Apple Power Macintosh 4400 - Manual (Page 147)

Cache configurations
A High Performance Module (256K level 2 cache) provides an overall
increase in your computer’s performance. If your computer doesn’t already
include a level 2 cache, you can add one by having an Apple-authorized
dealer or service provider install a cache DIMM in the cache slot on the main
logic board of your computer.
Opening the computer
IMPORTANT To avoid generating static electricity that may damage
components, do not walk around the room until you have finished installing
the expansion card or memory and closed the computer.
1 Shut down your computer by choosing Shut Down from the Special menu.
You can also press the Power key on the keyboard.
2 Unplug all the cables except the power cord from the computer—you’ll unplug the
power cord later on. (Don’t forget to unplug the cable that connects your keyboard to
the computer.)
Leaving the power cord plugged in helps protect the computer from damage
caused by electrostatic discharge.
3 Unscrew and remove the three screws on the back of the computer.
Remove these three screws.
147 Installing Expansion Cards and Additional Memory