Dell OptiPlex GX1 Reference And Installation Manual page 97

This chapter describes how to install the following options:
Industry-Standard Architecture (ISA) and Peripheral Component Interconnect
(PCI) expansion cards
System memory
Video memory (OptiPlex GX1 only)
Microprocessor
This chapter also includes instructions for replacing the system battery, if necessary.
Use Figure 6-1 to locate the system board features.
Installing System Board Options 6-1