JonAbbott wrote:VA5000 however doesn't seem to run a lot of games and simply crashes - this is definitely an issue with the VA5000 JIT.
The issue here seems to be with VA5000's implementation of the VIDC chip, any game that changes the screen size through VIDC causes an instant lock.
Games that don't touch VIDC work, for example
Jet Fighter, No Excuses, Xenon 2: Megablast and
Zarch.
Games that alter the screen size via VIDC don't work, for example
Chuck Rock, Jahangir Khan World Championship Squash, James Pond, Lemmings, Rockfall, Rotor.
I'd advise not using VA5000 for running games and to use either Red Squirrel (VA5000's predecessor) or Arculator if you want a truly accurate Arc. Red Squirrel has the best user experience and doesn't suffer the mouse sync issues that VA5000 does, its filesystem is also compatible so there's no need to rename files within DOS.
Here's a break down of the emulators that are available and recommendations on using them for games:
ArcEM -
avoid. Painful to use on Windows as it suffers mouse sync issues and doesn't offer a full screen mode.
Arculator -
recommended. The only accurate Arc emulator, but does suffer user experience issues. The mouse can be choppy on multi-core CPU's once the mouse is captured and full-screen doesn't always match what you see when windowed. This is the only emulator to accurately emulate the IOC Timers and is recommended for games that palette bash or rely on T1 accuracy (eg. Lemmings, Lotus Turbo Challenge 2)
Known issues:
- OS_Byte 253,0,255 doesn't return the correct result (R1=1)
- Manchester United Europe - crashes after kick-off
- Adventure Classic Collection - hangs after selecting an adventure (CPU emulation issue)
- Grievous Bodily 'ARM - scrolling isn't correct (VIDC emulation issue - HDSR/HDER aren't fixed at flyback)
- Rick Dangerous - crashes Arculator (CPU emulation issue)
Archie - untested
Red Squirrel -
recommended. The best all round emulator, provided you don't need IOC Timer accuracy. It has the best user experience, with a synced mouse and flawless full screen emulation. The IOC Timer issue does cause games that palette bash to look pretty bad, but for all other games its probably the emulator to use.
Known issues:
- IOC Timer emulation isn't 100%
- Grievous Bodily 'ARM - scrolling isn't correct (VIDC emulation issue - HDSR/HDER aren't fixed at flyback)
RPCEmu -
avoid. There are several flaws in it's emulation of the ARM MMC which make it unsuitable for running ADFFS, very few games will run under ADFFS on this emulator. I did raise the issues with the developers back in 2013 and await a fix.
Virtual A5000 -
avoid. Similar to Red Squirrel in that it's based on the same codebase. It suffers the same issues emulating IOC Timers and hangs when the screen geometry is changed via VIDC parameters. By default it has 16mb or RAM, which is incompatible with ADFFS on RISCOS 3.1, this needs reducing to 8mb before ADFFS will load floppy images.
VirtualRPC-SE -
avoid. Similar to Red Squirrel in that it's based on the same codebase. A lot of functionality that was in Red Squirrel has been removed and it suffers the same issues emulating IOC Timers. It comes with RISCOS4, which is unsuitable for runing games.
VirtualRPC-SA -
avoid. Although untested, it's based on the Red Squirrel codebase, so probably also suffers IOC Timer inaccuracy.
VirtualRPC-AdjustSA -
avoid. Although untested, Adjust is unsuitable for running games.