Motherboard Description
23
PCI Connectors - J2C1, J2D1, J2E1, J2E2 (continued)
Pin Signal Name Pin Signal Name Pin Signal Name Pin Signal Name
A18 GND B18 REQA- A49 AD9 B49 GND
A19 Reserved B19 Vcc A50 KEY B50 KEY
A20 AD30 B20 AD31 A51 KEY B51 KEY
A21 3.3 V B21 AD29 A52 CBEO- B52 AD8
A22 AD28 B22 GND A53 3.3 V B53 AD7
A23 AD26 B23 AD27 A54 AD6 B54 3.3 V
A24 GND B24 AD25 A55 AD4 B55 AD5
A25 AD24 B25 3.3 V A56 GND B56 AD3
A26 IDSEL B26 CBE3- A57 AD2 B57 GND
A27 3.3 V B27 AD23 A58 AD0 B58 AD1
A28 AD22 B28 GND A59 Vcc B59 Vcc
A29 AD20 B29 AD21 A60 SREQ64- B60 SACK64-
A30 GND B30 AD19 A61 Vcc B61 Vcc
A31 AD18 B31 3.3 V A62 Vcc B62 Vcc
1.10.10 Power Supply Connectors
When used with a power supply that supports remote power on/off, the motherboard can turn off
the system power via software control (“soft-off” is a manufacturing option). The Powerman
utility supplied for Windows 3.1x allows for soft-off as does the shutdown icon in Windows 95
Start menu. The system BIOS will turn the system power off when it receives the proper APM
command from the OS. For example, Windows 95 will issue this APM command when the user
selects “Shutdown the computer” option. APM must be enabled in the system BIOS and OS in
order for the soft-off feature to work correctly. In order for the system to recognize the presence of
a “soft-off” power supply, the supply must tie pin 14 of the PWS Control connector (J7M2) to
ground. If power to the system is interrupted due to a power outage or the power cord being
unplugged, when power is reapplied, the system will return to the state it was in when the power
was disconnected. If the system was turned on when power was disconnected, the system will turn
back on when power is reapplied.
CAUTION
If the coin-cell battery is removed from the motherboard and AC power is disconnected, the next
time the system is plugged in, power will automatically be turned on without pushing the “on”
button. BIOS can detect this condition, and will attempt to turn off the power supply when this
occurs. This is due to functionality of the SMC I/O controller.