IBM THINKCENTER 8189 - Manual (Page 41)

Types 8128, 8187, 8188, 8193, 8414, and 8431
The following illustration will help you locate the various components in the
computer.
1 Optical drive 7 Memory connectors
2 USB connector 8 Microprocessor and heat sink
3 USB connector 9 AGP adapter connector
4 Optional drive bay 10 Battery
5 Hard disk drive 11 PCI adapter connectors
6 Diskette drive
Chapter 6. Replacing FRUs 35