Re: Second Opinion on unknown PET option roms

From: Hans Liss <Hans_at_Liss.pp.se>
Date: Mon, 6 Sep 2021 21:39:17 +0200
Message-ID: <64fbfc28-29f0-b8bc-f8c7-4b8c6800b7a2_at_Liss.pp.se>
Better link: http://www.zimmers.net/anonftp/pub/cbm/firmware/misc/unknown/

The low count of "a9" bytes in several of these is a sure sign it's not 
6502 code. I took a quick look at a few:

  * 8in-cpm-trbdos.bin is definitely Z80 code (or 8085, perhaps?). A CPM
    "driver" for 8-inch floppies, perhaps?
  * 740turbo1-1.bin is also Z80 code.
  * I suspect ultima-ii-v1-73.bin is also Z80 code.
  * create-new-base.bin and 40-80-60h.bin seem to be something else,
    like not program code at all.

I found a fairly useful disassembler at 
https://onlinedisassembler.com/odaweb/, by the way. I tend to use wfdis 
for 6502 code, but this one has many other architectures and accepts 
small hex dumps as input.

/Hans

On 2021-09-06 19:23, Bo Zimmerman wrote:
> Hello all,
>
> Dave McMurtrie contributed a nice pile of PET option rom images to the 
> funet/zimmers archive _at_ 
> http://www.zimmers.net/.../computers/pet/other/index.html
>
> I had no trouble identifying and classifying most of them. However, 
> there were several that I could either not get working, properly 
> disassembled,, or just couldn't identify.  This is fairly new to me, 
> so I created a special place for them here:
> http://www.zimmers.net/ano.../pub/cbm/firmware/misc/unknown/
>
> If anyone out there enjoys digital archeology, I'd ask you to give a 
> second or third opinion on some of those unknown roms. It's possible 
> the eproms were just corrupt or unreadable, but I'd sure like someone 
> else to concur before I throw any of the images out.
>
> - Bo Zimmerman
>
>
Received on 2021-09-06 22:03:57

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