File:IBM 5322 Computer Service Manual SY34-0171-0.pdf

IBM 5322 Computer Service Manual, order number SY34-0171-0, December 1980. Volume 1 of the IBM System/23 Service Library, covering the IBM 5322 computer of the IBM System/23 Datamaster system — processor, processor features, power supply, keyboard, CRT display unit and diskette drives.

This is the machine's own CE manual, and it settles several things that community accounts of the Datamaster have got wrong:

• The power supply is ferroresonant, not linear. It has a resonant capacitor C6, a tapped transformer with jumper-selected mains taps, and IBM's own DANGER notice: "Up to 800 Vac is generated in the power supply."
• Each DC output has its own fuse: F1 −5 V (0.5 A), F2 +12 V (1.5 A), F3 −12 V (0.5 A), F4 +24 V (1.5 A), F5 +5 V (10 A), plus F6 on the AC input.
• IBM publishes voltage tolerances and peak-to-peak ripple limits for all five rails and for Power Good, and a method for measuring ripple with a service meter and a 0.22 µF series capacitor.
• The CRT is 305 mm (12 in.), displaying 24 lines of 80 characters.
• The keyboard has 83 keys.
• The 5322 model numbers encode the configuration: second digit is memory (1 = 32K, 2 = 64K, 3 = 96K, 4 = 128K), third digit is diskette (0 = none, 1 = one drive 0.25 MB, 2 = two drives 0.5 MB, 3 = one drive 1 MB, 4 = two drives 2 MB).
• Three power supplies were built — PN 6838279 (60 Hz, Canada and US), 6838280 (60 Hz, GBG/I) and 6838281 (50 Hz, GBG/I) — with different fuse layouts and different mains-tap jumper tables.

Scanned by bitsavers.org and mirrored at the Internet Archive as item bitsavers_ibmsystem2ComputerServiceManualDec80_16181636. Hosted here so the Datamaster pages can cite a copy that will not move.

Copyright International Business Machines Corporation, 1980. Hosted for the non-commercial repair and preservation of a machine IBM withdrew forty years ago. If you are the rights holder and want this taken down, please say so and it will be removed.