NEC EXPRESS 320Lb-R - Manual (Page 46)

2-12 General Description
CPU Module
Group 1 and group 2 have the same configuration.
1 Module handle
2 Cooling fan
3 CPU module board
4 CPU socket #2 (additional)
5 AC inlet (in the back)
6 Backpanel connector (in the back)
7 CPU socket #1 (standard)
8 DIMM
9 Power unit
10 Power backboard