8595 / 9595 XP 486 Planar
95 XP 486 Planar (FRU 33F5717, sticker 92F1480)
95 XP Ports and Operator Panel
On the earliest 8595s, the power button has no shutter and is surrounded by a raised lip. On later models, the power button is covered with a shutter.
J4 Remote Power-ON Request
The J4 pin header can be used to turn the system on (and off) from some external source. This can be achieved by connecting pin 2 to ground (either of the remaining pins). This will only work if the hidden switch SW1 on the Op Panel has been pressed to enable the Remote Power-ON feature.
Pin 2 is directly connected to pin 29 of the nearby Op Panel connector (J3).
SIMM Connector Versions [Grey or Green]
8MB ECC SIMMs from IBM (Option P/N 92G7208, FRU P/N 92F0098) may not fit properly in the SIMM connectors of some systems.
The following system types and models are potentially affected:
Early production 8595 system boards have gray plastic SIMM connectors which physically interfere with the installation of the referenced 8 MB ECC SIMM.
Later production system boards used a green SIMM connector, which is compatible with the larger SIMMs. Many earlier systems, which have been serviced in the past 18 months, could have the later production system board (green SIMM connectors) already installed.
All system boards with green memory SIMM connectors, regardless of model number or processor upgrade are not affected.
Note: 9595 model 0LF is the only model of 9595 to use the 8595 system board, FRU P/N 92F0270, (identified by a single serial and a single parallel port).
Planar Limitations (or not...)
From the Godfather:
Ed. Tom: Huh? What is this "synchrostream mode" supposed to be? Also, the 64-bit streaming mode has a theoretical bandwidth of 80 MB/s, and it's definitely not a "normal" transfer mode in the PS/2 world. The T4 boards support the 32-bit 40 MB/s streaming mode. But this same mode is supported by the "M" complex and that platform was shipped together with the 1S1P planar. So there should be no difference between the two planars from this point of view... In fact, official documentation confirms that the planar itself supports streaming data transfers (up to 80 MB/s). See HERE.
For information again: The "small" 9595s model -xLx (Type 2) and -xMx (Type 3) had the old planar - all others usually had the 9595A-planar (Type 4 -xNx, -xPx, -xQx).
Ed. Checked a -xKx and -xMx planar. Same chipset, same oscillator values. Only difference was some SMD oscillators replaced metal ones. A few less logic chips (Ed. What chips exactly? I have noticed that some 1S1P boards have a PAL at position U55, and other don't. Is that it?). And the -xLx, -xMx planars are a lovely green.
Supported MCA Features
(from PS/2 Models 95 XP 486, 90 XP 486, 55LS and P75 486 Fundamentals, Oct 1990)
All of the 32-bit Micro Channel slots on the IBM PS/2 Model 90 XP 486 and Model
95 XP 486 systems are full 32-bit implementations of the Micro Channel Architecture.
In addition to the basic Micro Channel features the IBM PS/2 Model 90 XP 486
and Model 95 XP 486 systems support the following enhancements to the Micro
Channel architecture that were announced in November 1989:
These three new Micro Channel features are implemented on the planar boards of the Model 90 XP 486 and Model 95 XP 486 systems.
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