Intel MB899 - Manual (Page 21)

INSTALLATIONS
MB899 User’s Manual 17
J3: System Function Connector
J3 provides connectors for system indicators that provide light indication
of the computer activities and switches to change the computer status. J3
is a 20-pin header that provides interfaces for the following functions.
Hard Disk Drive LED
Reset Switch
Not Defined
ATX Power On Switch
Not Defined
Power LED
Speaker
Speaker: Pins 1 - 4
This connector provides an interface to a speaker for audio
tone generation. An 8-ohm speaker is recommended.
Pin # Signal Name
1 Speaker out
2 No connect
3 Ground
4 +5V
Power LED: Pins 11 - 15
Pin # Signal Name
11 Power LED
12 No connect
13 Ground
14 No connect
15 Ground
ATX Power ON Switch: Pins 7 and 17
This 2-pin connector is an “ATX Power Supply On/Off
Switch” on the system that connects to the power switch on
the case. When pressed, the power switch will force the
system to power on. When pressed again, it will force the
system to power off.