Date   : Thu, 20 Oct 2005 03:45:21 +0100
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Re: Adding copro support to BeebEm

David Hunt wrote:
> I have been thinking back to the old days and I recall a small daughter
> board next to the CPU with a white ROM sized chip all covered with gold and
> a bunch of logic chips surrounding it and also another 40 pin socket !?! 

Hmm, not sure there. Is this in one of the two copros that you have? Or 
a different one that your father used to own?

> I think the 4MB RAM was on the main board, I don't recall any expansion.
> Perhaps the memory ICs were higher capacity, e.g. 44256 vs. 41256 ? (262,144
> words of 4 bit vs. 262,144 words of 1 bit)

Far as I remember though, the 44256 uses four more pins than the 41256, 
and the board used in the cheese-wedge copro doesn't have the extra 
holes to take the higher-capacity chips - at least not in the boards 
I've seen. Maybe there's yet another flavour out there though...

> I think my Father's memory is about as reliable as the 32016 was. I'll ask
> him at the w/e but I'm not hopeful!

heh, thanks :)

> Anyone know how much a Cambridge Co-Pro is worth ?

Dunno, I've been giving them away! I suppose they'd fetch a few quid on 
ebay though, particularly if you have the original disks (I doubt they 
ever got to the stage of having nice cardboard sleeves around the boxes 
like other copros, so packaging doesn't come into it).

I have no idea what documentation shipped with them. I've got boxed sets 
of disks and docs for the Cambridge Workstation, but I think the beeb 
32016 copro shipped with its own branded stuff even though it was likely 
the exact same items with different covers/labels.

(Incidentally, some of the copros were branded as "Cambridge 
Coprocessor" whilst others are badged as "32016 Second Processor" even 
though they're identical inside. I have no idea why the name was changed 
at some point)

cheers

Jules