Zip-GS speed and cache

[casa@unm.edu (Jim Pittman)]

I recently ordered an 8-mHz/16-k cache Zip-GSX accelerator card from
EGO Systems. When I installed it, it didn't work. I called REMCorp per
the manual. They said, push down all socketed chips and try again; if
that doesn't help, set Switch S1-6 to "OFF" and try again. If that
works, then set S1-6 back to "ON" and set S1-8 to "ON" and try that.

Well, sure enough, the four memory chips weren't seated very well but
re-inserting them didn't change anything. Setting switch S1-6 to "ON"
worked (but the accelerator is thereby disabled). Then setting S1-6 to
"OFF" and S1-8 to "ON" worked. (With S1-7 "ON" and S1-8 "ON" there is
only 8-k cache instead of 16-k cache.)

After loading GS/OS System 6.0.1 and checking things out, "The.Analyst"
reported that the Zip was running at 9.3 mHz! The crystal oscillator,
instead of being 32-mHz for 8-mHz speed, was labeled "37.276260 mHz"!
I called REMCorp and told them this. They said that was the problem and
suggested that I replace the crystal with a 32-mHz crystal to get the
correct 8-mHz speed, and set S1-8 back to "OFF" to get 16-k cache.

I called Digi-Key and they said they had 32-mHz crystals. So I can get
a new crystal and slow the Zip down to 8-mHz. But -- if it runs okay at
9.3 mHz and 8-k cache, am I better off than I'd be at 8-mHz with 16-k?
Is the odd 9.3 mHz speed likely to cause any problems? (Digi-Key said
they could not supply a 36-mHz crystal for exactly 9.0 mHz speed.)

Or, could I get four different (presumably higher speed rating) memory
chips and run at 9.3 mHz and either 16-k or 32-k or 64-k cache? If so,
what chips would work?

Thanks for any enlightenment.

- Jim Pittman - University of New Mexico - casa@unm.edu