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" <billdeg@degnanco.com>
To: <cbm-hackers@ling.gu.se>
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.