|★ HARDWARE ★ PERIPHERIQUES ★ DK'TRONICS 256K SILICONDISC ★|
|Les extensions DK'Tronics (Les Cahiers de l'Amstrad||DK'TRONICS 256K SILICONDISC (Amstrad Computer User)||DK'TRONICS 256K SILICONDISC (Amstrad Action)||DK'TRONICS 256K SILICONDISC (CPC Magazin|
Owners of a Joyce usually soon learn to appreciate the speed of the memory disc when loading large documents or even when they just need another disc drive to put something on. Well, now DK'Tronics have brought out a 256k silicon disc for £99.95 that plugs into the back of your humble Arnold or 664.
A different type of case is needed if you want to use it on a 6128 - the current one is too deep and tends to bounce its butt on the ground when you type on the keyboard. As with the famous Amstrad speech synthesiser, the Basic manual supplied is just big enough to prop up the unit, but this is not everyones idea of "Software Support".
Tender ministrations of the Post Office notwithstanding, it comes in three bits - The bit with the RAM in it, the bit with a system ROM in it and a little manual-ette.
The modules are keyed to prevent you putting them on the wrong way round and should all fit very nicely into the back of your computer, with your existing disc drive interface going on the back of it all. You need to have at least one floppy disc drive fitted to make the thing work.
In practice, some add-ons (the Amstrad RS232 and the Maxam/Protext boards) do not have keying slots cut in them. That's no real problem, you just prang the locating keys out with a Swiss Army knife or (more drastic) slot the relevant edge connector with a hacksaw.
At this point I should mention that I had an early model and the ROM pack bit of the gizmo did not work. The review was continued with the ROM extracted and bunged into a ROM card in my Maxam board, which should cause no unexpected problems.
To use this device, you have to let the Arnold start up as normal with all the boxes plugged in the back and then type ISDISC to put all the patches in that make the disc work. Then, Whamo! 254k of RAM disc at your fingertips.
If you have one drive, the silicon disc now looks much like drive B, and if you have two drives, you now get a drive C. Strange as it may seem, the Amstrad disc operating system has no provision in it to tell what disc you are on anyway.
The commands A, B, DRIVE, DIR, ERA, REN and USER are put into the memory as RSXs and the manual claims that just about all the Basic file handling commands will now work as expected on the silicon disc.
In practice, I found that files that were created and did not contain anything, such as the "Dummy" file traditionally created to stop the buffers creeping down, still existed on the silicon disc but not on floppies. Also, most of my Utopia facilities refused to work, but Arnor do some funny things in Utopia.
The loss of some of the Utopia facilities (notably attempts to access drive C) was not much to worry about. However, the RAM disc ROM had a perfectly good routine to copy the contents of an ordinary floppy to RAM and vice versa. The only problem with that was that it wiped out any Basic program that happened to be in user memory at the time.
At least it warned you that this might happen. One should remember that the RAM disc has a capacity of 254k and a data format (that's the biggest one) floppy only has 178k on it. Putting quarts into pint discs doesn't go. Like DISCCOPY and DISCKIT, the copy routine wipes out all the old files on the floppy disc and replaces them with the new data.
I thought that I might try out the drive with Tasword D. But alas, Tasword does not recognise the RAM disc at all, and won't even edit properly on drive A any more. Both Maxam and protext got on fine with the RAM disc, but their CAT command still tried to look at disc A as it was displaying the directory of disc B.
The other main clever bit with this device is the way it converts your common or garden CP/M 2.2 into a CP/M with RAM disc. This involves moving your CP/M a bit and running a special file which contains all the patches (all in the manual, folks). The net upshot of all this is you have bags of RAM disc about, but even less main memory than was originally on the already under-TPA'd Arnold. Experiments with Mallard Basic revealed an 8k workspace - The Hitch-Hikers Guide to the Galaxy worked very nicely thank you, but Colossal Adventure expired through lack of TPA.
One of the few serious programs I tested was Micropen. This really benefitted from the RAM disc and spat out data as fast as its little screen could handle it.
Because of the boot sector not being on a RAM disc, you can't get away with taking the disc out of drive A. When you leave a program, it tries to re-boot. No disc, no joy. I could also find no way of making the C drive write protected.
This add-on gives you a big storage (and ego) boost with three drives on your system if you're lucky. It does have some practical purposes, but it gives the system a few disadvantages (less main memory) on the way.
The manual is adequate, but does miss out on a few important points, like telling you that the following command will delete any Basic programs you happen to be working on.
L'alinéa 8 de l'article L122-5 du Code de la propriété intellectuelle explique que « Lorsque l'œuvre a été divulguée, l'auteur ne peut interdire la reproduction d'une œuvre et sa représentation effectuées à des fins de conservation ou destinées à préserver les conditions de sa consultation à des fins de recherche ou détudes privées par des particuliers, dans les locaux de l'établissement et sur des terminaux dédiés par des bibliothèques accessibles au public, par des musées ou par des services d'archives, sous réserve que ceux-ci ne recherchent aucun avantage économique ou commercial ». Pas de problème donc pour nous!
CPCrulez[Content Management System] v8.7-desktop
L'Amstrad CPC est une machine 8 bits à base d'un Z80 à 4MHz. Le premier de la gamme fut le CPC 464 en 1984, équipé d'un lecteur de cassettes intégré il se plaçait en concurrent du Commodore C64 beaucoup plus compliqué à utiliser et plus cher. Ce fut un réel succès et sorti cette même années le CPC 664 équipé d'un lecteur de disquettes trois pouces intégré. Sa vie fut de courte durée puisqu'en 1985 il fut remplacé par le CPC 6128 qui était plus compact, plus soigné et surtout qui avait 128Ko de RAM au lieu de 64Ko.