Trouble with Apple //e & Unidisk 3.5 & 4mhz. ZIP chip
Ed Hillman
(enhanced) which has been in storage for 5-6 years. It is configured
as follows:
Slot 0 - AE Ramworks III
Slot 1 - Tymac printer card
Slot 2 - Apple Super Serial Card
Slot 3 - Videx Ultraterm
Slot 4 - Microsoft Softcard (Z-80)
Slot 5 - Apple Unidisk 3.5
Slot 6 - Apple Duodisk
Slot 7 - Sider 10meg Hard Drive
No-Slot clock under ROM on Sider interface card.
I set it up and all worked fine. I upgraded to ProDOS 2.0.3 and the
latest No-Slot Clock ".sys" driver and all worked well. (Not having
the NSC patch file for ProDOS 2.0.3.)
Last night I re-installed my 4mhz ZipChip and all seemed to work OK,
though I didn't do a through check-out.
Tonight I performed the capacitor removing mod on the Duodisk analog
board to avoid the disk trashing problem I read about in the FAQ's on
this newsgroup.
All seemed OK, until I tried to use my Unidisk 3.5. It would try to
read and write, but would mostly just lock up the machine requiring a
reboot. I started backtraking my changes to see what caused the
problem. First I made sure the ZipChip was set to slow speed on Slot
5. It was. Then I tried disabling the Zip in software. Still no good.
Then I completely removed the Duodisk frm the machine and still the
Unidisk 3.5 wouldn't work properly.
Finally, I replaced the Zip with the original 65C02 CPU and the
Unidisk started working again. Reinstalled the Dudisk and all was
still OK.
Evidently the ZipChip, even disabled will not allow the Unidisk to
operate.
I don't remember there being a conflict between the Zip and Unidisk,
but then for some reason I had pulled the Zip prior to putting the
machine in storage. (My memory doesn't work back that far... I've
unfortuantely hit 50 years old!)
Does anyone know of any such Unidisk/Zip conflict and any possible
workarounds?
Thanks for any info,
Ed
Ed Hillman
I received a response via e-mail that another person has had no
trouble with a zipchip/unidisk combination. He suggested I try
setting the zip chip with slot 5 (unidisk) set fast. This did not
help.
Since I have recently upgraded to newer ProDOS and a different clock
driver, I tried ging back to the older version of ProDOS (1.8). Still
no luck.
I have for the time being removed the zipchip and replaced the 65C02.
Since I'm not running any real speed demanding programs, this is my
best current option.
Any ideas out there?
Ed
Wayne Stewart
isn't working
for some reason.and slot 5 isn't slowing down. You could test this by
switching the
unidisk and duodisk cards around.
A "manual" way to make the ZipChip run at 1mhz is to hold down the
escape key
while powering up.
Supertimer
Try pulling the CP/M card. ZipChip is not DMA compatible,
so the CP/M card might be messing something up when
used with the ZipChip such that the UniDisk can't work.
Randy Shackelford
David Empson <dem...@actrix.gen.nz> wrote:
>Ed Hillman <ehil...@erinet.com> wrote:
>
>> Any ideas out there?
>
>My initial thought was some kind of DMA compatibility issue, as
>mentioned by SuperTimer. The UniDisk card itself doesn't use DMA.
>
>The only major thought that I have to add is that there is known to be
>something slightly odd about the UniDisk 3.5 card ("Liron"). For
>example, it does not work in a IIgs.
I had always heard that the card worked with the system running at 1 MHz.
Never had any inclination to test it naturally since Unidisks work on a
IIgs without the card.
>I think this is due to a bus timing issue, but I'd have to do rather a
>lot of searching through old information to locate anything useful on
>the subject.
>
>If it is a timing issue, the Zip chip could be causing a similar
>problem.
That'd make sense if the card won't run in a IIgs at normal speed.
>Another comment: you have an awful lot of cards in there. Do you have a
>heavy duty power supply? You might be running into a loading problem on
>one of the power rails. Try pulling every card except the Duodisk and
>UniDisk 3.5, and put the ZIP back in.
My //e has eight cards and it got to doing weird stuff which stopped after
putting in an AE P/S.
--
Offsite mail to this host gets nuked.
Louis Schulman
dem...@actrix.gen.nz (David Empson) writes:
>Ed Hillman <ehil...@erinet.com> wrote:
>
>> Any ideas out there?
>
>Another comment: you have an awful lot of cards in there. Do you have a
>heavy duty power supply? You might be running into a loading problem on
>one of the power rails. Try pulling every card except the Duodisk and
>UniDisk 3.5, and put the ZIP back in.
>
Yes, I thought the power supply was a likely culprit. I had a problem
with another accelerator causing crashes (it was a McT SpeeDemon) and it
turned out that the power supply simply couldn't meet the extra demand.
You could go the Bugg Power external route, or MC Price Breakers has a
6 amp drop in PS for $27.95 with a 2 year warranty.
Louis
David Empson
> Any ideas out there?
My initial thought was some kind of DMA compatibility issue, as
mentioned by SuperTimer. The UniDisk card itself doesn't use DMA.
The only major thought that I have to add is that there is known to be
something slightly odd about the UniDisk 3.5 card ("Liron"). For
example, it does not work in a IIgs.
I think this is due to a bus timing issue, but I'd have to do rather a
lot of searching through old information to locate anything useful on
the subject.
If it is a timing issue, the Zip chip could be causing a similar
problem.
Another comment: you have an awful lot of cards in there. Do you have a
heavy duty power supply? You might be running into a loading problem on
one of the power rails. Try pulling every card except the Duodisk and
UniDisk 3.5, and put the ZIP back in.
--
David Empson
dem...@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand
Ed Hillman
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?
I have put the 65C02 back in the machine for the time being. If I
can't get this resolved, I'll probably just put the Zipchip up on
ebay.
Ed
David Empson
> 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?