5-16
AS1020C-3 User's Manual
ATX PS/2 Keyboard and PS/2 Mouse Ports
The ATX PS/2 keyboard and the
PS/2 mouse ports are located on the
backplane. The mouse is the green
port. See the table on the right for
pin defi nitions.
PS/2 Keyboard and
Mouse Port Pin
Defi nitions
Pin# Defi nition
1 Data
2NC
3 Ground
4 VCC
5 Clock
6NC
PS_SMBUS
The PS_SMBUS header is for I2C,
which may be used to monitor the
status of the power supply, fans and
system temperature. See the table on
the right for pin defi nitions.
I2C Header
Pin Defi nitions
(PS_SMBUS)
Pin# Defi nition
1 Clock
2 Data
3 PWR Fail
4Gnd
5 +3.3V
Overheat LED
Connect an LED to the JOH1 header
to provide warning of chassis over-
heating. See the table on the right for
pin defi nitions.
Overheat LED
Pin Defi nitions (JOH1)
Pin# Defi nition
1 3.3V
2 OH Active
Power LED/Speaker
On JD1, pins 1, 2, and 3 are for the
power LED and pins 4 through 7 are
for the speaker. See the tables on the
right for pin defi nitions.
Note: The speaker connector pins are
for use with an external speaker. If
you wish to use the onboard speaker,
you should close pins 6 and 7 with a
jumper.
Speaker Connector
Pin Defi nitions (JD1)
Pin# Defi nition
4 Red wire, +5V
5 No connection
6 Buzzer signal
7 Speaker data
PWR LED Connector
Pin Defi nitions (JD1)
Pin# Defi nition
1 +Vcc
2 Control
3 Control