What does PS2

PS / 2

PS / 2 is a computer interface or a connection for keyboards or computer mice. The acronym PS / 2 originally dates back to 1987, when IBM launched a personal computer called PS / 2. This PC was the first to have this type of interface, which was used for the keyboard. The computer mouse was connected to a serial interface. Later the PCs got a second PS / 2 interface for the mouse.

In principle, PS / 2 is a serial interface which, despite the universal USB interface, does not seem to be dying out. The reason why many motherboards still have PS / 2 interfaces for mouse and keyboard is because of the demand.

  • The USB always transmits six commands at the same time from the keyboard to the computer. This is not enough for a quick typist. PS / 2 continuously transmits the keystrokes to the computer. This results in lower latency. Most keyboard typists don't notice this difference, of course.
  • PS / 2 can also be interesting for security reasons. While a USB port can be "misused" for all kinds of devices, the PS / 2 is only suitable for connecting a mouse or keyboard. Computers in which the USB ports are electrically or mechanically blocked are less susceptible to local manipulation by "bad" USB end devices.

Unfortunately, you cannot unplug a keyboard on the PS / 2 while the system is running without causing crashes or a dead system. USB is simply more flexible here.

Connector and cable

The PS / 2 plug or connection corresponds to the mini-DIN plug.


PS / 2 connections for mouse and keyboard


PS / 2 cable connections (extension) for mouse and keyboard

The connections for mouse and keyboard are mechanically identical. Only the assignment is different. To avoid mix-ups, the sockets and plugs are color-coded. Green represents the mouse and purple represents the keyboard. But there are also plugs and sockets that do not have this color coding.

Terminal devices for the PS / 2 interface

The mini-DIN plugs are a family of multi-pin electrical plug connections. They are used for a wide variety of electronic devices. The mini-DIN connector has a larger and older relative, the DIN connector. Both plugs are standards of the German Institute for Standardization (DIN).
The mini-DIN plugs have an outside diameter of 9.5 mm or a diameter of the metal collar of 7 mm. There are officially seven different versions with different numbers of pins. The structural differences ensure that the various plugs and sockets cannot be mixed up. However, there are also plugs and sockets outside the DIN standard.

Overview: Mini-DIN

The number after Mini-DIN refers to the number of pins. They are arranged so that a particular mini-DIN plug will not fit into another mini-DIN socket.

  • Mini-DIN 3
  • Mini-DIN 4 (e.g. for S-Video)
  • Mini-DIN 5
  • Mini-DIN 6 (e.g. for PS / 2)
  • Mini-DIN 7
  • Mini-DIN 8
  • Mini-DIN 9

The mini-DIN plugs are used in many different devices. Often used for audio / video signals, computer data or power supply.
The mini DIN 6 connector is the best known. The PS / 2 interface is used. The mini-DIN-4 is also often used. It is used for S-Video and is sometimes called the Hosiden connector.

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Computer technology primer

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Everything you need to know about computer technology.

Computer technology primer

The computer technology primer is a book about the basics of computer technology, processor technology, semiconductor memory, interfaces, data storage, drives and important hardware components.

I want that!