http://support.apple.com/kb/TA29779?viewlocale=en_US
It wasn't possible to do much high-end stuff on the 840av and 660av without a nubus card that could feed signals in compressed form to the co-processor, in particular where video was concerned. In effect, the DAV slot was to the AV Macs' co-processor what the PDS slot on other Quadras was to the 68040.
Needless to say, there were not many of these Nubus cards produced. One in my possession is the SpigotPower AV.
It wasn't possible to do much high-end stuff on the 840av and 660av without a nubus card that could feed signals in compressed form to the co-processor, in particular where video was concerned. In effect, the DAV slot was to the AV Macs' co-processor what the PDS slot on other Quadras was to the 68040.
Needless to say, there were not many of these Nubus cards produced. One in my possession is the SpigotPower AV.