Processor Complex Index
PS/55 Model 5560 Model 90 redesigned by IBM Japan

8590 / 9590 Planar
Early 8590 Planar
System Firmware
Planar Ports
   Mouse and Keyboard Ports
   Serial Ports
   Parallel Port
Front Panel Connector Pinout
DBA Artifact on 8590 (J16 and J23) (Yes, they DO work!)
8590 and 9590 Planar Differences
KB / Mouse Port Filter
64K Colors Supported under W98SE
Video RAM
   Video RAM Installation
9590 Floppy Controller
Memory Riser
   Orienting SIMMs on Riser
   Loading SIMMs
   8590 Memory Parity Errors / Configuration H095511
   ECA084 Model 90 Memory Riser Card
   Error 201
   Plastic SIMM Holders
   Memory Expansion Boards
Planar ADF Sections (PFF6F.ADF)

8590 / 9590 Planar (FRU 64F3287, sticker 91F7458)

U24 8Kx8 SRAM (NVRAM) SRM2264LC-12 (alt) or Sony CXK5864BP-12L
U77 22.1184 MHz Clock for "Type 3 High-Speed UART". Divided by 2.
U64 XGA Controller: Early TC110GC9AG / 1888676, Late TC110GC9AF / 74F5160
VRAM Toshiba TC524256BZ-10 / NEC D42274V-10 / OKI MSM514262
TDK ZJY-2P 2 Line Common Mode Choke (datasheet)
U14 37F0842 equivalent to INMOS G190 Serializer Palette DAC
U64 TC110GC9AF equivalent to INMOS G200 XGA Display Controller
U31 32K sprite memory, between U64 and J14. SRM20256LM12 or CXK58257AM-12L

Early 8590 Planar (FRU 64F3288, sticker 91F7467)

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).

Some of these early boards are cut differently in the area where the front panel and fan connectors are located (see the dashed outline). An example of such a board can be seen in this video (16:15).

System Firmware (POST & BIOS)

Firmware stored on the processor complex.

Planar Ports

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:

• Port #1 - DB25, Built-in planar feature
• Port #2 - DB9, Planar device #6

Pinouts HERE.

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).

Parallel Port

DMA Parallel Port
With most Microsoft products, enabling "Arbitration Level" results in problems, since IBM developed the DMA parallel port prior to the ECP/EPP industry standards being developed. You may have to disable Arbitration Level if your parallel port device fails to work.

Parallel Port Resources
PARALLEL 1 (03BC-03BF 1278-127F int 7)
Note: Parallel Port Arbitration Level "Disabled" sets Parallel 1 to Bi Directional mode
PARALLEL 2 (0378-037F int 7) Bi Directional
PARALLEL 3 (0278-027F int 7) Bi Directional
PARALLEL 4 (1378-137F int 7) Bi Directional (or so the Model 90 SSI says)
Disabled (no parallel port at all)

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.

Front Panel Connector Pinout

Looking at the planar (male) connector from the front (where the plug would go):

Note: The pins are marked differently at the bottom of the PCB (see the photos above).

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 HERE 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.

Martin Adams:
   One advantage the model 90 has over the 77 is the 8 SIMM slots. Eight 8MB SIMMs are allot cheaper than four 16MB sticks right now. We also have the caching SCSI that could have its cache upgraded. You don't have to pull adapter cards to reconfigure RAM. I prefer the planar mounted bus connectors too.

Differences between 8590 and 9590 Planars

9590s 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 Tomáš 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.

Video RAM

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

Place insertion tool (1) over empty VRAM socket (If you have one!) Align beveled corner (2) of VRAM chip towards the dot on the planar. Carefully align the pins with the socket (3) and firmly press the module straight down into place. Do not start one end before the other. You can slightly rock the chip side to side to install into a stiff socket, but be careful!

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:

• 1.44 MB 3.5" diskette drives
• 2.88 MB 3.5" diskette drives
• Internal tape backup unit
• 1.2 MB 5.25" 1 inch high diskette drive. (supported only by the Type 2 controller)

Memory Riser

Orienting SIMMs

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 Model 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 Model 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:
A. Count total modules (chips) on both sides of SIMM.
B. If 12 or less, the SIMM is LOW LOAD.
C. If greater than 12, the SIMM is HIGH LOAD.

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.

1. Install low load matched pair in J2&J4 of memory riser in J11.
2. If only 4 SIMMs will be installed, go to step 3, if not, proceed with step 4.
3. Install two remaining matched SIMMs in J1&J3 of memory riser in J11 and exit.
4. For 6 SIMMs go to step 5 (EXAMPLE 1) for 8 SIMMs go to step 7 (EXAMPLE 2)
5. For a LOW LOAD matched pair, install in J1&J3 of riser J11 and go to step 6. If remaining memory is HIGH LOAD then install a matched pair in J1&J3 of riser in J11.
6. Install remaining HIGH LOAD matched pair in J1&J3 of memory riser in J14 and exit.
7. Install a HIGH LOAD matched pair in J1&J3 of memory riser in J11.
8. If remaining memory is all HIGH or all LOW, install on memory riser in J14 and exit.
9. Install remaining LOW LOAD matched memory in J2&J4 and HIGH LOAD matched memory in J1&J3 of the memory riser in J14 and exit.

The following are examples of how to implement this procedure:

Example 1:

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.

Example 2:

The system above has eight SIMMs, four HIGH LOAD and four LOW LOAD. The system should be reconfigured as shown below in example 3:

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 201

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 Model 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 Model 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...

Warning! Memory adapters on the Micro Channel are NOT supported, although they may work. However, it is strongly recommended not to use them as they will significantly degrade the overall performance of the system, as memory on the Micro Channel is not cached.

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
   Installed Memory. . . . . . . . . . . . : nnnnKB (nn.nMB)
   Useable Memory  . . . . . . . . . . . . : nnnnKB (nn.nMB)

Built In Features
   Installed Memory. . . . . . . . . . . . : nnnnKB (nn.nMB)
   Diskette Drive 0 Type . . . . . . . . . : 1.44MB 3.5"
   Diskette Drive 1 Type . . . . . . . . . : Not Installed
   Diskette Drive 2 Type . . . . . . . . . : Not Installed
   Math Coprocessor. . . . . . . . . . . . : Installed
   Display F1 prompt to access System Pro. : Yes [T4 only?]
   Serial Port   . . . . . . . . . . . . . : SERIAL_1 (DB25 port)
   Serial Transmit Arbitration Level . . . : Shared 4
   Serial Receive Arbitration Level. . . . : Shared 3
   Parallel Port . . . . . . . . . . . . . : PARALLEL_1
   Parallel Port Arbitration Level . . . . : Shared 7
   Preempt Enable/Disable  . . . . . . . . : Enable
   Video I/O Address . . . . . . . . . . . : Instance x: nnnnh - nnnnh
   Video ROM Address Space . . . . . . . . : Annnn - Annnn
   Video Arbitration Level . . . . . . . . : Arbitration Level x
   Video Fairness. . . . . . . . . . . . . : Fairness xx
   Useable System Board Memory . . . . . . : Parity [T3, T4 only]
   Bypass System Programs on Error . . . . : Disabled [T4 only]
   Processor . . . . . . . . . . . . . . . : Pentium 60 [T4 only?]

Slot 1 - (Card Name)

Slot 2 - (Card Name)

Slot 3 - (Card Name) This is an AVE slot, XGA and XGA2 will not fit...

Slot 4 - (Card Name)

Planar Device 5 - Integrated Fixed Disk and Controller [T0 only]
   DMA Arbitration Level . . . . . . . . . : Level x
   DMA Burst Pacing Interval . . . . . . . : xx Microseconds
   DMA Pacing Control  . . . . . . . . . . : Disabled
   Time To Release . . . . . . . . . . . . : x Microseconds
   Fairness On/Off . . . . . . . . . . . . : On
   Primary/Alternate Port Addresses  . . . : Primary

Planar Device 6 - Serial Port No. 2 (DB9 port)
   Serial Port . . . . . . . . . . . . . . : SERIAL_2
   Serial Transmit Arbitration Level . . . : Shared x
   Serial Receive Arbitration Level. . . . : Shared x

Planar Device 7 - Integrated Fixed Disk and Controller [T0 only]
   DMA Arbitration Level . . . . . . . . . : Level x
   DMA Burst Pacing Interval . . . . . . . : xx Microseconds
   DMA Pacing Control  . . . . . . . . . . : Disabled
   Time To Release . . . . . . . . . . . . : x Microseconds
   Fairness On/Off . . . . . . . . . . . . : On
   Primary/Alternate Port Addresses  . . . : Alternate

Planar Device 8 - Empty

System Memory Explained

Total System > Installed Memory = Planar plus memory expansion adapter
   [minus defective or misconfigured memory]

Total System > Useable Memory = Installed minus any ROM shadowing
   [minus defective or misconfigured memory]

Built In Features> Installed Memory = Planar memory only
   [minus defective or misconfigured memory]

   1.44MB, 2.88MB

Serial Port [DB25 or DB9 Port]
   Serial 1 - 8 or disabled.  Must be enabled if using an ASCII terminal as a system console.
      <"SERIAL 1 (03f8h-03ffh 083f8h-083ffh, int 4)>, 2 (2f8-2ff 82f8-82ff, 3), 3 (3220-3227 b220-b227, 3), 4 (3228-322f b228-b22f, 3), 5 (4220-4227 c220-c227 3), 6 (4228-422f c228-c22f  3), 7 (5220-5227 d220-d227 3), 8 (5228-522f d228-d22f 3),  Disabled

Serial Transmit Arbitration Level
   Use any level. Shared with other devices. Dedicated, only this device can use that level.
      <"Shared 4" >, 3, 1, 0, 7, 6, 5, Dedicated 7, 6, 5, 4, 3, 1, 0, Disabled

Serial Receive Arbitration Level
   Use any level. Shared with other devices. Dedicated, only this device can use that level.
      <"Shared 3>, 1, 0, 7, 6, 5, 4, Dedicated 7, 6, 5, 4, 3, 1, 0, Disabled

Parallel Port
  Parallel 1 through 3 or disabled.
       <"PARALLEL 1"  (03bc-03bf 1278-127f int 7)>,  2 (0378-037f int 7), 3 (0278-027f int 7),  Disabled

Note: PARALLEL_2 is the one Windows calls LPT1!
Note: PARALLEL_1 includes the I/O range 1278-127D to support DMA operations. DMA can be turned off via Arbitration Level if it is incompatible.

Parallel Port Arbitration Level
   Use any level.  Shared, other devices can use same level.  Dedicated, only this device can use that level.  <Disabled> sets port in compatibility mode [known as bidirectional].
      <"Shared 7">, 6, 5, 4, 3, 1, 0, Dedicated 7, 6, 5, 4, 3, 1, 0, Disabled

Note: IBM 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....

Preempt Enable/Disable
   Complex CPU can preempt continuous data transfers by other devices for its use of MC.
     <"Enable">, Disable

Video I/O Address
  Address range for display controller registers, and location of video coprocessor registers.
        <"Instance 6: 2160h - 216Fh">, 1 (2110-211F), 2 (2120-212F), 3 (2130-213F), 4 (2140-214F), 5 (2150-215F)

Video ROM Address Space [Slot 0 in "Memory Map"]
   Memory address range used for system video ROM.
        <"C0000-C1FFF" >, C2000-C3FFF, C4000-C5FFF, C6000-C7FFF, C8000-C9FFF, CA000-CBFFF, CC000-CDFFF, CE000-CFFFF, D0000- D1FFF, D2000-D3FFF, D4000-D5FFF, D6000-D7FFF, D8000-D9FFF, DA000-DBFFF, DC000-DDFFF, DE000-DFFFF

Video Arbitration Level
   Video sub-system arbitration levels.
        <"Arbitration level 13">, 12, 11, 10, 9, 8, 14

Video Fairness
   Whether video sub-system coprocessor follows fairness algorithm for bus usage.
        <"Fairness On">, Off

ADPItem 1 Usable System-Board Memory   (Exec)
   Type of Usable Memory on planar.  Either parity or error-correcting-code (ECC)

Bypass System Programs on Error [T4 only]
  Enabled Disabled

Processor (Exec)
   Pentium 60 [T4 only?]