I contacted Creative Tech support with the exact same question. The following is their answer:
"James,
Below is the pin layout information for the internal SB1394 connector (JP6) on the Sound Blaster Audigy family of cards.
Pin Assignment
1TPA+
2TPA-
3PHY_GND
4PHY_GND
5TPB+
6TPB-
7NC
8NC
9PHY_GND
10KEY (Not Used)
The internal SB1394 interface is normally reserved for connecting to the internal AudigyDrive shipped with the Sound Blaster Audigy Platinum or the breakout back plate shipped with the Sound Blaster Audigy Platinum eX.
Creative Labs does not support connecting 3rd party devices directly to the onboard SB1394 connector. The pin layout information is provided for your convenience only. The labeling of IEEE1394 connectors or wires on 3rd party devices may be different from labeling provided above. When connecting 3rd party devices to the SB1394 interface, always verify the labels on the cables or connectors first before connecting them together. Please, note that you connect any 3rd party device at your own risk and any damage that results to your Audigy card voids your warranty. Please, let us know if you have anymore questions."
Not very helpful, I'm afraid, since the labeling on the front port wires doesn't match the labeling on the pinout.