Permission to distribute this document has not been given.
comments to Robert Perelegre

THE DISCIPLE

The multi-purpose interface from
Miles Gordon Technology for

ROCKFORT PRODUCTS

USER MANUAL

Copyright 1987

NOTICE

This manual, and the information contained herein, is copyright material and may not be reproduced, transcribed, stored in a retrieval system, translated into any language or computer language, or transmitted in any form whatsoever without the prior written conset of Miles Gordon Technology.

The manual is intended to provide the user with detailed information adequate for the efficient installation and operation of the equipment involved. However, while every effort has been taken to ensure accuray, the manufacturer and distributor assume no liability resulting from any errors or omissions in this manual, or from the use of the information contained herin.

Miles Gordon Technology reserves the right both to change the specifications of the Disciple and to revise this publication from time to time without obligation to notify any person of such revision or changes.

Thrid Edition .............. August 1987

CONTENTS

INTRODUCTION, Key Features
SETTING UP YOUR SYSTEM
MAKING THE DISCIPLE COMPATIBLE WITH YOUR SYSTEM
USING A DISK DRIVE
Loading the DOS                                            The Autoload File
The Catalogue                                                 Spectrum Reset Button
Disk Drive Syntax                                            The Snapshot Button
Saving and Verifying                                        Abbreviated Syntax
Loading a Program                                          Wild-Card Files
Breaking a Program                                         The Inhibit Button
Renaming a File                                               Formatting New Disks
Copying a File                                                 Care of your Disks
Erasing a Filed                                                 Error Reports
USING JOYSTICKS                                     USING A PRINTER
Snapshot Printing
Printing form a Commercial Word Processor
NETWORKING
Setting up the Network
The Shared Access Network
The Independent Station Network
USING OTHER PERIPHERALS
ADVANCED USER SUPPLEMENT - INTRODUCTION
   APPENDIX A: ADVANCED DISCIPLE SYNTAX
      Reading from/Writing to a Sector
      Using Streams and Channels
      The Execute File
   APPENDIX B: THE POKE @ COMMAND
   APPENDIX C: DISCIPLE COMMAND CODES
      User File Information Area
      Examples of Command Codes in Use
   APPENDIX D: TECHNICAL SPECIFICATIONS
      Port details
      Disk connector - Pin description
      Printer connector - Pin description
   QUICK REFERENCE GUIDE
   GUARANTEE DETAILS

INTRODUCTION

The Disciple is an interface which allows the Spectrum range of computers to be connected directly and simultaneously to:

* One or two disk drives with the standard Shugart SA400 type connector. The Disciple will accept 5 1/4", or 3 1/2" drives, whether they are 40 track or 80 track, single or double sided, single density or double density.

* Any centronics paralle-type printer.

* One or two standard (Atari-type) joysticks.

* Most other standard Spectrum peripherals.

OTHER KEY FEATURES of the Disciple are:

* Rapid transfer speed: in double density mode, a 48K file can be loaded from disk in approximately 3.5 seconds, a 128K file is less than 10 seconds.

* Large storage capacity: using two double sided, double density disk drives, up to 1.56 Megabytes is available. None of the computer's memory is used by the Disciple.

* A snapshot button allows instant transfer of everything held in the computer's memory to disk.

* A powerful printer interface permits graphics and full-screen printing; a unique facility is that the Disciple can interrupt a game at any point and print out the entire graphics screen.

* Two network connectors provide a network which is compatible with Sinclair Interface1; with the Disciple attached, up to 63 computers can interact in a system using a single disk drive or printer.

* All the Disciple interfaces use a simplified syntax similar to the Spectrum's own Basic. Or the normal Microdrive commands can be used, if preferred.

SETTING UP YOUR SYSTEM

IMPORTANT: Before connecting any peripheral to your computer, always disconnect the power supply first. Failure to do so could damage your computer.

With the power off, carefully connect the peripherals you are using into their sockets, as shown in the diagram above. The front half of your Disciple will fit neatly underneath the computer, supporting it at a convenient typing angle. Whe the Disciple is in place, tighten the screws at the base of the unit for a secure attachment to the computer. If you normally use the Sinclair Interface 1, do not connect it yet: you will be told how to use the Interface 1 with the Disciple in the later section - The Inhibit Button.

Press the Inhibit Button twice. You will notice that when the Inhibit Button is on, it will lock into place; when it is off, it will spring out of the lock. Make sure that the Inhibit Button is off before you start work.

For the first steps, you will need to have your cassette recorder attached to the Spectrum in the normal way.

Connect the power and the normal Specturm introductory screen will appear on your monitor/TV. Turn on the disk driver power and insert a blank disk.

If your are using a Spectrum 128K or Plus 2, go into the Edit mode, and then move the cursor to select Screen. Then press ENTER. This has the effect of removing the logo from the bottom of the screen, and the commands that you enter will appear at the bottom of the screen instead of the top.

MAKING THE DISCIPLE COMPATIBLE WITH YOUR SYSTEM

The Disciple has been designed to work with a wide variety of disk drives and printers, but each of these may have a slightly different mode of operation. To enable the Disciple to be compatible with your system, therefore, you first step is to give the Disciple instructions telling it which peripherals you are using, and how you intend to use the. You will only need to do this the first time you use your system, because the information will then be permanently stored on disk, ready for use as soon as you connect the Disciple.

This is how to set the parameters for your system.

* Load the cassette tape supplied with your Disciple as follows:

- Set up your system - including a cassette recorder - as shown in the diagram. Insert the cassette in your cassette recorder, and set the recorder's volume level at about 3/4 of maxium volume.
- Type                               LOAD ""
- Press                              ENTER
- Press "Play" on your cassette recorder.

* While the program is loading, insert a floppy disk into your disk drive. (If you are using two disk drives, you must insert it into drive 1 - your disk drive manual may refer to it as drive A). If possible, use a floppy disk which has never beed used before.

* Wait until the message "Press any key to continue" appears on the screen. (If this message does not appear at the end of loading, check that the lead from the recorder into the computer has been correctly attached - refer to your Spectrum manual. If the connections are correct, try adjusting the volume level on the recorder and start again. Red and blue horizontal lines on the screen during loading should indicate that the program is loading properly.)

* Press any key. You will then be asked a series of simple questions about your system. Type in the answers to each of the questions in turn, remembering to press "ENTER" when you are satisfied that your answer is correct. If you make a mistake, don't worry: you'll be offered the opportunity to go through the questions again at the end, if you need to.

These are the questions you'll be asked. Study them and decide on the answers before you start work on the computer. Write your answers in pencil on the dotted lines below, so that you have a record of the values you enter - in case you wish to change them later.

1(a) Is disk drive 1 a 40 track drive?                   (Your answer)...Yes/No...

 (b) Is disk drive 1 an 80 track drive?                                        ...Yes/No...

 (c) Is disk drive 1 double sided?                                                ...Yes/No...

 (d) Is disk drive 2 a 40 track drive?                                          ...Yes/No...

 (e) Is disk drive 2 an 80 track drive?                                        ...Yes/No...

 (f) Is disk drive 2 double sided?                                                ...Yes/No...

2. Enter disk drive stepping rate in milliseconds                      ..................

You may not fully understand the significance of all these different types of files yet. There will be further explanation later in the manual, and the regular newsletters published by the Disciple Users' Club explore the more specialised file-types in detail.

The right-hand column in the catalogue tells you the starting address of the file, and, after the comma, the number of bytes used if it is a code file. If it is a file in Basic, the number will show the line at which the program starts.

The amount of free space left on the disk is displayed in kilobytes at the bottom of the screen.

If your directory fills the screen, and you wish to scroll down to the next screen, press ENTER.

You can also display an abbreviated directory by typing CAT 1! (or CAT 2!). This would show the same directory in the following format:

Both the full and the abbreviated directory can be listed on screen simultaneously. Or you could, for example, list disk 1 in full and disk 2 in the abbreviated form.

If you wish to print out the catalogue on your printer, you can use the special CAT #3 command. For example, to send the catalogue on drive 1 to the printer, you enter:
                     CAT #3;1
To print an abbreviated catalogue from drive 2, you would enter:
                     CAT #3;2!

Disk Drive Syntax

When you use the Disciple and a disk drive, Basic commands typed on the computer keyboard are followed by a Syntax Operator - a code to let the computer know that the instructions are directed toward the disk drive, and not, for example, toward a casstte recorder.

For ease of explanation in the manual, the syntax operator will be referred to as D1, meaning that the instruction is for drive numer 1. However, when you are working on the computer, the following options are also available:

(Programmers should not that D* is particulary useful when your disk file autoruns and calls up another file on the same disk unit. You should also note that a variable can be assigned for drive number 1 or 2 but not for *.)

By typing a upper case D rather than a lower case d when saving a file, the abbreviated disk catalogue will be displayed automatically when the save is complete. A new catalogue also appears automatically if you type an upper case D when erasing or renaming a file.

(For those who are familiar with the Sinclair Microdrives, note that you can use Sinclair Microdrive syntax with the Disciple. For example, to load a file from drive1, you could type:
                LOAD *"m";1;"file-name"
In this case, the syntax operator D1 is replaced by *"m";1;
For further details of Microdrive commands, refer to the Microdrive manual.)

Saving a File and Verifying

On the ZX Spectrum, you save programs on cassette using statements which you are probably familiar with. As an example, type in this short program called Squares:

                10 REM Squares
                20 FOR n=1 TO 10
                30 PRINT n,n*n
                40 NEXT n

To save on cassette, you would type:

                SAVE "Squares"              ENTER

To save the program on the disk in drive 1, you type:

                SAVE D1 "Squares"        ENTER

(Remember that D1 can be either d or D, 1 or 2 or *)

The screen border will flash, and after about 2 seconds the program will be saved. Try it and see.

As described in the last section, if you have SAVEd using a capital D, the disk directory is automatically displayed. If you have done the example, you will see the program Squares shown on the directory as the las entry, followed by BAS (showing that this is a BASIC program file), and then the figure 1 (showing that 1 sector has been used).

If you wish, you can now do a further check to ensure that the program has been saved, by entering:

                VERIFY D1 "Squares"

Provided the program has been saved correctly, the screen will display then OK message. (If you ever have difficulty with saving a file, check that you have started with a formatted disk - see the later section in this manual.)

Now, with the program saved to disk, you can clear it from the Spectrum's memory by entering:

                NEW

Loading a program

Next, you can re-load the program Squares by entering:

                LOAD D1 "Squares"

The program will be loaded when the OK message appears. But so far we haven't typed in an instruction which make the program run. Let's do that now by entering:

                SAVE D1 "Squares" LINE 10

Of course, we already have a program called Squares on the disk, so you will be asked if you wish to overwrite the old one. You must enter either Y(=Yes) or N(=No).

We will enter:              Y
Then:        LOAD D1 "Squares"

By now, you will probably have realised that all the normal Basic statements that are used with cassette-based system can be used with the Disciple and a disk drive - with the simple addition of the short syntax operator, D1.

Breaking into a Program

To break into the program and stop Squares running, use the normal Spectrum command - BREAK.

Note that BREAK will stop the computer running all normal routines, but it will have no effect during a disk read/write operation until the disk activity has been completed.

Renamig a file

To rename a file, we use the two keywords ERASE and TO. For example, to rename your program Squares as Example 1, you enter:

                ERASE D1 "Squares" TO "Example 1"

The catalogue which automatically appears (if you have typed in a capital D) confirms that the file-name has been changed.

Note that your file-names can be any combination of letters and numbers - or even spaces - but the maxium number of characters you can use is ten. The Disciple allows you to type your file-names in upper or lower case letters (or both); in the catalogue, the file-names will appear exactly as you originally typed them, but when you re-load a file it will not matter if letters originally typed as lower case letters are changed to upper case or vice versa.

Copying a file

To copy a file we use the keywords SAVE and TO. Try copying the program you have written by entering:
                SAVE D1 "Example 1" TO D1 "Newcopy"

You will see that before the copy is made, you are given the opportunity to change the disk. If you don't need to change the disk, simply press the SPACE bar and the file will be copied with the new file-name.

You could also give the instruction:
                SAVE D1 "Example 1" TO D1

This would mean that you wished to copy the file onto drive 1 and to keep the same file-name. This is obviously useful if you wish to make a back-up copy of a file onto another disk. Again, you are given the opportunity to change the disk before you press the SPACE bar to make the copy. If you don't change the disk but press the SPACE bar, you'll be given the message that the "File-name exists" and you'll be asked whether you wish to overwrite the existing file. Press Y(=yes) to overwrite, or N(=no) to cancel the command.

If you are using two disk drives with the Disciple, you can also copy a file from one drive to the other, using the syntax:

                SAVE D1 "File-name" TO D2

If you add a file-name after D2, the new copy will have this as its new file-name; otherwise, the new copy will have the same name as the original file.

When copying is complete there is an automatic NEW instruction to the computer and the computer's tilte screen is displayed. To check that the copy has been made, call the CATalogue by entering CAT 1.

Erasing a file

Suppose you have finished with the program now called Example 1. To erase it from the directory of the disk, enter:

                ERASE D1 "Example 1"

During the ERASE, the border will flash, and the catalogue will be displayed automatically (if a capital D has been typed), showing that the file is no longer available and that more space on the disk has been made free.

(Programmers - note that, unlike Interface 1, the Disciple returns an error message if you try to ERASE a non-existent file.When using programs originally written for Microdrive with the Disciple, you will sometimes have to delete an ERASE command in the listing to avoid the error message.)

Creating and Autoload File

An autoload file is one which loads as soon as you RUN the operating system; you are allowed one autoload file per system disk.

For an illustration of an autoload file, let's rename the file Newcopy. Enter:

                ERASE D1 "Newcopy" TO "Autoload"

The new catalogue should tell you that the file is now called Autoload. Now turn off the power to your Spectrum; everything in the computer's memory, including the disk operating system will be lost.

Turn on the power again and load the operating system from your system disk by entering RUN. Your Autoload file (which, you'll remember, is the original Squares program) will be loaded at the same time, and instead of the normal Disciple title screen you'll see the Squares program running.

If, however, you do not want your autoload program to autoload, then enter:
                RUN boot
instead of:
                RUN

Using the Spectrum's Reset Button

If you use a ZX Spectrum +, a ZX Spectrum 128K, or a Spectrum 128K+2, your computer will have a reset button which allows you to reset your system without havint to turn off the power.

But when you press the computer's reset button once, the Disciple still retains the operating system in its own memory. You don't have to reload the Disciple's operating system - you can just carry on giving normal Disciple commands.

However, if the computer's reset button is pressed twice consecutively, the Disciple's operating system is no longer retained in memory. To be able to use Disciple commands, you will first have to load the operating system from your system disk (or techically, "boot up") afresh.

Saving a File with the Snapshot Button

By holding down the CAPS SHIFT key on your Spectrum's keyboard and then pressing then Snapshot Button on the Disciple once at any time during the course of a program, you are able effectively to "take a photograph" of anything held in the computer's memory at that time, and save it to the last drive in use, shown by the indicator light on the disk drive.

Make sure that the Disciple is connected and that your system is booted up with the system disk in drive 1. Then load in any program (a game is best for demonstration) in the normal way - from disk or from cassette. (If you're loading from cassette, use the Spectrum's normal LOAD "" command.)

When the program has loaded, press CAPS SHIFT and the Snapshot Button simultaneously. You'll notice that your program will be frozen at its current status, and you will see a number of thin multi-coloured lines filling the borders. You now have the following options:

Press key 3 on the Spectrum to save only the current SCREEN. A screen save will occupy 7K of memory space on the disk. The borders will flash until the save is complete, and when the flashing has finished, you can continue with the program from the point at which you left it.

Press key 4 on the Spectrum for a 48K PROGRAM to be saved to disk. Every time you save a 48K file, 48K of memory space (or actually 97 sectors) will be used on the disk. When you press key 4, the borders will flash, showing that the program is being saved. When the borders stop flashing, the save will be complete and the program will resume from the point at which you left it. If you want to, you can take more snapshots at later points in the program util your disk is full - if your drive has a capacity of 780K and you are using an empty formatted disk, the maximum number of 48K snapshot saves you could take would be 16.

Press key 5 on the Spectrum for a 128K PROGRAM to be saved to disk. Every time you save a 128K file, 128K of memory-space willbe used on the disk (=256 sectors). Again, the borders will flash for a few moments, but then the program will appear to be frozen again. If the picture on your screen (the picture - not the border) has changed, press key Y(=yes) on the Spectrum; if the picture has not changed, press the key N(=no) on your Spectrum. The borders will then continue to flash until your 128K save is complete. You will then be able to resume from the point at which you left the program.

If you have loaded the program on drive 1, but wish to save your snapshot file to drive 2 - or vice versa - press the CAPS SHIFT key on the Spectrum at the same time as pressing key 3, 4 or 5.

When you've saved a snapshot file, press the computer reset button (or in the case of the Spectrum 48K, turn off the power and boot up the system again) and call up the catalogue - enter CAT 1. You'll see that your snapshot file is labelled "Snap A/B/C" etc, with the letter of the alphabet dependent upon the file's position in the directory. Clearly it will be difficult to remember the precise contents of your snapshot file if this were the only name possible. So you'll need to give your snapshot file an identifiable file-name. First, choose a new name for the file you have snapshotted and then rename it using the ERASE ...... TO keywords. (In case you've forgotten how to do this, refer to the section RENAMING A FILE). Use the capital D in the syntax operator, so that the new catalogue is automatically displayed.

To relaod the snapshot files, you enter:

                LOAD D1 "Your new file-name" S                    (for a 48K file)
                LOAD D1 "Your new file-name" K                   (for a 128K file)
                LOAD D1 "Your new file-name" SCREEN$     (for a screen file)

The S, K and SCREEN$ identifiers are important, and without them the programs will not load. (If you are using Microdrive syntax, you will also need to type in the correct identifier at the end of the LOAD command for snapshot files.)

Abbreviated Syntax

Now that you've learnt the basic disk drive commands, we can introduce you to a much easier way of loading a file. You can enter just:

                LOAD p6

This has the effect of loading the program labelled number 6 in the directory. This command will be particulary useful when loading a code file. Normally you would have to type, for example:

                LOAD D1 "music" CODE 40300,1750

- stating the start address and the number of bytes used. But using the abbreviated syntax, you can simply enter:

                LOAD p4

MERGE and VERIFY can also be used with the program number in this way.

Using the "p" command, you do not need to type S, K, or SCREEN$ in order to load snapshot files.

Wild-Cards Files

Wild-card files allow you to CATalogue, copy (using the SAVE...TO syntax), or ERASE a group of similar files in a single operation. Let us imagine, for exemple, that you have a series of file called:

                numbers1, numbers2, numbers3, numbers4

To erase all of them, you could enter:

                ERASE D1 "n*"

The effect of the star is to say that all the rest of the file-name doesn't matter: you wish to erase all files commencing with "n". Be careful: this really means all files beginning with "n".

You could also enter:

                ERASE D1 "??mb*"

You would then erase all files which have "mb" as their third and fourth letters. The effect of each question-mark is to say that "this letter is of no significance".

The same syntax - using ? and * - is available for the SAVE .... TO and CATalogue commands. Thus, if you wanted a copy all the files on disk 1 to disk 2, you could enter:

                SAVE D1 "*" TO D2

Or, if you wanted to copy you "numbers" files to drive 2 and also give them a new file-name, you could enter:

                SAVE D1 "numbers*" TO D2 "figures*"

(Note that if you are using wild-cards, the new file-name must have the same number of letters as the first - in this case seven letters.

Also note that when you copy files, whether form one disk to another or to the same disk, it is not possible to copy a snapshot file. This precaution is necessary in the interests of the software houses, who would not wish to support a device which could encourage commercial piracy. It is possible, of course, to take a second snapshot of the same file.)

The Inhibit Button

You may find that you have a peripheral which appears not to work with the Disciple. This may be because the peripheral in question has its own ROM and there is interference between the ROM on the Disciple and that on the peripheral. (This is the case for example, when you use Interface 1 with the Disciple.) In these cases, follow this procedure:

1. With the power off, attach the peripheral behind the Disciple. Keep the disk drive attached and make sure your have a system disk ready.

2. Turn the power on and load the Disciple's operating system by entering RUN. You can load a program from disk if you want to.

3. Press the Inhibit Button once, so that it is locked in: this gives you the capability of switching off the Disciple's operating system. To actually turn off the sytem, enter OUT 31,0. You can now no longer use your disk drive (although the Disciple's printer and joystick ports remain active), but you will probably be able to use your peripheral. If now, for example, you entered CAT 1 with Interface 1 and a Microdrive attached behind the Disciple, you would display the Microdrive's directory, not the Disciple's.

4. When you wish to use the Disciple's disk drive again, you can either press the Inhibit Button again (so that it is no longer latched in), or you can enter OUT 31,16. You can then continue to use the Disciple in the normal way. So, if you have loaded a program from Microdrive into the computer, you could now save it to disk, with either the SAVE command, or with the Snapshot Button.

(Programmers' note: You can use OUT 31,0 and OUT 31,16 in your programs to turn the Disciple's DOS on and off. See List 1 in Appendix A.)

Formatting New Disks

Before a floppy disk is used for the first time, it must be formatted. You can also format a previously-used disk: the effect will be to wipe the disk clean of information.

You must therefore be careful not to format a disk which contains any files you wish to keep. It is also risky to format a disk while you are holding a program in the Spectrum's memory. (This is because the format command uses approximately 8000 bytes of Spectrum memory from address 49152 upwards; any program residing here will be overwritten with format information.)

To format, insert the disk in drive 1 or 2 and enter:

                FORMAT D1 (or D2)               - for double density format, or
                FORMAT SD1 (or SD2)           - for single density format.

It is good practice to ensure that you always have spare formatted disks when you start work: then, if you fill your original working disk, you can easily substitute a spare disk without interrupting your program to format.

After formatting a new disk, it is always a good idea to copy the Disciple's system file onto it, so that you always have a spare system disk available. You can do this by entering:

                SAVE D1 "Sys 3b" CODE 0,6656

If you are using two disk drives, the following command is available:

                FORMAT D1 TO 2

This command formats the disk in drive 1 and copies the contents of the disk in drive 2 to the disk in drive 1, sector by sector. BE VERY CAREFUL NOT TO FORMAT THE WRONG DISK. Remember that the first-named disk is always the one which is cleared of data, and the second-named whose contents are copied. Because the copying is done a sector at a time, the copying process takes much longer than when you use the SAVE...TO command; but the FORMAT...TO command will give you a new disk which is identical in every respect to the one which has been copied.

Care of your Disks

Your floppy disks are valuable, not only because of the information they hold, but also because of the time you have spent creating them. Make these safety procedures a habit:

Error Reports

There are a number of standard Spectrum error messages which will appear on screen if the command you have typed in cannot be obeyed. For full details, consult the Spectrum manual.

When you are using the Disciple, these standard error messages may continue to appear, but there are some additional error reports which refer specifically to disk handling problems. These are some of the more important you may meet:

USING JOYSTICKS

There are two Atari-type joystick ports on the Disciple, one on the left as you look at the computer from the front with the Disciple attached, and the other on the right. If you are using only one joystick, you must always connect it to the right-hand port (as Figure 1).

When you load commercial software programs, you are normally asked to select either Kempston or Sinclair (Interface 2) compatibility. When using the right-hand joystick port you can select either Kempston or Sinclair modes. When using the left-hand joystick, you can only select Sinclair mode.

Once connected, the joysticks are operational inmedialely.

Occasionally, you may encounter a game which appears not to work with the joystick in the Kempston mode. If this is the case, select the "keyboard" control option from the menu at beginning of the game instead of the Kempston option. Then, when you are asked to press the keys which you wish to use for Up/Down/Fire etc, move the joystick in the appropriate direction instead. You will then find that you have full joystick control.

USING A PRINTER

One of the features of the Disciple is the ease with which a printer may be used. Simply connect you centronics paralled type printer at the printer port, set up the appropriate system for the printer (as described in MAKING THE DISCIPLE COMPATIBLE WITH YOUR SYSTEM), and you are then able to operate th printer using three simple printer commands - LPRINT, LLIST and SAVE SCREEN$ 1. (COPY SCREEN$ 1 is an alternative to COPY SCREEN$.)

LPRINT and LLIST have exactly the same meaning as PRINT and LIST, except that instead of making information appear on the screen, they send it to your printer. To see how they work, set up your system with the printer and enter the following program:

                10 LPRINT "This program"
                20 LPRINT "prints out the character set"
                30 FOR n=32 TO 255
                40 LPRINT CHR$ n;
                50 NEXT n
                RUN

When you run the program, the LPRINT command sends the heading and the list of characters directly to the printer.

Now enter LLIST - and the listing of your program is sent to the printer.

Then enter LIST to restore the program listing to the screen. Finally enter SAVE SCREEN$ 1: now the contents of the screen are copied (technically, "dumped") to the printer.

SAVE SCREEN$ 1 is a particularly powerful command: if you've set up your system to print graphics, you can dump screen pictures to your printer.

(Note one peculiarity of the Spectrum Basic though. If you have written a program listing on screen, you cannot dump the screen directly to your printer. First, you have to enter LIST; only then can you enter SAVE SCREEN$ 1 to dump the listing to your printer. This is a hardly problem - a faster way of achieving the same result is to write your program, then to enter LLIST.)

If you have an Epson-compatible printer (or one which understands the control code ESC * for bit image graphics selection), you will probably be able to use SAVE SCREEN$ 2. This will allow you to print a double-sized screen dump sideways down the page on your printer, with the various colours on the screen interpreted as shades on the print-out.

The Disciple accepts two commands - TAB and AT - which allow you to position your text at a certain point on the printed line. Enter this statement:

                LPRINT TAB 8; "This line is indented"

Now enter:

                LPRINT AT 4,4; "This line is less indented"

The number in the two commands tell the computer at which character position on the line printing should begin.

Finally, programmers should note that if a control character is to be sent to the printer using LPRINT, the you must precede it with CHR$ 27 (even when you want to output CHR$ 27). To output CHR$ 27, CHR$ 65, CHR$ 40 you would enter:

                LPRINT CHR$ 27; CHR$ 27; CHR$ 27; CHR$ 65; CHR$ 27; CHR$ 40

Or, a simpler way would be to enter POKE @ 6,1, as described in Appendix B. It is then not necessary to precede the control characters with CHR$ 27. When you've finished, enter POKE @ 6,0.

Snapshot Printing

Uniquely, the Disciple allows you to temporarily halt a program at any point and to print out the current screen contents. This facility offers exciting new possibilities to games players: in an adventure game, for example, you can print out the screen at each new location, gradually building up a complete picture of all the available screens.

To experiment with snapshot printing, load a normal commercial program preferably a game with good graphics to show the facility at its best. When you wish to print a screen, hold the CAPS SHIFT key on the Spectrum and press the Snapshot Button - in the same way as if taking a snapshot save. As usual, the program is paused; if you the press key 1 on the Spectrum, you will send a 32-column screen dump to the printer. If instead you press key 2 on the Spectrum and you have a Epson-compatible printer (that understads ESC *), you should be able to send a double-sized screen dump to the printer - just as if you had entered the command SAVE SCREEN$ 2.

When printing is complete, the program will resume form the point at which you left it.

Printing from a Commercial Word Processor and other Serious Software

Commonly, commercially-produced word processors and spreadsheets have a special printer driver built into the software to allow you to send your work to a printer. In some cases, it will be possible to follow the instructions in the software package to set up the printer driver for your printer, and increasingly, the major pieces of serious software for the Spectrum are being modified to allow for printing with the Disciple.

If the software you wish to use does not offer the option of printing with the Disciple, and you have no success when you try to print, try the following:
   i) If you are offered the opportunity to define your own printer driver by the software package, choose this option and then enter POKE @6,1. Then, when you've finished your printing, enter POKE @6,0 Or, if you can get a Basic listing of the program, type these two statements into the program at the points where printing commences and ends respectively. For example, Tasword II will print successfully with POKE @6,1 at line 279 and POKE @6,0 at line 281. The very powerful POKE @6,n statement is explained in Appendix B.
   ii) If this fails, contact the User Club - another user may have solved your problem.
   iii) Or contact the software house for more advice. (The reason why more and more software is now being modified for printing with the Disciple is because of user pressure on software houses.)

NETWORKING

The two network connectors allow computers with the Disciple to communicate with up 62 simular computers/Disciples. It is important to not that this can be a SHARED ACCESS NETWORK with all stations sharing a single disk drive and printer held at the master station, and with the master computer controlling all the other machines. This makes the Disciple particularly effective in a school classroom. Or you can use an INDEPENDENT STATION NETWORK, in which up to 8 computers, each equipped with Disciple, disk drive and possibly printer, come together to exchange files.

We refer below to MASTER stations, ASSISTANT stations and PUPIL stations.

Setting up the network

For each computer in the network, you will need to supply a screened cable (microphone-style) with two standard 3.5mm jack-plugs, one attached at each end of the cable. (The cables are not supplied because you will know best how long you need them to be; both cables and jack-plugs are cheap and easy to buy.)

To link computers in the network, plug one end of the network lead into either of the Disciple's network sockets on the first computer and the other end into the nearest Disciple network socket on the next computer. This second computer can then be connected to a third in the same way, using its other network socket, and so on.

The Shared Access Network

Link your computers with network leads as described above, and fit the single master station and (optionally) up to 8 assistant stations with disk drive(s) and printer(s). All computers at pupil stations must have the Disciple and a screen.

The master station and assistant stations create their own system files, typing in the appropriate codes for the drives and printer as described in MAKING THE DISCIPLE COMPATIBLE WITH YOUR PERIPHERALS. In the section in the system file on networking, the master indentifies itself as the master machine in a shared access network, and is then automatically allocated station number 1. Assistant machines identify themselves with station numbers from 2 to 9 - make sure that each station uses a different number. The system files are then saved for permanent use on system disks as usual; if, as in a school classroom, the computers are in fixed positions and you intend to use the network regularly, you will simply be able to boot up the master and the assistants from their respective system disks on subsequent occasions.

With their system disks in drive 1, the master and assistants then load their systems normally by entering RUN.

Without disk drives, pupil stations obviously cannot boot from a system disk. Instead each pupil is allocated a station number between 10 and 63. Then, after each pupil station is turned on, a FORMAT n command is entered. Station number 10, for example, enters:

                FORMAT N10     (Here and elsewhere, you may use a lower-case "n")

When the Disciple receives this command, it understands that it is a pupil in the network (from FORMAT n) and that its station number is 10.

You are now ready to start work with the network. But first, you should note that no matter which of the network operations described below you are using, it is never possible to transfer a snapshotted file from one machine to another across the network. These are the Disciple's shared access network commands:

- The Master sends a file to all stations.

- A Pupil or Assistant sends a file to all stations.

- The Master or Assistant sends a file to one station.

- A Pupil or Assistant sends a file to another Pupil or Assistant station.

By now you will have understood the principle that there must be an exchange of messages between sending and receiving stations before files can be transmitted across the network. But this is only true if the station receiving the message is a pupil or an assistant. The master station does not need to reply to messages from assistants or pupil, as shown in the next batch of network commands:

- A Pupil inspect the directory on the master disk.

- A Pupil loads a file from the master disk.

- A Pupil sends a file to the master disk.

The master station is also able to "steal a screen" from a pupil station, in order to inspect the work being at that position. The master can also force a file upon any pupil station. For these operations, a special F command is used, and the pupil stations do not need to send a message back to the master.

- The Master "steals a screen" from a Pupil station.

- The Master forces a program upon a Pupil station.

When the network is in use, pupil stations cannot erase files or use the "p" command for LOADing; but the master and assistant stations can continue to use the standard Disciple disk commands - CAT, SAVE, VERIFY, LOAD, ERASE, ERASE...TO, SAVE...TO - normally. Master and assistant stations can also continue to use the snapshot button for saving and printing, and send the normal Disciple commands to the printer. So:

- To print out work done at a Pupil station.

If a station tries to access a disk drive while another station is already using it, or to communicate with a station already engaged in a network operation, the Disciple will allow the first task to be completed before the second commences: threre will be a short waiting period for the second station, but it is not necessary to repeat the command. Pupils will know that their network task has been completed when the OK message appears on their screens. Should two stations try to communicate with another computer on access the same disk drive at the same instant, priority will be given to the computer with the lowest station number.

The independent Station Network

This is a network in which up to 8 stations act as independent units, equipped with their own disk drives and perhaps printers, but choose to be linked together for the transfer of files.

Set up each station as described in Setting up the Network. Each computer will need to create its own system file, following the instructions in MAKING THE DISCIPLE COMPATIBLE WITH YOUR SYSTEM. When dealing with the section on networking in the system file, all computers will state that they are not the master machine in a shared access system, but they may wish to type in a station number from 2 to 9, which will then be stored permanently on their system disks.

Each computer loads the system file by entering RUN with the system disk in drive 1. If you have set your station number in the system file, you are ready to join the network inmediately. If not, you should now enter a FORMAT N command with your station number. If you are station 4, you enter:

                FORMAT N4

(In an independent station network, you must load your system file before you enter the FORMAT command. Be careful not to enter a FORMAT D rather a FORMAT N command, or you may find that you've formatted a disk instead of setting up a station.)

You can now transfer files as follows:

- Send a file to all stations.

- Send a file to one station

USING OTHER PERIPHERALS

Most other Spectrum peripherals can be connected to the Disciple via the through port at the back of the unit.

In the rare cases when peripherals may not work with the Disciple, try disenabling the disk operating system, as described in the section The Inhibit Button. This will solve most problems, although the mice and midi interfaces that we know of are currently incompatible. We regularly discuss any incompatibility problems that arise with hardware and software manufacturers and will always attempt to find solutions - though they will not always be instant. In fact, in the coming months, it is hoped that we will be able to produce a mouse environment for the Disciple if there is sufficient demand. Details of our progress will be reported in the Disciple Users' Group newsletter.

ADVANCED USERS' SUPPLEMENT

In this section of the manual, we describe:

Much of this information may be difficult for an inexperienced user to understand. We recognise also that the truly advanced user - the programmer and the hardware designer - may need information than we are able to include here.

Whatever reason you may have for needing extra information - wether it is to catch up on general background reading or to discover the detailed inner workings of the Disciple - we'd like to recommend membership of INDUG, the Independent Disciple Users' Group, which can be contacted at 34 Bourton Road, Gloucester GL4 0LE, England. INDUG publishes a regular newletter, FORMAT, helping with problems and queries of all types, as proviening a number of other services to Disciple users.

APPENDIX A: ADVANCED DISCIPLE SYNTAX

Reading from and Writing to a Sector

This command is used for reading from or writing to a specified track and sector on the disk to a memory location in the Spectrum memory area, where:

Workin with a monitor program , this powerful command allows you to access a single sector on the disk from Basic. This will be useful if , for example, you wish to examine and correct a corrupted sector on the disk (and incidentally the Disciple's Sector Data Lost error message tells you the corrupted track and sector number); or for breaking into, examining and modifying a snapshot file.

Using Streams and Channels

This command is used to open a file on the disk and attach a stream number to it, so that you can PRINT out to or INPUT from that stream, where:

The Disciple's OPEN # command differs from the Interface 1 command with the addition of the IN and OUT statements. However, if you choose not to specify the IN or OUT, then the default is the same as Interface 1; an input file if the file-name is found in the directory, and an output file if the file-name is not found in the directory.

You can also use:

- for Interface 1/Microdrive compatibility.

Files created with OPEN # statement are identified as OPENTYP files in the catalogue.

This command closes the file and the stream opened in the previous command. Here, S = Stream number. If you do not type in the stream number, then all current open streams will be closed.

The * in this command is used to fail syntax, correcting the bug in the Spectrum ROM, and must be used. If you are using programs originally written for Microdrive with the Disciple, you will have to add the * to any CLOSE # statements.

This is an example of a write file:

NOTE that:
   a) You can only open output files to one disk drive at a time.
   b) You can open input files from more than one disk drive at a time.
   c) You can have as many open files as there are streams available.

This command reads the file and outputs it to the specified stream, (where D1 = D1 or D2, and S = the stream number, from 4 to 16.)

This command reads the file and writes it to the second file.

This command clears all streams and channels that may be open.

This command clears the screen and attribute area, and resets BORDER, PAPER, INVERSE, BRIGHT, OVER and FLASH.

The Execute File

An execute file is a machine code file occupying up to one sector length (510 bytes) of memory. When loaded from disk it is executed (RANDOMIZE USR) in the DRAM, and not in the Spectrum memory as other files are. An execute file gives the programmer the ability to execute utility routines - such as renumbering a program - without affecting or using the Spectrum memory.

To save a sector length of memory as an exeucte file, enter:

- where:

To load the execute file and run it internally in the Disciple DRAM area, enter:

After execution, control is returned to the user program.

APPENDIX B - THE POKE @ COMMAND

The POKE @ command allows a value between 0 and 255 to be stored in the variables area of the disk operating system (GDOS). POKE @ statements can either be entered while work is in progess, to effect temporary changes to the system variables, or written directly int Basic program listings to cause changes every time the program is run. By reading through the descriptions of the first few POKE @ comands, you will quickly see how they can be used.

POKE @0,n     (n = 0 to 8)     [RBCC]     default 7

The boder colour change occurs essentially every time a sector is read from or written to the disk. This variable ins ANDed with the sector value, then output to the screen boder.
   If 0 is chosen, no border colour chagne will occur.
   If 7 is chose, all sectors will change the border colour.

Therefore, if your originally set up your "system" file to allow flashing borders, but wish temporarily to stop the flashing, you can enter POKE @0,0; this would avoid the need to make a permanent change to your system file.

POKE @1,n     (n = 40 or 80 + 128)     [TRAKS1]     default 208

This variable holds the number of tracks and whether double or single sided for disk drive one.

POKE @2,n     (n = 40 or 80 + 128)     [TRAKS2]     default 208

This variable holds the number of tracks and whether double or single sided for disk drive two.

POKE @3,n     (n = 0 to 255)     [STPRAT]     default 6

This variable allows you to set the GDOS for the different step rates of drives (usually 12 to 30 milliseconds). The step rate is not allowed to go lower than 6 milliseconds.

POKE @4,n     (n = 0 to 63)     [NSTAT]     default 1

This variable sets the network station number. Remember that numbers are reserved as follows:
          0 = network off
          1 = master station
          2 -9 = assistant stations
          10-63 = pupil stations

POKE @5,n     (n = 0 to 255)     [WIDTH]     default 80

This variable sets the number of characters allowed per line when using LPRINT and LLIST with the centronics printer port.

POKE @6,n     (n = 0 or 1)     [PCODE]     default 0

If the setting is 0, then the printer driver looks for attribute codes such as TAB and AT within LPRINT and LLIST commands.
If the setting is 1, then the printer driver outputs directly to the printer the absolute value of the code 0 to 255. This is essential for sending control codes to the printer. E.g:
          POKE @6,1: LPRINT CHR$ 27; CHR$ 65: POKE @6,0

The POKE @6 statement will often need to be written into programs for serious applications - word processors, spreadsheets, etc - to allow codes embedded in the software to be sent directly through to the printer without inteference from the Disciple. See for details of POKE @6 with Tasword II.

POKE @7,n     (n = 0 to 255)     [LSPCE]     default 12

This variable sets the printer line fedd in increments of n/72 of an inch during graphics printing.

POKE @8,n     (n = 0 to 255)     [LFEED]     default 1

This variable sets the number of line feeds automatically executed by the printer driver after a carriage return.

POKE @9,n     (n = 0 to 255)     [LMARG]     default 0

This variable sets the number of spaces inserted automatically by the printer driver after a carriage return. It is used for left hand margin control.

POKE @10,n     (n = 0 or 1)     [GRAPH]     default 1

If the setting is 1, the printer driver generates the graphic representation of £, # and © on LPRINT and LLIST statements.
If the setting is 0, the normal printer character is output.

POKE @11,n     (n = 0 or 1)     [ZXPNT]     default 0

If the setting is 0, the GDOS uses the centronics printer port.
If 1, the the printer channel is unchanged by GDOS. It is assumed that you are using a serial printer with Interface 1 or the ZX printer attached at the through connector.

POKE @14,n (and POKE @15,n)     (n = 0 to 65536)     [ONERR]          default 0

If the setting is 0, then GDOS returns to the Spectrum on errors which do not relate to hook codes or GDOS syntax statements.
If and address is poked into these two locations, it makes a call indirectly to this address for further syntax checking. Necessary when adding extra commands to the syntax.

APPENDIX C - DISCIPLE COMMANDS CODES

The command codes are used in machine code routines to effect control of the disk subroutines, enabling serious programmers and software houses to directly drive the disk unit to their own purposes.

When using Sinclair hook codes or command codes and an error is found -e.g. disk full or bad sector then a return is made with the carry flag set and then register "A" holding the error number for interpretation by the calling routine.

The command codes recognised by the Disciple are as follows:

USER FILE INFORMATION AREA (UFIA)

DISCIPLE COMMAND CODES IN USE - EXAMPLES

These examples show how to use the command codes firstly to save a code file from screen memory, then to load it back to screen memory. Please remember to save your registers before using a command code.

	
  	0000		  00001  ;**********************
	0000		  00002
	0000		  00003  ;Example ONE
	0000		  00004
	0000		  00005  ;Save a code file from
	0000		  00006  ;screen memory
	0000		  00007
	0000		  00008  ;**********************
	0000		  00009
	0000		  00010  		ORG  49000
	BF68		  00011
	BF68		  00012
	BF68		  00013  ;Open file and set header
	BF68		  00014
	BF68 DD21E8BF 00015  SAVE	LD   IX,DSTR1
	BF6C CF		  00016			RST  8
	BF6D 35		  00017			DEFB 35h		;HOFLE
	BF6E		  00018
	BF6E		  00019
	BF6E		  00020  ;Save data block to disk
	BF6E		  00021
	BF6E ED5BFABF 00022  		LD   DE,(HD0D)
	BF72 ED4BF8BF 00023			LD   BC,(HD0B)
	BF76 CF		  00024			RST  8
	BF77 37		  00025			DEFB 37h		;HSVBK
	BF78		  00026
	BF78		  00027
	BF78		  00028  ;Close the file
	BF78		  00029
	BF78 CF		  00030			RST  8
	BF79 38		  00031			DEFB 38h		;CFSM
	BF7A		  00032
	BF7A C9		  00033			RET
	BF7B		  00034
	BF7B		  00035
	BF7B		  00036  ;**********************
	BF7B		  00037
	BF7B		  00038  ;Example TWO
	BF7B		  00039
	BF7B		  00040  ;Load a code file into
	BF7B		  00041  ;screen memory
	BF7B		  00042
	BF7B		  00043  ;**********************
	BF7B		  00044
	BF7B		  00045			ORG  49100
	BFCC		  00046
	BFCC		  00047
	BFCC		  00048  ;Get a file from disk
	BFCC		  00049
	BFCC DD21E8BF 00050  LOAD	LD   IX,DSTR1
	BFD0 CF		  00051			RST  8
	BFD1 3B		  00052			DEFB 3Bh		;HGFILE
	BFD2		  00053
	BFD2		  00054
	BFD2		  00055  ;Load header of disk file
	BFD2		  00056
	BFD2 11F7BF	  00057			LD   DE,HD00
	BFD5 0609	  00058			LD   B,9
	BFD7 CF		  00059  LOOP	RST  8
	BFD8 3C		  00060			DEFB 3Ch		;LBYT
	BFD9 12		  00061			LD   (DE),A
	BFDA 13		  00062			INC  DE
	BFDB 10FA	  00063			DJNZ LOOP
	BFDD		  00064
	BFDD		  00065
	BFDD		  00066  ;Load data block to memory
	BFDD		  00067
	BFDD ED5BFABF 00068			LD   DE,(HD0D)
	BFE1 ED4BF8BF 00069			LD   BC,(HD0B)
	BFE5 CF		  00070			RST  8
	BFE6 3D		  00071			DEFB 3Dh		;HLDBK
	BFE7		  00072
	BFE7 C9		  00073			RET
	BFE8		  00074
	BFE8		  00075
	BFE8		  00076
	BFE8		  00077  ;User File Information Area
	BFE8		  00078
	BFE8 01		  00079  DSTR1	DEFB 1			;Drive
	BFE9 00		  00080  FSTR1	DEFB 0			;N/A
	BFEA 00		  00081  SSTR1  DEFB 0			;N/A
	BFEB 64		  00082  LSTR1  DEFB 'd'		;Device
	BFEC 07		  00083	 NSTR1  DEFB 7			;Screen$
	BFED 54727920 00084  NSTR2  DEFM 'Try 1     '
	BFF1 31202020
	BFF5 2020
	BFF7 03		  00085  HD00	DEFB 3			;Code file
	BFF8 001B	  00086  HD0B   DEFW 6129		;Lenght
	BFFA 0040	  00087	 HD0D	DEFW 16384		;Start
	BFFC 0000	  00088  HD0F	DEFW 0			;N/A
	BFFE FFFF	  00089	 HD11	DEFW 0FFFFh		;Not used

TECHNICAL SPECIFICATIONS

Port Details

  
  ------------------------------------   1-33 Ground (0V)   22 Write data
 | 33                             3 1 |     8 Index         24 Write gate 
 |  o o o o o o o o o o o o o o o o o |    10 Disk1 select  26 Track00
 |                                    |    12 Disk2 select  28 Write protect
 |  o o o o o o o o o o o o o o o o o |    16 Motor on      30 Read data
 | 34                             4 2 |    18 Step dir.     32 Side select
  ------------------------------------     20 Step pulse
  View from the back of the Disciple

  
  ----------------------------      1 Strobe        13 D5
 | 25                     3 1 |     3 D0            15 D6
 |  o o o o o o o o o o o o o |     5 D1            17 D7
 |                            |     7 D2            21 Input busy
 |  o o o o o o o o o o o o o |     9 D3          2-22 Ground (0V)
 | 26                     4 2 |    11 D4
  ----------------------------
  View from side of the Disciple