Sinclair ZX Spectrum General Maintenance: Revision history

22 September 2026

• curprev 17:5217:52, 22 September 2026 Josh talk contribs 21,725 bytes +16,120 Rebuild against Sinclair ZX Spectrum Service Manual: ULA Vcc corrected to pin 14 (pin 40 is ground); PSU corrected to 9V centre-negative UK1400 and the wrong "9.0-10.5V unloaded" band removed; -5V test point corrected from TR4 collector to IC6 pin 1; unsourced 10-15 year recap interval, Ray Carlsen PSU and ULA pin 28 audio claim removed; 7K010E removed from the 48K ULA list; broken image and non-existent category fixed; refs added; Unverified data cleared undo

21 September 2026

• curprev 21:5321:53, 21 September 2026 Josh talk contribs 5,605 bytes +20 Verification drive: flag unverified component data pending check against a primary source undo

12 May 2025

• curprev 10:4010:40, 12 May 2025 Josh talk contribs 5,585 bytes −79 No edit summary undo Tag: Visual edit

4 May 2025

• curprev 10:4810:48, 4 May 2025 Josh talk contribs 5,664 bytes −849 →🔍 Identify Your Model and Board Revision undo
• curprev 10:4810:48, 4 May 2025 Josh talk contribs 6,513 bytes −23 No edit summary undo Tag: Visual edit
• curprev 10:4710:47, 4 May 2025 Josh talk contribs 6,536 bytes +2,054 Automated update by bot undo
• curprev 10:4410:44, 4 May 2025 Josh talk contribs 4,482 bytes −335 No edit summary undo Tag: Visual edit
• curprev 10:4310:43, 4 May 2025 Josh talk contribs 4,817 bytes −106 No edit summary undo Tag: Visual edit
• curprev 10:4110:41, 4 May 2025 Josh talk contribs 4,923 bytes +184 Automated update by bot undo

2 May 2025

• curprev 15:5415:54, 2 May 2025 Josh talk contribs 4,739 bytes −6 No edit summary undo
• curprev 15:5415:54, 2 May 2025 Josh talk contribs 4,745 bytes +12 No edit summary undo
• curprev 15:5315:53, 2 May 2025 Josh talk contribs 4,733 bytes −261 →🛠️ Sinclair ZX Spectrum General Maintenance undo
• curprev 15:5315:53, 2 May 2025 Josh talk contribs 4,994 bytes +4,994 Automated update by bot