Acorn Electron and Plus 1 Expansion

The Acorn Electron was introduced as direct competition for computers priced at the cheaper end of the home computing market in the early to mid 1980's such as the range of low end computers produced by Sinclair. With cut down expandability, the Electron was intended to be on the whole compatible with it's big brother, the BBC Microcomputer and in general achieved that aim but did have some significant differences such as a lack of support for the MODE 7 screen mode and a single channel sound generator as opposed to the BBC Micro's three channels + 1 noise channel.