Editing Serial port (section)

===Connectors===
The only connector specified in the original RS-232 standard was the 25-pin D-subminiature, however, many other connectors have been used to save money or save on physical space, among other reasons. In particular, since many devices do not use all of the 20 signals that are defined by the standard, connectors with fewer pins are often used. While specific examples follow, countless other connectors have been used for RS-232 connections.

The 9-pin [[D-subminiature|DE-9]] connector has been used by most IBM-compatible PCs since the Serial/Parallel Adapter option for the [[IBM Personal Computer/AT|PC-AT]], where the 9-pin connector allowed a serial and parallel port to fit on the same card.<ref>{{Cite web|title=IBM PC AT Serial/Parallel Adapter|url=http://www.minuszerodegrees.net/oa/OA%20-%20IBM%20PC%20AT%20Serial_Parallel%20Adapter.pdf|url-status=dead|archive-url=https://web.archive.org/web/20200224102106/http://minuszerodegrees.net/oa/OA%20-%20IBM%20PC%20AT%20Serial_Parallel%20Adapter.pdf|archive-date=2020-02-24}}</ref> This connector has been standardized for RS-232 as [[TIA-574]].

Some miniaturized electronics, particularly [[graphing calculator]]s<ref>{{Cite web|title=TI-73...92+/V200 TI Link Guide|url=http://merthsoft.com/linkguide/cable.html|access-date=2020-08-14|website=merthsoft.com}}</ref> and hand-held [[Amateur radio|amateur]] and [[two-way radio]] equipment,<ref>{{Cite web|title=Technical Section |url=https://www.miklor.com/COM/UV_Technical.php#progcable|access-date=2020-08-14|website=Miklor.com}}</ref> have serial ports using a [[phone connector (audio)|phone connector]], usually the smaller 2.5 or 3.5&nbsp;mm connectors and the most basic 3-wire interface—transmit, receive and ground.

[[8P8C]] connectors are also used in many devices. The [[EIA/TIA-561]] standard defines a pinout using this connector, while the [[rollover cable]] (or Yost standard) is commonly used on [[Unix]] computers and network devices, such as equipment from [[Cisco Systems]].<ref>{{Cite web|title=Cabling Guide for Console and AUX Ports|url=https://www.cisco.com/c/en/us/support/docs/routers/7000-series-routers/12223-14.html|access-date=2020-08-14|website=Cisco }}</ref>

Many models of [[Macintosh]] favor the related RS-422 standard, mostly using circular [[mini-DIN connector]]s. The Macintosh included a standard set of two ports for connection to a printer and a modem, but some [[PowerBook]] laptops had only one combined port to save space.<ref>{{Cite web |title=Classic Mac Ports |url=https://whitefiles.org/tec/pgs/h10b.htm |access-date=2020-08-14 |website=WhiteFiles.org }}</ref>

[[10P10C]] connectors can be found on some devices.<ref name="National Instruments 2013">{{cite web |url=http://www.ni.com/pdf/manuals/371253e.pdf |publisher=National Instruments |title=Serial Quick Reference Guide |website=NI.com |date=July 2013 |access-date=2021-06-18 }}</ref>

Another common connector is a {{resx|10|2}} [[pin header]] common on motherboards and add-in cards which is usually converted via a [[ribbon cable]] to the more standard 9-pin DE-9 connector (and frequently mounted on a free slot plate or other part of the housing).<ref>{{Cite book |url=https://www.intel.com/content/dam/support/us/en/documents/motherboards/server/s5000pal/sb/s5000pal_s5000xal_tps_r2_0.pdf |title=Intel Server Board S5000PAL/S5000XAL Technical Product Specification |pages=38 }}</ref>

{{Gallery
| CiscoConsoleCable.jpg | A Cisco rollover cable using the 8P8C Yost standard.
| Mac lc printer modem ports.jpg|Pair of female [[Mini DIN-8]] connectors used for [[RS-422]] serial ports on a [[Macintosh LC]] computer.
| CAN Connecteur.svg|Pin numbering looking into a<br/>male [[D-subminiature|DE-9]] connector.
| DE-9 Female.svg|Pin numbering looking into a<br/>female DE-9 connector.
}}