Sinclair ZX81: Revision history

23 September 2026

• curprev 20:1320:13, 23 September 2026 Josh talk contribs 8,076 bytes +2,453 Cite to Sinclair's ZX81 Service and Assembly Manual and circuit diagram SRC 049; ROM is 8 KB (infobox said 4 KB, contradicting the body), CPU clock is 3.25 MHz on every issue, X1 is a 6.5 MHz ceramic filter; remove the unsourced Issue 1/2 errata table, the Kansas City Standard tape claim, the 27 s/KB loading figure, the truncated 40-way pinout table and the wrong ROM keyword map undo

23 April 2026

• curprev 09:4709:47, 23 April 2026 ZXSpectrum128 talk contribs 5,623 bytes +1 At a speed of 300 baud (bitrate would be more precise) you can only transfer 37,5 bytes per second. Thus 1024 bytes take some 27 seconds to load. undo Tag: Visual edit

12 May 2025

• curprev 10:3110:31, 12 May 2025 Josh talk contribs 5,622 bytes −48 No edit summary undo Tag: Visual edit

2 May 2025

• curprev 14:2514:25, 2 May 2025 Josh talk contribs 5,670 bytes +13 →📜 Schematic & PCB undo Tag: Visual edit
• curprev 14:1514:15, 2 May 2025 Josh talk contribs 5,657 bytes −34 →See Also undo
• curprev 14:1514:15, 2 May 2025 Josh talk contribs 5,691 bytes +3 No edit summary undo
• curprev 14:1414:14, 2 May 2025 Josh talk contribs 5,688 bytes +34 No edit summary undo
• curprev 14:1114:11, 2 May 2025 Josh talk contribs 5,654 bytes −1,586 Automated update by bot undo
• curprev 14:0514:05, 2 May 2025 Josh talk contribs 7,240 bytes +4,777 Undo revision 3032 by Josh (talk) undo Tag: Undo
• curprev 14:0514:05, 2 May 2025 Josh talk contribs 2,463 bytes −4,777 Automated update by bot undo Tag: Reverted
• curprev 14:0214:02, 2 May 2025 Josh talk contribs 7,240 bytes +3,593 Undo revision 3030 by Josh (talk) undo Tag: Undo
• curprev 14:0114:01, 2 May 2025 Josh talk contribs 3,647 bytes −3,593 Automated update by bot undo Tag: Reverted
• curprev 14:0014:00, 2 May 2025 Josh talk contribs 7,240 bytes −115 Undo revision 3028 by Josh (talk) undo Tag: Undo
• curprev 13:5713:57, 2 May 2025 Josh talk contribs 7,355 bytes +115 Automated update by bot undo Tag: Reverted
• curprev 13:5013:50, 2 May 2025 Josh talk contribs 7,240 bytes +5,123 Undo revision 3026 by Josh (talk) undo Tag: Undo
• curprev 13:4813:48, 2 May 2025 Josh talk contribs 2,117 bytes −5,123 Automated update by bot undo Tag: Reverted
• curprev 13:4513:45, 2 May 2025 Josh talk contribs 7,240 bytes +4,819 Undo revision 3024 by Josh (talk) undo Tag: Undo
• curprev 13:4513:45, 2 May 2025 Josh talk contribs 2,421 bytes −4,819 Automated update by bot undo Tag: Reverted
• curprev 13:3813:38, 2 May 2025 Josh talk contribs 7,240 bytes +14 No edit summary undo Tag: Visual edit
• curprev 13:3413:34, 2 May 2025 Josh talk contribs 7,226 bytes +6,522 Undo revision 3021 by Josh (talk) undo Tag: Undo
• curprev 13:3313:33, 2 May 2025 Josh talk contribs 704 bytes −6,522 Automated update by bot undo Tags: Replaced Reverted
• curprev 13:2913:29, 2 May 2025 Josh talk contribs 7,226 bytes +6,495 Undo revision 3019 by Josh (talk) undo Tag: Undo
• curprev 13:2513:25, 2 May 2025 Josh talk contribs 731 bytes −6,495 Automated update by bot undo Tag: Reverted
• curprev 13:2313:23, 2 May 2025 Josh talk contribs 7,226 bytes +4,328 Undo revision 3017 by Josh (talk) undo Tag: Undo
• curprev 13:2213:22, 2 May 2025 Josh talk contribs 2,898 bytes −4,328 Automated update by bot undo Tag: Reverted
• curprev 13:0913:09, 2 May 2025 Josh talk contribs 7,226 bytes +7,226 Automated update by bot