The Raspberry Pi, a credit card-sized computer designed and built for enthusiasts and priced at under £22 - went on sale in the UK on Wednesday only to sell out minutes later.

The computer, which was created by Robert Mullins and Eben Upton and released by the Raspberry Pi foundation, went on sale at 6am at computer shops RS Components and Premier Farnell and is designed to get people excited about computing just as they did in the heyday of the BBC Micro.

The Raspberry Pi is a credit-card sized computer board that plugs into a TV and a keyboard. It has a HMDI socket, a video output, two USB ports, Ethernet, audio output and SD card slot. Power is provided either by a battery or a standard mobile phone charger. 

It might look like a board of electronics and nothing more, but it is a miniature ARM-based PC which can be used for many of the things that a desktop PC does - like spreadsheets, word-processing and games. It also plays High-Definition video.

The idea of the new computer is to not only to encourage kids and adults alike to program, but also to be used as a low-cost media centre.

Both RS Components and Premier Farnell are taking pre-orders for the second batch when it arrives.