24-Bit Digital I/O Board for PCI Bus

The PCI-DIO24 and PCI-DIO24H are low cost, 24-bit, logic level digital I/O boards for the PCI bus for IBM or compatible PC’s. The PCI-DIO24 is based on the industry standard 82C55 chip, and the 82C55 I/O pins are brought directly to the board’s I/O connector. The 82C55 is a powerful 24-bit chip which functions as two 8-bit ports (Ports A and B) and a third 8-bit port (Port C) that may be further divided into two 4-bit ports (Ports C-HI and C-LO). The CMOS outputs of the 82C55 are suitable for driving a wide array of logic devices, although the chip’s ±2.5 mA drive capability may not be enough for some applications.