Re: TranswarpGS & GS/OS 6.0.1?

[supertimer@aol.com (Supertimer)]

edhel@apple2.com (Edhel Iaur, Esq.) wrote:

>I've got a version 1.5 TranswarpGS with (AFAIK) all the original parts
>(8K cache, 7(?) MHz, etc.), and it seems to work, except it doesn't
>install its CDA and it won't boot past GS/OS's "Welcome to the IIGS"
>title screen.  The red progress bar doesn't even START to move.  Can
>something be done, or should I just return it?
>
>Further information: It seems to run Apple //e software just fine.
>I'd really like to get it to run GS/OS stuff, though...

This sounds like a failing CPU.  The older 65C816 chips were shaky
when pushed to TWGS/ZipGS speeds.  Over time, the performance
of these older chips may degrade, especially at the fast speeds.  Also,
the chip could be stable on one TWGS/Apple IIGS combination,
but when the TWGS is put in another IIGS, the chip could fail.  More
specifically, the older 65C816 had problems with processing 16-bit
instructions at high speeds so when the chip begins to fail, 16-bit
software would crash first before 8-bit mode is affected.

The solution to your problems is to replace the 65C816 with a new
one from Western Design Center.  The new chips are rated at
14Mhz, but are actually apparently 20Mhz chips.  WDC does not
test for higher speeds because they don't have the equipment,
but CMD builds 20Mhz accelerators for the Commodore 64 and
Commodore 128 and contracts an outside agency to test the chips
at 20Mhz.  They have yet to have one failure at 20Mhz!

A side benefit of upgrading the TWGS is that if you also replace
your current oscillator with a 50Mhz one, like I and many other
csa2 readers have, your TWGS will run at 12.5Mhz rather than 7Mhz.

Once you experienced the added speed, 7Mhz will seem VERY
sluggish.