AMD2901s (was e: Inside old games machines, was: Re: Simulated CP/M-68K?)

[Antonio Carlini]

der Mouse wrote:
>
> Heh.  I have a MicroVAX-II simulator that's sort of on hold.  I had
> similar issues; there are some undocumented (as far as I can tell)
> aspects of the hardware which the ROM POST code depends on.  (For
> example, the CPU has an instruction stream prefetch buffer, and the
> hardware can run out of the prefetch buffer even though the stuff
> there is not what would be fetched from those addresses now, under
> some circumstances.  I had to give the simulator a prefetch buffer.
> :-/)

I've scanned the 78032 manual and I'm sure it's online somewhere.

I'd be (very) surprised if the IB is not documented somewhere in
there. Console code generally pulls all kinds of tricks to try and
work reliably even in a context where the user could mangle almost
any bit of memory from the console. making full use of the hardware
is just par for the course!

Antonio