54191 DM54191 DM74191 Synchronous Up Down 4-Bit Bi.
National Semiconductor
DM74191 - Synchronous Up/Down 4-Bit Binary Counter with Mode Control
54191 DM54191 DM74191 Synchronous Up Down 4-Bit Binary Counter with Mode Control June 1989 54191 DM54191 DM74191 Synchronous Up Down 4-Bit Binary Co.