Editing Parallel port (section)

{{short description|Computer interface}}
{{redirect|LPT}}
{{redirect|Printer port}}
{{About|the Centronics style port|the concept in general|Parallel communications}}
<!-- NB. Left here to maintain link continuity for now. Should be removed at a later stage, as the term "LPT" either refers to "line printers", or to logical device names in operating systems such as DOS, but not to the parallel port hardware in PCs, and therefore this article is NOT the primary topic of "LPT". -->

{{infobox connector
| name = Parallel port
| type = Point-to-point
| image = [[File:Parallel computer printer port.jpg|frameless|150px]]
| logo = 
| caption = A [[DB-25]] connector often used for a parallel printer port on [[IBM PC compatible]] computers, with the printer icon.
| designer = [[#Centronics|Centronics]], [[IBM]]
| design_date = 1970–1981
| manufacturer = Centronics, Dataproducts, Intel, IBM, Compaq, Nortel, etc
| key_people = 
| production_date = 
| superseded = 
| superseded_by = 
| superseded_by_date = 
| external = Yes
| hotplug = Usually not
| length = {{convert|2.3|cm|abbr=on}}
| width = 
| height = 
| electrical = 0 to +5.0 volt [[direct current|DC]]
| earth = Dedicated pins
| maximum_voltage = 5 volts DC
| maximum_current = 
| data_signal = [[Parallel communication|Parallel]]
| data_bit_width = Variable
| data_bandwidth = '''PP:''' 150&nbsp;[[kB/s]],<ref name="James">James, Kevin. ''PC interfacing and data acquisition : techniques for measurement, instrumentation and control''. Oxford; Boston : Newnes, 2000. {{ISBN|9780750646246}}. p. 256</ref><br/>'''EPP:''' 2 [[megabyte|MB]]/s<br/>'''ECP:''' 2.5 MB/s
| data_devices = 2, unless [[Software_protection_dongle|devices provide passthrough]]
| data_style = Application dependent
| cable = Usually up to 25 wires including ground; optionally shielded
| physical_connector = [[DB-25]], [[D-subminiature|DB25F]], [[Micro ribbon|"Centronics" 36-pin Amphenol]], [[D-subminiature|DC-37]], others
| num_pins = 8 data, 4 output control, 5 input control, 8 ground
| pinout_image = [[Image:25 Pin D-sub pinout.svg|200px|frameless]]
| pinout_caption = IBM PC-compatible parallel port pinout
}}

[[File:Centronics-36F.jpg|thumb|Micro ribbon 36-pin female, such as on printers and on some computers, particularly industrial equipment and early (pre-1980s) personal computers.]]
[[File:Mini-Centronics 36 pin with Micro-Centronics 36 pin.jpg|thumb|Mini-Centronics 36-pin male connector (top) with Micro ribbon 36-pin male Centronics connector (bottom)]]
[[File:Apple_II_Parallel_Printer_Card.jpg|thumb|The Apple II Parallel Printer Port connected to the printer via a folded ribbon cable; one end connected to the connector at the top of the card, and the other end had a 36-pin Centronics connector.]]

In [[computing]], a '''parallel port''' is a type of [[Hardware interface|interface]] found on early [[computer]]s ([[personal computer|personal]] and otherwise) for connecting [[peripheral]]s. The name refers to the way the data is sent; parallel ports send multiple [[bit]]s of data at once ([[parallel communication]]), as opposed to [[serial communication]], in which bits are sent one at a time. To do this, parallel ports require multiple data lines in their cables and [[Computer port (hardware)|port]] connectors and tend to be larger than contemporary [[serial port]]s, which only require one data line.

There are many types of parallel ports, but the term has become most closely associated with the '''printer port''' or [[#Centronics|Centronics port]] found on most personal computers from the 1970s through the 2000s. It was an industry [[de facto standard|''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 in new computers because of the rise of [[USB|Universal Serial Bus]] (USB) devices, along with [[Print server|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|PC-compatible]] computers. It was primarily designed to operate [[Dot matrix printing#Personal computers|printers]] that used IBM's eight-bit [[extended ASCII]] [[character set]] to print text, but could also be used to adapt other peripherals. Graphical printers, along with a host of other devices, have been designed to communicate with the system.