The Raspberry Pi bare board Linux computer being launched by the charitable Raspberry Pi Foundation looks set to appear around three weeks from now. It is designed to help people learn computing in the same way that the Sinclair Spectrum and BBC Micro did in the eighties. At $25 or $35, it is very basic – you have to buy the ‘luxury’ ‘B’ version to get an Ethernet socket – but it the board does provide a USB interface (for mouse, keyboard, printer etc), HDMI and phono/RCA video sockets and an SD card slot. The basic ‘A’ version comes with 128 Mb RAM compared with 256 Mb for the ‘B’.