8595 / 9590
Model 90 Front View
Model 90 Planar
DBA Artifact on 8590s
8590 and 9590 Planar
9590 Floppy Controller
Marked 2.88MB Floppy Drives on 8590s
Serial Port Speed
Memory Expansion Boards
Badge- If grey, XGA. If blue, XGA-2
(Blue means ISO compliant).
Floppy 1.44MB (8590) or 2.88MB
5.25" Bay Has three rails. The
outside ones are for a 5.25" drive. The left rail and the center rail are
for a 3.5" drive.
8590 / 9590 Planar
IBM intended originally to bring out a "low-end" Mod. 90 with DBA-ESDI
and a 386DX-25 / DX-33 processorboard - but luckily dropped these plans.
(Ed. Someone, either the US Army or
a big insurance company (different rumors) had 386DX-20 complexes made
for it- the infamous "Type 0"). So these DBA-connectors
are "design artifacts" which can be found regularly on IBM boards and cards
... the planar descriptor file for the Mod. 90 however contains informations
on board features, but these are no longer supported from the machines
firmware and BIOS. No need to bother with these ports, they are non-functional.
The later series Mod. 90 no longer had the DBA-ports - only the soldering
spots remained until the end of the production.
VRAM chips are Toshiba TC524256BZ-10, mfd 9309 or NEC D42274V-10, mfd 9214
should work too.
If you have a different Video ZIP make that works, send
me a note
The 8590 systems have 8 sockets for video memory
available. The 9590 systems come with 4 VRAM chips (512HB) soldered to
NOTE: Even though IBM Canada site
sez the 9590 has XGA-2 integrated into the planar, IT DOES NOT!!! It has
512K soldered on the planar, plus 4 sockets for the 512K video memory upgrade.
The 95xx just means ISO compliant. That's why the 9590 came with XGA-2
cards in them.
between 8590 and 9590 Planars
The 9590 lacks the DBA artifacts, has 512K video memory soldered
on the planar, and is a pretty green. The 9590 planar is identified as
an XP 90 system board under setup. It does not support Synchrostream. The
parallel port is a standard one, no Expressprint.
On my 9590, it is a 82077AA If you know what it is on a 8590,
Three Floppy Experience
Just because people said it isn't done, I threw three 1.44MB
floppies into my 9590. All three showed up under setup as 1.44MB drives.
Under DOS, they are accessable as A:, B:, and D:. Under W95, it blows the
mind of the IOS driver and Win95 says you must shut the system down and
restart Windoze. But under safe mode, I was able to access and read off
the D: floppy.
I will eventually try it under NT 4.0 just for snorts 'n grins...
* Marked Floppiy Drives
Older 8590s may have their floppy controllers FRIED if
you use a 2.88MB floppy that has an asterisk ( * ) on the upper surface
of the eject button. The 9590 is not affected by this charming quirk.
The 8590 and 9590 DMA serial ports support speeds from 300 bits
per second to 345.6K bits per second.
Loading SIMMs Onto
Memory must be loaded in matched
pairs (size and speed) into sockets J1+J3 and J2+J4 for interleaved configurations.
(Type 1, 3, and 4 complexes). Type 2 complexes allow you to stuff SIMMs
in the sockets in any order or combination, but if not in matched pairs
(J1+J3, J2+J4) there will be a performance hit.
Don't stuff one Riser with modules (especially double-sided)
and leave the other blank. It *hates* imbalance on the memory drivers.
Try to organize them the way to achieve a balanced load on *both* memory
risers by having equal number of chips per pair, then on both risers.
Certain releases of the Mod. 90 had problems with the
double-sided SIMMs - especially with the 8MB ... I vaguely remember a sort
of pamphlet from IBM dealing with this issue - but cannot remember if I'd
copied it into a file or kept in in paper form and if: where I have left
it. At least the problem is not listed in the ECA-database.
Error code 201 says "Reseat system board memory"
and can afflict the systemboard as well as the memory only. I would suggest
to remove the memory risers, reseat all modules, plug them back and see
if they are seated properly.
I would also suggest that you start with one single
pair of matching memory modules in the connectors J1 + J3
(Peter, pay more attention when you post!!!) on riser J11 - the one closer
to the processorboard. This is just to test out if your problem is memory-
or systemboard related.
If the machine comes up fine (counts memory) - install
the next pair in sockets J1 + J3 in Riser J14 - the on closer to the power
supply to keep balanced load of the memory decoder lines. As I wrote: the
Mod. 90 has a sensible feeling for imbalanced memory modules and may "spin
out" with somewhat strange and unexplainable errors by no obvious reason.
There once was a recommendation from IBM on that topic and they explicitely
mentioned it for the Mod.90 - particularly for those cases where double-sided
memory modules are used (which put a higher load on the decoder lines).
SIMM Holder Clips
There also was a problem with local power-drops on the early Mod. 90
memory riser cards (the ones with all-plastic SIMM-sockets). Improved versions
had metal holder clips. And - logically - you should not mix the two versions.
Riser Card Support Bracket
There *must* be a plastic Support Bracket clipped over the 2 (two !)
memory riser boards to properly fix them. This part is called "memory riser
card support bracket" and is FRU 57F3029. It also has a "bay" to guide
the SCSI-cable surface wave filter (that large heavy ferro-oxide block).
You can't. Sort of. The 90 will accept an expanded memory card's memory
IF there is less than 16MB on the risers. But IF the 90 has 16MB or more,
then setup disables the expansion board memory. If you can cram 64MB on
the risers, who the heck needs another 16MB on a card?
Planar Main Page
9595 Main Page