21 Feb
2018
21 Feb
'18
11:09 a.m.
On 2/21/18 6:41 AM, Paul Koning via cctalk wrote:
SIMH in principle allows the writing of cycle-accurate
CPU simulators, but I don't believe anyone has bothered.
Atari 2600 requires it.
Any simulation of an embedded system that did cycle counting for timing
would require it as well.
One situation that isn't handled correctly in MAME right now is where a CPU is stalled
by holding /WAIT
or /DTACK off to wait for a peripheral to acquire data, the way that the Tarbell floppy
interface works,
for example.
That is tricky to cleanly and efficiently implement where each component is modeled
independently and
glued together with a higher-level framework.