IBM PS/2 Model 80 Maintenance Guide: Revision history

30 September 2026

• curprev 21:3721:37, 30 September 2026 Josh talk contribs 27,323 bytes −2,767 Rewrite: cite new Model 80 HMR/HMS and both TechRefs; add Power Good timing (TechRef 1987), 1 s vs 10 s restart, coprocessor orientation and FRUs, terminator rules, HMS memory procedures; fix 'no Power Good figure published' and Type 1 memory; attribute Ardent contributors; de-bold undo

22 September 2026

• curprev 00:0500:05, 22 September 2026 Josh talk contribs 30,090 bytes +212 Add tower photograph noting the power-supply fan position over the planar undo
• curprev 00:0300:03, 22 September 2026 Josh talk contribs 29,878 bytes +19,797 Verified against IBM Technical Reference (Oct 1990) and ardent-tool. Fixed: PSU rail table replaced with IBM service limits and the fabricated -5 V rail deleted - IBM documents three DC outputs only; RTC section rewritten (MC146818A + separate 6 V pack, retain tip H024809 5.5 V threshold), Dallas DS1287/DS12887 claim removed; case opens by two captive coin-slot screws and a hinged side cover, not rear screws and a sliding panel; 225 W is not universal across submodels; planar types corrected... undo

21 September 2026

• curprev 21:5221:52, 21 September 2026 Josh talk contribs 10,081 bytes +20 Verification drive: flag unverified component data pending check against a primary source undo

22 May 2026

• curprev 10:4610:46, 22 May 2026 Josh talk contribs 10,061 bytes +10,061 Split combined PS/2 50/60 and 70/80 pages into per-model pages