Serial Port A
Part number 4000832,4000859,A99386-109

Serial A is an optional port, accessed through a 9-pin internal header (J9A2). A standard DH-10 to DB9 cable can be used to direct Serial A out the back of a given chassis. The Serial A interface follows the standard RS232 pin-out. The motherboard has a Serial Port A silkscreen label next to the connector as well as a location designator of J9A2. The Serial A connector is located next to the P64-C low-profile PCI card slot.

Serial A Header Pinout

Serial Port Multiplexer Logic

The motherboard has a multiplexer to connect the rear RJ45 connector to either Serial Port A or Serial Port B in both the 955 and 975 chassis. This facilitates the routing of Serial Port A to the rear RJ45 connector if Serial Port B is used for Serial Over LAN (SOL) in both servers. This serial port selection can be done through the BIOS Setup option.