Re: ZipGS vs TransWarp? (REQ: techie help)

[pubpc1@library.ucla.edu]

spec@vax2.concordia.ca (Mitchell Spector) wrote:
>In article RKFAIRCLOTH@unca.edu (Rhonda K. Faircloth) writes...
>>I have a Transwarp, with 8K cache. Anybody figure out how to "homebrew"
>>an update to 32K? I suspect that I'll need to obtain a different version
>>of the firmware as well as the usual (de)soldering.
>
>    It is possible to upgrade the 8K cache daughterboard, though you'll
>need a burned copy of the newer ROM (version 1.7 or higher) among other
>things. Harold H (I don't want to mispell his last name :) once mailed
>me detailed step by step instructions, as he's done it himself before.
>You can ask him about it, or with his permission, I could post dig up
>the instructions and post them here.
>
>    Another option is SHH Systems in Germany, they construct and sell
>new 32K daughterboards, but you may be on your own as far as finding 
>the ROM firmware chip (they may have a limited supplies of originals,
>you'll have to check with them). For a closer solution, check with 
>ABC Direct in the United States, they were selling 32K cache options
>for the TransWarp GS at one time.
>
>Mitchell Spector
>spec@vax2.concordia.ca

Why upgrade the ROM at all?

I read the articles in the NAUG newsletter about upgrading the TWGS
years ago and I remember that the ROM and GAL upgrades were only
needed if you were using the old engineering grade chips.  When the
real 14MHz CPUs appeared, the author updated the article and said
that for up to 10MHz speeds, the original parts were all that were
needed if using the 14MHz 65C816 because it was "clearly superior"
to the old chips (it didn't need the special delays for some
16-bit instructions that were programmed into the upgraded ROMs).

I would recommend that the author buy the 32K cache from SHH, get
a fast CPU from WDC, and put in a 40MHz oscillator and be happy with
10MHz operation.  A 10MHz TWGS performs at the level of a 12MHz
ZipGS according to the NAUG tests.

-Scott G.