Michael_D'Alessandro%Wayne-MTS%UMich-MTS.Mailnet@MIT-MULTICS.ARPA (07/04/84)
What follows is a heavily edited exchange from WCSC:MICROS,
the Wayne State University microcomputer conference. This
exchange covers territory similar to the problems described by
Jim Byrd. I hope it's of help...
Michael D'Alessandro
2) James Sedensky: As a starter, we have just encountered a
problem with using our Microsoft CP/M Softcard on our
departmental IIe. When we attempt to boot the disk, the drive
"whirs" for a few seconds and "Apple II" appears on the screen
and everything comes to a halt. The LED on the Softcard
remains lit. We have successfully booted this disk and
Softcard on two other IIe's and on a II+. We've exchanged both
the disk drive and drive interface card without success. At
this point we can only speculate that the problem is on the
motherboard. No other problems have been encountered with this
particular IIe, including previous use of slot #4 (recommended
for the Softcard) with a Hayes modem. Does anyone have any
further suggestions before we are forced to bring the IIe back
to Lyceum for repair (unfortunately it's out of warranty)?
- - - - -
4) Larry Boulet: Try booting your Softcard with a 48K version
of CP/M if you have it. I know the 56/60K versions look at the
ROM's before loading past them and even the smallest
inconsistency will cause the software to hang.
- - - - -
5) James Sedensky: I've tried the "jiggling" technique which is
an old standby, but withour success. Presumably this IS the
48K version which we're using: as I indicated, it works fine
on other 64K and 128K IIe's and on a 48K II+. Any other ideas
--- or do we punt ???
- - - - -
6) Marcus Watts (neti): Besides trying the 48k version, you
should also try putting the softcard into another slot. It
doesn't matter which slot the Z80 is in, the software will
find it. Also try taking out all the other cards; one of them
may be interferring in some bizarre way. [Incidently, the 48k
version should announce itself as such. or there's a low-core
location that points to the top of memory.]
- - - - -
7) Clarence Wilkerson: Does the modem card now work in slot #4
with the CP/m card out?
- - - - -
8) James Sedensky: Marcus: I've already tried removing all the
boards from all the slots except the disk drive board and have
tried the CP/M card in slots 2,3,4,7 --- all without success.
As far as I know, the modem card still works in slot 4 but
I'll check it again. At this point, I'm just about convnced
the problem is somewhere on the otherboard.
- - - - -
9) Mark Wolcott: YOU MAY TRY REPLACING THE Z-80 ON THE
MICROSOFT CARD. I BELIEVE THAT THERE WAS A BAD BATCH USED BY
MICROSOFT. THE PROBLEMS YOU DESCRIBE WERE MOST EVIDENT WHEN
THE IIE FIRST CAME OUT. THE CARD TIMING WAS OFF BY JUST ENOUGH
TO CAUSE A FAILURE IN SOME IIE'S AND NOT OTHERS.
- - - - -
11) Jon Zeeff: Has anyone found a CP/M card for the Apple IIe
that works on all IIe's (and doesn't use on board memory)?
Certain Microsoft cards work only with certain Apples
(supposedly a timing problem).
- - - - -
13) James Sedensky: Jon, this is exactly (I think) the problem
we're having with our Microsoft CP/M card). The people at
Lyceum say this is not an uncommon problem. Supposedly Lyceum
can solve our problem by a timing change on the motherboard.
Whether this will then make this CP/M card usable on our
departmental IIe but not on others on which it previously DID
work remains to be seen.
- - - - -
15) James Sedensky: Jon, Lyceum just called to say they had
replaced the main processor and all the socketed chips to try
to get the Microsoft CP/M card to work on our IIe --- all
without any success. So they exchanged the entire motherboard
and CP/M booted without any problem. They could have continued
checking individual components but that would have cost a smal
fortune in labor. This way, Apple gives us a new motherboard
for $55.00 (plus $25. labor)
- - - - -
16) Marcus Watts (neti): It sounds like it might well have been
a broken PCB trace anyway.
- - - - -dudek@utcsrgv.UUCP (Gregory Dudek) (07/11/84)
Regarding CP/M cards and apple II-type machines, one thing I did not
see mentioned was that you might have power supply
problems. Although most TTL stuff as used in Apple ][-style machines
will work with 4.8 volts or so, the z-80 seem to be much more
finickey and require an honest-to-goodness 5 volts. If you supply
is delivering under 5 volts, it is possible that almost everything
under the sun will work except your z-80 card (or it may work
erratically).
If you want to try fixing things yourself, there should be a little
hole in the bottom of the power supply with has a trim-screw underneath
it. Adjust this while using a voltmeter to check out what you
are doing.
(Note also that this must be done while the suppy is connected
to the system -- the supply will fail to operate in a "no-load"
condition.)
--
Gregory Dudek
{cornell,decvax,ihnp4,linus,utzoo,uw-beaver}!utcsrgv!dudek