The K589AP26 chips are a bus driver (4-channel switch) with inversion and are designed to control trunks (buses) in digital computing devices. They have in each channel 1 a bus for receiving information only, 1 bus for information only, and 1 bidirectional bus for receiving and issuing information, and provide connection of machine words with a length of 4 digits in one of two directions. Contain 196 integral elements.