groepaz wrote:the game does very few actual accesses to the VIC, so its almost useless to tell the differences by looking at the game code...
Yeah, I realise that. We won't know unless we manage to source the chip itself, which isn't impossible, but is extremely unlikely. I would assume that any customisation was done at Ryoto Electrics request, so if the game isn't using it, then the chances are the unused registers would do what they would normally do.
I've been thinking about building a clone of this machine in hardware as well, but not having this customised version of the 6560 means that the ROMs would have to be patched so it doesn't turn on the reverse mode. The same might need to be done to stop the multicolour mode as well, although that could probably be handled by hardwiring the 4th line of the colour data bus so its always off rather than coming from colour RAM.
groepaz wrote:one thing that is obvious though is that the defaults differ
I haven't yet worked out what you mean by defaults. I don't think the control registers themselves have intended default values on startup of the chip.
groepaz wrote:meanwhile, i have it kinda working without a patched kernal.... the monkey patched screen copying stuff makes it kindof slow to play however...
Hopefully I can give this a go later today. Looking forward to it.