Abstract: A card for insertion into a personal computer including a body block and display block. A reception section in the body block receives data from the personal computer. The data is converted by a parallel to serial data converter and optically transmitted to the display block through an optical transmission circuit and an LED. In the display block, the optically transmitted data is received through a photo detector and an optical reception circuit. The received data is converted by a serial to parallel converter and displayed on an LCD through a display unit control section and a control signal generation circuit.