Sony PCV-R528DS - Manual (Page 66)

VAIO Digital Studio Reference Manual 58
Memory Module (DIMM) Connectors
Both sides of each Dual Inline Memory Module (DIMM) look very
similar. The side with pin 1 has a small "1" to the left of pin 1. Be sure to
orient a DIMM correctly in the DIMM connector (a small triangle on the
connector indicates pin 1).
1234
5
OM04710A.VSD
DIMM2 DIMM1
1 11 1
Indicates pin 1
Memory module (DIMM)
OM04908B.VSD