Parallel port printer port or Centronics port found on most personal computers from the 1970s through the 2000s. It was an industry "de facto" standard for many years, and was finally standardized as IEEE 1284 in the late 1990s, which defined the Enhanced Parallel Port (EPP) and Extended Capability Port (ECP) bi-directional versions. Today, the parallel port interface is virtually non-existent because of the rise of Universal Serial Bus (USB) devices, along with network printing using Ethernet and Wi-Fi connected printers. The parallel port interface was originally known as the Parallel Printer Adapter on IBM PC-compatible computers. It was primarily designed to
Parallel port If no printer port is present at 0x3BC, the second port in the row (0x378) becomes logical parallel port 1 and 0x278 becomes logical parallel port 2 for the BIOS. Sometimes, printer ports are jumpered to share an interrupt despite having their own IO addresses (i.e. only one can be used interrupt-driven at a time). In some cases, the BIOS supports a fourth printer port as well, but the base address for it differs significantly between vendors. Since the reserved entry for a fourth logical printer port in the BIOS Data Area (BDA) is shared with other uses on PS/2