More info to follow.
Acorn Computers Ltd. was a British company established in Cambridge in the late '70's. The company produced a number of computers which were especially popular in the UK. These included the Acorn Electron, the BBC Micro, and the Acorn Archimedes. The BBC Microcomputer is the most well-known, due to its adoption in education. The BBC Model A had 16kb of RAM, and the Model B had 32. It was followed by the BBC Master
Though the company was broken up into several independent operations in 1998, its legacy includes the development of RISC personal computers. One of its operating systems, RISC OS, continues to be developed by RISC OS Open. Some of Acorn's former subsidiaries live on today—notably ARM Holdings, which is globally dominant in the mobile phone and PDA microprocessor market.
(Above information partly sourced from Wikipedia).