Apple Performa 6400/180 - Manual (Page 185)

Upgrades DRAM DIMM Upgrade - 14
Resistor Present at U34
1 Turn the logic board
over so that you are
looking at the soldered-
side of the board.
2 Locate chip U34 as
pictured in the graphic.
If a resistor package
(SIP network) is on top
of the U34 chip, as seen
in this picture, the logic
board supports EDO
memory.
Bottom of Logic
Board
U34 Resistor