Updated: 04/26/2017 by Computer Hope
Symbol featuring two arrows traveling in opposite directions

Bidirectional is a communications mode transmits data in both directions (send and receive), but not at the same time. Bi-di (bidirectional) is also a printer port mode that was introduced by IBM in 1987 with their introduction of the PS/2 computer.

The bidirectional port is an 8-bit port capable of transmitting between 75 and 300 KBps. It was available as either a type 1 or type 3 port, which used a DMA (Direct Memory Access).

BDO, Parallel port, Printer terms, Unidirectional