Re: Pet 8088 coprocessor board for sale on Ebay

From: B Degnan <>
Date: Sun, 16 Jan 2011 14:20:28 -0500
Message-Id: <>
At 02:08 PM 1/16/2011, you wrote:
>W dniu 2011-01-16 20:00, Hoffmann-Vetter, Martin pisze:
> > Have you read this:
>Yes, but this info is also mostly speculation :-(
> > Try it! The BASIC is the same on the low profile and the high 
> profile. Only different version about the used memory exists.
> > The Kernal is usable an both profile versions, too. It detect the 
> hardware (profile version) about a externaly hard jumpered pin from the tpi.
> > My last info is: You must use the correct basic roms!
>OK, I will swap all the EPROMs, it's an easy task so I shouldn't find
>excuses to avoid that :-) We should eliminate all possibilities.
> > That's the best idea. Becauce we know the correct requirement for 
> the coprocessor board. The question is, who writes this message? 
> The MS-DOS loader at the 6509 side or the firmware at the 8088 side?
>As far as I can see, it is written by code inside MSDOS.SYS file on the
>8088 side. Now how to extract this file for disassembling...

I have the listing for the 8088/6509 interprocess communications ROM, 
on the card.  I will post it to

..momentarily so it will be with the schematic online.


       Message was sent through the cbm-hackers mailing list
Received on 2011-01-16 20:00:17

Archive generated by hypermail 2.2.0.