22 Dec
1998
22 Dec
'98
5:55 a.m.
>You write that the SuperPET without 6809 were
called 8096 - which
>is IMHO completely wrong. The 64k memory expansion of the SuperPET and
>the 8096 are completely incompatible.
>- SuperPET: RAM mapped into $9***, with an I/O
register providing
> the upper 4 address bits
>- 8096: This is actually an add-on board to the
8032 that provides
> 64k expansion port in the upper half of the address space - you
> could remap all the ROM and I/O with two 32k banks of RAM.
> Bank selection was separate for $8000-$bfff and $c000-$ffff.
> You could even write-protect the RAM.
Andre is completly right here about the technical difference.
To quote my mail regarding this thing:
Tue, 15 Dec 1998 21:25:54 +1 Re: "Single
instance" machines
To get this straight, we are talking about the 8096, a modified
8032 with the big metal case and a 'Universal PET' board, and
a daughterboard pluged into to give 64 K of additional mem.
Now the 6809 PET (SP, MMF, etc.) has also a
daughterboard, placed
in the same position, that replaces the 6502 CPU with a cable to
the add-on board. On the board ist the original 6502, the 6809, a
6551, 64k RAM and some ROM. The RAM is maped, instead of to $9xxx
(if my memory is correct) in 4K steps (and the ROM on the daughter-
board did replace the Kernal ROM, when the 6809 was active - if my
memory is correct).
>So I doubt that the SuperPET were similar to the
8096.
>Especially as the 8x96 RAM expansion would make it difficult for
>the 6809 to access the additional RAM.
>But then, you never know CBMs numbering scheme :-)
Jep, Commo Numbering is a synonym for more like Random Numbering :)
Just like my MMF/8096 Bastard - 8096 case, 8096 labled on the front,
but 6809 daugtherboard and MMF label on the back - and named MMF in
the shipment papers.
Sometimes I think they have known from the very first begining
that Commodore might be collectable and tryed their best to
confuse us (or the russians ?).
So PET freaks: which is right? I always thought the
non-6809 CBM 9000 *was*
the 8096, but he does have a lot of info about the SuperPET on his pages
Both are based on the 8032 board, but with different daughter boards.
Both daughter boards added 64K, but thru different techniques.
But as always you never can be shure what Commodore realy did build.
Gruss
Hans
--
Ich denke, also bin ich, also gut
HRK