Measurement Computing's CIO-INT32 can accept up to 32 vector interrupts and output an interrupt to the PC. The board contains two Z8536 chips each of which accepts up to 16 independent inputs that can be used to generate interrupts from bit patterns or individual bit states or transitions. The interrupt outputs from two X8536 chips can be ANDed by an on-board jumper.
Many other functions can be performed by the CIO-INT32 including digital pattern recognition, counting with six, 16-bit counters, and up to 40 lines of digital I/O. The 16-bit counters can be set up independently or chained together in groups of three.
The CIO-INT32 has a pair of Z8536 I/O chips interfaced to the ISA bus. All of its I/O lines are accessible through a 50-pin header connector. The I/O pins of an Z8536 are TTL levels.