QUICK DISC MAKES A CHANGE

Considering the price of disc drives, the new Triton Quick Disc from Radofin - anyone remember the Aquarius? - Electronics Ltd looks like a good deal. For only £119.95 you get a disc drive and an interface for the Spectrum. First impressions can be deceptive but, and it is a big but, it does offer disc drive speed at a very reasonable price.

As with other fast storage devices in its price range, the microdrive and wafer drive, it is dedicated to the Spectrum. Therefore, if you decide to change computer you will have to throw it away.

The Spectrum interface is hard wired to the drive using just over 1/2 metre of cable. That is 5cm too short if you want to put the drive on the left of the Spectrum. On the side of the interface is a two position switch to denote first and second drive - the interface for the second drive plugs into the back of the first. The instructions say that only the second drive or a ZX Printer should be plugged into the interface, which is a problem if you want to add a printer or joystick interface.

Unlike all other disc drives the 2.8in does not use concentric tracks but a spiral, as on a record. Despite that it is still quick, although not as fast as a normal drive, with most timings taking just a few seconds. Formatting takes eight seconds, CAT three seconds, saving roughly 10 to 15 seconds and loading well under 10 seconds.

The instructions, which admittedly are provisional, say "...after 3 accessments (?), a few seconds rest is recommended.". Presumably they refer to the drive, not the user, but the instructions suggest that the drive is not up to heavy use.

Each disc can hold 100K, 50K on one side, arranged in 2.5K sectors. The drive is single sided so the discs must be taken out and turned over to reach the other side.

The commands used to access the disc are a re-hash of the microdrive commands. You can SAVE and LOAD Basic, code and data, FORMAT the disc, obtain a CAT, ERASE files or COPY them from one drive to another. They also contain some interesting anomalies.

The command to save is SAVE *d;t; "filename" where'd' is the drive and Y is the type of file - Basic, code, data. To load any file you use LOAD *d; "filename."

Despite scouring the manual - and not exactly being a stranger to disc drives - I could not find a way to save a Basic program so that it auto ran.

The one good feature of the drive is that it only uses the printer buffer. That means you can clear down to as low as 24000 and still use the drive. Transferring your programs to disc is, therefore, made easier.

For the price, and the ease of use, it is well worth considering but the commands are basic and not well thought out.

Radofin Electronics (UK) Ltd, Hyde House, The Hyde, London, NW9 6LG.

Varios
Disc Drive
Triton
£129

The Quick Disk is designed as a cheap alternative to floppy disc drives, with only a slight reduction in performance.

There are three versions, Spectrum, Commodore 64 and MSX available, each priced at £129 with 100K 3in discs available at £1.99. The hardware consists of the disc drive and an interface box which plugs into the rear expansion socket of the computer. The performance of the drives is only marginally slower than normal disc drives.

A file takes a minimum of one sector and there are 20 by 2558 byte sectors per side, providing a maximum of 20 files/programs per side. Data files may be transferred between the three types of computers using the discs.

The drive repositions itself at its start position after every operation; this adds a further three to four seconds before the next disc access can be made, but does leave the head out of harms way and the data safe.

The quick disks overall are slightly quicker than the Spectrum Microdrives and appear to be reliable. Command format is simpler than Microdrive, but only just. As the quick disk built in software does not take up any additional space in memory, most software can be converted to run on the quick disk very easily using the conversion program provided in the manual.

There are a few problems with the Spectrum version - the only printer that can plug in directly is the obsolete ZX Printer, the Alphacom 32 does not work from the rear of interface. Interface 1 cannot be connected which loses the RS-232 port and modem facilities although a standard Centronics adaptor does work.

The MSX and Commodore versions do not have to sell against competitively priced products and appear to be good value for money, the Spectrum version needs tidying up to produce a viable alternative to Microdrives and stringy floppies.

DiSKO TECH

Get the low-down on hi-tech. YS disk jockey, Iolo Davidson takes two new disk drives out for a spin. Prepare for a close encounter of the 3" kind!

Mention disk drives and most people's minds immediately turn to thoughts of speed, but that's only one of the advantages. In fact, some disk drives won't even give you much in the way of speed.

Some would say the major advantage of disk over tape, and especially over stringy-floppy tape cartridges (and they're pretty fast anyway), is the greater reliability and security of data storage. This is at least as important as fast access if you're using the disk for business - a loading error could mean financial disaster.

The third advantage of disks is the filing system used by disk operating systems. It's true that stringy tapes, like the Microdrive, have a similar kind of thing, so this isn't exclusively an advantage of disk, but you certainly don't get it on cassette!

The disk operating system, or DOS (you realise, of course, that some software houses, like Digital Research and Microsoft, are also DOS houses!), keeps a DIRectory or CATalogue of the programs or data files on each disk. You can use the DIR or CAT (Speccy uses CAT), command to see what's on a disk, and the other DOS commands allow you to SAVE, LOAD or ERASE files, without having to manually operate rewind, play and record controls. It's this that makes the real difference - it's quick and easy for your programs to use the disk to store and retrieve data - and not just the sheer speed of disk loading.

The Spectrum disk drives we're looking at here share all the above advantages, though to varying degrees. The only real drawback is the price. It's not too much to pay for what you get, but it's still a lot of cash to splash out on what's supposed to be a peripheral. You probably ought to think twice about stumping up the readies if you're really only interested in nothing more than world record non-stop JSW marathons.

YOU SPIN ME ROUND...

Both these drives use the new smaller size disks, rather than the industry standard 5.25" workhorse. But it's not so long ago that the standard size was eight inches, and 5.25s were reckoned to be toys, so pay no attention to any dinosaur who pooh-poohs diddy disks. The new sizes, in the region of three inches, are every bit as good as 'real' disks, except for the amount of storage available per disk. Problem is, these three inchers cost at least twice as much as Microdrive cartridges or 5.25 inch disks, and sometimes a fair bit more.

Perfection is unobtainable anywhere in the known universe (When did you last visit Castle Rathbone? Ed.), but I've seen nearer misses than these two. Certainly, both drives are more reliable than the Microdrive, but neither DOS offers much improvement on the arduous Microdrive syntax. If you already have one of Sinclair's little brown stringy spoolers (and assuming that it works for you), then suffer on - there's no point forking out again for something slightly better. Also, you can't connect disks and Microdrives at the same time, because the shadow ROMs clash.

But, and it's a big but, if you're still using cassette and need more speed, or if your Microdrives treat you like they treat me, then either of these machines will give you fast storage and more reliability than Microdrives at only double the price.

Transferring your own programs to disk is a doddle, but the commercial software that's designed to be copied to Microdrive or Wafadrive, is still going to give problems.

Now, there are plusses and minuses on both drives. Of the two, I'd put my money on the Opus as it has more storage on line at one time and the extra interfaces. The Triton would fit different keyboards more easily, it didn't hum or overheat, and it was faster, despite a rather dodgy DOS. But, despite all my griping, these are both good products, not just the toy for the boy whose Dad has everything!

TRITON DQ

QD stands for quick disk, a name given to the top-loading 3" version of the minidisk drive. This isn't the same as the Hitachi designed 3" disk used on the Amstrad, which is front loading and has a protective shutter. The top-loader is less widely used than the Sony or Hitachi type, so you may have trouble tracking down the disk - a point to bear in mind.

There's nothing intrinsically wrong with the smaller disk, but there are differences. One is that the drive has a flip-up door that you slide the disk into and then shut, just like on a standard cassette tape machine. You turn the disk over to see the other side, again like a cassette. There's no sliding shutter to protect the magnetic surface.

More importantly, the 3" quick disk is generally capable of less storage than the 3.5" though this does depend partly on the drive mechanisms. The Triton's 50K per side for 100K per disk is typical, and compares with Opus's 178K per disk. This limits the amount of storage that you can have active at any one time to, say, one large arcade game.

The Triton file directory is more informative than that of the Opus, with info on file type (Basic, Code or Data), start address and size. Pretty essential stuff, this.

After that advance on the Discovery, the QD starts slipping back. There are no interfaces for printers or joysticks, only a through connection for the Spectrum edge connection, which you're told to use only for the ZX Printer or another Triton QD. Mind you, I did manage to connect a Kempston interface - it doesn't fit properly physically, but it's all right electrically.

The command syntax is neither usefully identical to the Microdrive syntax, nor a simplification. It's different enough to be incompatible with programs using Microdrive commands, but just as much of a chore to type. Some disk commands cannot be used within a program, and other must have a line to themselves. There's a default to the disk (there are no Microdrive type channels anyway) which disposes of the "m", but you must add a type specifier for Basic, Code and Data when saving.

Plus, there's lots of opportunities for operator error built-in. You must not power-up the Spectrum before the disk drive, you must nor touch the (hair-trigger) eject button during a disk access, you must not access the disk continuously more than three times without a few seconds rest. In an ideal world, these mistakes would be made impossible by the hardware or operating system - not left as pitfalls for the user to avoid.

If you've got the gelt, you can buy another QD and chain the edge connectors to run two disks at once. This'll probably be more expensive than adding a second disk to the Discovery, and it'll certainly take up a lot more disk space, as you can't stack a top-loading unit.

The QD has its DOS in ROM and uses the printer buffer as workspace when loading and saving, so very little memory is used by the disk system. Most software shouldn't have any trouble with space, unless it has some of its own code in the printer buffer, like some tape copiers do.

THE EXPRESS GANG

If you don't enjoy your tea while waiting for your program to load from the audio cassette recorder, or you're just generally of a nervous disposition, you will have considered acquiring an improved storage medium for the Spectrum. Most people reckon that they can transfer their games collection on this new acquisition and will be able to call off any desired game at the bat of an eyelid! Whoops, not quite so...

Most storage devices require some sort of operating system, which enables the user to access the various functions. With the Spectrum this usually means that the operating system provides an extension of the BASIC instructions, without interfering with the normal cassette commands. These functions can thus be called up within BASIC and executed either directly from the keyboard or from within the BASIC programme. The commands are usually reminiscent of the BASIC Microdrive commands, but do vary quite a bit from disc system to disc system. The only other alternative access to the drive functions is via machine code, but unless the manufacturers provide the necessary information regarding the entry points to the various machine code routines, this approach may be impossible or of little interest to the average user.

It may be noted that until recently none of the drives had a hardware triggered interrupt facility, which would allow the games program execution to be interrupted and the complete contents of the Spectrum memory to be dumped, a perfect way of copying cassette games onto disc/cartridge. The Microdrive in combination with the excellent Mirage interface manages to do this and the latest addition is the improved version of Technology Research's Beta Disk interface with TR-DOS V4.

For the other interfaces, if the user knows what he is doing, there is the possibility of breaking into the program and manipulating it onto disc in various sections, but only if the operating system memory requirement does not interfere with the program execution area.

The drives vary considerably in the memory requirements and some drives make it their business not to use a single byte of the standard 48K available to the Spectrum, an obvious advantage.

In this issue of CRASH Franco Frey begins a survey of the Spectrum fast storage market which will include such mundane things as the Sinclair Microdrive right up to systems which make the Spectrum appear to be an add-on.

Not all these storage devices belong to the desirable group of floppy disc drives. We review Microdrive/Interface 1 lookalikes such as the Wafadrive with its stringy floppy cartridges; the latest entry, the Triton, with its peculiar spiral track motion disc system and the horde of standard Shugart compatible floppy disc drives such as the Beta Disc, Kempston, Timex, and Opus. Many of these products include added benefits such as serial and parallel interfacing and some even provide joystick interfaces.

The units will be individually reviewed and scrutinised right down to the last bolt or screw. We shall be specifically looking at the cost and performance of the individual storage media, the mechanical and electronic performance of the devices and, most important of all, how the operating systems involved interface with the good old Spectrum.

So here comes the crazy Express gang....

HARDWARE: Large cream coloured disk drive unit with integrated power supply and mains lead connected via permanent lead to black coloured interface box which connects to the Spectrum system edge connection. Interface provides an expansion port for printer or other add-on. A slide switch is provided for drive selection. Interface 1 may not be connected to the system, as it uses same ROM configuration.

SYSTEM DESCRIPTION:

Although the TRITON QUICKDISK uses hardjacketed floppy disk media, it falls under the category of the stringy floppy systems, as the access is not random but sequential. Unlike the standard disk drives, where individual tracks may be accessed by positioning the read/write head with a stepper motor, the TRITON QD combines the floppy disk rotation with a continuous linear tracking of the head and thus creates a single spiral track along the disk similar to a record groove.

The spiral is completed within eight seconds whereupon the linear motion disengages and returns to the start position. This means that consecutive access time is restricted to eight seconds. In general this works out faster than the Microdrive and similar to the Wafadrive. Formatting requires only one go and this means an extremely fast formatting time. The interface caters only for one drive and should a second drive be required, a second interface will have to be installed.

OPERATING SYSTEM:
Extended Basic residing in shadow ROM.

SYSTEM COMMANDS:
FORMAT formats and initialises a diskette.

CAT * examines and displays file contents on screen: Bytes free, Filename, Type (Basic-b, Data-d, Machine code-m), Size (bytes) and Execution address.

SAVE * ; b; "filename" stores BASIC program to diskette on selected drive number.

SAVE * ; d; "filename"; stores a data file to a diskette on selected disk drive.

SAVE * ; m; "filename"; stores a machine code program to a diskette on selected disk drive.

LOAD * ; "filename" loads a file from diskette in selected disk drive.

ERASE * ; "filename" deletes a program from diskette in selected disk drive.

COPY * TO drive number>; "filename" copies a file from one drive to the other.

COPY # formats a diskette on drive 2 and block transfers files from drive 1 to drive 2. Neither copy command can be used in BASIC program mode.

ERROR REPORTS:
13 error messages

EXTRA FACILITIES:
Second drive requires extra interface.

MANUAL:
Preliminary manual sufficient, contains most necessary information.

APPLICATION PROGRAMS:
None, but listing of utility included for transferring unprotected programs from tape to disk.

CRITICISM:
Slow access due to loop time.
Fairly expensive for stringy floppy type drive without serial or parallel ports.

COMMENTS:
Longer life media compared to cartridge tapes.

MEDIA:
2.8 inch hard jacketed floppy disk with write protect tab. Price £2.99

TECHNICAL SPECIFICATION:
Number of drives per system: 2
Storage capacity (formatted): 100Kbytes (2 sides)
Number of sectors: 20 per side
Sector size: 2.5Kbytes
Data transmission rate: 101.6 Kbits per sec
Recording density: 4410 BPI

TIMING:
Formatting: 8 sec
Cataloguing: 2.5 - 8 sec
Loading a screen: 2.5 - 8 sec

PRICE:
£119