The PC-36C is a 24 line digital I/O Board using industry standard fast 8255 PPI chip to provide 24 DIO lines arranged in three 8-bit ports: Port A, Port B and Port C. Wait-state generation has been incorporated in the PC-36C in order to allow operation fast computers with fast Bus Clock speeds. An additional signal-conditioned external interrupt line is available. This allows pulses of up to 24V to be fed into the line. It can be used as an external trigger OR an automatic startup/shutdown trigger. A jumper enables the external trigger line to be commoned to digital ground or be completely isolated.