Apple Power Macintosh 9600 - Manual (Page 105)

If you are installing a 12-inch card, make sure the other end of the card fits
into the proper card guide.
5 Press the card gently but firmly until the connector is fully inserted.
m Don’t rock the card side to side; instead, press the card straight into the
slot. (Rocking the card can damage the PCI slot.)
m Don’t force the card. If you meet a lot of resistance, pull the card out and
try again.
m To see if the card is properly connected, pull it gently. If it resists and stays
in place, it’s connected. (Make sure you don’t pull the card so much that
you accidentally disconnect it.)
Note: In rare cases, a 12-inch PCI card may have long ports that make it
difficult to insert into the slot. If you have tried several times to insert a card
and are still unsuccessful, skip now to “Installing an Unusually Long PCI
Card,” next.
(back of computer)
If the PCI card you are installing is full-length (12 inches), be sure that
it fits in one of the six card guides toward the front of the computer.
105 Installing PCI Expansion Cards and Additional Memory