Re: Problems: ZIP //e

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

In article <30vup4$s2a@cg57.esnet.com>,
Max Cohan <mcohan@cg57.esnet.com> wrote:
> I'm running control software Version 2.0, it talks about 4Mhz speed
> my box says 8Mhz.

Don't worry about it - the software and documentation was never
updated when the ZIP 8000 was released.  Any speeds referred to by the
documentation should be doubled (e.g. if you're writing directly to
the ZIP's registers to select the speed).

> The system, and actual problem are outlined below...
> 
> I just got a Zip 8000  (8 Mhz)
> I'm having all sorts of problems
> I'm running
> Slots 1&3 = empty
> 2 = Super Serial Card
> Aux = RamWorks 2
> 4 = Apple Mouse
> 5 = ThunderClock Plus
> 6 = DuoDisk controller
> 7 = Profile Controller
> 150 ns RAM on mainboard (changed from 24ns? due to errors, from old XT)

You're barking up the wrong tree regarding RAM speed.  The ZIP CHIP
always accesses Apple II memory at the normal speed of the 65C02,
synchronised with the system clock.  The rest of the computer is
completely unaware of its presence.  Chaning the RAM speed will have
no effect on the operation of the computer.

The ZIP CHIP caches all read operations, so if another read occurs to
a location which is already in the cache, the memory access to the
Apple II can be skipped and the cache is read directly (the cache
memory is inside the ZIP chip).

> HOWEVER  with ProDOS 2.0.3 I have to turn 'Language Card Caching'
> OFF... I'm not sure what that does...

I'm not entirely sure.  It obviously determines whether the language
card area is cached by the ZIP chip, probably taking into account the
active RAM bank (main or auxiliary) and/or ROM.

I have a strong suspicion that the problem is the RamWorks card.  These
cards work by bank switching auxiliary memory between multiple RAM
banks on the card.  The ZIP may not be aware of this bank-switching,
and will return incorrect data if caching occurs in auxiliary memory at
any time.

Try removing the RamFactor and see if the problem goes away.

Also try setting ALL slots to slow.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand