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Emulating a Z80, and, So that's why CP/M 3.1 is so slow...
- Subject: Emulating a Z80, and, So that's why CP/M 3.1 is so slow...
- From: steve@dosius.zzn.com (Dosius)
- Date: 9 Sep 2003 18:30:58 -0700
- Newsgroups: comp.sys.apple2
- Organization: http://groups.google.com/
- Xref: archiver1.google.com comp.sys.apple2:34778
We're working on emulating the Z80 in EMU][, which has come a lot
farther than my attempts in Dapple. Well, we have CP/M 3.1 booting,
but not yet 2.2 (I have to figure how to implement some ops myself,
possibly, and the code is very different from any of the other Z80
cores I have). Right now, I'm trying to get the "CP" opcode to work.
Well, interestingly enough, while running CP/M-80 3.1 on EMU][, there
was visibly a lot of alternating between the 6502 and the Z80, and, as
with Apple Oasis, it ran like molasses.
That would explain it...the frequent CPU switching probably slowed the
system down to a crawl. No wonder it dragged.
-uso.