2. Parallel port

2.1 Definition

Originally conceived as a simple interface for a printer, the parallel port has evolved into a means of connecting various peripherals to the computer. It allows input, output or bidirectional links. For specific applications, there are numerous devices for data collection, testing or control. The parallel port is the interface of choice for many smaller projects requiring communications between the computer and an external device.

A parallel port transfers several bits at a time, while a serial port transfers only one bit (even if it allows transfer in both directions at the same time).

Several manufacturers have introduced improvements to the parallel port, adding new possibilities and increasing the speed of information...