48-Bit Digital I/O Board Can Be Stacked 16 High

A compact and inexpensive 768-bit I/O system can be built with the LPT48IO general-purpose digital I/O interface board, which uses the firm's mezzanine bus to allow up to 16 of these boards to be stacked. The board is populated with two 82C55 chips that allow independent selection of all operating modes and functions. The board also features one DB37 female connector that duplicates the standard 24-I/O pinout and provides access to ports A, B and C of one of the 82C55 chips. Additionally, an on-board 40-pin header parallels the DB37 pinout for use with ribbon-cable headers in embedded applications. Each of the 48 bits on the board can source or sink 2.5 mA. Other I/O boards available include the LPT24HDV, a 24-channel high current driver board, and the LPT24OPT, a 24-channel optically isolated ac/dc digital output interface board.