Apple PowerBook 165 - Manual (Page 147)

Upgrades PSRAM Expansion Card - 9
Note:
To verify that the
upgrade is successful, check
the Total Memory message
(for systems with virtual
memory switched off) or the
Built-in Memory message
(for systems with virtual
memory switched on). The
memory size should be 4 MB
of soldered RAM plus the
RAM on the expansion card.
If the memory size is
incorrect, replace the
expansion card. If the
memory size is still
incorrect, send the
computer to Apple.