Re: Pet 8088 coprocessor board for sale on Ebay

From: Bill Degnan <>
Date: Mon, 17 Jan 2011 12:03:36 -0500
Message-ID: <729ea7a0$475f8e61$4d7c5add$@com>
> > I have the listing for the 8088/6509 interprocess communications ROM, 
> > the card.  I will post it to
> >
> > ..momentarily so it will be with the schematic online.
> Thanks for posting it. I am analyzing the code with Ruud schematics to
> see what port lines are responsible for what. It should help us to write
> our own 8088 programs, maybe this would also be that way to check why
> the board does not work.
> I am looking for a way to transfer the MSDOS.SYS file from the CBM disk
> to my PC for disassembly. I tried extracting it from the D80 archive,
> but I can't quite figure out how the sectors are arranged with regard to
> FAT entries, and some sectors are filles with all 00 :-(

Yes, there's something happening strange with that disk.  When you are in 
native CBM-II mode all you see are the two PRG files, BOOTMS.PRG and 
MSDOS.PRG.    Is the entire MS DOS in MSDOS.PRG?  BOOTMS.PRG I suppose sets 
up the environment.  Does what I am asking make sense?Has anyone here taken 
the D80 file and made a bootable disk?  Yes (I have the system packed away 
at the moment, but I am getting itchy to test it out given the 

When I got the disk from Bruce Feirson, he told me he just copied the disk 
using COPY 1 to 0.  If there is no other way I will make a copy of this 
disk for anyone who wants one.  I also have a few versions of CP/M-86 and a 
Z80 emulator.  My 8088 is flakey at best, sometimes works, sometimes does 
not.  I have to stand on one foot sometimes with my hand on my head to get 
it to work.


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Received on 2011-01-17 18:00:19

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