1971 · Push-Button Personal Computer · Work 961 of 1,871
A one-man computer company in a family garage in Los Angeles on a bright afternoon, on a folding table a flat wide computer box forty-nine centimetres wide of sky-blue painted sheet steel with slanting sides, its light grey front plate held by four corner screws, along its top a row of eight small round lamps, three glowing soft yellow-white, below them a row of square push keys in alternating black and cream-white, every key plain, smooth and unmarked, a fingertip pressing one cream key, plain brown shipping cartons stacked beside, the chrome bumper of a parked car at the edge, the roller door half open onto sunlit palms.
What it was used for
John Blankenbaker began designing the Kenbak-1, a computer for personal use, in autumn 1970, had the machine built by spring 1971 and announced it in Scientific American in early September 1971. The Computer History Museum gives 750 dollars and records that it was not a kit but a finished, working computer with 256 bytes of memory. It was sold mainly to schools: according to the Kenbak-1 Registry the majority of units sold by the Kenbak Corporation went to schools, more than 40 in all, among them to Italy, France, Spain, Mexico and Canada. Prospective buyers had the machine on approval for about 2 weeks, shipping cost about 8 dollars, and the first serial number was 167.
What was new
There was no microprocessor in it; the Computer History Museum notes that none yet existed. The machine was built from small- and medium-scale integrated circuits, and its memory consisted, according to the Kenbak-1 Registry, of 2 MOS shift registers of 1,024 bits each - serial and slow, operated by switches and lamps. What was new was not computing power but packaging: a complete, assembled, working computer under 1,000 dollars, shipped singly to buyers. The barb: the company was undercapitalised, had 5 outside investors and could not sustain the long ordering cycles of schools - and it was this machine that the jury of The Computer Museum in Boston later chose as the first personal computer in its "Earliest PC Contest".
What the sources leave open: Price, 256 bytes, about 40 units sold and the contest come from the Computer History Museum, which dates the contest to 1986; the Kenbak-1 Registry says 1985, so the year is left out here. Timeline, shift registers, school customers, serial number 167 and the capitalisation come from the Kenbak-1 Registry, which reproduces Blankenbaker's own account. Neither source gives a total number of machines built.