OMB-DIO-488 & OMB-DIO-232 from $595
40-Bit Digital I/O RS-232 and IEEE-488 Interfaces
Data Acquisition and Control for IBM PC/XT/AT and Compatibles

These programmable interfaces provide TTL level digital input and output capability to RS-232 and IEEE-488 based system. The 40-bit digital I/O port is software programmable in groups of eight bits for input or output.

Five additional line provide complete digital I/O handshaking, including data latch input, service request input, new data input, clear output, and trigger output. Programming is simple, accomplished using high level ASCII commands.