The 26 pin connector is for an Apple AV monitor. Kind of like the Commodore 1084S, only with Apples usual proprietory greed it has a different connector. Cant remember the name but it is possibly HDI-26 or maybe HDI-45. Most of the AV Power Macs also had another card which would take the Apple 15 pin monitor as well as having 4 S-Video ports. With the AudioVision monitor this would allow you to use 2 monitors at the same time, as well as sound systems perhaps. No I've never tried it.