It is necessary to make notice that the author of this page has a formation computer science, consequently, in some sections they will be descriptions from this point of view. I would thank the critics that are made to this work. These will be obviously fruit of the practice and the experience. These critics will enrich this material in future editions. The Input Output Ports constitute in the means for which the microprocessor of a computer communicates with its environment.
Ports exist for each interaction of the unit of main prosecution with their auxiliary devices.
This way, a port of entrance of the keyboard, a port exists of exit for the videotape, an input port for the mouse, etc. Each port is designated by a number. In the moment that the parallel port was presented, the matrix printers were the main device external that you could connects. Second, there was not a standard for the electric interface. This caused many problems when it was wanted to guarantee the operation in multiple platforms.