Graphics Card:

The Powermac G3 Came Standard With A 16MB ATI 3D Rage PCI Mac Edition Card, there are only a few available upgrade cards.

Start By Removing this Screw.

Once that's done, pull the card out.

Sorry Guys, Regular PCI Cards Won't work here, only Mac Edition PCI-Compatible Cards, and this card won't work in a PC, Also, graphics cards only work in the first slot, the other 4 PCI Slots won't support graphics cards.