Measurement Computing's CIO-DIO96 is a 96-line digital I/O board with four 82C55 parallel-interface chips. The board provides the 96 lines in 24-line groups based on the 82C55 specification.
Each 82C55 chip controls 24 CMOS/TTL-compatible digital I/O pins. Each 24-line group is divided into three eight-line ports, or two 8-line ports and two 4-line ports. Each port is programmable for input or output.
All I/O lines are set to input mode (high impedance) on power up and reset. Locations are available for installing pull-up or pull-down resistors.
All signals pass through a 50-pin connector.