The 8590 and 9590 uses the same reference and diagnostics disks used by the 8595 / 9595 systems. For a list by processor complex, go HERE.
8590 / 9590 Planar
U77 22.1184 MHz Clock for "Type 3 High-Speed UART". Divided by 2.
This version of the planar can be found in some early 8590s, and is largely identical to the later and more common revision. The most notable difference is the strangely positioned fan connector (J5) and presence of the keyboard and mouse filter (LN5).
There are some other minor differences in the speaker amp area, and some of the resistor networks that are populated on the later version are missing here. These early boards also tend to come with quite a few bodge wires and other fixes (see HERE or HERE).
Mouse and Keyboard Ports
The new keyboard/mouse controller used on Model 90 and Model 95 XP 486 systems provide additional functions for mouse support. These include the ability to separately receive and send data to the keyboard and mouse ports simultaneously. This is not possible on previous PS/2 systems as only one I/O port is used for both keyboard and mouse data.
Source HERE (physical page 37).
Serial Ports (In Accordance With EIA-232-D)
Two serial ports:
Note: Current Loop interface is not supported on either serial port.
Dual DMA serial ports (Type 3 Serial Controller), one DB25 and one DB9. The DB9 port requires feature number 0217 or 0242 for attaching devices with 25-pin D shell connectors.
The DMA serial port supports 300 bps to 345.6K bps. DMA reduces CPU loading and overhead at higher speeds. Speeds up to 345.6K bps are supported using IBM Enhanced EIA-232-D which requires a special shielded cable up to 20 feet long.
Ether serial port can be set to Serial 1-8, with different arbitration levels for Transmit or Receive. Both ports are limited to Int 3 (Serial Controller chapter of HITR says Type 3 Serial Controllers can use Int3 or Int4. YMMV).
DMA Parallel Port
Parallel Port Resources
Note: The Parallel_1 dual I/O address range of (03BC-03BF 1278-127F int 7) has the Bi-Di compatible port at 03BC-03BF, while enabling dedicated or shared DMA operations enables DMA operations at 1278-127F (Model 90 SSI says 1278-127D... YMMV). The split was due to the old [and obsolete] MDA and Printer adapter I/O range.
Note: IBM defines Parallel_2 as 0378-037F int 7, while everybody else calls it LPT1... So if you use a MS product, and your printer won't print, check to see if both refer to the same I/O range. IBM only supported Int 7 on any PS/2 planar parallel port.
J1 on 90 Planar
DBA Artifact on 8590 (J16 and J23)
IBM brought out a "low-end" Model 90 with DBA-ESDI and a 386DX-20 processor board.
A big insurance company (Aetna?) had 386DX-20 complexes made for it - the "Type 0". Apparently, so did Royal Bank...
DBA-ESDI Boot Support with the Type 0
Daniel Hamilton dug down into the
Type-0 abyss and found out while yes you can boot from
the DBA-ESDI drive, you must still have a SCSI drive on
a Spock to provide IML. Read his further bone-chilling
adventures in the DBA-ESDI Temple of Doom
Being able to boot from a DBA-ESDI drive as C: offers a
simple upgrade path for the Model 70 to Model 90, just
by swapping the drive out.
Differences between 8590 and 9590 Planars9590s lack DBA-ESDI artifacts, have 512K VRAM soldered on planar, and is a pretty green. The 9590 planar shows up as an XP 90 system board under setup. The parallel port has DMA support, but no Expressprint and no Wake on Ring.
KB / Mouse Port Filter (LN5)
While consoling Tomás Slavotínek over his lack of a Model 90, he sent me a picture of a sweet early production Model 90 from an auction. Not even dust inside...
And what do I see but an EMI filter next to the KB / Mouse port. Why is it present on the early boards but not on the later ones? We will most likely never know, the engineering notes were hidden [oh, the humanity!].
A better picture of the filter HERE (different sample).
64k Colors under W98SE
W98SE has 640x480x64k at 60Hz support. This requires 8 Video ZIPPs to be installed.
VRAM chips are Toshiba TC524256BZ-10 or NEC D42274V-10. Model 90 systems have 8 sockets or 4 sockets / 4 soldered VRAM.
Note: Any reference that says the 9590 has XGA-2 on the planar IS WRONG!!! It has 512K soldered on the planar, plus 4 sockets for the 512K video memory upgrade. To make the 9590 ISO compliant they had to install XGA-2 cards in them.
Ed. It is possible (Loch Ness Monster or Big Foot likely...) that IBM did do a few XGA-2 Model 90 planars. Never seen or heard of one. BUT... I have seen a picture of a P75 with an active matrix LCD screen instead of a plasma display. So _MAYBE_ the IBM Canada site referred to a short lived variant...
Video RAM Installation
Note the white dots towards the rear of the planar.
Insert VRAM Into Sockets
Which Slot for the XGA-2?
For complexes with search IML BIOS (T1 / T2 with upgrade BIOS, all T3 / T4), the XGA-2 may be installed in Slots 1, 2, and 4. For T1 or T2 with non-IML search BIOS, Slot 1 must be filled with an IBM SCSI adapter, and only Slots 2 and 4 may be used for the XGA-2. Slot 3 is an AVE slot and is physically incompatible. For a full discussion, go HERE.
Note: The AVE at the rear of Slot 3 is disabled when XGA is in extended graphics mode.
9590 Floppy Controller
Intel 82077AA. Go HERE for more
info. The Model 90 uses the
40-pin floppy header
on the planar. The Model 90 Type 2 diskette controller is compatible with the
Type 1 controller used on previous PS/2 systems. It supports:
When inserting SIMMs onto the riser, orient the notch on the SIMM with the notch on the riser. Always wondered why the riser had that seemingly useless extension to the right. Think of the riser as a big SIMM with it's notch. Like to like...
Plastic 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.
Loading SIMMs Onto Memory Risers
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...
Ed. Please genuflect while absorbing the riser/slot illustration. Remember, for interleaved configuration, you place matched speed/size SIMMs in A1-B1, A2-B2, and so on. Please note that the SIMM pairs do NOT cross between memory risers. The Model 95 uses separate A and B banks (A1, A2, A3, A4 then B1, B2, B3, B4) while the Model 90 uses both banks on both cards, A1, A2, B1, B2 then A3, A4, B3, B4).
8590 Memory Parity Errors / Configuration H095511
Unbalanced loading of SIMMs may cause parity errors when using four or more SIMMs.
Classify each SIMM as HIGH or LOW LOAD based on the following:
This chart shows number of modules (chips) on each type of SIMM and its LOAD:
If the SIMMs are either all HIGH LOAD, or all LOW LOAD, then install in both memory riser cards and exit this procedure.
Memory SIMM Configuration Procedure
Note: For this procedure, memory will always be installed in matched pairs starting with J1&J3 then J2&J4 on memory riser cards. Riser card in J11 will always be fully populated first.
The following are examples of how to implement this procedure:
This system has six SIMMs and it has been determined that the four 2MB SIMMs are LOW LOAD and the two 8MB SIMMs are HIGH LOAD. According to this procedure, no change is required.
The system above has eight SIMMs, four HIGH LOAD and four LOW LOAD. The system should be reconfigured as shown below in example 3:
ECA084 - Model 90 Memory Riser Card
If memory riser card FRU P/N 33F4905 is populated with "MIXED SIMMs" and is experiencing any of the following errors: DOS NMI, OS/2 TRAP 0002, POST, or diagnostic memory errors, replace both memory riser cards with new FRU P/N 81F8823 (two required).
Note: "MIXED SIMMs" is defined as SIMMs with 12 modules or more per SIMM, mixed with SIMMs having less than 12 modules per SIMM mounted on the same riser card. If FRU P/N 81F8823 is already installed, this ECA is not applicable.
Original scan from Al Savage out on the left coast
The "bad" riser (33F4905) has six electrolytic capacitors on the front. The "good" riser (81F8823 or 81F8827) has only the silk screen outlines for the caps (also a lot more SMD resistors and caps on the back). Both risers have metal clips and white SIMM sockets.
Error code 201 says "Reseat system board memory" and can afflict the planar 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 on riser J11 - the one closer to the processor board. This is just to test out if your problem is memory- or planar 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 explicitly 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).
Memory Expansion Boards
You can't. Sort of. The 90 (and 95) does not cache expansion board memory. So in addition to the overhead in negotiating for control of the Micro Channel bus, you have to give up the advantage of the 486 cache...
Ed. With the advent of eight SIMM sockets and higher density SIMMs, the need for memory cards fell off dramatically...
AdapterId FF6F Built In Features (Model 90)
Total System Memory
System Memory Explained
Total System > Installed Memory = Planar plus memory expansion adapter
Total System > Useable Memory = Installed minus any ROM shadowing
Built In Features> Installed Memory = Planar memory only
Serial Port [DB25 or DB9 Port]
Serial Transmit Arbitration
Serial Receive Arbitration
Note: PARALLEL_2 is the
one Windows calls LPT1!
Parallel Port Arbitration
developed the DMA parallel port prior to the ECP/EPP industry
standards being developed. If you are using a parallel
port connected device and it is misbehaving, Disable the
Arbitration Level. Sad but true....
Video I/O Address
Video ROM Address Space [Slot
0 in "Memory Map"]
Video Arbitration Level
ADPItem 1 Usable System-Board
Bypass System Programs on
Error [T4 only]