IBM PS2 Model 55 Technical Reference (February 1989)
The IBM Personal System/2 Model 55 SX Technical Reference, First Edition (February 1989), is IBM's 68-page model-specific hardware and software interface reference for the PS/2 Model 55 SX (8555). A second edition of October 1990 is also hosted here and adds the power supply section.
What it contains
[edit | edit source]- Section 1, System Overview — model and submodel bytes, system board features, the I/O address map, performance and physical specifications and acoustical readings.
- Section 2, Programmable Option Select — the system board POS address map and setup registers.
- Section 3, System Board — the 386SX and its coprocessor, Micro Channel implementation, the bus adapter, the diskette and fixed disk connectors, memory and the memory connectors, the RT/CMOS RAM map and real-time clock bytes, and system control ports.
Physical specifications: 8.64 kg, heat output 140 W.
What it does not contain
[edit | edit source]This is a programming and interface reference, not a service manual. There are no FRU part numbers, no removal and replacement procedures, no symptom-to-FRU index and no component values — IBM put those in the model's Hardware Maintenance Reference and Hardware Maintenance Service pamphlets. There are no schematics; the planar is described as a block diagram and a set of register and connector tables.
It is also not self-contained. IBM split the PS/2 Technical Reference library into volumes, and this one carries only the model-specific part. Anything common to the family — Micro Channel architecture, the serial and parallel port controllers, the instruction sets, the keyboard scan codes — is in the Hardware Interface Technical Reference volumes, and BIOS in the BIOS Interface Technical Reference.
The May 1988 editions in particular have no power supply section at all — IBM only added one to these books in the October 1990 revision. For rail voltages and protection limits on a May 1988 machine, use the October 1990 edition of the same technical reference, or the model's Hardware Maintenance Reference.
Download it here: IBM PS2 Model 55 Technical Reference Feb89.pdf