Instruction manual

10 PCM-7890 User Manual
Jumpers and connectors
Connectors on the board link it to external devices such as hard
disk drives, a keyboard, or floppy drives. In addition, the board
has a number of jumpers that allow you to configure your system
to suit your application.
The following tables list the function of each of the board's
jumpers and connectors.
Jumpers
Label Function
J1 System temperature thermal sensor
J2 Reserve for future use (default : 1-2 close)
J3 CPU frequency ratio
J4 Clear CMOS
J5 COM3 RI pin voltage select
J6 COM4 RI pin voltage select
J7 DOC address select
J8 ATX soft-power switch connector
J9 Reserve for future use
J10 COM2 RS-232/422/485 select
J11 LCD driving voltage select
J12 LCD clock select
J13 Reserve for future use (default : 1-2 close)
J14 COM2 RS-232/422/485 select
J15 Audio output select