Toshiba Satellite M50 (PSM53) - Manual (Page 48)

TOSHIBA M50 2-7
The Grand Tour
Battery Pack The battery pack powers the computer when the
AC adapter is not connected. For detailed
information on the battery pack, refer to
Chapter 6,
Power and Power-Up Modes .
Docking Port Use this port to connect an optional Advanced
Port Replicator III.
(The availability of this function depends on the
model you purchased.)
Keep foreign objects out of the docking port. A pin or similar object can
damage the computer's circuifry.