Appendix C Keyboard
Compaq Personal Computers
Changed - July 2000
C-16
 
 
C.3 CONNECTORS
 
Two types of keyboard interfaces are used in Compaq systems: PS/2-type and USB-type. System
units that provide a PS/2 connector will ship with a PS/2-type keyboard but may also support
simultaneous connection of a USB keyboard. Systems that do not provide a PS/2 interface will
ship with a USB keyboard. For a detailed description of the PS/2 and USB interfaces refer to
chapter 5 “Input/Output” of this guide. The keyboard cable connectors and their pinouts are
described in the following figures:
Pin Function 
1 Data 
2 Not connected 
3 Ground 
4 +5 VDC 
5 Clock 
6 Not connected 
Figure C–9. PS/2 Keyboard Cable Connector (Male)
Pin Function 
1 +5 VDC 
2 Data (+) 
3 Data (-) 
4 Ground 
Figure C–10. USB Keyboard Cable Connector (Male)
 
 
 
 
65
4 3 
21 
12 3 4