C70:info-cpm (07/16/82)
>From rconn@BRL Fri Jul 16 14:22:14 1982
Eliot,
First of all, do you want an EMULATOR or a SIMULATOR? To
me, Emulation implies changing the microcode of one processor to
make it look like another. The VAX 11/780, for instance, has a
PDP 11/70 emulation mode, in which case the User MicroControl-
Store is programmed to recognize PDP 11/70 machine code.
If you want a simulator, that's basically what DDT, SID,
ZDT, and ZSID are. They simulate execution of machine code by a
processor and allow you to watch what happens while the code
runs. You can watch registers change and even examine what hap-
pens to memory between each instruction. The EM8080 program you
mention is what I would call a simulator.
Note: You HAVE to have a microprogrammable machine in
order to perform emulation. The AMD2900 bit-slice chips would be
an example. There are several GP-machines, such as the GenRad
2900 (number correct?) and the Tektronix 85xx-series. They pro-
vide cross-software capability like what you are probably looking
for, but they are probably outside the price range you are in. I
have not seen any public-domain simulator for a Z80 which runs on
an 8080 ... ZDT and ZSID both run on a Z80 for a Z80 and are
rather complete simulations.
RickC70:info-cpm (07/17/82)
>From G.dag@Ucb-C70 Sat Jul 17 14:45:48 1982
I don't think I can help you with your emulator, but my
curiosity is peeked. Why do you need such an animal.
David