Install Pairs Of Memory Modules; Memory Slots Inside The System Unit - DEC DECstation 5000 Model 100 Series Hardware Operator's Manual

Install pairs of memory modules

Look at the numbers printed beside the memory slots
1.
inside the system unit. Find the empty slot with the lowest
number.
Notice that each memory slot has two connectors. You must
install memory modules in pairs, one in each connector of a
slot.
Figure 5-5. Memory slots inside the system unit
5–8 Internal Hardware Options
Four memory modules
already installed
Memory
slot numbers
WS33O033