File:Ferranti Archives SPEC-FER-NOT-094 Handwritten test procedure for the ZX Spectrum ULA 5C102.pdf
Summary
[edit | edit source]An eight-page handwritten procedure headed "ULA5C102 Testprogram", setting out how Ferranti exercised the ZX Spectrum ULA type 5C102 on a tester. It works through each function in turn: reading the keyboard inputs, clocking and reading the video counter (312 lines per field, lines 0 to 191 active, the first 4/7 of each active line active), the line and frame sync decodes, the dot-pattern and attribute latches, highlight, flash (toggling every 32 counts of stage S), foreground, background and border colours, the MIC and loudspeaker outputs, the EAR input, the U and V colour-difference levels, memory read and write strobes, the CPU clock (one quarter of the master clock) and CPU clock halting during screen access.
The notes give pass levels for the combined tape and loudspeaker pin: 0.65 to 0.85 V with the speaker bit low and the MIC bit high, below 0.3 V with both low, and above 3.7 V with both high; the EAR input should read 1 at 1 V and 0 at 0.5 V. They also list the expected U and V voltages: U black level 2.011 V with colour steps of -0.963 V (blue), +0.321 V (red) and +0.642 V (green); V black level 1.928 V with steps of -0.227 V, +1.364 V and -1.136 V, reversed in sign on odd lines, and suggest a tolerance of about 20 mV.
The document is undated. The same order of tests appears in the Membrain tester programs SPEC-FER-COD-090, SPEC-FER-COD-091 and SPEC-FER-COD-092. Part of the Ferranti Archives 2026.
Archive record
[edit | edit source]| Catalogue ID | SPEC-FER-NOT-094 |
|---|---|
| Date | Undated |
| Origin | Ferranti |
| Document type | Notes |
| Device or subject | 5C102 (Spectrum) |
| Catalogue description | Hand drawn/written description of ULA 5C102 Test Program |
| Original file name | {{{filename|}}}
|
| Found in | SPEC-FER-FOL-098 |
| Pages | 8 |
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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| current | 15:58, 16 October 2026 | 0 × 0 (3.28 MB) | Josh (talk | contribs) | Ferranti Archives 2026: SPEC-FER-NOT-094 |
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