File:Ferranti Archives TV-FER-SCH-165 Sinclair TV test box sequencer logic, 12 October 1983.pdf
Summary
[edit | edit source]Ink schematic "Sequencer logic" of the Sinclair TV test box, dated 12 October 1983. As drawn, a front-panel push-button, debounced by cross-coupled 74L00 and 74L10 gates, starts one test step per press and is locked out until that step has finished. Each step is a chain of three 74121 monostables: pulse A (470 nF and 4K7, 1.5 ms), which also clocks a 74163 counter on to the next step; pulse B (22 µF and 15K, about 200 ms), which lets the relays and measuring circuits settle; and pulse C (1.5 ms), the strobe that samples the pass and fail flags. The counter drives a 74154 4-to-16 decoder, whose active-low "walking zero" outputs select the relays and checks for each step, and a 7447 decoder with a front-panel seven-segment "test number" display. A "reset and sync" button clears the counter, through a fourth 74121 because the 74163's clear is synchronous, and on a separate board closes a 5 V relay that joins pins 21 and 22 of the device under test. The relay drivers are TV-FER-SCH-160 and TV-FER-SCH-161, the pass and fail logic TV-FER-SCH-166, and the step table TV-FER-DAT-167. Part of the Ferranti Archives 2026.
Archive record
[edit | edit source]| Catalogue ID | TV-FER-SCH-165 |
|---|---|
| Date | 12 October 1983 |
| Origin | Ferranti |
| Document type | Schematic |
| Device or subject | Pocket TV Test Box |
| Catalogue description | Pen schematic of Sinclair TV Test Box Sequencer Logic |
| Original file name | {{{filename|}}}
|
| Found in | TV-FER-FOL-168 |
| Pages | 1 |
Source
[edit | edit source]Ferranti Archives 2026, original scan on Google Drive.
Author
[edit | edit source]Ferranti Electronics Limited
Licence
[edit | edit source]Ferranti Archives 2026: source and terms of use
This scan is part of the Ferranti Archives 2026, a collection of Sinclair-related documents from Ferranti's files, catalogued in 2026 and released through the Happy Little Diodes YouTube channel (video, catalogue). The archive presents the documents for preserving and archiving material of historical interest, and for non-commercial, educational and archival research. Its terms state that consent is strictly limited to non-commercial use, and that any commercial exploitation of the documents or their contents, including use in connection with the manufacture, marketing or sale of goods, is strictly prohibited by Sky UK Limited.
Copyright remains with the rights holders. The file is not freely licensed and is hosted here for preservation and repair reference only, under the archive's terms. Personal information was redacted by the archive before release; if you find any that remains, please tell [email protected].
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| Date/Time | Dimensions | User | Comment | |
|---|---|---|---|---|
| current | 10:41, 18 October 2026 | 0 × 0 (20.51 MB) | Josh (talk | contribs) | Ferranti Archives 2026: TV-FER-SCH-165 |
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