Acorn Computers was a British computer company, based in Cambridge, that became one of the defining forces in early UK home and educational computing. It is best remembered for two machines and one chip: the BBC Micro, the Archimedes, and the ARM processor that grew out of its in-house research.
Acorn won the contract to build the computer for the BBC’s national Computer Literacy Project, and the resulting BBC Micro became the dominant machine in British schools through the 1980s, exposing a generation of pupils to programming. That success gave Acorn both the resources and the motivation to design its own processor rather than depend on chips from American vendors.
In October 1983 Acorn began a RISC research project to build that processor, and on 26 April 1985 VLSI Technology produced the first working ARM silicon, the Acorn RISC Machine. The chip’s first home in a consumer product was the Acorn Archimedes. The Centre for Computing History describes the Archimedes as “Acorn Computers Ltd’s first general purpose home computer based on their own 32-bit ARM RISC CPU,” released in mid-1987 as one of the first RISC-based home computers.
The most consequential thing Acorn ever did was let ARM go. In 1990 the processor architecture group was spun out as a separate company, Advanced RISC Machines, formed as a joint venture between Acorn, Apple, and VLSI Technology. That spin-out, made to fund and broaden the ARM design beyond Acorn’s own machines, eventually became Arm Holdings, whose architecture would power the overwhelming majority of the world’s smartphones.
Acorn itself faded as a computer maker over the following decade and was broken up, but its legacy proved enormous. The design discipline of its small engineering team, captured in the ARM architecture, outlived the company many times over and shaped the direction of mobile and embedded computing worldwide.