Amstrad User Group

Nederlandstalig

Emulators

A common phenomenon, that you see with most popular computers, is the release of an emulator: a program that emulates an older computer system on a newer computer system. Usually out of nostalgic motives, for instance to be able to run Donkey-Kong again, but sometimes also useable to exchange data.

Three have been written for the JOYCE, see the links page to download. This page contains a brief description and review of the various emulators.

A PCW emulator for the PC (Unix, DOS or Windows), written by John Elliott. The best emulator for the PCW, although there are a few issues. The other emulators share these and they do not run or run considerable less well. JOYCE, as the emulator is appropriately named, emulates a PCW from the 8000 series, equipped with a bootable 3.5" disc drive for the 8000-series. It can also emulate the PCW 9512, PcW 9256, 9512+ and 10. Because the PCW and PcW are compatible for 99% this means that one boot disc (for one model) will typically do: not many Dutchies have other (than 8000-) models.

In order to create a boot image of a regular 8000 Early Morning Start disc (a 3") you will need to connect a 3" drive to a PC to be able to rip it. This is possible, see 3" on a PC but PCWTrans, the image software that comes with JOYCE. is not able to make an image of a 173kb CF2 disc, only a a 706kb CF2DD disc. You need CPDRead/Write to create a CF2 boot disc on a 3" drive, or use 22DISK to format a 3.5" disc in your PC on CF2 and then to copy J14CPM3.EMS (or similar file, depending on your version and language) on to it: that will save you the trouble from connecting a 3"disc drive to a PC. The latter is still a lot of (tricky) work.

Except for this issue there is little else to restrict you from using JOYCE. The emulation has some extra features (when compared to the original) like 2048 RAM, a parallel Centronics and a serial RS232 port. Basically, all expansion options are already emulated. A fast PC is recommended: 233mHz will do for an acceptable performance. I noticed that a 1gHz PC is too fast - you really need to use the utility TIMINGS that comes with JOYCE. This program is part of a whole set of utilities which comes on a disc image, ready for use with JOYCE.

That collection of utilities is one of the great features of JOYCE. There is a driver which allows using virtual hard discs with a maximum size of 8 megabytes each. My Pentium allows up to 7 hard discs but the number in your PC will depend on the configuration. You can use PC directories to store data and (using a detour) real disc drives. The virtual disc drives are of course reserved for use with the image file stored on hard disc (or CD) but the built-in support for true disc drives makes it optional to read and write from a real 3" drive. Rather slow and noisy, but it does work! There are IMPORT and EXPORT utilities, a collection of GSX drives and other drivers for setting, for instance, the keyboard or mouse.

The emulation is great, there are just a few programs that cannot be run. DISCTOOL by Matthijs Vermeulen is amongst these, because of the use of advanced, direct BIOS instructions. But favourite programs like LocoScript en MicroDesign work fine! I often use JOYCE as an intermediary to store data, which facilitates the maintenance of a large software library.

The entire software library used to be on discs, but this got out of hand when the number exceeded some hundreds of 3", 3.5" and/or 5.25" discs. And when occassional disc-errors started to occur, the problem became worse. Now, with CPDRead even copyprotected discs are no longer a problem, so we have the entire collection on CD. Fast, less messy and yet transportable (back) to the real thing: the PCW.

Copyrights, however, can pose a problem with the creation of disc images. Again, one more time: the HCC!Amstrad GG is opposed to the making of illegal copies. We will only install or convert software when the original program is available. Although there are still copyrights on, for instance, LocoScript and CP/M, obtaining a legal copy is not difficult or expensive. The club has plenty of legal copies that can be used as a (start of day) disc image for JOYCE.

An emulator for Apple Macintosh, with which I am unfamiliar. The few things that I know of is that the author, Richard F. Bannister, no longer has the source code, so that the development is halted. You can only get the running software and I never saw it working (I do not have a Mac).

Another emulator for the PC, a derivative from MASS, an emulator dedicated to games and consoles. M.E.S.S. is the version for more serious use and this system is supposed to emulated hundreds of computer systems. The Amstrad CPC emulation works indeed, but I cannot confirm the claim that M.E.S.S. can emulate all PCW's and PcW's. M.E.S.S. works using ROM drivers and boot discs and, because the PCW does not have ROM memory, this driver would be nothing else than a routine to load the boot image. But these boot images, that work with JOYCE, do not work with M.E.S.S., so...

The error message refers to an illegal checksum of the driver and, although I have the source code (by Kevin Thacker) and have tried to fix the problem in Maxam assembler, I am unable to get it working. I would appreciate news and updates regarding M.E.S.S. but as JOYCE works fine for the PCW 8256, 8512, 9512, PCW 9512+, 9256 and 10 I will not spend more time on the issue.

It is a different story with the PcW 16, Anne, supposed to be emulated by M.E.S.S. too. The boot disc is freely available on the Internet and the image is loading promising. But after the message 'checking memory...' M.E.S.S. is requesting the rescue disk of the PcW 16 and then crashes. Basically a perfect emulation of the real thing, as my PcW 16 is doing that all the time! But a bit disappointing nevertheless and I will probably take another look after I have restored the non-virtual PcW 16 again (out of action at this time too..).

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