Interface recognition

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Use this guide to find out which type of interface (connector, pinout and protocol) your input device has.

Use of the a plug in the wrong port could often lead to electrical damage. Most ports are not hot-swappable, so you would need to turn off your device before inserting/removing the plug.


The 5-pin XT and AT plug

5-pin DIN

8-pin DIN

10-pin DIN

13-pin DIN


Two PS/2 ports (left, middle) and an ADB port (right)

4-pin mini-DIN

  • Apple Desktop Bus (ADB). Mostly keyboards and mice, but also others such as joysticks and dongles. All peripherals but mice have two ports: either could be connected upstream to the host and the other downstream. The chain terminates with the mouse.
  • Vintage Macintosh AV OUT port.

5-pin mini-DIN

Pins are laid out like a 6-pin mini-DIN but one pin is missing and the stud is in the centre.

6-pin mini-DIN

  • PS/2 interface. Plugs (and ports) are often green or purple with a symbol of a keyboard or mouse to distinguish between which type of device goes where. When a downstream port is found is on a device, it accepts only a peripheral of the same type (keyboard or mouse).
  • Silicon Graphics proprietary keyboard and mouse. Used only for the Indigo, whereas newer systems got PS/2 ports. Like ADB, keyboards have two ports: one to the host and one to the mouse.
  • Commodore Amiga 4000 or Amiga CD32. The CD32's port also carries RS-232.

7-pin mini-DIN

8-pin mini-DIN

Keyboard, mouse:


  • Intergraph InterPro/InterServe keyboard.
  • NEC PC-98 series keyboard.


Game controller

  • Joystick port for Commodore 16-line "home office" computers: Commodore Plus/4, 16 and 116
  • PC Engine gamepad/controller
  • Phillips CD-i gamepad/controller


9-pin mini-DIN

Modular connector

Nomenclature: yPxC. First digit is width in pins, second is number of pins actually present/connected.

Modular connectors are often incorrectly called RJ9 (4P4C) or RJ11 (6PxC). Those are actually specific interfaces, not connector types.

Some keyboards have it on the keyboard side, either for a detachable cable (with standard plug at the other end) or as interconnect between main (or left and right) and numeric keypad.


Terminal keyboards: Many different variations exist. Including

Computer keyboards:





Female DE-9 plug

Primarily mice:

  • Serial interface. Primarily "serial mice" and trackballs. Some unorthodox devices also use it. Some joysticks with Game port use it for secondary input. Thumbscrews are common, whereas other interfaces with DE-9 ports tend to not have them. If the device is labelled as running on 12V, that is also an indicator for serial interface because most other with this port run on 5V.
  • Bus mouse. Multiple types exist for: Amstrad PC, Commodore PCs/Commodore Amiga and Atari PC/Atari ST, NEC PC-98, among others.


  • Atari Controller port: Primarily joysticks and mice for 8-bit and 16-bit home computers from Atari and Commodore. These support also numeric keypads, light pens, rotary knobs, and various other peripherals. There were add-on cards and adaptors for using Atari-compatible joysticks on other platforms.
  • J-PC: Japanese home-computer peripheral port. Mostly joysticks and mice. Sometimes compatible with Atari port but dangerous when not.

Primarily handheld joysticks:

Primarily gamepads:

  • Sega 8-bit/16-bit controller port. Sometimes compatible with Atari port but dangerous when not. (Mouse did exist but is rare and Sega-branded. Keyboard is very rare)
  • 3DO gamepad. Often a game-pad with passthrough and headphone jack.
  • "Famiclone": clone of Nintendo FamiCom/Nintendo Entertainment Systems. Often in style of Nintendo or Sony PlayStation controller. Probably works only with the type of console it was originally sold with.

Male DE-9 plug

Female DE-15 plug

Same size as DE-9 but with 15 pins. Also used by VGA.

Male DA-15 plug

Female DA-15 plug

  • Neo-Geo game controller.
  • Mindset joystick and mouse port.

Phone connector

6.35 mm TRS (¼ inch)

3.5mm TRRS

  • Often used as interconnect between halves of a split ergonomic keyboard. The protocol is often special to the keyboard model, based on I²C. The tip/ring assignment varies.

2.5mm TRS

  • Sometimes used for MIDI


See also

External links