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Re: 20 MHz 65816





M. Pender wrote:

Thanks, it should be a nice project if I get it working.  I think there
might even be a commercial market for a 20 MHz IIgs accelerator board.

The general plan is to study the approaches used by the Zip GSX and the
TranswarpGS and to simplify the design.  Aesthetically, the difference
between the two is amazing.  The Transwarp looks like a nightmare to
manufacture, with DIP switches and a daughterboard.

In comparison, the GSX is such a clean card that it is practically a work of
art.  The circuit traces are laid out in nice organized patterns, it looks
like they minimized the path length for the circuit routing, and the
on-board memory layout is a model of how to conserve space.

As I understand the two design philosophies, the Zip plan was to recreate
the II on the card, whereas the Transwarp approach was to fetch instructions
and data for the cache, process on the card, and to use a type of glue logic
(implemented in gate arrays) to look for memory accesses or instruction
combinations that require the processor to slow down.

If anybody knows where I can find some of the engineering documents for
either of these cards, I would love to study them.

The ZipGS is a caching accelerator as the TransWarpGS is. The major
difference was that it used a custom chip to replace a lot of the
individual ones the TransWarpGS used. The story that circulated
when they stoped production was that another run of this chip was
$10K+ and there was no market for that many cards. At that time at
least the cards just were't selling. Someone bought a ZipGS and posted
that Alltech had said there was only one ZipGS left, it took two months
to sell.


There were a couple of II+,IIe accelerators that were almost computers
on a card, the Titan and even more so the TransWarp(not the
transWarpGS). The TransWarp doesn;t use the II, II+ or IIe processor
or motherboard RAM so you can run with those sockets empty.

For ZipGS or TransWarpGS knowledge Tony Diaz is the first person that
comes to mind. ///SHH Systeme offers ZipGS and TransWarpGS repair so that's a possibility.