Re: fastest GS accelerator?

[fmlin@netcom.com (Frank M. Lin)]

In article <2C12EA0D.29799@news.service.uci.edu> andrep@balboa.eng.uci.edu (Andre Prellwitz) writes:
>Could anyone verify if the following is correct?  The fastest you can get a
>ZipGS to run is ~12Mhz (reliably) due to the cache bottleneck (or whatever),
>but a Transwarp GS has been pushed to do ~15Mhz, with minor (major?) mod-
>ifications/gals/cache chips.  Will the ZipGS ever have its bottleneck
>removed for when the 20Mhz ASIC Enterprises chip is released/produced?
>
>Thanks in advance...

Dunno about the max speed for Zip, some thing limits it to around 12mhz.

For up to 12mhz, it's plug and go.

Zip:

buy new '816, plug-in
buy new crystal (s), plug-in ( might need difference size )
might need faster SRAMs, plug-in

TWGS:
buy 32k cache, plug-in ( this gives you noticable improvement + latest ROM )
buy new '816, plug-in
buy new crystal (s), plug-in ( TWGS uses 1/2 TTL )
need proper version of GALs of speed above 10mhz, and DMA fixes

12+mhz should require voltage increase, but if you're lucky, you don't need
to.  You can try faster crytals with the stock voltage.  Worst thing could
happen is system won't work.  FYI, my TWGS can do 13.75mhz at 5v.  About
5.2v for 15mhz.

Each '816 is different, so your milege may vary.  Maybe 12mhz is the fastest
yours well go.

Maybe I'll construct a mini-FAQ for TWGS/Zip upgrade...


-- 
frank m. lin
fmlin@netcom.com