AT keyboard
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AT Keyboard | ||
---|---|---|
Type | Keyboard connector | |
Production history | ||
Designer | IBM | |
Designed | 1984 | |
Superseded by | PS/2 connector Universal Serial Bus | |
Specifications | ||
Data signal | Serial data at 10 to 16 kHz with 1 stop bit, 1 start bit, 1 parity bit (odd) | |
Pins | 5 | |
Connector | DIN connector | |
Pin out | ||
|
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Pin 1 | CLK | Clock signal |
Pin 2 | DATA | Data |
Pin 3 | N/C | Not connected. Reset on older keyboards |
Pin 4 | GND | Ground |
Pin 5 | VCC | +5V DC |
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 5-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 Many Enhanced keyboards used this, though it was eventually superseded by the PS/2 connector and many modern computers use Universal Serial Bus (USB) connectors instead.