IBM PC Keyboard - Connection

Connection

System Connector Pinout Transmission Protocol Command Strings Image
PC 5-pin DIN

(DIN 41524)
"AT" connector

 1 CLK

2 DATA
3 -RESET
4 GND
5 +5V

 2 start bits,
8 data bits,
make/break bit (keydown/keyup),
1 stop bit

keyboard reset via pin 3 to ground

 Not supported
XT 5-pin DIN
(DIN 41524)
"AT" connector		 1 CLK

2 DATA
3 N/C
4 GND
5 +5V

 2 start bits,
8 data bits,
make/break bit (keydown/keyup),
1 stop bit

keyboard reset via sequence on DATA and CLK lines

 Not supported
AT 5-pin DIN
(DIN 41524)
"AT" connector		 1 CLK

2 DATA
3 N/C
4 GND
5 +5V

 1 start bit,
8 data,
1 parity (odd),
1 stop bit
keyboard reset via command string		 Supported
PS/2 6-pin Mini-DIN
(DIN 45322)
"PS/2 connector"		 1 DATA

2 N/C (or MOUSE DATA)
3 GND
4 +5V
5 CLK
6 N/C (or MOUSE CLK)

 1 start bit,
8 data,
1 parity (odd),
1 stop bit
keyboard reset via command string		 Supported
Later
PC compatibles		 4-pin USB
Type A connector		 1 +5V

2 Data −
3 Data +
4 Ground

 sync field plus
8-bit bytes as packets
(HANDSHAKE, TOKEN, DATA, Special packets),
least-significant bit first.		 Supported

Read more about this topic:  IBM PC Keyboard

Famous quotes containing the word connection:

    “Parents have railed against shelters near schools, but no one has made any connection between the crazed consumerism of our kids and their elders’ cold unconcern toward others. Maybe the homeless are not the only ones who need to spend time in these places to thaw out.”
    —Anna Quindlen (b. 1952)

    “Morality becomes hypocrisy if it means accepting mothers’ suffering or dying in connection with unwanted pregnancies and illegal abortions and unwanted children.”
    —Gro Harlem Brundtland (b. 1939)

    “We should always remember that the work of art is invariably the creation of a new world, so that the first thing we should do is to study that new world as closely as possible, approaching it as something brand new, having no obvious connection with the worlds we already know. When this new world has been closely studied, then and only then let us examine its links with other worlds, other branches of knowledge.”
    —Vladimir Nabokov (1899–1977)