The Commodore plus/4 is a home computer from the 1980s and typical with other computers of that era comes with a built-in keyboard and was designed to connect to a television set.

The +4 has a number of built in I/O interfaces. These include a serial UART, 8-bit parallel port, cassette port and a CBM IEC serial bus.

The video output can drive composite video inputs on TVs or, for example, a Hauppauge HVR900H (2040:6600) capture board in Linux (see photo). This setup has low latency and is very usable in Linux, but this may not be the case elsewhere.

 1   2   3   4   5   6   7   8   9   10  11  12
GND 5V  RES *P2 P3  P4  P5  RxC ATN  9V  9V GND

GND P0  RxD RTS DTR P7  DCD P6  P1  DSR TxD GND
 A   B   C   D   E   F   H   J   K   L   M   N

*CST SENSE