Sony PCV-RS100 - Manual (Page 52)

VAIO Computer System Reference Manual 36
7 Align the module over the appropriate slot, noting the location of pin
1 on the module and pin 1 on the slot.
8
Carefully but firmly insert the edge of the module into the slot.
Press down
here
Handles
Pin 1 side
DDR-DIMM 2
Memory module (DDR-DIMM)
Indicates pin 1
1 1 1 1
DDR-DIMM 1