Re: Upgrade conundrums...

[dempson@actrix.gen.nz (David Empson)]

In article <4ts6gs$5d9@nntp.seflin.lib.fl.us>,
z008729b@bcfreenet.seflin.lib.fl.us (Martin Gruen) wrote:

>Okay as stupid as it is to followup my own post, but I reviewed the FAQ 
>on accelerator upgrades and need to ask another question.  For an out of 
>the box ZipGS, if I want to put a 14 mhz chip on it, do I require the 
>crystal oscillator and SRAM (or anthing else I missed), or isn't it 
>necessary at that speed, and I can just swap  chips?

If you have just bought a ZipGS, which is running at 7MHz or 8MHz, then
you will definitely need to replace the crystal oscillator to run at a
different speed.

The crystal directly controls the maximum speed of the card, so you will
have to replace the existing one with one that is four times the desired
execution speed of the card (e.g. 48 MHz for a 12 MHz ZIP, 56 MHz for a 14
MHz ZIP).

The cache RAM will probably also have to be replaced.  I can't give you
exact figures, but you will probably need 40 ns RAM or faster for the TAG
RAM, and may also need to get faster DATA RAM.

-- 
David Empson
dempson@actrix.gen.nz
Snail Mail: P.O. Box 27-103, Wellington, New Zealand