Re: Emulating a Z80, and, So that's why CP/M 3.1 is so slow...

[mjmahon@aol.com (Michael J. Mahon)]

Dosius wrote:

>mjmahon@aol.com (Michael J. Mahon) wrote in message
>news:<20030910021726.17885.00000962@mb-m05.aol.com>...

<snip>

>> But in a real system, switching CPUs is not a very expensive
>> operation, since, at least in the SoftCard model, each CPU is
>> just waiting to be "tagged" while the other CPU is running.
>
>I thought the 6502 had to run half an op's length every so many cycles
>or it would "forget" where it was.

Yes, but that just figures into the effective clock speed of the
Z80, which is never great in the SoftCard design.

I would pin most of the sluggishness on the code, not
the processor "tags".

-michael

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