Re: Can't go faster than 10MHZ on my IIGS

[supertimer@aol.com (Supertimer)]

"Dana Eckel" <deckel@info-link.net> wrote:

>Ok,
>   I have a Zip GS 1.02 with 32MHZ crystal, upgraded to 64K of Cache. My
>IIGS is a Rom 1 unit. I have tried 40 MHZ, 50MHZ, and 64MHZ crystals with no
>success. Could my ram cache be bad? How do I know it is even seeing the 64K.
>I used skinny chips that are offed from Jameco and the adaptor from
>Digi-Key. And yes I also have a WDC-14 chip installed too.
>
>Thanks for any help you could offer.

For the ZipGS, try switching the DIP switches to reflect 32k of
cache.  If you have 64k of physical cache, then any of the DIP
switch settings (8, 16, or 32) work.  Then change the switches
to reflect 16k.  Decreasing the amount of cache addressed will
increase your chances of going higher in clock speed.  As
previously mentioned, there is a part that sometimes has to be
replaced to get over about 12Mhz, but you should be able to
get over 10Mhz easy with the WDC-14 part.  Note: There is not
a huge performance difference between 16k of cache versus
64k of cache when your processor speed increases this much.
You will definitely be better off with, for example, a cache setting
of 16k and a clock speed of 12Mhz compared with a cache
setting of 64k of and clock setting of 8Mhz you currently have.