Hi all,

Slightly off topic...

I've been trying to extend the Flexible Co Processor (see Matchbox sized 6502 / Z80 / 6809 Co Pro) to include an x86 core. This should allow it to mimic an Acorn Master 512 system, and run DOS PLUS and GEM.

I'm currently using the "zet" core: http://zet.aluzina.org/forums/index.php

I've made some headway with this project over the Christmas break:

This is it trying to boot DOS PLUS. For it to get this far, quite a lot is working!

For some reason, it's now trying to seek to track 155 on the floppy disk.

I'm really struggling to debug this, due to the limited IO capabilities, and was thinking of stepping back and trying to do some more basic verification of the CPU (as I have already found bugs in the PUSHA/POPA instructions, and there may be more lurking).

Is anyone aware of any test suites for x86 processors? I was looking for something similar to that written by Klaus Dormann for the 6502, which I have found incredibly useful.

Dave

Is there any mileage in running a Z80 testsuite, and removing the inapplicable tests? I think zexall has been mentioned somewhere recently.

Also there's a pointer to
https://code.google.com/p/corkami/sourc ... asm?r=1569
and to the idea of checking Qemu's sourcecode, at
http://www.vogons.org/viewtopic.php?t=38447

A good thought. Z80 and x86 are both compatible at the source-code level with the 8080, so there's common ground there. But x86 is not object-code compatible with 8080, so the Z80/8080 test suite's source would have to be reassembled for x86, and there's an issue that would need checking. If the author has used self-modifying code (which of course makes assumptions about object code format) then the reassembled test suite may be useless. And self-modifying code seems more than ordinarily likely to be employed, given the exhaustively repetitive nature of a test suite. Still, the idea's worth looking into.

PS- Interesting project, hoglet -- good luck!

-- Jeff

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In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
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