Sinclair ZX80 Troubleshooting Guide: Revision history

22 September 2026

• curprev 17:5417:54, 22 September 2026 Josh talk contribs 11,776 bytes +51 Correct CPU clock attribution: Sinclair's ZX80 circuit diagram labels the CPU clock 3·2 MHz, not 3.25 MHz; both figures now given with the derivation undo
• curprev 17:3317:33, 22 September 2026 Josh talk contribs 11,725 bytes +5,033 Rewrite from Sinclair ZX80 circuit diagram. Removes all ULA content (the ZX80 has no ULA), corrects ROM to IC2/8332, RAM pin numbers to 2114 Vcc 18 / GND 9, removes invented edge-connector pin numbers and the TR1 video transistor. Adds real IC map, checkpoints and refs; fixes red category undo

21 September 2026

• curprev 21:5321:53, 21 September 2026 Josh talk contribs 6,692 bytes +20 Verification drive: flag unverified component data pending check against a primary source undo

12 May 2025

• curprev 10:2810:28, 12 May 2025 Josh talk contribs 6,672 bytes −110 No edit summary undo Tag: Visual edit

4 May 2025

• curprev 10:5810:58, 4 May 2025 Josh talk contribs 6,782 bytes +1,199 Automated update by bot undo
• curprev 10:5510:55, 4 May 2025 Josh talk contribs 5,583 bytes +5,583 Automated update by bot