Re: Schematics for Accelerators

[dempson@actrix.gen.nz (David Empson)]

<pilgrimer@my-deja.com> wrote:

> I do not own a TWGS, a ZipGS, or any accelerator and, with prices
> climbing, availability shrinking, and no-one making any new ones, I
> doubt I can come up with one in my price range...SO....
> Query: Does anyone know of a source for the schematics for the more
> popular "Speed-Up boards" --as they are called in an old manual I have?

Well, I wouldn't like to discourage anyone, but I doubt you would get
very far.

The ZipGS uses a custom ASIC designed by Zip Technologies to implement
all of the interesting acceleration logic.  It wouldn't be too hard to
derive a circuit diagram of the board, but the actual functionality of
the card is nearly all tied up inside this "black box" chip.

You can't buy this chip anywhere, and even if you got the design and
made your own, you couldn't sell them without licensing, because the
techniques used by the Zip are patented (though the patent may be due to
expire in a few years).

The TransWarp GS might be slightly easier, because it uses PLDs
(programmable logic devices) to implement some of its special functions.
I haven't had a close look at this card, so I don't know if there are
any more complex chips on there.

Even if the TWGS is just using PLDs (or CPLDs), this may not help.  Most
PLDs have a security feature which protects their contents from being
read externally, and I would have expected Applied Engineering to use
this feature.

There are no other accelerators for the IIgs.

The situation may be easier with accelerators for 8-bit machines.  The
Zip Chip (and Rocket Chip) are in the same boat as the ZipGS, but the
card-based accelerators (e.g. Speed Demon and TransWarp) might be
feasible.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand