Re: ZipGS more stable with slower SRAMS?

[martin.kaeser@auge.de]

Paul Schultz wrote:
> =

> Before I go out and buy slower SRAMS for my ZipGS, could someone
> explain why the ZipGS may be more stable at higher speeds with
> "not-so-fast" SRAMS in the DATA cache (around 35-45ns) instead
> of fast SRAMS (15ns)?

Our local expert told me:

The Zip first reads the Tag RAM and then the Data RAM. =

At speeds > 10 MHz, it gets the timing wrong. The Tag RAM is still =

driving data on the bus and the Data RAM is beginning to put data on the =

same bus corrupting data.

Using a slower Data RAM gives the tag ram more time to get off the bus.

My Zip is "unsafe at any speed" using 15ns SRAMs. It crashes at 7MHz =

with the same frequency as with 16.5 MHz.

 I have no idea where to look for 45ns SRAMs and i think i=B4ll put a TTL =

driver chip on my Zip to delay the chip enable of the Data RAMs. Did =

anybody try this?

martin