IBM ThinkPad Mini Dock - Manual (Page 10)

(5) The Universal Serial Bus (USB) connector is for connecting a USB 1.1
device.
(6) The line-out jack, a jack 1/8 inch (3.5 mm) in diameter, is for connecting an
external stereo audio device.
(7) The line-in jack, a jack 1/8 inch (3.5 mm) in diameter, is for connecting an
external stereo audio device.
(8) The power jack is for connecting the ac adapter.
(9) The mouse connector is for connecting a mouse.
(10) The keyboard connector is for connecting an external keyboard or an
external numeric keypad.
(11) The external-diskette-drive connector is for connecting an
external-diskette-drive.
Note: If your ThinkPad computer does not support the external-diskette-drive,
you cannot use the connector.
(12) The parallel connector is for connecting a parallel device.
(13) The serial connector is for connecting a serial device.
(14) When you attach a mechanical lock to the security keyhole, the release
button is locked so that the computer cannot be removed from the ThinkPad
Port Replicator.
ThinkPad Port Replicator II
4 ThinkPad Port Replicator, ThinkPad Port Replicator II, and ThinkPad Mini Dock: User’s Guide