Re: Trouble with Apple //e & Unidisk 3.5 & 4mhz. ZIP chip

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

Ed Hillman <ehillman@erinet.com> wrote:

> I have narrowed the problem to my Tymac PPC-100 (Tackler?) print card
> in slot 1. When it is out of the slot, everything works OK. When I
> reinsert it, the problems with the unidisk return.
> 
> No other card seems to be involved. I removed everything but the Sider
> Host card in Slot 7, the unidisk in slot 5 and the print card in slot
> 1. When the print card is in, the unidisk screws up; when it's out
> everything works fine.
> 
> Any ideas?

My guess: the Tymac card is violating the signal loading rules for the
slots, and the UniDisk 3.5 interface card is most sensitive to this.

(Any such violation is likely to slow down signal transitions, making
the UniDisk's timing sensitivity even worse.)

How hard would it be to replace the printer interface card?

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand