Parallel Port
16.1 Introduction
This chapter discusses parallel communications. The Centronics printer interface transmits eight bits of data at a time to an external device, normally a printer. A 25-pin D-type connector is used to connect to the PC and a 36-pin Centronics interface connector normally connects to the printer. This interface is not normally used for other types of interfacing as the standard interface only transmits data over the data lines in one direction, that is, from the PC to the external device. Some interface devices overcome this problem by using four of the input handshaking lines to input data and then multiplexing using an output handshaking line to multiplex them to produce eight output bits.
As technology has improved ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access