Parallel port the ports in this manner in many cases, though this is often fairly hidden. In SCO UNIX and Linux, the first parallel port is available via the filesystem as /dev/lp0. Linux IDE devices can use a "paride" (parallel port IDE) driver. For consumers, USB and computer networks have replaced the parallel printer port, for connections both to printers and to other devices. Many manufacturers of personal computers and laptops consider parallel to be a legacy port and no longer include the parallel interface. Smaller machines have less room for large parallel port connectors. USB-to-parallel adapters are available that can make
Serial port of the full standard: they traded off compatibility with the standard against the use of less costly and more compact connectors (in particular the DE-9 version used by the original IBM PC-AT). The desire to supply serial interface cards with two ports required that IBM reduce the size of the connector to fit onto a single card back panel. A DE-9 connector also fits onto a card with a second DB-25 connector. Starting around the time of the introduction of the IBM PC-AT, serial ports were commonly built with a 9-pin connector to save cost and space. However, presence of