I was given a Mac Plus a while back... and never tested it....
Decided to give it a quick test...
Other than needing a boot floppy which I'll have to dig up.... it powers
on, video
looks good, monitor is stable and all...
But there is a faint sound (think of it as a cross between crickets
chirping and clicks)
and after a while, it smells to me a bit like ozone at the top of the Mac.
I'm thinking maybe high voltage leakage ?
Anyone have any experiences with these old Macs that can point me at
what to look
for ?
It might well be OK as it is... but I don't want to risk damage occuring
as other
than a few dings and scrapes and a bit of yellowing, it is in remarkable
condition.
-- Curt
I have a Zenith Z100 user manual (with some pages still in shrinkwrap) and
a winchester supplement that I've run on Ebay a couple times. Is anyone
here who's not on speaking terms with Ebay who'd like this?
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
Hi
Could anyone out there with an 8/e confirm the following:
1. Knob set to STATE, SR Keys Down
2. Press ADDR LOAD - do MD DIR and DATA CONT light up?
3. Press EXAM - do MD DIR and DATA CONT light up?
4 Raise DEP - do MD DIR and DATA CONT light up?
Rod Smallwood
At 12:00 -0500 4/10/08, David Griffith wrote:
>I've just brought up a Mac SE/30 with fresh disks and noticed that the
>monitor occasionally gets wavy or shudders. How should I proceed in
>fixing this?
I had a long, long series of problems with my Mac Plus. They
got pretty much cured when I took loose the power cable connecting
the Analog/video board to the digital board, cleaned the pins (sanded
lightly and wiped with ethanol), and put some silicone oil spray on
to inhibit corrosion. I had previously done this at the digital board
end, but the resistance (ohms to tens of ohms, and variable,
responding to temperature and vibration) was at the analog board end.
I finally discovered I could diagnose these by using an ohmmeter
between the solder pads on the back sides of the boards at either end
of the cable.
I don't know how many differences there are between SE/30 and
Plus, but some, for sure. Be very careful disconnecting at the analog
board end of the cable - pull too hard, and your hand can smack into
the thin end of the CRT, letting the vacuum out. I have a .pdf of the
Apple Service Manual for the SE/30, which I'll be happy to forward
(off-list, obviously).
On the Plus, there are also a set of variable resistors on
the analog board setting various parameters (width, height, etc.) of
the video. Those might also be corroded. Running them back and forth
and then back to the original settings might clear that, or some
contact cleaner (which is probably a better treatment for the
connectors than what I list above) might be a good idea.
Finally, capacitors on the analog board might be going bad.
An ESR meter could give you some indications there.
Additional clues from somebody with an SE/30 would be very valuable!
At 12:00 -0500 4/10/08, Ian Primus wrote:
>But I have a
>book at home, forget the name, but it's a Macintosh
>repair guide that has a lot of good info to help
>pinpoint failed parts. It has a purple cover. Anyone
>remember this book? This is going to drive me nuts all
>day. :)
The "Dead Mac Scrolls"? "Macintosh Repair and Upgrade
Secrets"? Google for Larry Pina, I think he's the most-recognized
author in this area.
At 12:00 -0500 4/10/08, David Griffith wrote:
>It happens perhaps once every ten seconds. The disturbance is something
>like a ripple or wave that crawls up the side of the screen.
Oh. Probably my advice above is good in general but not
specific to this problem. I think the Pina books may well address it
though. If Jeff W. is listening, he can probably verify that.
--
- Mark, 210-379-4635
-----------------------------------------------------------------------
Large Asteroids headed toward planets
inhabited by beings that don't have
technology adequate to stop them:
Think of it as Evolution in Fast-Forward.
I have one of these new in the box, only opened for inspection. Has all
SGI docuemntation,
boot rom, video board, all new in the original massive box (about 20x20x4).
If your interested make an offer. I'm only keeping one of my Indy's,
and that one already
has XZ so I don't need this new one.
-- Curt
Title says it all... I picked up a "new" (still in shrink-wrap)
AboveBoard MC with the intent of using it in my PS/2 model 80 and I'm
having serious issues getting it to function properly.
The Model 80 has 4mb of planar memory installed, and I've been running
it with no issues with an Orchid Ramquest 8/32 stocked with 8mb of
memory (so 12mb total). In an attempt to get a little more memory, I've
tried running with the Orchid replaced by the AboveBoard...
The AboveBoard came with 4mb installed (4 1mb simms) which I initially
replaced with 32mb (8 4mb simms, known good). I've since tried running
with the original RAM, as well as other RAM I have lying around, without
any success. I've tried running in different slots (both 32 and 16 bit)
with no change. I've also adjusted the ram speed in the configuration
page (options are 100ns or 80/85ns) with no change, though it seems
slightly happier with 80/85ns selected.
The behavior is very random -- sometimes the startup memory count (which
is separate from the memory count in the PS/2's BIOS) fails to count all
the memory -- on these occasions you can see it "pause" slightly during
the count as if it's hitting bad memory and skipping over it. Sometimes
it counts all the memory just fine. Regardless, the OS crashes or
panics (tried NT & Debian Linux, haven't tried OS/2 yet) eventually.
I've run memtest86 on it and what I find is that if the memory count is
successful, memtest reports no errors, but attempts to run actual OSes
crash after awhile.
I've read that the Model 80 has trouble (not sure precisely /what/
trouble) with more than 16mb of memory, but even limiting the AboveBoard
to 4mb is problematic.
Anyone have any ideas? Similar/different experiences?
Thanks,
Josh
The problems with SA850's eating media was well known at the time, as well as
the switch to a bicompliant head. If anyone cares, there are still folks around
the Valley that worked on the problem.
Apple got around the problem with by putting the heads on opposite ends of the media
on the Twiggy, but it had other well-known problems.
Here is some interesting history on the development of the double sided
floppy drive.
I Googled for - shugart sa450 1976
Start reading around page 170
In the Matter of "Certain Double-Sided Floppy Disk Drives and Components
Thereof"
Investigation No. 337-TA-215
USITC Publication 1860
May 1986
United States International Trade Commission, Washington DC
Michael Holley
www.swtpc.com/mholley
>Date: Fri, 11 Apr 2008 21:11:07 +0100
>From: "Liam Proven" <lproven at gmail.com>
>>
>> I'm trying to find a Micron Xceed Color30 card and Greyscale30 card for a
>> Mac SE/30.
>It /is/ possible to clone one - q.v.
>
>http://home.earthlink.net/~gamba2/microngray.html
Actually, that project was just to clone the Grayscale adapter card.
It did not include the frame buffer main card. The main card was
based on a custom chip by Micron--not an FPGA unfortunately. So the
chances of cloning it without having to redesign the bulk of the
logic is nill.
Now, it really shouldn't be that hard to whip something up with an
FPGA and either some fastish SRAM or an open core DDR2 controller and
one DDR2 memory chip. However, figuring out all the ins and outs
of properly interfacing to the Mac OS of the time has had me slowed
and stopped for a while. It's probably not all that difficult, but
it is tedious and there is a lot of information to sort through. One
of the hardest parts is knowing which information I actually need.
For every useful tidbit I find, I've gone through 20 chunks of old
Mac knowledge which don't apply but were in the way.
Jeff Walther
