Apple Power Macintosh 7100/80AV - Manual (Page 8)

Basics Power Macintosh System Overview - 6
5 The Power Macintosh AV systems use the same logic
board as the non-AV versions. The only difference is that
the AV versions have the Power Macintosh AV Card
installed in the PDS slot.
The Power Macintosh 7100/66 and 7100/80 systems
must
have a video card installed in the PDS slot. These
systems use the Power Macintosh 2 MB Video Card. A
missing card can result in a system that won't boot or a
system that crashes.