Acorn are the company which made the BBC B computer in '81/'82. This box was the equivalent in the UK of the Apple ][ in the USA - expandable, solid, etc. The BBC B was much more advanced than the apple, but was made later on... it had multiprocessing options & lots of good stuff (second 6502 cpu, second z80, second 32016, second 68000, second ARM1-development-cpu). There are emulators available, and the games were arcade-quality for the time (unlike the apple ][!) - eg, Rocket raid (scramble), Snapper (pacman), Meteors (asteroids), etc. The BBC games scene produced Elite, which was well ahead of its time!

Acorn had networking done & dusted very early on, too. Back in 1980 you could buy fileservers (System III, I think) and clients (Acorn Atom) from them running Econet (about the same as Appletalk in terms of speed & wiring). Allegedly, Bill Gates came to see them back in the early 80's and they offered to show him their networking technology - his reply was (allegedly, again) "what's networking?"

For the followup, acorn looked at existing CPUs, didn't like any of them, and so invented the ARM CPU in-house. Silicon worked first time, and by '87 they were selling the Archimedes range of ARM2 based machines, having also designed the A/V chip, the IO controller and the memory controller. Lots of us in this office got our hands on ARM CPUs back in 1987 :)

ARMs got very sucessful, as you probably know. Almost every mobile phone has one, they had 77% of the risc market share in 2000 (cf mips 11%, hitachi sh 7%, power pc 3%, other 2%).

Acorn never managed to get the hang of marketing though; the products were good but a bit expensive and never mass market. Like Apple, they sold well into education until PCs just became unbeatable. Rumour has it that the ARM was almost used for Apples instead of PowerPC.

What was left of acorn spun-off a chip design part (element 14, which then got bought by Broadcom for megabucks) and the remaining machine design part got bought by Pace, who make set-top-boxes. Acorn at that point was worth rather a lot less than their share of ARM!

...and there the story ends. A lot of ARM is made up of ex-acorn bods, and it's almost impossible to go into a pub in cambridge without running into people who used to work for acorn.

Hugo