Parallel port is actually an external interface that is commonly found on older PCs that were used during the early 1980s to early 2000s. It was used to connect with peripheral devices such as printers and external storage devices. At the same time, USB started being used in its place , which provides a smaller connection and in this, you also get significantly faster data transfer rates.

By the way, this parallel port is a hallmark of old computer technology – which was quite large in size and there was a speed slow. A standard parallel port connector has a total of 25 pins of two rows which are surrounded by a metal casing. It is just one inch thick and has two screw-in connectors that help the cable to stay in one place.

Parallel port cables that are used for printing also have a very large 36-pin “Centronics 36” connector that connects with a printer. Talking about the original parallel port standard, it used to be unidirectional and it could transmit the data at maximum speed of 150 kbps .

As printers started to become more advanced, it became necessary to increase the connection speed and also provide bidirectional communication. Send a PC in place of a ” Print ” command and expect the print job to succeed, while the bidirectional capability allows printers to send messages back to the PC, such as “ready,” “printing,” And “complete.” Faster transmission speeds enable parallel ports to be used for other tasks, such as an external storage devices for example the Iomega Zip drive.

IEEE 1284

This parallel port was later standardized by IEEE as ” IEEE 1284 “. This standard defined many new versions of the parallel port, including Enhanced Parallel Port (EPP) and Extended Capability Port (ECP). In this, EPP could transmit data up to 16 Mbps (2 MB / s). The data transfer rates of ECP are around 20 Mbps to 2.5 MB / s through an ISA bus.

You probably know that the first version of USB was not much faster than a parallel port, whereas there were many other improvements in it, such as a smaller connector and the ability to make it electrical. voltage so that an external device can be powered.

It also used to be hot-swappable, meaning that a USB device can be safely connected or disconnected when a computer is running. In this way, connecting or disconnecting a peripheral through an IEEE 1284 connection, this can damage the device or that PC. But since USB 2.0 was introduced, which used to provide data transfer rates of around 480 Mbps, then the use of parallel port was completely lost and along with this IEEE 1284 standard also in the history of computer Lost somewhere.

« Back to Wiki Index