9 Apr
2008
9 Apr
'08
6:14 a.m.
On 09/04/2008, Josh Dersch <derschjo at msu.edu> wrote:
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?
I have an IBM expansion in my Model 80. Can't remember what model
offhand, I'm afraid - I fitted it >10y ago. It has, from memory, 4 x
2MB parity SIMMs in it. I also have 8MB on the planar for 16MB total,
and you can spot the difference during the POST text very easily -
when it trips over from planar RAM to MCA-slot RAM, the speed of the
RAM test drops by something like 25-33%. It's very noticeable.
At the time, I was wondering if I could find a 2nd expansion board or
even a 3rd, populate 'em with cheap 1MB SIMMs and get 32MB or so. I
had slots to spare. However, on doing some reading at that time, I
found, as I recall, that there was only 1 specific board that could
extend a Model 80 past 16MB and it needed to be the sole RAM
expansion. I /think/ that you needed to max out the planar first, too.
A distant memory suggests that it was a Kingston RAM expansion that
could do it. I think multiple boards adding <=4MB each to an 8MB
machine could take you to 16MB, but getting above 16MB was very
difficult and even 11-12y ago, getting hold of those special boards
for >16MB was expensive.
So my '80 rests at 16MB, no more, even though I did have more suitable
SIMMs. :?( However, in 16MB, it ran NT Server 3.51SP5 really rather
nicely and was a responsive fileserver on my network, driving 3 or 4
SCSI disks across 2 controllers (1 internal, 1 external), a SCSI
CD-ROM and a SCSI Exabyte 8mm tape drive. Not bad for a machine that
was ~10y old when it was pressed into service, running an OS that
wasn't released until 7y after the H/W was discontinued.
It's still sitting in my garage. Not powered it on this century. :?(
Hope it still works.
--
Liam Proven ? Profile: http://www.linkedin.com/in/liamproven
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