Acorn Archimedes

The Acorn Archimedes is a family of personal computers designed by Acorn Computers of Cambridge, England. The systems in this family use Acorn's own ARM architecture processors and initially ran the Arthur operating system, with later models introducing RISC OS and, in a separate workstation range, RISC iX. The first Archimedes models were introduced in 1987, and systems in the Archimedes family were sold until the mid-1990s alongside Acorn's newer Risc PC and A7000 models.

The first Archimedes models, featuring a 32-bit ARM2 RISC CPU running at 8 MHz, provided a significant upgrade from Acorn's previous machines and 8-bit home computers in general. Acorn's publicity claimed a performance rating of 4 MIPS. Later models featured the ARM3 CPU, delivering a substantial performance improvement, and the first ARM system-on-a-chip, the ARM250.

The Archimedes preserves a degree of compatibility with Acorn's earlier machines, offering BBC BASIC, support for running 8-bit applications, and display modes compatible with those earlier machines. Following on from Acorn's involvement with the BBC Micro, two of the first models—the A305 and A310—were given BBC branding.

The name "Acorn Archimedes" is commonly used to describe any of Acorn's contemporary designs based on the same architecture. This architecture can be broadly characterised as involving the ARM CPU and the first generation chipset consisting of MEMC (MEMory Controller), VIDC (VIDeo and sound Controller) and IOC (Input Output Controller).

Having introduced the BBC Micro in 1981, Acorn established itself as a major supplier to primary and secondary education in the United Kingdom. However, attempts to replicate this dominance in other sectors, such as home computing with the BBC Micro and Acorn Electron, and in other markets, including the United States and West Germany, were less successful.

As microprocessor and computing technology advanced in the early 1980s, microcomputer manufacturers had to consider evolving their product lines to offer increased capabilities and performance. Acorn's strategy for business computing and development of more capable machines involved a range of "second processor" expansions, including a Z80 second processor running the CP/M operating system, a commitment made by Acorn when securing the BBC Micro contract.

Meanwhile, established platforms like CP/M running on Z80 processors faced competition from the IBM PC running PC DOS and computers with a variety of operating systems on Intel processors such as the 8088 and 8086. Systems using the Motorola 68000 and other processors running the Unix operating system also became available. Apple launched the Lisa and Macintosh computers, and Digital Research introduced its own GEM graphical user interface software, building on previous work by Xerox.

Acorn's strategy seemingly evolved to align with Torch Computers—a company that Acorn considered acquiring—which had already combined BBC Micro hardware with second processors (and modems) to produce their Communicator product line and derivatives. In 1984, Acorn introduced the Acorn Business Computer (ABC) range, based on the BBC Micro architecture, offering models with different second processors and capabilities to respond to computing trends at the time. These models received generally favorable reviews from the computing press. However, with Acorn facing financial strain, the company was rescued by Olivetti in 1985, leaving the ABC's future uncertain in the expected restructuring process. Ultimately, only one of the variants—the Acorn Cambridge Workstation—would reach the market, in a somewhat different form than originally planned.