Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!apple!portal!cup.portal.com!Fletcher
From: Fletcher@cup.portal.com (fletcher sullivan segall)
Newsgroups: comp.sys.amiga.emulations
Subject: Re: CPU-emulators
Message-ID: <41080@cup.portal.com>
Date: 9 Apr 91 03:05:22 GMT
References: <9587@star.cs.vu.nl>
Distribution: na
Organization: The Portal System (TM)
Lines: 38

>
>At this moment I think there are two ways of doing it:
>	1- Compare every Opcode and jump to a routine which executes the
>	   instruction

This was discussed in depth just recently.

>	2- Do it more or less the way the microcode does it.
>	   Ok in software you can't do more operations at the same moment.
>	
Your emulation routines will essentially be the microcode of the processor.
Trying to emulate an intermediate processor would only slow the whole
thing down.

On the other hand, if you can rewrite the microcode in the 68000....

>Questions:
>	1- Is there any reaction on these ways.
>	   (Or: I want to start a discussion)
>	2- Are there any books about 6502, Z-80, 8088 microcoding.
>	   or is this real TOP-SECRET.

At least until the Z80-B, all Z80's were hard-coded.  I imagine this
is also true of the 6502.


                           -F. Sullivan Segall
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