes if desired and terminating the text line with ENTER To exit from this mode use the control function CC see Section 0 0 and
51. he particular features of Hisoft Pascal Section 1 gives the syntax and the semantics expected by the compiler Section 2 details the various predefined identifiers that are available within Hisoft Pascal from CONSTants to FUNCTIONS E Section 3 contains information on the various compiler options available and also on the format of comments Section 4 shows how to use the line editor which is an integral part of Hisoft Pascal The above Sections should be read carefully by all users Appendix 1 details the error messages generated both by the compiler and the runtimes Appendix 2 lists the predefined identifiers and reserved words Appendix 5 gives details on the internal representation of data within Hisoft Pascal useful for programmers who wish to get their hands dirty Appendix 4 gives some example Pascal programs study this if you experience any problems in writing Hisoft Pascal programs 0 2 Compiling and Running For details of how to create amend compile and run an HF program using the integral line editor see Section 4 of this manual Once it has been invoked the compiler generates a listing of the form xxxx nnnn text of source line where xxxx is the address where the code generated by this line begins nnnn is the line number with leading zeroes suppressed If a line contains more than 80 characters then the compiler inserts new line characters so that the length of a line is never more than 80 characte
52. hics program segment and append it to any existing program note that in order Far it to Function correctly the Turtle Graphics must be preceded by a normal PROGRAM heading and a VAR declaration TYPE CONST and LABEL declarations are optional and there must be no Procedures or Functions declared previous to the inclusion of the Turtle Graphics package As in the majority oF Turtle Graphics implementations Hisoft Pascal s TURTLE creates an imaginary creature on the screen which the user can move around via same very simple commands This turtle can be made to leave a trail in varying colours or can be made invisible The turtle s heading and position are held in global variables which are updated when the creature is moved or turned obviously these variables can be inspected or changed at any time The facilities available are as Follaws Global Variables HEADING this is used to hold the angular value of the direction in which the turtle is currently Facing It takes any REAL value in degrees and may be initialised ta 0 with the procedure TURTLE see below The value 0 corresponds ta an EASTerly direction so that after a call to the procedure TURTLE the turtle is Facing left to right As the heading increases Fram rera then the turtle turns in an anti clockwise direction XCOR YCOR these are the current x y REAL co ordinates of the turtle on the screen The SPECTRUM graphics screen has a size of 254 174 pixels and the tu
53. his procedure allows ZBO machine code to be inserted within the Fascal program the values C1 MOD 255 C2 MOD 256 C3 MOD 256 s are inserted in the object program at the current location counter address held by the compiler Ci C2 C3 etc are integer constants of which there can be any number Refer to Appendix 4 for an example of the use of INLINE 2 3 5 5 USER V USER is a procedure with one integer argument V The procedure causes a call to be made to the memory address given by V Since Hisoft Pascal holds integers in two s complement form see Appendix 3 then in order to refer to addresses greater than 7FFF 32767 negative values of V must be used For example 4COOO is 16384 and so USER 16384 would invoke a a call to the memory address WCOOO However when using a constant to refer to a memory address it is more convenient to use hexadecimal The routine called should finish with a ZBO RET instruction C9 and must preserve the IX register 2 3 9 6 HALT This procedure causes program execution to stop with the message Halt at PC XXXX where XXXX is the hexadecimal memory address of the location where the HALT was issued Together with a compilation listing HALT may be used to determine which of two or more paths through a program are taken This will normally be used during de bugging 2 3 5 7 POKE X V POKE stores the expression V in the comouter s memory starting from the memory address X X is of tvpe integer
54. ill be placed at AFF9 AFFA AFFB and AFFC Local variables Local variables cannot be accessed via the stack very easily so instead the IX register is set up at the beginning of each inner block so that IX 4 points to the start of the block s local variables e g FROCEDURE test VAR i j INTEGER then i integer so 2 bytes will be placed at IX 4 2 and IX 4 1 i e IX 6 and 17 5 J will be placed at 17 8 and IX 7 534 Parameters and returned values Value parameters are treated like local variables and like these variables the earlier a parameter is declared the higher address it has in memory However unlike variables the lowest not the highest address is fixed and this is fixed at IX 2 e g PROCEDURE testG REAL j INTEGER then j allocated first is at IX 2 and IX 3 i is at IX 4 IX 5 IX 6 and 1 7 Variable parameters are treated just like value parameters except that they are always allocated 2 bytes and these 2 bytes contain the address of the variable e g PROCEDURE test i INTEGER VAR x REAL then the reference to x is placed at IX 2 and IX 3 these locations contain the address where x is stored The value of i is at IX 4 and IX 5 Returned values of functions are placed above the first parameter in memory e g FUNCTION testi INTEGER REAL then i is at IX 2 and IX 3 and space is reserved for the returned value at IX 4 IX 5 IX and 1 7 55 APPENDIX 4 SOME EXAMPLE H
55. ing a certain number of lines the list will pause if not yet at line number m hit control function CC to return to the main editor loop or any other key to continue the listing 40 Command K n K sets the number of screen lines to be listed to the display device before the display is paused as described in L above The value n MOD 255 is computed and stored For example use KS if you wish a subsequent List to produce five screen lines at a time 4 2 3 Text Editing Once some text has been created there will inevitably be a need to edit some lines Various commands are provided to enable lines to be amended deleted moved and renumbered Command D n m All lines from n to m inclusive are deleted from the textfile If m n or less than two arguments are specified then no action will be taken this is to help prevent careless mistakes A single line may be deleted by making m n this can also be accomplished by simply typing the line number followed by ENTER Command M n m This causes the text at line n to be entered at line m deleting any text that already exists there Note that line n is left alone Sa this command allows you to M ove a line of text to another position within the textfile If line number n does not exist then no action is taken Command N lt n m gt Use of the N command causes the textfile to be renumbered with a first line number of n and in line number steps of m Both n and m m
56. l Error will be generated 2 3 5 Further Predefined Procedures 2 3 5 1 NEW p The procedure NEW p allocates space for a dynamic variable The variable p is a pointer variable and after NEW p has been executed p contains the address of the newly allocated dynamic variable The type of the dynamic variable is the same as the type of the pointer variable p and this can be of any type To access the dynamic variable p is used see Appendix 4 for an example of the use of pointers to reference dynamic variables To re allocate space used for dynamic variables use the procedures MARK and RELEASE see below 2 3 5 2 MARK v1 This procedure saves the state of the dynamic variable heap to be saved in the pointer variable vl The state of the heap may be restored to that when the procedure MARK was executed by using the procedure RELEASE see below The type of variable to which vi points is irrelevant since v1 should only be used with MARK and RELEASE never NEW For an example program using MARK and RELEASE see Appendix 4 29 2 3 5 3 RELEASE v1 This procedure frees space on the heap for use of dynamic variables The state of the heap is restored to its state when MARK v1 was executed thus effectively destroving all dynamic variables created since the execution of the MARK procedure and as such it should be used with great care See above and Appendix 4 for more details 2 3 8 4 INLINE CI C2 C3 T
57. llest is 3 9E 59 There is no point in using more than 7 digits in the mantissa when specifying reals since extra digits are ignored except for their place value When accuracy is important avoid leading zeroes since these count as one of the digits Thus 0 000123456 is represented less accurately than 1 23455E 4 Hexadecimal numbers are available for programmers to specify memory addresses for assembly language linkage inter alia Note that there must be at least one hexadecimal digit present after the K otherwise an error ERROR 51 will be generated 1 4 UNSIGNED CONSTANT constant identifier Note that strings may not contain more than 255 characters String types are ARRAY L 1 N OF CHAR where N is an integer between 1 and 255 inclusive Literal strings should not contain end of line characters CHR 3 if they do then an ERROR 68 is generated The characters available are the full expanded set of ASCII values with 254 elements To maintain compatibility with Standard Pascal the null character is not represented as instead CHR O should be used 1 5 CONSTANT constant identifier 2 The non standard CHR construct is provided here so that constants may be used for control characters In this case the constant in parentheses must be of type integer E g CONST bs CHR 8 cr CHR 3S3 1 6 SIMPLE TYPE type identifier Scalar enumerated types identifier identifier may not have m
58. ly access the ZBO s putput ports without using the procedure INLINE The value of the integer parameter P is loaded in to the BC register the character parameter C is loaded in to the A register and the assembly instruction QUT C 6 is executed E g OUT 1 A outputs the character A to the 2890 port 1 2 3 6 Further Predefined Functions 2 3 4 1 RANDOM This returns a pseudo random number between and 255 inclusive Although this routine is very fast t gives poor results when used repeatedly within loops that do not contain 1 0 operations If the user requires better results than this function yields then he she should write a routine either in Pascal or machine code tailored to the particular application 2 3 5 2 NI ICCOO X may be of any scalar type except real and SUCC X returns the successor of X Examples SUGCCCA returns B SUCC S returns amp 2 3 6 3 FRED X X may be of any scalar type except real the result of the function is the predecessor of X Examples PRED Cj3 returns i PRED TRUE returns FALSE 2 3 6 4 ODD X X must be of type integer ODD returns a Boolean result which is TRUE if X is odd and FALSE if X 15 even 2 3 6 6 ADDR V his function takes a variable identifier of any type as a parameter and returns an integer result which is the memory address of the variable identifier V For information on how variables are held at runtime within Hisoft Pascal see Appendix 3 For an e
59. ly plots the point X Y ON or OFF depending on whether the first parameter is TRUE or FALSE PROCEDURE PLOT ON BOOLEAN X Y INTEGER BEGIN IF ON THEN WRITE CHR 21 CHR O ELSE WRITE CHR 21 CHR L IMTEGFD 21 FA EXC CID IY SCA 3 00 H 2 40 ME 4 LO B UD42 LD C CXe 2 0 HES 122 gt CALL 225 ROM PLOT routine END Called by the LINE procedure LIMEL is used to pass the correct arguments to the DRAW routine in the SPECTRUM ROM PROCEDURE LINEL X SX SY INTEGER BEGIN IWED 21 FA 50 uw MCA 100 54 2 00 Fx 4 CIN 0 042 iD E XH D 00 144 6 HO VE B CW B OXC6 lO C UDX48 2 KD FA 24 gt CALL PEA ROM ORAH routine BD LINE draws a line from the current plot position x y ta Xx 4 The line may be on or off depending on the value of the BOOLEAN parameter ON PROCEDURE LINE ON t BOOLEAN X Y INTEGER VAR SGX SGNY INTEGER BEGIN TF ON THEN WRITE CHR 21 CHR O ELSE WRITE CHRU21 CHR L IF X48 THEN SGNXi 1 ELSE SGAXi 1 The DRAW routine that is to be called IF 48 THEN SGNY 1 ELSE 5801121 within LINEL needs tne absolute values Cof X ard Y and their signs 1761 ABS X ABS Y SEX SONY Plot the line 20 n Exarele of the use of PLOT and LINE PLOT ON 50 50 07 LIMECON 180 50 draws a line from 50 50 to 150 0 3 Output through the ROM There are occasions where it is useful to output directly th
60. ly through the TVIO device and not through a Pascal WRITE LN statement We give below a Pascal procedure that takes an integer as a parameter and outputs its CHR value directly ta stream 0 PROCEDURE CHAROUT I INTEGER BESIN THLINE 4D0 PE 902 HFS KD 75 19 KE 41B HE 00 467 KI FL 67 499 400 825 19 END Note that the routine at address 1975 must be called before any attempt is made to access the NewBrain operating system and the routine at 1926 must be subsequently called before returning ta Hisoft Pascal Tape Stream 3 is opened as a TAPE device 1 stream by Hisoft Pascal 4T The buffer size allocated is 600 ive 5 units this may be changed by POKEing location 19FA with the required size in 254 byte units Note that you should not allocate such a large buffer size that would corrupt the compiler which starts at 0 52 Printer Owing to the range of different printers that may be attached to the NewBrain Hisaft Pascal makes na assumptions as to the type of printer available Instead it is simply assumed that the user has already opened the relevant printer driver on stream 4 before entering the package Thus stream 4 is used by the Pascal as the printer stream this stream is not opened or closed by Hisaft Pascal Compiler listings may be sent to the printer by using the P option see Section 3 2 of this manual Runtime output may be directed to the printer by using WRITE CHR 14 all subsequent outpu
61. nce it is handled within the line input routine of the monitor and Hisoft Pascal handles characters not lines at a time The SFTLOCK and GRPH key of the MZ80B are supported Any return ta the SHARP monitor from within the compiler or runtimes requires you first ta hit any key an the keyboard this is so that runtime error messages etc may be inspected a direct return ta the monitor clears the screen Note that all data recorded on tape is in SHARP tape format and not in Hisoft Pascal Format this is because of the software tape interface used by the SHARP computers This means that there is na loader for the compiler or object code files you simply use the relevant LOAD command of the monitor ta reload object code dumped to tape via Translate On the MZ80K and MZ80A the Hisoft Pascal package resides From location 1200 while on the MZ80B it starts at 1220 The end address of the package may be ascertained through use of the editor s X command Ta make a copy of the package on tape you could use a Pascal program such as this PROGRAM save CONST 5tart 11200 181220 for the MZB BX finish 45E00 ascertain this from the X comands TEUFE 410F 0 x L0C0 on the HZBOEX execute 1121E 4123 on the M8081 namez HPATZ tor whatever you wisht BEGIN POKECIRFE CHR B0 set up the header buffert PIKE IRFEH nane f POKE IBUFE 4 CHR 13 depends on the length of name a POKECIBFE H8 f inish start POKE IBU
62. nd lt gt 1 14 PARAMETER LIST EO amin r E o tae 3 A type identifier must be used following the colon otherwise ERROR 44 will result Variable parameters as well as value parameters are fully supported Procedures and functions are not valid as parameters 1 15 STATEMENT Refer to the syntax diagram on page 17 Assignment statements See Section 1 7 for information on which assignment statements are illegal When assigning to subrange variables the value is not checked for being within the subrange for efficiency reasons 15 CASE statements An entirely null case list is not allowed i e CASE OF END will generate an error ERROR L3 The ELSE clause which is an alternative to END is executed if the selector Cexpression overleaf is not found in one of the case lists constant overleaf If the END terminator is used and the selector is not found then control is passed ta the statement following the END FOR statements The control variable of a FOR statement may only be an unstructured variable not a parameter This is half way between the Jensen Wirth and draft ISO standard definitions GOTO statements It is only possible to GOTO a label which is present in the same block as the GOTO statement and at the same level You may not use GOTO to jump out of a FOR statement Labels must be declared using the Reserved Word LABEL in the block in which they are used a label consi
63. ntimes and wish to place them safely in high memory locations Finally you will be asked Table size What you enter here specifies the amount of memory to be allocated to the compiler s symbol table Again either enter a positive decimal number followed by ENTER or simply ENTER by itself in which case a default value of available RAM divided by 15 will be taken as the symbol table size In nearly all cases the default value provides more than enough space for symbols The symbol table may not extend above machine address 8000 32768 decimal If you specify so large a value that that this happens then you will be prompted again for Top of RAM etc At this point the compiler and integral editor will be relocated at the end of the symbol 2 table and execution transferred to the editor To whet your appetite and to give you a tee for the pack ege we now give an example of using the editor and compiler to create compile and run e small Pascal program Firstly let s load the Pascal into the computer take the tape supplied put it into your tape recorder with the side labelled Hisoft Pascal uppermost ad rewind the tape to the beginning Now refer to the Implementation Note at the back of the manual to see how to load the Pascal into your machine on the ZX SPECTRUM you just type LOAD and press ENTER Once the Pascal has been loaded into the computer it will automatically run itself and produce the Top of RAM messag
64. of CTRL O ta CTRL 9 to change the character set generated by the keyboard is not supported fram within the Hisoft Pascal editor in practice this is not a restriction since the case in which it is most useful is ta generate characters whose ASCII value is greater than 127 these characters should never be included in a Pascal program since the editor would try to treat them as Reserved Words Instead you should use CHR to WRITE these characters eig WRITE CHR 236 to generate in character set 2 C and Y are reached via GRAPHICS and GRAPHICS respectively within character sets 1 and 2 Video Stream 0 is opened as a TVIO device 0 stream but is only used For output Initially the videa is configured as 40 characters by 24 lines this may be changed to 80 characters by 24 lines through use of an extra editor command the W command Using W flips between a screen width of 40 and 80 characters From within a Pascal pragram most characters are passed straight through ta the video driver thus enabling the range of control sequences supported by the TVIO device to be maintained However 3 character values are trapped and interpreted by Hisoft Pascal these are CHR 8 which is changed internally ta CHR 24 far backspace CHR 12 which is converted to CHR 31 for clear screen and CHR 15 which is used to flip the printer stream see below on and off IF you wish ta output any of these character values then they must be output direct
65. of ensuring that the user does not use an element of data in a manner which is inconsistent with its definition At one end of the scale there is machine code where no checks whatever are made on the TYPE of variable being referenced Next we have a language like the Byte Tiny Pascal in which character integer and Boolean data may be freely mixed without generating errors Further up the scale comes BASIC which distinguishes between numbers and strings and sometimes between integers and reals perhaps using the 7 sign to denote integers Then comes Pascal which goes as far as allowing distinct user enumerated types At the top of the scale at present is a language like ADA in which one can define different incompatible numeric types There are basically two approaches used by Pascal implementations to strength of typing structural equivalence or name equivalence Hisoft Pascal uses name equivalence for RECORDs and ARRAYs The consequences of this are clarified in Section 1 7 et al let it suffice to give an example here say two variables are defined as follows VAR A ARRAYE A C 1 OF INTEGER E ARRAVYLE A C 1 OF INTEGER 19 then one might be tempted to think that one could write A B but this would generate an error ERROR 10 under Hisoft Pascal since two separate TYPE records have been created by the above definitions In other words the user has not taken the decision that 8 and B should represent the
66. ompile correctly and produced an ERROR message then press E followed by lt ENTER gt to get back to the editor then press L ENTER to list your program and compare it with the one given If you see a mistake in any line then simply type that line number then a space and then the correct text followed by lt ENTER gt he ass Now let s try another program 110 10 SENTER 10 PROGRAM CHARTOASC 20 VAR EH CHAR 3S0 BEGIN so REFEAT ac WRITE ENTER A CHARACTER 2i b READLN 7 READ CH go WRITELN CH IS ORD CH IN ASCII 9o UNTIL CH 100 END 110 CC Now compile C and run this program it will prompt you to enter a character followed by XENTER and then print out the ASCII equivalent of that character This will repeat until yau enter a space as the character For those who know Pascal well we would encourage you to study the use of READLN and READ in the above example of reading characters also study the relevant sub sections 2 3 1 4 and 2 5 1 5 We hope that the above examples have given you some idea of how to use Hisoft Pascal please now read the rest of this section then the Implementation Note for your system and then Section 4 Good Luck 0 1 Scope of this manual This manual is not intended to teach you Pascal you are referred to the excellent books given in the Bibliography if you are a newcomer to programming in Pascal This manual is a reference document detailing t
67. ore than 256 elements 1 7 TYPE type identifier The reserved word PACKED is accepted but ignored since packing already takes place for arrays of characters etc The only case in which the packing of arrays would be advantageous is with an array of Booleans but this is more naturally expressed as a set when packing is required 1 7 1 ARRAYs and SETs The base type of a set may have up to 256 elements This enables SETs of CHAR to be declared together with SETs of any user enumerated type Note however that only subranges of integers can be used as base types All subsets of integers are treated as sets of 0 255 Full arrays of arrays arrays of sets records of sets etc are supported Two ARRAY types are only treated as equivalent if their definition stems from the same use of the reserved word ARRAY Thus the following types are not equivalent TYPE tablea ARRAYL1 100 OF INTEGER tableb ARRAY 1 100 OF INTEGER So a variable of type tablea may not be assigned to a variable of type tableb This enables mistakes to be detected such as assigning two tables representing different data The above restriction does not hold for the special case of arrays of a string type since arrays of this type are always used to represent similar data See Section 1 18 for a further discussion of this strong TYPEing 10 1 7 2 Pointers Hisoft Pascal allows the creation of dynamic variables through the use of the Standard
68. ough room in the computer s memory for the source and object code to be present at the same time It 15 however possible to compile such programs by saving them to tape and using the F option then only 128 bytes of the source are in RAM at any one time leaving much more room for the object code This option may not be nested The compiler options may be used selectively Thus debugged sections of code may be speeded up and compacted by turning the relevant checks off whilst retaining checks on untested pieces of code 37 SECTION 4 THE INTEGRAL EDITOR 4 1 Introduction to the Editor The editor supplied with all versions of Hisoft Pascal is a simple line based editor designed to work with all 280 operating systems while maintaining ease of use and the ability to edit programs quickly and efficiently Text is held in memory in a compacted form the number of leading spaces in a line is held as one character at the beginning of the line and all Hisoft Pascal Reserved Words are tokenised into one character This leads to a typical reduction in text size of 25 NOTE throughout this section the DELETE key is referred to instead of the control code CH It appears more natural to do this The editor is entered automatically when Hisoft Pascal is loaded from tape and displays the message Copyright Hisoft 1982 3 4 All rights reserved followed by the editor prompt gt In response to the prompt you may enter a command line of t
69. rougn the SPECTRUM ROM RST 10 routine rather than use WNRITE LN For example when using the PRINT AT control code this code should be followed by two 8 bit values giving the X Y co ordinate to which the print position is to be changed However if this is done using a Pascal WRITE statement then certain values of X and Y e g 8 which is interpreted by Hisoft Pascal as BACKSPACE will not be passed to the ROM and thus the print position will not be correctly modified You can overcome this problem by using the Following procedure SPOUT outputs the character passed as a parameter directly through the SPECTRUM ROM RST 410 routine and thus avoids any trapping by Hisoft Pascal of the value output PROCEDURE SPOUT C CHAR BEGIN INLINEGFD 21 32A HC CLD NAA 00 E 2 CID AJCDG2 gt 07 RST 10 gt END Example of the use of SPOUT SPOUT CHR 22 SPOUT CHR B gt SPOUT CHR 13 Csets the print position to line 8 colum 13 Hisoft hope that you will find the above routines useful and that they will enhance the way in which you use Hisoft Pascal 75 HISOFT PASCAL TURTLE GRAPHICS FOR THE 2X SPECTRUM Hisoft Pascal for the ZX SPECTRUM now 15 August 1983 comes complete with a Loga style Turtle Graphics package on the 8 side of the program cassette The package is written in Pascal and may be loaded from within the Hisoft Pascal editor by using the command G TURTLE This will load the turtle grap
70. rs The listing may be directed to a printer if required by the use of option P if supported see Section 3 You may pause the listing at any stage by pressing CS subsequently use CC to return to the editor or any other key to restart the listing If an error is detected during the compilation then the message ERROR will be displayed followed by an up arrow which points after the symbol which generated the error and an error number see Appendix 1 The listing will pause hit E to return to the editor to edit the line displayed P to return to the editor and edit the previous line Gf it exists or any other key to continue the compilation If the program terminates incorrectly e g without END then the message No more text will be displayed and control returned to the editor If the compiler runs out of table space then the message No Table Space will be displayed and control returned to the editor Normally the programmer will then save the program on tape re load the compiler and specify a larger Table size see Section 0 0 If the compilation terminates correctly but contained errors then the number of errors detected will be displayed and the object code deleted If the compilation is successful then the message Run will be displayed if you desire an immediate run of the program then respond with Y otherwise control will be returned to the editor During a run of the object code
71. rtle may be positioned on any point within this area iF an attempt is made to move the turtle out of this matrix using LINE see below then the message Out of Limits will be displayed and the pragram will be aborted with a HALT message Initially XCOR and YCOR are undefined use of the procedure TURTLE initialises them to 127 and 87 respectively thus placing the turtle in the middle of his paal PENSTATUS an INTEGER variable holding the current status of the pen ie the trail left by the turtle 0 means the pen is down 1 means the pen is up PROCEDURES The procedures PLOT LINE and SPOUT given in the Product Application Note 2511 ars included as standard in this package refer to 5511 For further details The only essential difference in their implementation here is that LINE calls a procedure CHECK which ensures that XCOR and YCOR cannot go outside the screen boundaries The other procedures available are 76 INK C INTEGER this takes an integer between 0 and 8 inclusive and sets the ink colour of the turtle s pen accordingly PAPER CiINTEGER sets the background paper colour of the screen ta the colour associated with the parameter C which is an integer in the range 0 8 inclusive COPY downloads the current screen to the ZX Printer useful for sending a completed graphics page to the ZX Printer PENDOWN CHINTEGER sets the turtle state so that it will leave a trail in the ink colour as
72. sociated with the parameter C which may he an integer between 0 and 8 inclusive This procedure assigns 0 ta PENSTATUS PENUP subsequent to a call to this procedure the turtle will not leave a trail Useful for moving from one graphic section to another PENUP assigns the value 1 to PENSTATUS SETHD AtREAL takes a REAL parameter which is assigned to the global variable HEADING thus setting the direction in which the turtle is pointing Remember that a heading of 0 corresponds to EAST 90 to NORTH 180 ta WEST and 270 to SOUTH SETXY X Y REAL sets the absolute position of the turtle within the gu area to the value X Y Nu check is made within this procedure to ascertain if X Y is out of bounds procedure LINE does this check FWD L REAL moves the turtle forward L units in the direction of its current heading A unit corresponds ta a graphics pixel rounded up or down where necessary BACK L REAL maves the turtle L units in the directly opposite direction to that in which it is currently heading iie 7 180 the heading is left unchanged 77 TURN A REAL changes the turtle s heading by A degrees without moving it The heading is increased in the anti clockwise direction VECTOR A L REAL displaces the turtle s position by L units at a heading of A the turtle s heading remains A after the displacement RIGHT AREAL an alternative ta TURN RIGHT changes the turtle s heading in the clockwis
73. sts of at least one and up to four digits When a label is used to mark a statement it must appear at the beginning of the statement and be followed by a colon P 5 16 STATEMENT unsigned integer 1 n variable puis function identifier procedure identifier O m3 BEGIN ix ii Eun RE statement Be Or ex vei of constant Eed ELSE statement unsigned integer 17 ts 1 16 BLOCK Casey p 0707 0 G 4 peas sues O a G G CD pee pO Mad Exod p S CST g FORWARD ecz FET identifier 2 parameter list gt YX type identifier 18 Forward References As in the Pascal User Manual and Report Section 11 C 1 procedures and functions may be referenced before they declared through use of the Reserved Word FORWARD e g PROCEDURE aly t FORWARD procedure a declared to be PROCEDURE b x t forward of this statement BEGIN alp procedure a referenced END PROCEDURE a actual declaration of procedure a BEGIN bla END Note that the parameters and result type of the procedure a are declared along with FORWARD and are not repeated in the main declaration of the procedure Remember FORWARD is a Reserved Word 1 17 PROGRAM Groon finire D H week Gen Since files are not implemented there are no formal parameters of the program 1 18 Strong TYPEing Different languages have different ways
74. t that has been written to tape using P if you want to include text then the text must have been written to tape using the WH command To make a back up copy of HP4TM16 praceed as follows 1 Load HP4TM14 from tape and answer the Top OF RAM etc messages normally 2 Return ta BASIC using the editor s B command hit ENTER twice 3 Use SAVE 11241271165 CODE 24598 19736 to save the Pascal to tape 4 You can subsequently use LOAD CODE to reload the compiler inta the Spectrum but note that you must then enter it only via RANDOMIZE USR 24598 far a cald start or RANDOMIZE USR 24503 for a warm start Note that you are authorised by Hisoft to make only one working copy Please da not hesitate to contact us if you experience any difficulty with Hisoft Pascal we can only salve the problems if we know what they are 72 PRODUCT APPLICATION NOTE 41 1X SPECTRUM SOUND AND GRAPHICS WITH HISOFT PASCAL This note gives details on controlling the sound and graphics capabilities of the ZX SPECTRUM using Pascal pracedures from within Hisoft Pascal 1 Sound The following two procedures defined in the order given below are required to produce sound with Hisoft Pascal This procedure uses machine code to pick up its parawmelers and then passes then to the BEEP routine within the SPECTRUM ROM PROCEDURE BEEPER A B i INTEGER BEGIN THLINE 00 HE 2 H0 44 3 CID L CX42 UD OH D3 2 00
75. t will go to the printer until another WRITE CHR 14 is received when output will revert to the screen Making a working copy 1 Load the Pascal from the master tape and answer the questions Top of RAM etc in the normal ways 2 Now use the B editor command press the character B and then NEWLINE to return to BASIC 3 Enter the following BASIC program overtyping the existing loader program 18 OPEN ATEL 1 X HPATG 20 FOR I 6144 TO 24082 30 X PEEK I 40 PUT 31 X 50 EXT I 68 CLOSE 13 END 4 Run the above program and the configured version of HP4TG will be saved to tape remember to press RECORD and FLAY on your tape recorder 5 Ta load back this configured version of the Pascal use the following BASIC program 11 OPEN TH 1 x45 PATE 26 FUR I 6144 TO 24082 36 GET 1 X 40 POKE I X 50 NEXT I CLOSE 1 5 END To re enter the Pascal use CALL 4208 for a cold start destroying any test test or CALL 6213 for a warm start preserving the state of the compiler editor as you left it Loading Object Code dumped using T ranslate If you have dumped the object code of your Pascal program to tape via the Editor s T command then the code may be re loaded and executed by using the Hisoft HP4T Loader program supplied on the master tape Simply load this from the tape via LOAD RUN it and then put the tape with the object code on it into your tape recorder and press PLAY the code will be loaded and e
76. the line is returned to the Hisoft Pascal editor the screen line transmitted must be as it would have been if you had typed it in directly from the line editorj specifically any line that begins with ay sign will not be accepted by Hisoft Pascal line editor nes it will ignore leading PEEL 69 Some extra procedures are included in the MZ700 version of Hisoft Pascal 4T and these are as follows PAPER I this procedure takes an INTEGER parameter in the range 0 7 and it sets the paper colour of all subsequent output to the colour corresponding to this number INK I takes an INTEGER parameter in the range 0 7 and sets the ink colour of all subsequent output to this colour see page 80 of the M2700 Qwner s Manual for number to colour correspondence MUSIC S takes a string of characters as a parameter and then passes this string to the MUSIC procedure within the M1700 operating system See page 55 of the MZ700 Owner s Manual for details of the specification of the music string Note that Hisoft Pascal insists that any string must not run over a line boundary TEMPO T takes an INTEGER parameter in the range 147 and sets the tempo of any subsequent MUSICal output according the value of this parameter The MZ700 Colour Plotter Printer is supported by using control codes as given on pages 198 200 of the MZ700 Owner s Manual For example to draw a green line on the plotter From within a Pascal program
77. the relevant Implementation Note If you enter a line with a line number that already exists in the text then the existing line will be deleted and replaced with the new line after you have pressed ENTER If the automatic incrementing of the line number produces a line number greater than 32767 then the Insert mode will exit automatically If when typing in text you get to the end of a screen line without having entered 128 characters the buffer size then the screen will be scrolled up and you may continue typing on the next line an automatic indentation will be given to the text so that the line numbers are effectively separated from the text 4 2 2 Text Listing Text may be inspected by use of the L command the number of lines displayed at any one time during the execution of this command is fixed initially see your Implementation Note but may be changed through use of the kK command Command L n m This lists the current text to the display device from line number n to line number m inclusive The default value for n is always 1 and the default value for m is always 22767 i e default values are not taken from previously entered arguments To list the entire textfile simply use L without any arguments Screen lines are formatted with a left hand margin sa that the line number is clearly displayed The number of screen lines listed on the display device may be controlled through use of the K command after list
78. the string s is empty then the first Hisoft Pascal file on the tape will be loaded regardless of its filename While searching of the tape is going on you may abort the load by hoiding CC down this will interrupt the load and return to the main editor loop Note that if any textfile is already present then the textfile that is loaded from tape will be appended to the existing file and the whole file will be renumbered starting with line 1 in steps of 1 ZX Spectrum owners should consult their Implementation Note for details of using tape and Microdrives with Hisoft Pascal 43 4 2 5 Compiling and Running from the Editor Command C n This causes the text starting at line number n to be compiled I you do not specify a line number then the text will be compiled from the first existing line For further details see Section O 2 Command R The previously compiled object code will be executed but only if the source has not been expanded in the meantime see Section 0 2 for more detail Command T n This is the Translate command The current source is compiled from line n or from the start if n is omitted and if the compilation is successful you will be prompted with Ok if you answer Y to this prompt then the object code produced by the compilation will be moved to the end of the runtimes destroying the compiler and then the runtimes and the object code will be dumped out to tape with a filename equal to that pre
79. tj you will be prompted with enter two digit hexadecimal numbers as given below two digits letters at a time with each number terminated by CR or ENT When you have entered the last hexadecimal number and terminated it with CR or ENT control will automatically return to the editor The hexadecimal numbers to enter are 20 06 CD 45 14 C3 12 00 FS CD A 12 F1 FE OD CO 3E OA FS CD BD 12 87 28 FA F1 D3 FF 3E 80 D3 FE DB FE OF 30 FB AF D3 FE C DB FE FE F2 20 F 38 FF C9 This code assumes that your printer does not generate an automatic line Feed on receipt of a carriage return character If your printer does generate an automatic line feed then you should not enter FE as the 14th hexadecimal character but instead you should enter C You have now modified the I O Primitives within the Hisaft Pascal package to interface with a parallel printer Now yau must save the package ta tape Da this as instructed above The above modification allows you to use a parallel printer such as the EPSON FX80 series with Hisoft Pascal through use of the compiler P option or by WRITE CHR 14 from within a Pascal program Note that the above program is not necessarily the most efficient way to implement this modification it does however have the advantage of giving you a free read a hex number Function If you have any queries regarding this note please do not hesitate to contact us 68 HISOFT PASCAL VERSION 1 5 FOR THE SHARP M7700 SE
80. tring in the current line If an occurrence of the find string is detected in a subsequent line within the previously specified line range then the Edit mode will be entered for the line in which the string is found Note that the text pointer is always positioned at the start of the found string after a successful search S substitute the previously defined substitute string for the currently found occurrence of the find string and then perform the sub command F i e search for the next occurrence of the find string This together with the above F sub command is used to step through the textfile optionally replacing occurrences of the find string with the substitute string see Section 4 5 for an example 42 1 insert characters at the current pointer position You will remain in this sub mode until you press ENTER this will return you to the main Edit mode with the pointer positioned after the last character that you inserted Using DELETE tor BACKSPACE within this sub mode will cause the character to the left of the pointer to be deleted from the buffer while the use of CI control function will advance the pointer to the next tab position inserting spaces X this advances the pointer to the end of the line and automatically enters the insert sub mode detailed above C change sub mode This allows you to overwrite the character at the current pointer position and then advances the
81. ust be present and if the renumbering would cause any line number to exceed 32767 then the original numbering is retained Command F n m f s The text existing within the line range n lt x lt m is searched for an occurrence of the string the find string If such an occurrence is found then the relevant text line is displayed and the Edit mode is entered see below You may then use commands within the Edit mode to search for subsequent occurrences of the string f within the defined line range or to substitute the string s the substitute string for the current occurrence of f and then search for the next occurrence of f see below for more details Note that the line range and the two strings may have been set up previously by any other command so that it may only be necessary to enter F to initiate the search see the example in Section 4 3 for clarification Command E n Edit the line with line number n If n does not exist then no action is taken otherwise the line is copied into a buffer and displayed on the screen with the line number the 41 line number is displayed again underneath the line and the Edit mode is entered All subsequent editing takes place within the buffer and not in the text itself thus the original line can be recovered at any time in this mode a pointer is imagined moving through the line starting at the first character and various sub commands are supported which allow you to edit the line
82. viously defined for the find string You may then at a later stage load this file into memory see your Implementation Note whereupon it will automatically execute the object program Note that the object code is located at and moved ta the end of the runtimes so that after a T ranslate you will need to ceload the compiler however this should present no problems since you are only likely to T ranslate a program when it is fully working i If you decide not to continue with the dump ta tape then simply type any character other than Y to the Ok prompt control is returned to the editor which will still function perfectly since the object code was not moved 4 2 6 Other Commands Command B This simply returns control to the operating system For details of how to re enter the package see your Implementation Note Command 0 n m Remember that text is held in memory in a tokenised form with leading spaces shortened into a one character count and all Hisoft Pascal Reserved Words reduced to a one character token However if you have somehow got some text in memory perhaps from another editor which is not tokenised then you can use the O command to tokenise it for you Text is read into a buffer in an expanded form and then put back into the file in a tokenised form this may of course take a little time to perform A line range must be specified or the previously entered values will be assumed 44 Command
83. xample of the use of ADDR see Appendix 4 2 3 5 7 PEEK X T The first parameter of this function is of types integer and is used to specify a memory address see Section 2 3 5 5 The second 32 argument is a type this is the result type of the function PEEK is used to retrieve data from the memory of the computer and the result may be of any type In all PEEK and POKE the opposite of PEEK operations data is moved in Hisoft Pascal s own internal representation detailed in Appendix 3 For example if the memory from 5000 onwards contains the values 50 61 73 63 61 6C in hexadecimal then WRITE PEEK 5000 ARRAY 1 6 OF CHAR gives Pascal WRITE PEEK 5000 CHAR gives P WRITE PEEK 5000 INTEGER gives 24912 WRITE PEEK GISOOO REALD gives 2 46227F 29 see Appendix 3 for more details on the representation of types within Hisoft Pascal 2 3 6 7 SIZE V The parameter of this function is a variable The integer result is the amount of storage taken up by that variable in bytes 2 3 6 8 INP P INP is used to access the ZB0 s ports directly without using the procedure INLINE The value of the integer parameter P is loaded into be BC register and the character result of the function is obtained by executing the assembly language instruction IN A C SECTION 3 COMMENTS AND COMPILER OF TIONS 3 1 Comments A comment may occur between any two reserved words numbers identifiers or special symbols see Appendix 2 A
84. xecuted automatically 53 HISOFT PASCAL IMPLEMENTATION NOTE SHARP MZZ20K MZ80A and MZ80B Loading Hisoft Pascal from tape Unpack the supplied cassette tape from its case and load it into your machine with Side A the side with the label uppermost Now ensuring that you are in monitor mode on your SHARP computer type the relevant command to load a file from tape L on the MZ80A and MZ80B and LOAD on the MZ80K followed by CR or ENT On the MZ80B you will be prompted to enter a filename simply press CR or ENT After a while the message Loading HP4Txxx should appear if this does not happen or if you subsequently experience any problems in loading the tape then stop the tape rewind it to the beginning press RESET or BREAK and try to load the tape again IF you continue to have problems loading the Hisoft Pascal tape then please return it to Hisoft for replacement however we trust this will never happen Once the package has been loaded it will execute automatically and the message Top of RAM will be displayed consult Section 0 0 of the Hisoft Pascal Programmer s Manual for details of how to proceed from here Implementation on the SHARP MZ80K MZ80A and MZSOB The implementation of Hisoft Pascal on the SHARP cpmputers is fairly straightforward with one or two exceptions which are discussed below The various control codes mentioned in the Programmer s Manual are reached as Follows on the MZ80K MZ80A and M2
85. y Hisoft Pascal The information on the amount of storage required in each case should be of use to most programmers the SIZE function may be used see Section 2 3 6 7 other details may be needed by those attempting to merge Pascal and machine code programs A 3 1 1 Integers Integers occupy 2 bytes of storage each in Z s complement form Examples 1 80001 rhe 0100 256 FFOO The standard Z80 register used by the compiler to hold integers is HL A 3 1 2 Characters Booleans and other Scalars These occupy 1 byte of storage each in pure unsigned binary Characters B bit extended ASCII is used 45 5B E T n Booleans ORD TRUE 1 so TRUE is represented by I ORD FALSE O so FALSE is representd by O The standard 280 register used by the compiler for the above is A A 3 1 5 Reals The mantissa exponent form is used similar to that used in standard scientific notation only using binary instead of denary Examples 23 2 10 or 1 0 2 121 10 or 1 0 2 51 12 5 1 28 10 or 2542 11001 27 1 1001 when normalised 0 1 1 0x10 or Kt s amp h Wala ma ERMEN isk so now we need to do some binary long division 0001100 101 o 100000000000000 101 110 101 1000 101 at this point we see that the fraction recurs O OOOL 1 004 7 H 4 11 1001100 2 answer So how do we use the above results to represent these numb

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