AT keyboard
Encyclopedia
The AT keyboard was a keyboard
with 84 keys introduced with the IBM PC/AT computer. It succeeded the 83-key PC/XT keyboard
and therefore did not have many of the features seen on modern keyboards such as arrow keys and dual ctrl
and alt
keys. It was later replaced with the 101-key Enhanced keyboard. Nonetheless, "AT keyboard" remains a popular name for any keyboard that uses the five-pin DIN connector
. This connector is often considered a Legacy port
. Many Enhanced keyboards used this, though it was eventually superseded by the PS/2 connector
and many modern computers use Universal Serial Bus
(USB) connectors instead.
Compared to the 83-key XT keyboard, the AT keyboard uses a different communication protocol and a different set of scancode
s. Despite having the same connector, the two are not interchangeable.
Computer keyboard
In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
with 84 keys introduced with the IBM PC/AT computer. It succeeded the 83-key PC/XT keyboard
IBM PC keyboard
The keyboards for IBM PC compatible computers are standardized. However, during the 3-plus decades of PC architecture being constantly updated, multiple types of keyboard layout variations have been developed....
and therefore did not have many of the features seen on modern keyboards such as arrow keys and dual ctrl
Control key
In computing, a Control key is a modifier key which, when pressed in conjunction with another key, will perform a special operation ; similar to the Shift key, the Control key rarely performs any function when pressed by itself...
and alt
Alt key
The Alt key on a computer keyboard is used to change the function of other pressed keys. Thus, the Alt key is a modifier key, used in a similar fashion to the Shift key. For example, simply pressing "A" will type the letter a, but if you hold down either Alt key while pressing A, the computer...
keys. It was later replaced with the 101-key Enhanced keyboard. Nonetheless, "AT keyboard" remains a popular name for any keyboard that uses the five-pin DIN connector
DIN connector
A DIN connector is a connector that was originally standardized by the , the German national standards organization. There are DIN standards for a large number of different connectors, therefore the term "DIN connector" alone does not unambiguously identify any particular type of connector unless...
. This connector is often considered a Legacy port
Legacy port
A legacy port is a computer port or connector that is considered fully or partially superseded. The replacement ports usually provide the functionality of the legacy ports with higher speeds, more compact design, or plug and play and hot swap for greater ease of use; special USB adapters are often...
. Many Enhanced keyboards used this, though it was eventually superseded by the PS/2 connector
PS/2 connector
The PS/2 connector is a 6-pin Mini-DIN connector used for connecting some keyboards and mice to a PC compatible computer system. Its name comes from the IBM Personal System/2 series of personal computers, with which it was introduced in 1987...
and many modern computers use Universal Serial Bus
Universal Serial Bus
USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....
(USB) connectors instead.
Compared to the 83-key XT keyboard, the AT keyboard uses a different communication protocol and a different set of scancode
Scancode
A scancode is the data that most computer keyboards send to a computer to report which keys have been pressed. A number, or sequence of numbers, is assigned to each key on the keyboard.- Variants :...
s. Despite having the same connector, the two are not interchangeable.