[Coco] XRoar Accuracy (was: Introduction)

[Jayeson Lee-Steere]

>
>
> Daggorath is extremely timing sensitive and no emulator I've tried gets
> the attract sequence exactly right. I think. XRoar is very close to Coco 3
> videos available but I'm not sure which one is off. The sequence on XRoar
> is actually better than what shows on the Coco 3 - you can hear the
> wizard's image close by and it ends with a knight and stone giant in front.
> I suspect I will probably need to trace a real Coco with a logic analyzer
> to get things right. And that is where a North American Coco becomes
> important.
>

Following up on an earlier post of mine, I got hold of a USA Coco 1 and a
ran it with the Daggorath cartridge. It turns out that XRoar runs it, as
best I can tell, perfectly. On the other hand, the two reference videos I
have seen from the Coco 3 are slightly off, and as I mentioned above, not
quite as good. The Coco 3 being off is a bit of a surprise to me, as best I
can tell the only factors relevant to Daggorath are the timing of the
VSYNC interval and CPU.

Nice work Ciaran, the whole emulator is very well polished. (I'm still
looking forward to hooking up the logic analyzer for my work though).

- Jayeson Lee-Steere