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Discovery disc system operating manual Assembling you

1. Drive number 4 has not been implemented There is no requirement for this and you should use drive numbers 1 and 3 for copying on single drive systems INDEX Assembly 3 4 Autorun 6 15 27 BREAK SHIFT SPACE 10 18 catalogue file 11 23 28 CAT Sy 10 VL 235 28 CAT 23 channels 11 12 16 1 7 1 8 22 b 12 15 16 22 25 26 MGAT 22 9 2 60 28 CODE 22 26 TaT Q22 28 4 15 22 24 k 11 16 18 22 25 26 m TI I2 160 22 237 295 260 p 16 22 26 S 11 12 16 18 22 26 12 16 22 25 26 23 26 binary channel 16 default access options 26 slow channels 25 text channel 16 8 19 23728 ra Ww 8 9 18 19 20 21 23 2 7 TEP HRe E eC E PEAT compacting a disc 28 connections 30 Copying a disc 8 Copying a file 11 12 fn an DATA 13 14 24 25 27 Disc Disc Disc care 8 drive number 5 11 title 5 11 24 Hemera End of file 10 12 13 1 ERASE 21 24 9 25 26 12 13 19 29 Error Reports 6 7 Expanding a file EXP 20 26 28 T2 Fil Fil lename 22 le pointer 21 27 File specification 23 File transfer 12 15 FORMAT 5 7 11 15 20 26 20 24 28 IN 8 19 26 INKEYS 10 18 21 25 28 INPUT 8 19 20 21 25 r Joystick 7 15 16 INE 6 LLIST 9 LOAD 6
2. 32 RND 1 LET count 0 20 PRINT AT 2 0 I have chosen a number between PRINT AT 3 0 1 and 32 30 PRINT AT 5 2 You have to guess it in the PRINT AT 6 2 smallest number of guesses 40 INPUT Your guess guess 50 IF guess gt number THEN PRINT guess is too big LET count count 1 GOTO 40 60 IF guess lt number THEN PRINT guess is too small LET count count 1 GOTO 40 70 PRINT guess is the correct answer It took you count 1 guesses Now just before you try the game we can show you very quickly how to save it on disc by typing SAVE m 1 guess ENTER Again you can check whether it has worked by typing CAT 1 ENTER The programme guess should now appear in the list of disc contents You have just learnt how easy it is to save your programme on disc Now try the game by simply pressing RUN ENTER If the programme fails to run you may have made a programme entry mistake Retype any incorrect lines and then type SAVE m 1 guess ENTER This will save the correct version and automatically replace the incorrect programme Now try the game again 5 Now type NEW ENTER This removes the programme Don t worry the programme is still stored on your disc so you can bring it back whenever you want Instead of entering the game programme all over again all you have to do is to type LOAD m 1 guess ENTER To make sure the programme is back type LIST ENTER The programme will be displayed and ca
3. FORWARDS i Pressing the fire button adds 16 to the value of stick Line number 220 tests if the fire button is pressed or not If it is not pressed the condition stick lt 16 will be true and the programme jumps back to line 130 If the button is pressed the programme continues with line number 230 and saves the screen turns the joystick off and then stops Channels and streams In earlier sections of the manual we have seen that the Spectrum identifies different parts of the system by using a single letter in double quotes These different items are called channels The main channels available on the Discovery system are K Input from the keyboard and output tithe lower part of the Screen S Output to the upper part of the Screen P Output to the ZX printer m Input or output to a disc file b Input or output to the parallel port t Input or output to the parallel port Note 1 The m channel needs further information to specify it completely For example m s1 data refers to the file data on the disc in drive number 1 Note 2 The b channel sends and receives characters without changing them in any way The t channel does make changes to the characters For output BASIC tokens are expanded and graphics characters are printed as see the reference section for details For input characters have their most significant bit set to zero The t channel is used as a text channe
4. 7 10 17 aloes 25 13 25 14 1 30 27 5 24 25 27 LPRINT 9 17 LPRINT 25 25 MERGE 10 14 Microdrive 9 MOVE 9 11 G 15y 26 12 25 ry 25 26 28 29 Ta G Ei OPEN 8 9 Lo 19 20 21 26 OUT 8 19 20 26 Parallel port 30 POINT 21 22 27 Printer 9 12 30 Printer width 26 PRINT 8 9 18 IQs 20 2i 27r 28 RAM disc 22 28 29 Random accessable 8 RND 20 21 26 SAVE 5 6 7 8 9 20522 DF 13 14 15 24 25 27 SCRNS 11 SCREENS 7 Sector 10 T3 14 25 27 23 26 28 Streams 16 17 18 Tape to disc 6 7 Track 10 T9 USR routines 8 VE 14 RIFY 7 13 19 10 27 15 DR 29 28 Di DY 34
5. GOTO 130 210 IF stick 10 THEN DRAW 1 1 GOTO 130 220 IF stick lt 16 THEN GOTO 130 230 SAVE m 1 sketchb SCREEN 240 FORMAT j 0 STOP Save this as the file updatejoy by typing SAVE m 1 updatejoy ENTER Now load the programme joysketch and list it by typing LOAD m 1 joysketch ENTER LIST ENTER The new programme lines can be merged from the file updatejoy by typing MERGE m 1 updatejoy ENTER Now list the programme and you should find that the programme lines you entered have been combined with the existing programme Lines 140 190 of the original programme have been overwritten while lines 200 240 have been added The changes allow the programme to detect other positions of the joystick and to move accordingly This programme is further explained in the next section of the manual 14 To save the programme on disc so that it will run automatically type SAVE m 31 joysketchb LINE 10 ENTER Use of the LINE option to the SAVE command means that when loaded again the programme will run automatically from line number 10 First check that the programme has been saved correctly by using VERIFY i e by typing VERIFY m 1 joysketchb ENTER Provided that this is successful remove the programme by typing NEW ENTER Now load the programme again by typing LOAD m 1 joysketchb ENTER The programme should run automatically The MERGE command can also be used to load an autorun programme withou
6. and align the unit s connector with the connector at the back of your Spectrum Now slide the two connectors firmly into place If the connection is complete the hole in the base plate and the vacant screw hole on the underside of your Spectrum should be aligned Now take the special screw resided with your unit and pass it through the hole provided on the underside of the base plate into the Spectrum Tighten the screw gently Fixing is complete when the rubber pad on the base plate touches the computer Take care not to over tighten the screw during this operation Now with the Discovery unit in position take the rubber feet provided and peel off the paper backing Position the rubber feet on the front underside edge of the computer as indicated in the diagram Spectrum A hole is already provided on the underside of your Spectrum computer which will be used in the connection of your Discovery unit It is arrowed in the diagram Place your Spectrum on the platform at the front of the Discovery unit and align the connector with the connector at the rear of your computer Now slide the two connectors firmly into place Use the screw provided with your unit to complete the connection Pass the screw through the hole on the underside of the Discovery platform and into the fixing hole in your Spectrum Tighten it carefully Fixing is complete when the rubber pad on the top of the platform touches the computer Take care not to overtighten
7. catalogue entry If unspecified or given as 1 the length is set to one half of the largest space remaining on the disc While if given as 0 all of the largest space remaining will be allocated to the file When the channel inclosed the file length is correctly written In a similar way the EXP option can have a length specified This time the length given is the maximum size of the expansion required If there is insufficient room for the expansion then an error report will be generated If a length is not specified or given as 1 the file will be doubled in length or if insufficient space is available It will be expanded to fill the gap between the current end of the file and the start of the next file on the disc The RND option is used in two ways to create a random access file and to open an existing random access file To create a random access file two parameters must be given These are the record length and the number of records required in the file The number of records can be given as 0 or 1 when it behaves in the same way as for the OUT option For example OPEN 4 m 1 Dave RND 32 30 creates a random access file Dave with a record length of 32 bytes and with room for thirty records the length of the file will be 30 32 960 bytes To open an existing random access file only the record length is given For example to open the file Dave created above use OPEN 4 m 1 Dave RND 32 For the t channel a printe
8. disc system will allocate one half of the largest available space on the disc to the file For the EXP option the number represents the length by which the file is to be extended For example OPEN 11 m 2 Laurie EXP 256 will set up stream number eleven for output to the file Laurie on the disc in drive number two The output will be added to the end of the file and will not be more than 256 bytes long An error report will be generated if there is insufficient room on the disc for the expansion If the length is omitted or given as 1 the file is doubled in length or if insufficient space is available is expanded to fill the gap between the end of the file and the start of the next file on the disc Random access files The programmes just illustrated show the use of disc files for data storage In these programmes the information is saved and retrieved one item after another If you want to locate the third name and telephone number in the file you must first read and discard the first two names and telephone numbers Altering the information is even more difficult To improve this situation the Discovery disc system allows the use of random access files In a random access file each set of data called a record is a fixed number of characters which must be decided before you set up the file You can then point to the set of data that you require To create a random access file you use the OPEN command with the RND option for exa
9. including an apostrophe as a separator for the items in the variable list for example lines 120 and 130 in programme tell could be replaced by 120 PRINT 4 n t Line 130 prints the name and telephone number on the screen Line 140 returns to line 100 and the cycle repeats again Notice the similarity in the two programmes The only difference is in the sources and destinations of the data The list of telephone numbers can be extended by using the following programme 10 OPEN 4 m 1 telephone EXP 100 INPUT Name n Tel No t 110 ZF n END OR n end THEN CLOSE 4 STOP 120 PRINT 4 n 130 PRINT 4 t 140 GOTO 100 Save the programme on disc as tel3 and then run the programme It works in the same ways as tell Enter some extra names and numbers and finish with end or END and any number When it has been run you can display the updated file telephone by using the programme tel2 as before This time line 10 opens the file telephone on drive number one for expansion by using the EXP option When used with an m channel both the OUT and EXP options can be followed by a number For the OUT option this number represents the maximum length of the new file For example OPEN 6 m 1 Carol OUT 1000 will set up stream number six for output to a file Carol on the disc in drive number one The maximum length of the file is 1000 characters bytes If the number is omitted or given as 1 the
10. method is not used follow the instructions supplied with the disc programme Using tape based programmes To use tape based programmes the Spectrum must be connected to a suitable tape recorder using the lead supplied with the computer Connect the MIC and EAR sockets on the Spectrum to the corresponding sockets on the tape recorder and set the volume control to a high setting Full details on entering tape based programmes are contained in your Spectrum computer operating manual Transferring programmes from tape to disc To transfer a programme called IMPACT for example from tape to disc you will first need to load it using LOAD IMPACT ENTER Let the programme finish loading then type SAVE m 1 IMPACT ENTER For more information on transferring programmes from tape to disc see appendix 1 Using joysticks with Discovery When playing computer games you may often need to use five or more different keys This can make some games very difficult which is why many games now offer a joystick option The Discovery disc system has a joystick interface and is compatible with most games which allow joysticks to be used To use a joystick with a suitable programme plug the joystick into the socket illustrated Now you have to use a command to turn the joystick on Type FORMAT j 1 ENTER You can now run the game programmeWhen you have finished you can turn off the joystick by typing FORMAT j 0 ENTER You can also
11. stream must have been previously opened for output e g OPEN 4 1 directory CAT 4 2 CLOSE 4 This will put the catalogue of drive 2 onto a file called directory on drive 1 CAT lt drive gt is an abbreviation for CAT 2 lt drive gt and so if stream 2 is reallocated the output will be sent to the new channel CLEAR or CLEAR lt stream gt CLEAR clears out open streams and makes them available for further use CLEAR lt stream gt has the same effect but only on the specified stream CLOSE lt stream gt This command closes the specified stream and frees it for further use In the case of disc files it is important to close a file when access is finished particularly when writing to a file Closing a file writes any information still in the buffer to the disc file For serial files it also updates the catalogue entry setting the file length to the current position Failure to close a file will mean that information is lost and may also mean that the catalogue entry is incorrect Note that when you close streams 0 1 2 or 3 they are closed and then automatically reopened to their default channels CLS This command clears the screen and sets the display attributes to their defaults 23 PAPER 7 INK 0 BORDER7 FLASH 0 BRIGHT 0 OVER 0 INVERSE 0 CODE lt start address gt lt no of bytes gt This is an extension to the LOAD VERIFY and SAVE commands which allows a block of memory to be sav
12. that they are adjacent and therefore combines all of the free space To compact a disc in drive 1 type MOVE d 1 TO d 1 ENTER WARNING IF THE POWER IS DISTURBED OR THE SPECTRUM CRASHES DURING THE COMPACTING OF A DISC THE FILES ON THE DISC MAY BE DESTROYED IT IS WISE TO MAKE COPIES OF IMPORTANT FILES BEFORE COMMENCING THE COMPACTING PROCEDURE 6 The catalogue file The catalogue file can be accessed using the CAT channel The file consists of a series of sixteen byte entries one for each file on the disc and an end marker The first entry always refers to the catalogue file Each sixteen byte entry consists of three two byte numbers followed by a string of 10 bytes First number the low twelve bits of the number represent the number of bytes in the last block of the file 1 The top four bits are used by the system Second number the start block of the file Blocks on the disc are numbered from 0 not Third number the end block of the file inclusive The string is the filename or in the case of the catalogue file the disc title The end marker is another sixteen byte entry but only the second and third numbers byte numbers 3 to 6 inclusive are significant The second number is the number of blocks on the disc and the third number is 65536 in hex FFFF The third number can be used to detect the end of the catalogue file When a disc is formatted the catalogue file is set up for 62 files If you obtain a disc full erro
13. the specified record length 128 bytes in the example above When open for random access you can read or write to the file at the current position of the file pointer The POJNT command is then used to move the file pointer to a particular record in the file for example POINT 4 13 moves to the start of the thirteenth record of the random access file linked to stream number four The following programme shows how records can be read from the file we have just created 10 OPEN 4 m 1 random RND 10 20 INPUT which record n 30 IF n lt 1 or n gt 10 THEN PRINT Record number out of range GOTO 20 40 POINT 4 n 50 INPUT 4 f 60 PRINT Record number n is f 70 INPUT Another record y n sr 80 IF r y THEN GOTO 20 90 CLOSE 4 Now run the programme and enter some record numbers The corresponding names should be displayed Line 10 opens the file random for random access with a record length of 10 The string f is not dimensioned this time as this programme only reads from the file If the programme was also writing to the file then f would have to be dimensioned as this makes sure that it is always the correct length Line 40 moves the file pointer to the start of the required record Line 50 inputs the record Note that the record numbers do not have to be in orderi and this makes random access files very powerful and well worth the effort necessary to learn how to use them The erase command This co
14. there is insufficient space on the disc Try compacting the disc g disc 1 0 error this error occurs when there is a problem reading from or writing to the disc Possibilities are disc not in the drive specified drive not connected or corrupted information on the disc h file not found the filename given has not been found on the disc in the specified drive i hook code erorr this occurs when using machine code with microdrive hook codes It should not occur when using BASIC j file size error this occurs if you try to verify or write past the end of a file When a file is opened a length is always set even if it is half of the disc see OPEN in the reference section 1 verification failed m wrong file type the file specified in the command is not the correct type a ram corrupt this message occurs if there is an internal inconsistency e g if a channel contains the wrong channel length no message in this case the error code is given There is no message define for this error code 29 Appendix 3 Making connections to the Discovery system There are a number of different input output ports on the Discovery disc unit and these are now briefly described Peripheral through connector The Spectrum expansion connector is carried through to the right hand side of the Discovery unit and is labelled Peripheral through connector All lines are available except Al4 The A side of the connector is the co
15. 50 NEXT k 60 PRINT When run this programme loads and prints the random numbers saved by the programme rgen Note that the array name does not have to be the same in both programmes but that the array size 100 numbers does This extension can be used with string arrays as well as with arrays of numbers LOAD and SAVE can also be used to save machine code programmes by using the CODE option Type SAVE m 1 mcode CODE 32500 67 ENTER this will save the 67 bytes of codee starting from memory location 32500 This can be reloaded when required by using the corresponding load command LOAD m 1 mcode CODE ENTER 13 this loads the machine code at the same address as when it was saved To load at a specified address which may be different use the command LOAD m 1 mcode CODE 60000 ENTER This command loads the machine code starting at 60000 It does not check that the space which you have allowed for the machine code is large enough If you have set aside 100 bytes for a machine code programme you can make sure that other memory is not overwritten by specifying the length in the load command for example LOAD m 1 mcode CODE 60000 100 ENTER If the code in the file mcode is larger than 100 bytes an error report will be generated Using CODE any block of memory can be saved it does not have to be machine code To save the screen for example the command SAVE m 1 screen CODE 16384 6912 ENTER could be
16. Discovery disc system operating manual Congratulations on your purchase of the Opus Discovery disc system which has been specially designed to help you explore the full potential of your Spectrum or Spectrum computer Discovery not only complements your computer perfectly but offers you an exciting range of new options including 1 A flexible 3 1 2 inch disc system 2 A parallel printer interface 3 A joystick interlace compatible with most computer games with a joystick option 4 A monitor port 5 Peripheral through connector This user manual will take you step by step through the range of new functions offered by Discovery If you have not previously used a Spectrum computer we recommend that you first spend a little time reading your Spectrum manual in order to familiarize yourself with the computer s keyboard and the methods of programme entry After doing this you will be ready to explore the facilities now available to you through your Discovery disc system 2 Assembling you Discovery disc system Contents After unpacking your Discovery disc system you will find A The Discovery disc unit B The user manual C A fixing screw for securing the Spectrum and Discovery 1 unit D Two rubber support feet for the Spectrum Assembly Attaching the Discovery unit to your computer is very simple and preparing your new system for use will take you only a short time A Unplug the power supply from your computer Th
17. T 5 0 picture 20 PRINT AT 7 0 Use the fire button to end 30 PRINT AT 20 1 Press any key when ready 40 LET k INKEY IF k THEN GOTO 40 50 FORMAT j 1 110 BORDER 0 PAPER 0 INK 7 CLS 120 PLOT 0 0 DRAW 255 0 DRAW 0 175 DRAW 255 0 DRAW 0 175 130 LET stick IN 31 IF stick 0 THEN GOTO 130 140 IF stick 1 THEN DRAW 1 0 GOTO 130 150 IF stick 2 THEN DRAW 1 0 GOTO 130 160 IF stick 4 THEN DRAW 0 1 GOTO 130 170 IF stick 5 THEN DRAW 1 1 GOTO 130 180 IF stick 6 THEN DRAW 1 1 GOTO 130 190 IF stick 8 THEN DRAW 0 1 GOTO 130 200 IF stick 9 THEN DRAW 1 1 GOTO 130 210 IF stick 10 THEN DRAW 1 1 GOTO 130 220 IF stick lt 16 THEN GOTO 130 230 SAVE m 1 sketchb SCREEN 240 FORMAT j 0 STOP Line number 50 uses the FORMAT command to turn the joystick on while line number 240 turns the joystick off and then stops the programme The j channel is only used to turn the joystick on and off using the FORMAT command 1 turns the joystick on and 0 turns it off 15 Line number 130 uses JN 31 to obtain the position of the joystick If the joystick is not being moved a value of 0 is returned and this means that the programme jumps back to get another value The programme stays in this loop until a non zero value is obtained Line numbers 140 210 test the value of stick and move accordingly The relationship between positions of the joystick and values of stick obtained are shown in the following diagram
18. The full specification is lt stream gt For example OPEN 4 51 links stream four to stream one For this channel the quotes and the separator can be omitted and it can be specified as lt stream gt NOTE A Upper or lower case letters can be used in the channel specification and so for example k and K both refer to the keyboard channel NOTE B After using a channel other than the screen the screen attribute commands such as INK and PAPER may not work To avoid this problem include the command PRINT before using them V lt file spec gt In order to precisely stipulate a given file on the Discovery system the file name alone is insufficient You must also provide the drive number and inform the system that the file is on the disc unit The complete file specification is as follows m lt drive gt lt filename gt The m can be omitted from the specification as m is the default channel 2 Keywords used in the Discovery system CAT lt drive gt This command displays the catalogue of the disc in the specified drive The number given at the end of the list of files is the space still available on the disc in kilobytes rounded down e g CAT 1 displays the catalogue of the disc in drive number 1 on the screen provided that stream 2 is allocated to the screen CAT lt stream gt lt drive gt This command sends the catalogue of the disc in the specified drive to the given stream The
19. air or complete replacement at the discretion of the company of the defective equipment 7 The company does not accept responsibility for any loss or damage during transit to or from the dealer or the company but in this event every effort will be made to investigate complaints of loss or damage if they should arise 8 This guarantee does not affect the purchaser s statutory rights ADDITIONAL INFORMATION THE MOVE COMMAND On page eleven of the operating manual the MOVE command an amendment has been made to the instructions for transferring data from the K channel to the S channel and to the K channel All slow channels are now buffered It will therefore be necessary to press CAPS SHIFT and ENTER together before the characters you have entered at the keyboard will appear on the screen THE CAT CHANNEL When opening a stream to the CAT channel POINT should be used to select the required record before reading or writing data VIDEO MONITOR OUTPUT The video monitor output positioned at the rear of your Discovery unit provides a monochrome composite video signal and should therefore only be used with a video monitor If using a normal televison receiver you should connect the aerial lead supplied with your computer into the TV socket provided at the rear of your Spectrum as outlined in the assembly instructions DEFAULT CATALOGUE the default catalogue size has been extended from 62 to 110 files DRIVE NUMBERS
20. am already open This happened because the programme did not close the streams it was using with the CLOSE command 18 The only way of stopping the programme is to break into it and this leaves the stream open This is poor programming practice and should be avoided If you have to break into a programme or if the programme fails any open streams can be reset by using the CLEAR command Type in the command CLEAR ENTER Now run the programme again This time it should run as before Using CLEAR to reset a stream used for output to a file channel may mean that part of the information is lost Closing a stream linked to an output file writes any remaining information to the disc This is not done by the CLEAR command which just resets the streams and makes them available again If you wish you can clears single stream the command CLEAR 5 just resets stream five The OPEN command links a specified channel device to the given stream You can specify whether the channel is to be used for input or output by using the OPEN command for example if you type OPEN 7 b IN you will link stream 7 to the b channel for input only Similarly the command OPEN 5 m 1 test OUT will link stream 5 to the disc file test on drive number one The file is to be used for output Disc file channels have a number of other options and these are described in the next section on data storage As the examples just shown illustrate t
21. d by the ENTER character Line 140 returns to line 100 and the cycle repeats again Now load and list the programme tel2 from the introductory section 10 OPEN 4 m 1 telephone IN 100 PRINT 4 110 JF USR 432 0 THEN CLOSE 4 STOP 120 INPUT 4 n t 130 PRINT n t 140 GOTO 100 Line 10 opens the file telephone for input This file input channel is linked to stream number four The ZN part of the OPEN command indicates that the file is to be used for input If the file cannot be found on the disc in drive number one then an error report is generated Line 100 sets the current stream to four ready for the call USR 432 This call returns the number of characters still to be read from the current stream Line 110 checks to see if the number of bytes not yet read from the file is zero If it is we have reached the end of the file and the channel is closed and the programme stops Line 120 inputs the next name and telephone number from the file stream four Note that the items in the variable list of the INPUT command n and t in this example must be separated by semicolons and not commas Alternatively each item can be input using a separate INPUT command for example line 120 could be replaced by 120 INPUT 4 n 125 INPUT 4 t Note also that the INPUT command requires that each item be followed by the ENTER character When printing to a file this can be achieved by printing the items separately or by
22. disc system writing to the disc and the disc is therefore Write protected As a further precaution you should keep copies of discs containing important information Disc copying To make a copy of a disc first format a new disc as already described in the operating manual Now remove the disc and insert the disc to be copied and type MOVE d 1 TO d 3 ENTER From this point on the programme will prompt you when it is necessary to swop the discs and complete the copying procedure Be careful not to mix up the source and destination discs your original and your copy It is a good idea to write protect the source disc your original before starting the copying procedure For those with two disc drives the disc swapping can be avoided by copying from one drive to the other To copy the disc in drive number one onto a formatted disc in drive number two type MOVE d 1 TO d 2 ENTER The disc will be copied automatically NOTE When the disc is copied it is also compacted See the later section on compacting a disc Using a printer with your discovery system The Discovery disc system can be used with a parallel printer To do this you will need a Discovery printer cable which can be obtained from your dealer The cable has a Centronics printer connector at one end and an edge connector for the Discovery disc unit at the other It also has a red strip along one edge which is used to ensure that the edge connector is correctly insert
23. ed To connect the Discovery unit and the printer first turn off the power to both units The edge connector for the Discovery unit should be inserted into the printer port located on the right hand side of the unit with the red stripe towards the rear i hi UU Mt The other end of the cable should be connected to the printer as outlined in the printer manual Now turn the power on again and type OPEN 3 t ENTER LPRINT Printertest abcdefghijklmnopqrstuvwxyz ENTER CLOSE 3 ENTER The line Printertest abcde etc should have been printed on your printer If not turn off the power and check all the connections before trying again Once the printer is working it can be used to list programmes and to print other information Load one of the previous example programmes and then type OPEN 3 t ENTER LLIST ENTER The programme will be listed on the printer Now type in the following programme 10 OPEN 4 t 20 PRINT 4 TAB 3 squares 30 FOR 1 1 TO 20 40 PRINT 431 31 1 50 NEXT i 60 CLOSE 4 When this programme is run the output a table of squares will be printed on the printer Information for microdrive users Except for the differences listed here the Discovery system is completely software compatible at command line level with the microdrive system BASIC programmes which work on the microdrive system should work unchanged The differences between the Discovery disc system and the m
24. ed loaded or verified When saving a block of memory the start address and number of bytes must be given in decimal When loading or verifying the start address and number of bytes may be omitted although you cannot omit the start address if you wish to specify the number of bytes Any value that is omitted is obtained from the file and will therefore be the same as when the block of memory was saved Loading a file overwrites the memory until all of the file is loaded and may overwrite information that is needed If you wish to load a file into a block of memory whose size is fixed this size should be given in the command The file is then only loaded if enough room is available For example SAVE 1 bytes CODE 1234 50 Saves 50 bytes starting at 1234 to the file called bytes on Drive 1 DATA lt array name gt This is an extension to the LOAD VERIFY and SAVE commands which can be used to save and load an array Numeric and string arrays can be saved and reloaded Note that the must be included e g SAVE 1 fred DATA AC saves the numeric array A to a file called fred on Drive 1 ERASE lt File spec gt This command erases the file specified The filename is removed from the directory and the space on the disc occupied by the file is made available for further use e g ERASE 1 Rowland erases the file called Rowland from disc 1 and generates an error report if the file is not found The full fo
25. erefore further divided into a number of equal parts called sectors On the Discovery disc system each track is divided into 18 of these sectors 10 Each sector holds 256 bytes and so a forty track disc will hold up to 180 Kbytes 1 Kbyte being 1024 bytes When you purchase a disc there is nothing recorded on it But before you can use it it must be set up This process is called formatting the disc and is done by using the FORMAT command for example FORMAT m 1 Disc Two ENTER formats a disc in drive number one and gives it the title Disc Two Formatting a disc erases any information that was stored upon it you may be re using an old disc and so you must be careful not to format any disc containing information that you want to keep Discovery however has been designed to prevent this happening If you try to format a disc that has already been formatted and given the name utilities for example you will be asked Destroy utilities Then if you wish to proceed you should type y to format the disc The disc title enables you to identify your discs and can be up to ten characters long For identification purposes each sector on the disc has an identification marker These markers are not written along with the information when it is saved but must be written before the disc can be used Formatting is the process of writing these markers When information is stored in a filing cabinet it is kept in cardboard folders w
26. eys together Spectrum users need only press the BREAK key Be careful however to avoid doing this when a disc drive is being used as it may corrupt the information on the disc Always try to make copies of important discs to safeguard your information Setting up the system FORMAT and CAT The Discovery disc system consists of the hardware and software necessary to enable your Spectrum to transfer information to and from a disc together with a number of extra facilities The system allows one or two disc drives to be used For those with a dual drive unit the left hand drive is drive number 1 The 3 1 2 inch discs used with the Discovery disc system have a hard case and are particularly robust Inside the case is a circular flexible disc with a magnetic coating When inserted into the drive the protective shutter is moved aside giving access to the recording surface When reading or writing the disc head moves across the required position and the information is read or written as the disc rotates under the head Unlike a record the information is not recorded on a continuous spiral path but on a series of concentric circles The disc head can be moved in and out across the surface to a number of fixed positions Once in position the head traces out a circular path or track on the disc as it rotates The number of tracks on the 3 1 2 inch discs used in the Discovery system is 40 Each track holds a large amount of data and is th
27. file is transferred you will be prompted to change discs when necessary Drive numbers one and three both refer to the physical drive number one When youchange from using drive number one to using drive number three and vice versa the disc system recognises the need to change discs and prompts you to do so The same situation applies with drive numbers two and four they both refer to physical drive number two Programme files can be moves in exactly the same way tell can be copied by typing MOVE m 1 tell TO m 3 tell ENTER The disc system uses the MOVE command for a number of special functions disc copying disc compacting and changing a file s position on the disc Disc copying and compacting are described elsewhere but if you want to move the location of file 1 on the disc use the command MOVE m 1 file1 TO m 1 file1 This can be useful if when trying to extend file1 you obtain a file size error This indicates that there is insufficient space at the current location to extend the file The MOVE command transfers data froman input channel to an output channel Information on the channels available to you is given in the later section on channels and streams One final example The b channel allows input and output using the parallel port without translation in contrast to the t channel This can be used if you want to transfer information to or from another Spectrum You can even do this with other com
28. g the MOVE command is not as tidy as that obtained by using the programme tel2 The MOVE command just takes characters from the file and puts them onto the screen It does not check what is being sent and makes no attempt to obtain a tidy display This is further illustrated by the next example Try to display the programme tell by using the MOVE command MOVE m 1 tel 1 TO S ENTER this does not provide a listing of the programme because programmes are not stored in the same way as data The MOVE command can only be used therefore to display data files In the same way the MOVE command can also be used to print a data file using the parallel printer interface by typing for example MOVE m 1 telephone TO t ENTER this will print the contents of the data file telephone on the disc in drive number one on a parallel printer connected to the parallel port When used for output the t channel sends printable characters to the parallel port and filters out other characters As with the screen display this will not work sensibly with programme files Those with a dual drive system can make a copy of the file telephone from a disc in drive number one onto a formatted disc numberr two by typing MOVE m 1 telephone TO m 2 telephone ENTER Those with a single drive system can make a copy by using the drive numbers one and three in other words by typing MOVE m 1 telephone TO m 3 telephone ENTER As the
29. he file to be used should be moved to the RAMdisc manipulated from there and then moved back onto the disc when the processing is completed Appendix 1 Transferring programmes from tape to disc The most straightforward method of transferring from tape to disc is to load the programme from tape and then save it to disc in the usual way This will not work however with programmes that run automatically and in these cases you can try merging the programme Suppose that you wish to transfer a programme called MAGNUM First type NEW ENTER To remove any unwanted programme or variables and then type MERGE MAGNUM ENTER If successful you can then save the programme to disc in the usual way If this fails you will need to use one of the programmes commercially available to carry out the transfer Some programmes on cassette come with instructions for transfer to microdrive and the same instructions will usually allow you to transfer the programme to disc Appendix 2 Error reports on the Discovery system The following error reports with their error codes are produced by the Discovery disc system a Invalid device name the channel identifier is incorrect Allowed device names are listed in the reference section b stream already open the stream specified is already in use c invalid drive number thedrive number given is incorrect Allowed drive numbers are 1 2 3 4 or 5 e write protected the disc in the f disc full
30. he type of use may be omitted from the OPEN command and the option that is then taken depends upon the channel being used Details on the use of channels is given in the reference section Data storage To explain data storage more fully let s return to the programme tell which we first used in the introductory section Load and list the programme to display 10 OPEN 4 m 1 telephone OUT 100 INPUT Name n Tel No t 110 JF n END OR n end THEN CLOSE 4 STOP 120 PRINT 4 n 130 PRINT 4 t 140 GOTO 100 Line 10 opens a file telephone on the disc in drive number one for output This file output channel is linked to stream number four The OUT part of the OPEN command indicates that the file is to be used for output If the file does not exist then a new file will be created if the file does exist then it will be replaced by the new file If you already have some names and numbers in your file and wish to add to them then you should use the programme tel3 given later and NOT use this programme again Line 100 asks fora name and telephone number and takes input from the keyboard Line 110 checks for the name end or END which is used to indicate the end of the list When found the channel is closed and the programme stops 19 Lines 120 and 130 print the name and telephone number to the file using stream number four e g PRINT 4 n sends the contents of n to stream number four followe
31. hich are labelled to allow a particular folder to be found easily In a similar way information on the disc is stored in files and each one is given a name The index of all files on the disc showing where they are located is stored in a special file called the catalogue file To display the catalogue file of a disc the CAT command is used e g CAT 1 ENTER This displays the catalogue of the disc in drive number 1 The catalogue of a newly formatted disc has the title that you specified when it was formatted and has no files present The number shown at the end of the list of files is the amount of space remaining on the disc in kilobytes 1024 bytes The catalogue contains the name and location of each file on the disc together with other information used by the disc operating system The catalogue is itself a file and this means that there is no restriction on the number of files allowed except the space available on the disc itself See the reference section for further details of the catalogue file The MOVE command One of the simplest things that you can do with your Spectrum is to take letters from the keyboard and display them on the screen This can be done by typing MOVE K TO S ENTER Now type in some letters the letters that you have typed will appear on the screen To finish press CAPS SHIFT and ENTER together The MOVE command takes input from the keyboard identified by the K and transfers it to the screen ident
32. iable 2 This command inputs values from the specified stream into the variables given The command is identical to the BASIC INPUT command and may therefore also try to output to the specified stream This is possible provided that the stream has been opened for output as well Care should be taken if using this facility and it is recommended that it is not used when inputting from a file In this case items in the variable list must be separated by semicolons and not commas to make sure that there is no output to the stream In the file the values to be read must be separated by the ENTER character and care must be taken to ensure that this is done when writing the file See PRINT below The stream being used for input can be changed from within the command for example INPUT 5 A 7 b 3c will get the value of A from stream number 5 and the values of b and c from stream number 7 LINE lt line number gt This extension to the SAVE command cn only be used when saving a programme It makes the programme run from the specified line number when it is reloaded e g SAVE 1 Chris LINE 10 saves the current programme onto the disc in drive 1 as a file called Chris so that when it is subsequently loaded it will automatically run from line 10 LOAD lt channel spec gt This command loads a programme and variables from the channel specified It can also be used with a number of extensions see CODE DATA and SCREEN LPRINT
33. icrodrive system are SAVE m 1 fred replaces the programme fred if it already exists INKEY 4 returns a null string when the end of file is reached 9 The list of files produced by the CAT command is not in alphabetical order You can MERGE programme files that have been saved using the LINE option The separator in the OPEN command can be a semi colon ora comma even for the channels k won and p Also some of the commands have been extended and these extensions are explained in the appropriate sections The Discovery disc system and the microdrive system cannot be used together and to transfer programmes from microdrive to disc they will first have to be saved on tape They can then be loaded from tape and saved onto disc Programmes supplied on tape with instructions to convert them for use on the microdrive system should convert to disc in exactly the same way Section 2 This section of the user manual covers the new commands of the Discovery disc system in more detail It uses the programmes and data from the introductory section in some of the examples given to illustrate the commands You should therefore work through the introductory section first and build up your own copy of the First Disc If you have entered and run a programme which does not stop normally in other words you find your computer has become stuck in a programme loop you can interrupt the programme by pressing the CAPS SHIFT and SPACE k
34. is will not be needed when using the disc drive system as the Discovery unit has its own power supply B Connect the Spectrum s TV output to your television set using the lead supplied with the computer Select an unused channel and tune it in to channel 36 If your television has manual tuning you will have to complete your fine tuning after the power has been switched on Connect the tape drive leads if you will be using a tape based programme C Before connecting the Discovery unit to your Spectrum you will need to study the two diagrams which cover both ZX Spectrum and Spectrum models D Plug your Discovery unit into the mains supply using the plug already supplied and fitted E Turn on the power supply to your Discovery unit and television set You are now ready to test the system and the following message should appear on the screen T JGR SINCLAIR RESEARTH LTD Some fine tuning may be necessary at this point to produce the best signal and therefore the sharpness of your screen image If the display fails to appear turn off the power supply and check all connections before trying again If the problem continues consult your dealer for further advice 3 ZX Spectrum In order to secure the Discovery unit to your ZX Spectrum you will first need to remove the self tapping screw which is located on the underside of your computer and is arrowed in the diagram Now place your computer an the platform at the front of the Discovery unit
35. ith a record length of 16 when POINT can be used to move to a given entry CODE this channel writes or reads directly from memory Use POINT to select the memory location at which you wish to read or write This channel provides a method of reading the shadow ROM and also gives access to the disc system hardware d this channel treats the disc as a single entity and is used by the MOVE command The full specification is d lt drive gt j this channel turns the joystick port on and off and is only used by the FORMAT command K the keyboard also outputs to the lower part of the screen m disc file The complete channelspecification is given below as lt file spec gt P the printer S the top part of the screen t input and output to the parallel port For input the top bit is set to zero giving codes between 0 and 127 For output character codes less than 32 are ignored except for CR which causes a CR or a CL LF pair to be sent see below Character codes greater than 127 are expanded if they represent BASIC tokens and are printed as if they represent graphics characters The full specification is t lt status gt 22 If status is 0 then when a CR is encountered a CR LF pair is sent if It is 2 then only a CR is sent If itis 1 then the ZX printer is emulated The status can be omitted and in this case the default is 0 this stream channel allows you to open one stream to another
36. l while the b channel is used as a binary channel Note 3 Other special channels are available These have been used in the examples and are described in the reference section Data is information in a form that can be processed by the computer and can be said to flow from input to output Using this analogy information moving around the system is called a data stream At any instant there may be several streams of data in existence Each data stream is identified by a number from 0 to 15 and is linked to various imput or output devices channels ZX printer PU Stream numbers 0 1 and 2 are already assigned and are best left alone at least until you become totally familiar with your system The assignments for streams 0 1 and 2 are O and 1 These are used for input from the keyboard and for output to the lower half of the screen Used automatically by INPUT and INKEY not INPUT or INKEY these use the specified streams 2 Is used for output to the upper part of the screen Used automatically by PRINT and LIST 3 Stream 3 is automatically assigned to the printer but it can be reassigned if you wish This is useful if you wish to redirect output to the printer as Stream 3 is automatically used by LPRINT not by LPRINT which uses the specified stream and LLIST In BASIC streams and channels are linked by using the OPEN command for example 17 OPEN 4 S ENTER associates stream number 4
37. les or discs on a single drive system Drive 5 refers to the RAM disc see later II lt stream gt The Spectrum uses streams to transfer data from a source to a destination Every stream used must be numbered between 0 and 15 an integer Stream numbers 0 1 and 2 are already reserved for use by the Spectrum system Stream number 3 is set up by the Spectrum for use with the ZX printer However this may be changed to use the Discovery printer port See OPEN command Normally streams 4 to 15 are available to the Discovery user III lt filename gt Every file on a Discovery disc has a name The name is made up of a stringexpression of between 1 and 10 characters e g utility or READ ME NOTE quotes is different from QUOTES upper and lower case letters are not taken to be identical IV lt channel spec gt The Spectrum computer uses a number of channels lo represent hardware For instance K represents the keyboard The Discovery unit adds a number of additional channels to the Spectrum The channel specifications available are b input and output to the parallel port characters are sent and received as 8 bits with no translation CAT this channel gives access to the disc catalogue file The complete channel specification is CAT lt drive gt Care must be taken if writing to the catalogue file as if this is corrupted then files on the disc may be lost This channel is best opened for random access w
38. lfled as S In this example and when working through the introductory section you will have noticed that different parts of the system are identified by a single letter in quotes For example K for the keyboard S for the screen or t for the parallel printer These different parts of the computer system are called channels Now try this MOVE K TO K ENTER Again type in some letters and this time the letters appear on the bottom part of the screen To finish press CAPS SHIFT and ENTER together The K channel can be used for input from the keyboard and for output to the lower part of the screen The examples just shown are of little practical use however and so let s try a number of more useful examples When you have run the programme Tell from the introductory section you can display the contents of the datafile telephone by putting the disc into drive number 1 and typing MOVE m 1 telephone TO S ENTER The contents of the file will be displayed on the screen Channel m is the disc file channel 11 You also have to tell the system which disc drive is being used and which file you require m 1 telephone refers to the file telephone on the disc in drive number one The command you entered transfers the contents of the file to the screen This time there is no need to indicate that the input has finished as this is done automatically when the end of the file is reached The output obtained by usin
39. lt stream gt variable 1 variable 2 This command prints the values of the variables in the variable list to the specified stream It works in exactly the same way as the PRINT command LPRINT LPRINT works in the same way as LPRINT lt stream gt above but always sends the variables to stream 3 LLIST This lists the programme to stream 3 which is set up by the Spectrum to be the ZX printer To list programmes using the Discovery printer port stream 3 must be opened to the t channel e g OPEN 3 t LLIST MERGE lt channel spec gt This command merges a programme and variables from the specified channel with the programme and variables already in the memory Any programme lines or variables that are duplicated will be overwritten by the new ones MOVE A TO B This command transfers information from an input channel or stream A to an output channel or stream B The process continues until end of file occurs in the input channel For input from a slow channel like the keyboard or the parallel port an end of file must be generated and this is done by pressing SHIFT and ENTER simultaneously File transfers using MOVE will be faster and involve fewer disc swaps if the Spectrum is first reset using PRINT USR 0 This enables the MOVE command to use the largest buffer possible If you have a programme in memory and a Spectrum reset is not convenient some space can be freed by using the CLEAR command OPEN lt stream g
40. m 1 tel2 ENTER When you run this programme it will list the names and addresses previously saved in the file telephone The programme above stores the names and telephone numbers one after another and to find a particular name and number all of the entries have to be shown Obviously it would be better if you could pick out the name and telephone number without having to read through all the entries in your file The Discovery disc system allows information to be stored in this way and an example of how to do this is given later in the section on Random Access Files Disc care and copying The Discovery Disc system uses 3 1 2 inch discs contained within a durable hard case Even so the following simple rules should be followed to minimise problems Do not touch exposed surfaces Keep away from magnetic fiends generated by televisions tape recorders loudspeakers etc Avoid dust cigarette ash or liquids lf the surface should become contaminated do not use the disc again as the contaminant will be transferred to the disc drive and may then contaminate other discs Important discs can be write protected so that they cannot be written to by the disc system To do this hold the disc as if you were going to insert it into the disc drive Underneath the disc on the left hand side you will find a slide covering a hole in the disc case When the hole is covered the disc can be written to Sliding the cover back to uncover the hole prevents the
41. mmand allows unwanted files to be removed from the disc For example the command ERASE 1 concorde removes the file concorde from the disc in drive number one If this short form of the command is used and the file does not exist then the error message file not found will be returned If the m channel is specifically included e g ERASE m 1 concorde and the file concorde does not exist then no error is produced This is to provide compatibility with Sinclair microdrives 21 REFERENCE GUIDE As you will have found if you have worked through the manual s introductory sections the Discovery system provides a disc operating unit which is not only powerful and flexible but also easy to use In this section we describe the commands together with all the options available with each command Many of the commands require similar expressions to be included for instance whenever a drive number is required it can be 1 2 3 4 or 5 So when you see lt drive gt in a command replace it with 1 2 3 4 or 5 according to the drive number which you wish to use The use of this notation will make it easier for you to understand the use of the commands 1 Notation I lt drive gt The Discovery unit can support two disc drives which are normally numbered 1 and 2 Drive 1 is normally on the left hand side Drive 3 can also be used to represent Drive 1 and Drive 4 to represent Drive 2 This is usually used for copying fi
42. mple OPEN 10 m 1 Paul RND 20 10 will create a random access file with a record length of twenty bytes and will hold 10 records i e the file will be two hundred bytes long Unlike the OUT option the 20 number of records must be given if you wish to create a random access file if you do not wish to specify the number of records use 1 for example OPEN 4 m 1 George RND 64 1 will create a random access file with a record length of sixty four bytes In this case the length of the file will be one half of the largest available space on the disc The following programme creates arandom access file and initializes it from the information in the data statements 10 DIM f 9 20 OPEN 4 m 1 random RND 10 10 30 FORi 1T0O 10 40 READ f 50 PRINT 4 f 60 NEXT i 70 CLOSE 4 80 DATA Dave Tan Laurie Rowland Eric 90 DATA Chris George Hector Paul Carol Note that the string is dimensioned to be nine bytes long but when printed the PRINT command adds an ENTER character which makes the record length ten bytes As there is an ENTER character at the end of each record the records can be input using INPUT so we do not have to read the record one byte at a time using INKEY To open an existing file for random access the RND option is used with just the record length given for example OPEN 8 m 1 Dave RND 128 assumes that the file exists and it is opened for random access with
43. mponent side of the board and A14 Is the NMI line When held high the ROMCS line B 25 disables the Spectrum ROM and the Discovery shadow ROM Joystick connector The joystick connector is positioned towards the rear on the right hand side of the Discovery unit and can be used with any Atari style joystick Parallel printer port The edge connector for the Parallel Printer Port Is also positioned on the right hand side of the unit It needs a standard 26 pin IDC connector and the pin connections are 1 strobe 3 DO 5 DI 7 D2 9 D3 11 D4 13 D5 15 D6 17 D7 19 Acknowledge 21 Ready odd numbers 21 to 25 and 26 no connection Even number 2 24 0V To use a parallel printer you will need a printer cable A cable with an edge connector at one end and a Centronics printer connector at the other can be obtained from Opus Supplies Ltd its part number is PCDC1 To connect two Spectrum computers you need a cable with an edge connector at each end The connection is straight through pin to pin and so the edge connectors can be crimped directly onto each end of the cable 30 The Discovery range The Discovery range from Opus Supplies has been specially developed with expansion in mind Discovery can be upgrade to a dual drive system by purchasing the Discovery This upgrade package will be fitted by Opus Supplies Under no circumstances should a purchaser attempt to fit this upgrade system as this will aut
44. n be run by typing RUN ENTER as before Summary To clear the guess programme and then recover it use the following sequence NEW ENTER LOAD m 1 guess ENTER LIST ENTER RUN ENTER If the message file not found should appear check your entry again Remember to type in your file name exactly as your original In this case guess is in lower case GUESS entered in upper case would produce file not found Automatic run facility Another useful feature of your Discovery disc system is its ability to run a programme automatically Type NEW ENTER Now type the following programme 10 BORDER 0 PAPER 0 INK 7 CLS PRINT AT 10 7 20 FOR i 1 TO 17 READ a PRINT CHR a NEXT i 30 DATA 73 116 39 115 32 97 117 116 111 109 97 116 105 99 32 33 Save the programme on disc by typing SAVE m 3 1 run LINE 10 ENTER Now type NEW ENTER RUN ENTER The programme runs automatically from line number 10 Typing RUN after typing NEW or after first switching on causes the programme you have selected to call run to run automatically 1f you find a favourite programme you may find it useful to name the programme run so that you can take advantage of the automatic run facility Using disc based programmes Games and other programmes supplied on disc will normally use the automatic run facility just outlined AII you need to do is to turn on your system insert your disc and type RUN ENTER The programme runs automatically If this
45. ogramme must have been saved on disc with the filename run with the LINE extension used to indicate the starting line of the programme This is done with the command SAVE m 51 run LINE lt line number gt ENTER If the LINE extension is not used the file run will be loaded automatically but it will not be run 4 Useful USR routines USR 0 this resets the Spectrum but not the disc system 27 USR 14070 this resets the disc system USR 8 this returns the version number of the disc software USR 432 this returns the number of bytes remaining in the current stream If the stream is of unknown length then it returns the value 1 PRINT 4 lt gt for example leaves four as the current stream NOTE 1 INKEY lt stream gt leaves the current stream unchanged NOTE 2 The commands PRINT 4 PRINT USR 432 will not work as the second PRINT resets the current stream to the screen To do this use PRINT 4 LET lenght USR 432 PRINT lenght This can be more usefully used to test for the end of a file without inputting a charachter using INKEY for example PRINT 4 IF USR 432 0 THEN PRINT eof 5 Compacting a disc The disc system stores the files on the disc on consecutive sectors After some use saving and erasing files the space on the disc becomes fragmented with small numbers of sectors that cannot be used To make use of these sectors the disc must be compacted This process moves the files so
46. omatically invalidate the guarantee Discovery 2 is available as a purpose built dual drive system Guarantee This Opus product is guaranteed for a period of 12 months from the date of purchase subject to the conditions listed below 1 The guarantee shall only be effective if the whole guarantee form is completed and returned to Opus Supplies Limited within ten days of the product s purchase 2 The guarantee applies only to the original purchaser and is not transferable The warranty applies only to products purchased from an authorized dealer to whom the equipment was sold by the company or direct from Opus Supplies 3 All repairs and modifications to the unit must be undertaken by the company via the dealer network The warranty is immediately invalidated if this procedure is not followed Where possible claims under the guarantce should be referred to the dealer from where the unit was purchased If this is not possible you should contact Opus direct When making a claim the customer s portion of the certified guarantee must be produced 4 Customers are liable for the carriage costs of units returned under the claims procedure 5 If after testing by the company no fault can be found with the system and the unit complies with the published specification the company reserves the right to charge a reasonable fee for testing and returning the unit 6 The liability of the company under this guarantee is limited to the cost of rep
47. puters providing suitable software is available To send a file sfile on disc number one use the command MOVE m 1 sfile TO b To receive information and save it in the file rfile use the command MOVE b TO m 1 rfile the computer receiving the information should carry out its commands first so that it is ready to receive when the machine sending the information starts 12 When the transfer is complete the person receiving should generate an end of file by pressing CAPS SHIFT and ENTER together This writes any remaining information to the disc To transfer programme files it is better to use LOAD and we will explain how to do this in the next section Load Save Merge and Verify These commands have the same effect as the corresponding cassette commands This section contains a number of further examples to illustrate the use of these commands Insert your copy of the First Disc into drive number one and type LOAD m 1 guess ENTER This will load the file called guess from the disc in drive number one To save the programme on another formatted disc insert the new disc into drive no 1 and type SAVE m 1 guess ENTER When loading a file if the file does not exist an error report file not found will be generated When saving a file if the file does not exist then a new file is created and the programme or other information is saved to that file If the file already exists then unlike the mic
48. r message but the CAT command shows that there is still space available then the catalogue file may be full It can be extended by using the commands OPEN 4 CAT EXP lt length gt ENTER CLEAR 4 ENTER when if possible the catalogue file will be extended The length can be calculated from the formula 16 No of extra files If no length is specified the catalogue file is doubled in length or if insufficient room is available is extended as far as possible Note It may also help to compact the disc as shown earlier 7 The RAM disc The Discovery disc system allows you to set aside pad of the Spectrum s memory as a RAMdisc To do this type CLEAR 32767 ENTER FORMAT 5 ramd The CLEAR command reserves the memory needed for the RAMdisc The disc system recognises drive number five as the RAMdisc and formats it accordingly Use the following programme to transfer some files from the First disc to the RAMdisc 28 10 READ f 20 IF f end THEN STOP 30 MOVE m 1 f TO m 5 f 40 GOTO 10 50 DATA tell tel2 tel3 telephone joysketchb end Now load the programme tel2 from the RAMdisc using LOAD m 35 tel2 ENTER and then make the following change 10 OPEN 4 m 5 telephone IN and run the programme You will notice how much faster the operations are when using the RAMaisc This is particularly useful when file processing providing of course that the file will fit into the available memory T
49. r width can be specified by using the RND option for example OPEN 4 t 0 RND 80 sets up stream four for output to the printer and sets the printer width to eighty characters If no printer width is specified then It defaults to 0 which means that no check on line length is carried out This option only applies to output using the t channel It has no effect on input 26 POINT lt stream gt lt record number gt This command is used with random access files to set the file pointer to the start of a given record Records are numbered consecutively starting from 1 It can be used with serial files provided that they have been opened as random access files with a record length of 1 In this case lt record number gt is used to point to a given byte in the file PRINT lt stream gt variable1 variable 2 This command prints the values in the variable list to the specified stream The items in the variable list can be separated by any of the separators used with the PRINT command When writing to a file which is to be read using another programme the items in the file must be separated by an ENTER character and they must therefore be printed separately or separated by apostrophes in the print list Printing to different streams can be carried out from the same print statement e g PRINT 5 SPECTRUM 8 disc 2 system will send SPECTRUM to stream 5 disc ENTER to stream 8 and system ENTER to the screen s
50. rm of the command ERASE m 1 Rowland produces no error if the file is not found FORMAT This command is used to set up channels j m and d FORMAT j lt status gt Is used to turn the joystick on and off lt status gt 0 turns the joystick off while lt status gt 1 turns the joystick on e g FORMAT j 51 turns the joystick on When the joystick has been turned on the current position of the joystick and the state of the fire button can be obtained by using JN 31 For example if using 1000 LET stick IN 31 the values of the stick can be interpreted from the diagram FORWARDS BACKWARDS Pressing the fire button adds 16 to the values of stick shown above FORMAT m lt drive gt lt disc title gt Is used to format a disc If the disc is already formatted then you will be asked to confirm that you wish to destroy the disc FORMAT 1 Rodger will format the disc in drive 1 and give it the title Rodger NOTE m may be omitted since it is the default channel 24 INKEY lt stream gt This command reads one character from the specified stream The stream must have been previously opened for input If the stream is associated with an m channel the command will only return a null string when the end of file has been reached Other slow channels will return a null string when a character is not available Slow channels are K t and b INPUT lt stream gt variable1 var
51. rodrive system it will be overwritten LOAD and SAVE can also be used to save the contents of the screen by using the SCREEN option Load the programme joysketch and modify it by typing 180 IF stick gt 16 THEN SAVE m 1 sketcha SCREEN FORMAT j 0 STOP ENTER Now save this new version as joysketcha by typing SAVE m 1 joysketcha ENTER Now run the programme When your picture is finished press the fire button and it will automatically be saved You can then reset the screen and reload the picture by typing CLS ENTER LOAD m 1 sketcha SCREEN ENTER CLS clears the screen and resets the screen attributes to their default values these are given in the reference section Another extension to the LOAD and SAVE commands allows an array to be saved and loaded The following programme generates 100 random numbers between 1 and 10 storing them in the array r This array is then saved on disc as the file rand no s Type 10 DIM r 100 20 FOR i 1 TO 100 30 LET r i 1 INT RND 10 40 NEXT i 50 SAVE m 31 rand no s DATA r Save the programme on disc with the name rgen using the command SAVE m 1 rgen ENTER Run the programme and then erase the programme and variables by typing NEW ENTER The array can be reloaded by using the corresponding LOAD command Type in the following programme 10 DIM c 100 20 LOAD m 1 rand no s DATA c 30 FOR k 1 TO 100 40 PRINT c k
52. sing the joystick s fire button You can even save the picture on disc by typing SAVE m 1 sketch SCREEN ENTER Spectrum owners have the abbreviated single key command SCRN Now to clear and reset the screen type CLS ENTER You can easily restore the picture by typing LOAD m 1 sketch SCREEN ENTER SCRN 7 After a few seconds the picture will appear as before Data handling As you are about to discover your computer is not only useful for playing games but also for storing information The following programme will show you how Type 10 OPEN 4 m 1 telephone OUT 100 INPUT Name n Tel No t 110 ZF n END OR n end THEN CLOSE 4 STOP 120 PRINT 4 n 130 PRINT 4 t 140 GOTO 100 Save the programme with the name tell by using the command SAVE m 1 tell ENTER Now run the programme If the programme fails to run check your entries correct them and save the programme again as outlined earlier Type in the names and telephone numbers of a few friends and complete your list with end and any telephone number The programme will save the names and telephone numbers in the file telephone and they can be listed whenever you require them Now type in the following programme 10 OPEN 4 m 1 telephone IN 100 PRINT 4 110 JF USR 432 0 THEN CLOSE 4 STOP 120 INPUT 4 n t 130 PRINT n t 140 GOTO 100 Save this programme as tel2 by using the command SAVE
53. t lt channel spec gt lt access gt This command associates the specified stream with the channel given Possible types of access are IN used for input only OUT used for output only For the m channel the following extra options are available EXP used to expand a serial file This option is output only and automaticallyadds information to the end of the file If the file does not exist then an error report will be generated RND used for random access files and allows input and output The type of access can be omitted and in this casette defaults for each of the channels are K IN and OUT g OUT p 3 OUT These channels always have these access options even if you try to change them You could open a stream for input from the K channel for example by using OPEN 4 1 IN which links stream four to stream one for input only The defaults for the other channels are b IN and OUT CAT IN CODE IN and OUT t IN and OUT IN and OUT m the m channel behaves in the same way as the m channel on the microdrive system If the file already exists it is opened for input while if it does not exist the file is created and the channel is set up for output to the file This is not the same as the OUT option where if the file exists it is overwritten For the m channel with the OUT option a length can be specified This length is the maximum size of the file and is used in the initial
54. t making it run Type NEW ENTER MERGE m 1 joysketchb ENTER Any programme and variables are removed by the NEW command As there is no programme in memory merging joysketchb has the same effect as loading except that the programme does not run automatically AII the commands just described can also be used with the b channel This channel sends and receives information from the parallel port Unlike the t channel characters are sent and received with no translation This channel can therefore be used with a suitable connecting cable for the transfer of programmes from one Spectrum to another The receiver should type LOAD b ENTER and then after loading the programme the sender types SAVE b ENTER Once the transfer is completed it can be checked using the VERIFY command The receiver types VERIFY b ENTER and the sender saves the programme again The programme is now in the receiver s memory and so the VERIFY command checks this against what is sent the second time Once transferred the programme can be saved to disc in the normal way This is much better than using the MOVE command as it allows the information sent to be verified and does not need an end of file to be generated from the keyboard The joystick programme Load the joysketchb programme without running it by using the MERGE routine described earlier LIST the programme 10 CLS PRINT AT 4 0 Use the joystick to draw a PRINT A
55. the screw during this operation Now take the rubber feet provided and peel off the paper backing Position the feet on the front underside edge of the computer as indicated in the diagram e ee xing scrow ag SECTION 1 How to start using your disc system This section of the operating manual has been written for those users with a single drive Dlscovery unit Those wlth a dual drive system will find certain tasks simpler particularly disc and file copying Drive 1 is the left hand drive To help you distinguish single key commands from those whlch must be typed in letter by letter all single key entries are marked in italic You are now ready to start using your Discovery disc system Take a disc and insert it as illustrated into the drive unit pushing it home until it clicks into place in drive 1 Firt steps With the disc in position type the following FORMAT m 1 First Disc ENTER You have now set up the first disc ready for use and given the disc the name First Disc You can easily check that this has been completed by typing CAT 1 ENTER This simple command lists the contents of the disc As there is currently no information on the disc only the title is displayed First Disc and the free space on the disc Playing a game To help you become more familiar with using your new disc system we have devised a simple game for you to play It s a guessing game Type 10 LET number INT
56. tream 2 SAVE lt channel spec gt This command saves the current programme and variables to the channel specified It can also be used with a number of extensions see CODE DATA LINE and SCREENS If a disc file is specified and it already exists on the disc it is replaced The old disc file is not overwritten and so it is not immediately lost e g SAVE 1 John CODE 16384 6912 saves the current screen to a file called John on drive 1 Note that a CLEAR command before saving will delete all variables and allow just the programme to be saved SCREEN This extension to the LOAD SAVE and VERIFY commands allows the screen to be saved and reloaded It is equivalent to CODE 16384 6912 e g LOAD 1 John SCREEN loads the previously saved file John from drive 1 to the screen VERIFY lt channel spec gt This command checks that the information that has been saved is the same as the information in the computer s memory and gives an error message if it is not It can be used with a number of extensions see CODE DATA and SCREEN 3 The autorun Facility After turning on the Spectrum or after resetting the machine by typing NEW ENTER it is possible to automatically run a programme from the disc in drive number 1 This is done by typing RUN ENTER when the disc system will look for a file called run on the disc in drive 1 If it is found it will be loaded and should run automatically The required pr
57. use the joystick in your own programmes We have devised a programme to show you how Type the following programme 10 CLS PRINT AT 4 0 Use the joystick to draw a PRINT AT 5 0 picture 20 PRINT AT 7 0 Use the fire button to end 30 PRINT AT 20 1 Press any key when ready 40 LET k INKEY IF k THEN GOTO 40 50 FORMAT j 1 110 BORDER 0 PAPER 0 INK 7 CLS 120 PLOT 0 0 DRAW 255 0 DRAW 0 175 DRAW 255 0 DRAW 0 175 130 LET stick IN 31 IF stick 0 THEN GOTO 130 140 JF stick 1 THEN DRAW 1 0 150 IF stick 2 THEN DRAW 1 0 160 IF stick 4 THEN DRAW 0 1 170 IF stick 8 THEN DRAW 0 1 180 IF stick gt 16 THEN FORMAT 0 STOP 190 GOTO 130 The command IN 31 on line 130 reads the position of the joystick and this is used to decide where to move next You can save the programme with the name joysketch on disc by using the command SAVE m 1 joysketch ENTER As this joystick programme has probably taken you some time to input into your computer it would be a pity to lose it You can check that the whole programme has been correctly saved by typing VERIFY m 1 joysketch ENTER This command checks verifies that what you have saved on disc is the same as the programme in the computer s memory and gives you an error message if it is not Having verified that the programme is saved correctly you can now run it by typing RUN ENTER When you have a sketch that you particularly like stop the programme by pres
58. used although it is simpler to use the SCREEN option described earlier This can then be redisplayed by using the corresponding LOAD command LOAD m 1 screen CODE 16384 6912 ENTER After saving a programme or other information using the SAVE command you can check that it has been saved correctly by using the VERIFY command All of the extensions like CODE can be used with this command Load the programme joysketcha and save it on another formatted disk by typing SAVE m 1 joysketcha ENTER You can check that it has been saved correctly by typing VERIFY m 1 joysketcha ENTER any difference between what is saved and what is in memory will cause an error report to be generated Now run the programme When ready to save a picture press the fire button The picture which you have chosen to save can be checked in the same way by typing VERIFY m 1 sketcha SCREEN ENTER any discrepancy will produce an error report The MERGE command combines a programme and variables from disc with one already in memory Any programme lines or variables that are duplicated are overwritten To illustrate this type in the following programme lines 140 IF stick 1 THEN DRAW 1 0 GOTO 130 150 IF stick 2 THEN DRAW 1 0 GOTO 130 160 IF stick 4 THEN DRAW 0 1 GOTO 130 170 IF stick 5 THEN DRAW 1 1 GOTO 130 180 IF stick 6 THEN DRAW 1 1 GOTO 130 190 IF stick 8 THEN DRAW 0 1 GOTO 130 200 IF stick 9 THEN DRAW 1 1
59. with the screen channel S POPE OCTOMN O COA OOS ODO D SOD OTOL er SOLES EP EP EP EE EP D This connection is added by tha command OPEN 4 S i Screen s The OPEN command makes the connection between stream four and the actual channel device S To break the connection and allow stream four to be used for something else you must use the following command CLOSE 4 ENTER Stream four can now be linked to another channel for example OPEN 4 t ENTER now associates stream four with the parallel port Type in the following programme which takes input from the keyboard and displays it on the screen in a similar way to the MOVE command MOVE men TO go 30 LET a INKEYS IF a THEN GOTO 30 40 PRINT a Run the programme Characters typed on the keyboard are printed on the screen This time to stop the programme press BREAK or SHIFT and SPACE together As written the programme uses the default channels Now type in the following programme 10 OPEN 4 K 20 OPEN 5 S 30 LET a INKEY 4 IF a THEN GOTO 30 40 PRINT 5 a This programme works in exactly the same way but it now uses stream 4 for input and stream 5 for output This programme is far from perfect To see why run the programme and after typing in a few characters stop it by pressing CAPS SHIFT and SPACE together BREAK Now try to run the programme again It will fail with the error report stre

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