A complete Single Board Computer with a size of only 25 x 43 mm ist the BASIC-Briefmarke I A. It features 8 universal I/Os that drive up to 25mA directly and is pluggable through a 12-pin header connector. The Die power supply is either 5V or 7...15V. Die BASIC-Briefmarke I A is programmed through the PCs parallel port into EEPROM as often as desired.