Franco Frey gets out his SHUGARTS, wonders why ALAN SUGAR hasn't produced a disk system for the Spectrum, and gets to grips with the DISCIPLE - the best thing in terms of disk interfaces since the (now unavailable) OPUS DISCOVERY.
With the demise of the opus Discovery, the Spectrum world has slipped back into a dark and diskless existence. Any hope of upgrading the current cassette-based games market with a user-friendly diskbase format, is quashed by the lack of a standard disk operating system for the Spectrum - or at least one that's properly supported by the original manufacturer. Sir Clive himself originally drove a nail into the Spectrum's coffin by introducing an unsuccessful upgrade in the form of the Microdrive - this time it's good old Alan Sugar who's slipped up, by not providing a disk system with the Spectrum 128K Plus 2. Plans may be afoot, but alas, they're far too late.
Along comes Alan Miles from MILES GORDON TECHNOLOGY to show the big boys what ought to be done, by introducing the Disciple - which takes off where the Interface One fell short. Could this be the beginning of the New Testament?
The Disciple is everything the interface One should have been - and more. The multi-purpose interface provides a disk interface for any two SHUGART (SA400) compatible 3 inch, 3.5 inch or 5.25 inch disk drives, a fully supported Centronics printer interface, two joystick ports and a local network system. In fact, most of the things any serious or games playing Spectrum user would love.
The Disciple could be mistaken for an over-large Interface One. It plugs into the interface edge connection of the Spectrum and acts as a wedge-shaped support for the keyboard.
DISK HERE, DISK THERE
Any single or double disk drive may be connected to the Disciple - as long as it meets with the SHUGART standard 34-way bus. Digging around in the office produced a CUMANA double disk drive for the BBC which worked a treat. The operating system can be configured with the help of a utility provided on cassette. This program enables the user to give all the details of the system, including all the parameters relating to the disk drives including the number of drives, tracks, sides, and the stepping rate in milliseconds. It then goes on to ask about the printer and the networking configuration.
Once satisfied, it formats a disk (in single or double-density format) and saves the system with the new settings. Boot-up from then on is simple.
On booting-up the Spectrum, RUN is performed and the system file is loaded from disk. Ready! The utility may be saved to disk for any future upgrades to the system, and with this done the boring cassette work can be forgotten.
The operating system is an extension of Sinclair BASIC. To direct the commands to the disk drive. the BASIC command must be followed by a Syntax Operator, which is either D1, D2 or D*, the latter accessing the last drive in use. Typing a capital D ensures an automatic display of the catalogue after the command has been performed, otherwise a lower case d will suffice. A normal file access could read like this:
LOAD D1 "SAMPLEFILE"
Ex-Microdrive users with the knack for convoluted commands, will be pleased to know that they can continue to use the Microdrive syntax. Apart from the usual LOAD, SAVE and VERIFY, the cassette-based user will have to include such instructions as FORMAT, CAT, ERASE and COPY into their repertoire. FORMAT D1 formats the disk in drive 1 in double-density format, FORMAT SD1 in single-density format. CAT 1 displays a directory of the contents of disk drive 1 in extended form, giving such details as program number (generated by the disk operating system), the filename (up to ten characters long), the number of disk sectors used, the type of file (BASIC, Code, Snapshot, Screen, Microdrive file, Specials, data array or character array) and finally the starting address of the file and the number of bytes used. CAT1! calls up an abbreviated version of the directory.
To save keyboard work, a file can be loaded using the program number designator generated by the directory system. If the 'simple' CODE was number 5, the file can be loaded with a LOAD p5 command.
As with any respectable DOS the Disciple recognises wild-card filenames. These can contain ? symbols representing any character and * symbols representing any quantity of characters in the name. ERASE D1 "DEL" erases any files starting with DEL Such as "DELTITLE" or "DEL". ERASE D1 "filename" deletes the file from the disk directory of drive 1. ERASE D1 "name1" "TO "name2" renames a file "namel" to "name2", COPY D1 "name1" "TO D2 "name2" copies a file from drive 1 to drive 2 and renames it "name2".
The Disciple has an auto-load file feature. When booting up the disk system with an initial RUN command, Disciple searches on the system disk for a file with the name "Auto-load" and loads and executes it automatically. All that is required is to rename the designated file "Auto-load".
The Centronics parallel printer interface on the Disciple provides the Spectrum with the choice of dot matrix or daisy-wheel printers - the printer port is fully supported by the system software, and initial configuration is affected via the Utility program. The Spectrum's normal printer channel (ZX printer or ALPHACOM) may be used, or the Centronics port brought into play. The number of line feeds, as well as the number of line spaces before the left hand margin and the graphic characters to be printed for £ and ? all have to be specified.
If the printer recognises EPSON type command codes, the system doesn't have to be configured any further, as the operating system uses default values. Otherwise all the necessary printer control codes can be input for printer initialisation, character pitch, line width as number of characters, n/72 inch line spacing, normal line text line spacing, bit image character mode for user defined screen graphics, and any other extra control codes for the printer used. The operating system recognises all the usual Spectrum print commands such as LPRINT (including TAB and AT syntax), LLIST and COPY SCREEN$. Experiments with a CANON PW-1156A printer proved immediately successful - to be able to print out a screen dump without messing about with printer control codes was little short of a miracle?
TO SHARE AND SHARE ALIKE
Two network connectors allow Spectrums equipped with Disciple to communicate with each other. There are basically two modes available: the Shared Access Network that allows up to 62 users to access the printer and disk drives of the master machine, and the Independent Station Network which provides file access to individual users each equipped with their own disk drives and printer. In each case the system file has to be configured so that the system can recognise whether a station is the master machine, and what the station number of each machine on the network is. If a Shared Access Network is set up, the users only need to input their station number with a FORMAT N9 (for station number 9) command. Sending a file "TEST" to station 9 involves loading it from disk with a LOAD D1 "TEST" command and transmitting it with a SAVE N9 command. N0 specifies a general broadcast, which can be picked up by any station using a LOAD N0 command.
Two Atari-compatible joystick ports are available on the Disciple. The right-hand port is used for single-player events. If a commercially-produced program asks the user to select Kempston or Sinclair mode, either option may be chosen. The left hand port supports only the Sinclair mode for two player games. The joystick ports do not have to be configured prior to use.
The SNAPSHOT button enables a 'photograph' to be made of the entire Spectrum 48K memory so that the memory contents may be saved to disk. The main use of this facility is the conversion of cassette-based games to disk for 'instant' load. To avoid pirating, a barrier has been set up in the operating system which prevents SNAPSHOT files being copied. At any given point in the game, pressing the button pauses the program and transfers the contents of the memory to disk in a SNAPSHOT file, which may be renamed at a later date. A further function is provided: by pressing CAP SHIFT and the SNAPSHOT button the current screen is dumped to the active printer port - excellent for mapping games!
To avoid serious clashes with other peripherals the Disciple provides an INHIBIT button which deactivates the operating system and shuts down the disk drives. The system can also be turned off with an OUT 31,0 command, and stays off until an OUT 31,16 command is received. In all cases the printer and joystick ports remain active.
A point to note is that should the Spectrum be reset with the computer's RESET button, the Disciple retains the operating system in its memory. So rather than reload the system file from disk, a simple OUT 123,0 reinitiates the operating system.
CAN I HAVE ONE!
The Disciple is excellent value for money. It not only offers an extremely versatile disk and printer option for the Spectrum, but also includes the facility to transfer commercial cassette-based software to disk. The manual is concise and informative. The fact that everything works first time (including the dreaded business of dumping screens to the printer) shows that this is a well worked out design. Well done Miles Gordon!
Producer: Rockfort Products, 81 Church Road, London NW4 4DP
Price: £89.95 inc VAT
Tel: 01 203 0191
Deja Vu! Another paper version of a favourite screen image, this time created with minimal effort with the DISCIPLE.
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