User`s guide

TransWarpGS boards vary just as do ZipGS boards. Some can be pushed to
higher speeds than others. If you decide to do a speed upgrade, get two or three
oscillators to allow for some experimentation.
For a step-by-step guide, download Scott G's TWGSupgrade.SHK. HyperCard
stack. (See Q&A 019 above)
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From: Wayne Stewart
I have a TransWarpGS with rev A GALs and a rev 1.5 ROM. It came as 7mhz
with an 8k cache. It was pretty unstable when I recieved it, so I put in a spare
14mhz 65c816 I had which stabilized it. Since I had a lot of rectangular
oscillators from my ZipGS upgrade experimenting, I made up an adapter so I could
use them in the TransWarp. With those two changes it's running at 14mhz.
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From: Andrew Roughan
It's time (June 2003) for an update on this article. I have recently
purchased some more oscillators from Clarke & Severn Electronics. They can now
provide custom programmed oscillators in 1/2 TTL packages for AU$6.98 each.
I am currently running my ROM 3 system at 14Mhz. I have a Transwarp GS with
ROM 1.8S and the 32k cache from Applied Engineering (35ns SRAMs). The GAL
versions are TWGS1A1, TWGS2B1, TWGS3B1, TWGS4B1, TWGS5A1, TWGS6A1, TWGS7A1,
TWGS8A1. I have the 14Mhz 65816 available from WDC. I have not purchased faster
SRAMs or modified the power supply.
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From: Rubywand
024- What kind of RAMs do I need for a TWGS or ZipGS
speedup?
If you upgrade your accelerator RAM, go for fast 32k x 8 Static RAM in a
28-pin Dip package. If your RAM sockets are "skinny" (about as fat as a typical
74xx TTL IC), you want a 300-mil wide package. Otherwise, you will need a 600-
mil wide IC or a socket adapter for 300-mil (or do the socket mods described
earlier in this FAQ).
Fast 600-mil package 32k x 8 SRAMs are fairly rare. However, the IDT71256
is supposed to be available at good speeds (25ns-40ns) in a 600-mil version from
Integrated Device Technology.
The selection of 300-mil 32k x 8 SRAMs is much larger: Cypress's CY7C199,
Hitachi's HM62256, ... .