Re: CBM 8296 programming info

From: Andre Fachat (
Date: 1998-02-17 21:34:26

Hi Olaf,

Olaf Seibert wrote:
> Yes, the 1.0 ROMs could not load/save from disk. Only tape. And it
> has some timing bugs there too.
Timing is not important in VICE. And I have decided to patch the
ROM IEEEroutines for load/save, which is much easier than catching the
bugs in VICE itself.

> Btw, for proper emulation of the 2001, you should make a character ROM
> with (for upper/lowercase mode) the upper and lowercase characters
> swapped. When they swapped those in the 30xx machines, all programs
> with lowercase characters broke. And they turned Li into lI, which
> looks a lot worse ;-)
Well. I have that now. But then PET2001 fires up in graphics mode, which
is unusable with the swapped chars. Are you sure about that?
Probably the ROM from has a fix for the charrom already

> > I hope at least that the stuff about 8096 in PETio.doc is enough, because
> > then the 8096, ie.  $FFF0 register seems - to my testing :-) - be fully
> > functional.
> It should be.
So 8096 works, only 8296 must wait for the next release.

> Another thing. This weekend I got a 8032 (a square one, finally) with

I only got one 8296D from Ruud lately, and using parts from another
of those boards I made it work again.

And many thanks for los96, although I didn't have the time to check it so


BTW: The "killer-poke" should be Poke $e842,62 (this is VIA DDRB)
This sets VIA PB5 to output. (Normal content is 30, + 32 for bit 5)
The two pokes below should speed up the screen output if it doesn't kill 
the machine, you are warned:

Email address may be invalid. Use "fachat AT physik DOT tu-chemnitz DOT de"
------Fight SPAM - join CAUCE, spammers...
Andre Fachat, Institute of physics, Technische Universität Chemnitz, FRG

Archive generated by hypermail 2.1.1.