From: Charlie (charles.lynch_at_ns.sympatico.ca)
Date: 2009-03-09 00:15:11
Hi Bill, I am certain that my machine boots up properly with the 256 roms and dos board installed. I can double check tomorrow. Charlie ----- Original Message ----- From: "B Degnan" <email@example.com> To: <firstname.lastname@example.org> Sent: Sunday, March 08, 2009 7:38 PM Subject: cbm 256-80 ROMS, PLA and 8088 co-processor. > To anyone who cares about the B Series 8088 Co-processor.. > > I have strong circumstantial evidence that the program space used by the > original CBM 8088 co-processor (intended for but not officially sold for > the B Series) conflicts with the space that the CBM 256-80 BASIC ROMS use, > and therefore a stock CBM 256-80 will not work with the 8088 co-processor. > That explains why the 2 256's with the co-processors I have came with B128 > BASIC ROMS in them. I will bet that no one with a 8088 co-processor and > 256 BASIC ROMS will be able to get it to work properly. By swapping ROMS > with another working system and/or working parts I learned of this > situation. Only when I had the following ROMS in a hi-profile B Series > system would the co-processor work: > > 901243-02 (B128 BASIC) > 901242-02 (B128 BASIC) > 901244-03 (probably not important KERNAL) > > Both the HIBOY PLA 906114-05 and 906114-04 work with the 8088 co-proc. > > To reiterate - "common knowledge" is incorrect, it's not the PLA that > makes a hi-profile board compatible with the 8088 co-processor, it's > probably the BASIC ROMS (you can't use the stock CBM 256-80 ROMs). > > I would need to dump the program listing of the 8088 co-processor to > confirm this. If there is a strong interest I will attempt to pull it > down, time permitting. This is one of those things I will do eventually, > and when complete I will share with this group. > > Bill Degnan > > > Message was sent through the cbm-hackers mailing list > Message was sent through the cbm-hackers mailing list
Archive generated by hypermail pre-2.1.8.