Re: Zip GS Cache RAM

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

In article <47o60b$42l@news.eecs.nwu.edu>,
Paul Brazis <paulb@eecs.nwu.edu> wrote:
> I have a 9MHz ZipGS with 8K ram. I am wishing to upgrade this to 64K. If this
> is possible, what # of chip do I need?

You need four 32Kx8 static RAM chips of sufficient speed (55 ns or
faster should be OK at 9 MHz).

> Also, do I need to switch DIP switches (I assume so)?

Yes.  Switches 7 and 8 of bank 1 control the cache RAM size:

1-7 1-8  Cache size

ON  ON   8K
ON  OFF  16K
OFF ON   32K
OFF OFF  64K

> Will this upgrade show a significant improvement (I assume so)?

It depends on the software you are running.

Increasing the processor speed of the ZIP usually has a more
noticeable effect than increasing the cache size.

A larger cache allows the ZIP to run at full speed for a greater
proportion of the time, and is most likely to come into play when
executing moderately scattered code.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand