Regarding the ZX Spectrum Serial Numbers Database please see here.
Number found on a ZX Spectrum is a serial number of the machine which indicates important information about the unit. Each given serial number is unique although mistakes can happen which result in two or more different machines bearing identical number. This is down to mechanical issues of the stamping equipment used and such phenomenon is very rare to observe. There is a possibility, however, that your ZX Spectrum has a long lost twin out there in the wild.
Serial numbers can generally be found on the bottom of the case although certain factories would hide the numbers inside the case. Some ZX Spectrums aren’t assigned serial numbers at all.
Standard format used for serial numbers is ZZZ-XXXXXX where:
– Z is a factory ID where the ZX Spectrum has been assembled. Often it’s also pointing to a period when the Spectrum was allocated its number.
– Y is a sequential number used to indicate the order in which the ZX Spectrum rolled off the production line. Number YYYYYY is linked to the ZZZ prefix.
The correct order is: 001-123456 … 001-123457 … 001-123458 …
The incorrect order is: 001-123456 … S01-123457 … 001-123458 …
The incorrect order is: 001-123456 … 028-123457 … 001-123458 …
There were 4 main factories which manufactured ZX Spectrum computers in Sinclair era for British market.
- Main Timex Factory in Dundee (Scotland, UK) where ZX Spectrum computers were first built. Prefix: 001-051; 101-151 The factory used colour coding indicating year of production:
Green – 1982/1983 Issues: 1, 2,3
Red – 1983/1984 Issues: 3, 3B, 4A, 4B, 5, 6A
Blue – 1984/1985 Issues: 3B, 4A, 4B, 6A
The Timex factory was manufacturing the largest amount of ZX Spectrum computers. The first 675,000 Spectrums have fixed 001 prefix which then changes to 002, 003, etc. to reflect week number thus ensuring continuity of the sequence while still only using 6 digits of the suffix.
The plant was also assembling Sinclair ZX81 and Spectrum 128K UK Toastrack computers.
Yellow –1985/1986 Spectrum 128 versions: 6K, 6U, 9G
- Thorn EMI Datatech Factory in Feltham (England, UK) has joined in ZX Spectrum computers manufacturing soon after to satisfy the market demand. Later also manufacturing Sinclair QL computers.
D01 Issues: 2, 3, 3B, 4A (estimated 600,000 units made)
Machines assembled in this factory can be recognised by a small round sticker often appearing next to the serial number either in green (16K) or white (48K). Same type of round sticker but in grey colour also appears inside the case attached to the motherboard on top of the TV modulator lid or on the surface of the beeper.
D03 Issues: Any. Prefix indicates the shell is used to hold a motherboard that has been rehoused or originates from a different factory.
- Samsung Factory in Korea also manufacturing Sinclair QL computers.
Prefix: S01 Issues: Samsung 3B and 4S (estimated 170,000 units made)
Samsung made machines can be recognised by the distinct green colour of the motherboards. Read more about Samsung-made Spectrums here.
- AB Electronics Factory in Abercynon (Wales, UK) only manufactured Spectrum 48K+ computers and Sinclair ZX Spectrum Interfaces. Prefix:
A01, A02 Issues: 4B, 6A (estimated 100,000 units made)
Spectrum 16K/48K (Rubber Keys)