The audio/video port differs from the C64's in that is has TWO audio outputs, instead of one audio OUT and one audio IN. However, it's NOT stereo, just different voltage levels :-)
_______ / \ / 8 7 \ | 3 6 1 | | 5 4 | \ 2 / \_______/ Pin| Signal ---+----------------------- 1 | LUMINANCE & SYNC 2 | GND 3 | AUDIO OUT (1Vpp) 4 | VIDEO OUT (composite) 5 | AUDIO OUT (0.5Vpp) [1] 6 | CHROMINANCE 7 | NC 8 | NC* I'm not sure if these are the original pin numbers, but it is very likely.
Note: All pictures show the jack side.