The BBC Microcomputer System, or BBC Micro, was a series of microcomputers and associated peripherals designed and built by the Acorn Computer company for the BBC Computer Literacy Project, operated by the British Broadcasting Corporation. Designed with an emphasis on education, it was notable for its ruggedness, expandability and the quality of its operating system.
After the Literacy Project's call for bids for a computer to accompany the TV programmes and literature, Acorn won the contract with the Proton, a successor of its Atom computer prototyped at short notice. Renamed the BBC Micro, the system was adopted by most schools in the United Kingdom, changing Acorn's fortunes. It was also moderately successful as a home computer in the UK despite its high cost. Acorn also employed the machine to simulate and develop the ARM architecture which is much used for embedded systems, including tablets and cellphones. Globally, as of 2013, ARM is the most widely used 32-bit instruction set architecture in terms of quantity produced.
While nine models were eventually produced with the BBC brand, the phrase "BBC Micro" is usually used colloquially to refer to the first six (Model A, B, B+64, B+128, Master 128, and Master Compact), with the subsequent models considered as part of Acorn's Archimedes series.