IBM PS/2 Model 50: Revision history

25 September 2026

• curprev 00:2000:20, 25 September 2026 Josh talk contribs 19,059 bytes −157 P4 verification: remove the now-duplicated manual link bullet (superseded by the fuller documentation line) undo
• curprev 00:1900:19, 25 September 2026 Josh talk contribs 19,216 bytes +258 P4 verification: link the IBM manuals hosted on this wiki that document this machine (they were unlinked from every article) undo

23 September 2026

• curprev 03:3403:34, 23 September 2026 Josh talk contribs 18,958 bytes +5,410 Rebuilt against IBM's Model 50 Technical Reference and Hardware Maintenance Reference (both hosted here) plus ardent-tool. Corrections: the RTC is a Motorola MC146818A soldered at ZM47 with a SEPARATE 6 V lithium battery (72X8498) in the battery/speaker assembly (FRU 33F5950), not a Dallas DS1287/DS12887 module; there is NO -5 V rail (IBM lists only +5, +12 and -12); the BIOS is four 27256s at ZM13-ZM16, not two 64 KB devices; the four channel connectors are described as IBM describes them (o... undo

23 May 2026

• curprev 17:3217:32, 23 May 2026 Josh talk contribs 13,548 bytes 0 Reduce infobox badge size from 250px to 150px undo
• curprev 17:2617:26, 23 May 2026 Josh talk contribs 13,548 bytes +60 Add IBM badge to infobox (logo = File:IBM PS2 Model 50 badge.svg) undo

22 May 2026

• curprev 11:1311:13, 22 May 2026 Josh talk contribs 13,488 bytes −1 →Submodels undo
• curprev 10:4610:46, 22 May 2026 Josh talk contribs 13,489 bytes +13,489 Split combined PS/2 50/60 and 70/80 pages into per-model pages