ULA: 6C001E-7 (date code 8418, probably made in Phillipines)
RAM: 48KB
Composite mod
Trivia
Was sold as partially working, with strange pixel artifacts. When I tested it, I only got a black screen with a white border.
The component date codes of this Speccy tell an interesting history. This machine was built in 1982, probably as 16K model. All components that are related to the 48K memory are socketed and have a 1983 date code, so the machine was probably extended to 48K in that year. As the only chip, the ULA has a 1984 date code. Maybe the original ULA got broken and was replaced in that year.
An important configuration jumper was missing. I have serious doubts that this machine was ever running stable after it was upgraded to 48K.
The outerior is in an exceptionally good state, almost in mint optical condition! This is even more remarkable as this is the oldest ZX Spectrum of my collection.
Restauration Works
Restauration was carried out in February 2022
Removed an overly complicated composite mod made by the previous owner, and just did the classic composite mod (reversible).
Repaired a coil damage: Wound new coil, preemptively replaced TR4, TR5, D16
Replaced 7805 with Traco Power TSR-1 DC/DC converter, removed heatsink
Calibrated video output
History
2022-03-13: Calibrated video output
2022-02-26
Recapped
Replaced 7805 with DC/DC converter, removed heatsink
2022-02-19
Replaced overly complicated mod with classic composite mod
Rewound burnt wires in the coil, replaced TR4, TR5, D16
