On 5 March 1981, Sinclair Research launched a computer that cost less than the television it plugged into by a factor of about ten. The ZX81 arrived in two forms with identical innards: a kit you soldered together yourself for £49.95, or a ready-built machine for £69.95. Either way, it was a provocation. Its predecessor, the ZX80, had been the first fully functional microcomputer under £100; the ZX81 halved the psychological barrier again, and did something arguably more important than the price cut. It went on sale in a high-street shop. W. H. Smith — the newsagent and stationer on every British high street — took the machine into its stores under an exclusive deal, and computing, which had lived in electronics magazines and mail-order small ads, was suddenly sitting between the magazines and the stationery, available to anyone with seventy pounds and a Saturday afternoon.
The numbers that followed rewrote the British industry. More than 1.5 million ZX81s were sold in total. By March 1982, a year after launch, Sinclair could announce 250,000 sold worldwide, with production running at 50,000 machines a month and 60 percent of them going abroad. The kit version, sold by mail order, accounted for over 300,000 sales by the end of January 1982 alone. When Smith’s exclusive expired after six months, Boots, John Menzies and Currys joined in. A computer had become a retail product, and a generation of British children learned a new Saturday ritual: go into Smith’s, look at the wedge, want the wedge.
Four chips and a price tag
The price was not marketing. It was engineering, and the engineering was a war on component count. The ZX80 had used 21 chips; chief engineer Jim Westwood’s redesign folded the logic into a single Ferranti uncommitted logic array — a ULA — and brought the ZX81 down to essentially four chips: the ULA, the ROM, a Z80 processor running at 3.25 MHz, and a single kilobyte of RAM. One kilobyte. The machine’s entire memory would not hold this article twice. Around those four chips, designer Rick Dickinson drew the famous black wedge case, and across its top Sinclair printed the other half of the revolution: a flat membrane keyboard, forty keys, every one of them printed with the BASIC keywords it could produce. The ZX81 did not ask you to type LET or PRINT letter by letter. You pressed one key and the keyword appeared, whole — a beginner’s interface disguised as a cost saving, which is the most Sinclair sentence imaginable.
The specification, read cold, is a dare: monochrome text and block graphics on a domestic television, no sound, programs saved to ordinary audio cassettes at a pace that made loading an act of faith, and a display system that famously split its attention — in FAST mode the screen blanked while the machine computed, because the processor was also the display driver. But the specification was never the product. The product was the price, and the place, and the promise printed in the adverts: personal computing, for the price of a good pair of shoes, from a shop you already trusted.
Sinclair did not sell Britain a computer in March 1981. He sold it permission — £49.95 of permission, stocked by W. H. Smith, to walk in off the high street and begin.
The bedroom-coding dawn
What Britain did with the permission is the rest of this package’s story. The ZX81 created the conditions of the British games industry in a single stroke: a vast, young, technically literate audience, in their bedrooms, with a machine that was fully programmable out of the box and a keyboard that taught BASIC by touch. Every owner was a potential developer; every developer was a potential company. Psion wrote Flight Simulation. Don Priestley, a schoolteacher, wrote Mazogs and Dictator from his freelance desk. Malcolm Evans, an aerospace scientist, received one for his birthday and invented 3D gaming on it. Kevin Toms, a programmer with a board game in his past, founded Addictive Games around a football management simulation written in BASIC. The distance from ZX81 owner to ZX81 publisher was one cassette, one advert in a magazine, and the postal service — and hundreds crossed it.
The kit deserves its sentence in the dawn story. For £49.95 — mail order, a wait, a box of components and a board — you did not just own a computer, you had made one, and the making was an education no manual could match. Fathers built them with sons; Jason Fitzpatrick of the Centre for Computing History has called the mail-order wait a kind of crowdfunding before crowdfunding existed, backers and all. When the machine you soldered yourself then ran your own programs, the relationship between Britain and computing changed permanently: the computer was no longer a priesthood’s instrument. It was a kit, from a shop, in a wedge, in the bedroom.
The ZX81’s reign was short — the ZX Spectrum arrived in April 1982 in colour, and Sinclair cut the ready-built ZX81 to £49.95 that May — but its work was done. It had proved a mass market existed, trained the audience and half the industry that would serve it, and established the template every British micro after it would follow: cheap, cheerful, programmable, and sold where ordinary people shop. The Spectrum gets the glory. The ZX81 dug the foundations, at £49.95 a time, six months of them exclusively through a newsagent.
Made in Dundee, sold everywhere
One more party belongs in the launch story: the manufacturer. The ZX81 was designed in Cambridge and made in Dundee, by Timex — the watch company whose Scottish plant became, improbably, one of the birthplaces of the British computer industry. The arrangement gave Sinclair a production capacity no startup could have built, fifty thousand machines a month at the peak, and it bound the two companies together for the sequel: Timex’s American arm would take the same wedge across the Atlantic as the Timex Sinclair 1000, the subject of its own feature in this package. The high-street revolution, in other words, had a factory behind it — and the factory was a watch factory, which explains a great deal about the machine’s discipline: few parts, tight costs, a product designed to be assembled quickly and sold everywhere. W. H. Smith supplied the shops. Timex supplied the flood. Cambridge supplied the nerve.
Smith’s bet deserves a final, specific credit. A newsagent does not have to stock a computer; in 1981 the safe move was to leave the strange wedge to the mail-order adverts and the electronics shops, and the entire British industry might have grown up smaller, slower and more southern without it. Instead the chain put its name, its windows and its tills behind the machine for six exclusive months, and in doing so told the country’s parents — the people who actually held the £69.95 — that this object was respectable, returnable and real. Distribution is destiny for new technology. The ZX81’s destiny was decided as much in Smith’s buying offices as in Sinclair’s laboratory.
The wedge that started it
Stand in front of one today — more than 1.5 million were made, so survivors are everywhere — and the object itself still argues Sinclair’s case: smaller than a hardback book, four chips, one kilobyte, a keyboard like a printed diagram. Everything about it says that computing’s price and priesthood were choices, not laws. In March 1981 a newsagent’s chain and a Cambridge calculator company chose otherwise, and British bedrooms have been full of programmers ever since.