Re: PET 8032 editor ROM

From: Olaf Seibert (
Date: 1998-02-23 21:14:50

Marko wrote:
> Andr=E9 Fachat notified me that the ROMs included with VICE have
> different editor ROMs from the ones that were in FUNET's ROM
> collection.  I noticed that the 4032 editor ROM differed only by one
> byte, and assumed that the copy in VICE is the correct one, because
> FUNET's copy was documented to be reconstructed.  But the 8032 editor

I reconstructed it from a printed disassembly, I think. That could
easily have gone wrong for a single byte.

> ROM is causing some trouble.  I saved VICE's version as
> /pub/cbm/firmware/computers/business/pet/edit-4-80-b-50Hz.901474-04?.bin,
> because it only has 12 different bytes from the 901474-04 ROM image
> that was already on FUNET.  All differences are after $e720, right
> after the dL"*^Mrun^M thing.  Does anyone know what the bytes are used
> for?  For the CRTC initialization perhaps?

Looks like it. Looking at the VICE version from within xpet, I see at
E07A some code that fetches values from that neighbourhood and stuffs
them into the CRTC. Perhaps there are even more versions of the editor
ROM around than I suspected?

Now I'm looking at VisiCalc again. Is there an option in VICE to let it
trap any access to a particular range of addresses? That would be
convenient, I think.

> 	Marko
___ Olaf 'Rhialto' Seibert  rhialto(at)   "I would be dead in
\X/ a week if I didn't do /something/. I'd be splattered all over the walls."

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