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:

    “The smallest fact about the connection between character and hormonal balance offers more insight into the soul than a five-story idealistic system [of philosophy] does.”
    —Robert Musil (1880–1942)

    “We will have to give up the hope that, if we try hard, we somehow will always do right by our children. The connection is imperfect. We will sometimes do wrong.”
    —Judith Viorst (20th century)

    “... instinct is the direct connection with truth.”
    —Laurette Taylor (1887–1946)