PS/2 Port

The PS/2 port is a 6-pin Female Mini-DIN connector, named after the IBM PS/2 (Personal System/2) computers that first featured it.

There are 3 different versions of the port found on ThinkPads and the Docks and Port Replicators:

• PS/2 Mouse
• PS/2 Keyboard
• PS/2 Mouse with PS/2 Keyboard (requires a PS/2 splitter cable for the keyboard)

PS/2 splitter connects mouse port pins straight-through to host combo port, splits power to both downstream ports, and routes keyboard port pins to remaining two pins in host combo port (these pins are not connected in standard applications). Compaq and Toshiba laptops follow this same plan. Dell does the opposite: mouse is routed to extra two pins, keyboard is straight-through; Dell splitters can be used with ThinkPads, when peripherals are connected to opposite labelled port.

Older ThinkPads typically feature the combined PS/2 port, meaning you need the special PS/2 splitter cable to directly attach a PS/2 Keyboard.
On Docks and Port replicators you can either find the combined port, or two individual ports for Keyboard and Mouse.
Later ThinkPads do not have a physical PS/2 port, but still have the logic integrated, all that is required is to attach the ThinkPad to a supported Dock or Port Replicator with a PS/2 port.

Current ThinkPads no longer expose PS/2 bus, not even through dock options.

• Wikipedia article on PS/2 Port

Models featuring this Technology

• ThinkPad 220, 560, 600
• ThinkPad A20m, A20p, A21e, A21m, A21p, A22e, A22m, A22p
• ThinkPad T20, T21, T22, T23

Docks and Port Replicators featuring this Technology

NOTE!

These devices only feature pass-through functionality, the actual PS/2 port logic needs to reside in the ThinkPad for the port to work

• ThinkPad Port Replicator
• ThinkPad Port Replicator II
• ThinkPad Essential Port Replicator
• ThinkPad Dock (two port)
• ThinkPad Dock II (two port)
• ThinkPad Advanced Dock
• ThinkPad Advanced Mini Dock
• ThinkPad Mini-Dock
• ThinkPad X4 Dock
• UltraBase X2 (combo port)
• UltraBase X3 (combo port)
• UltraBase X4
• ThinkPad 365 Port Replicator
• ThinkPad 365X Port Replicator
• ThinkPad 380/385 Port Replicator
• ThinkPad 560 Port Replicator
• ThinkPad Enhanced Port Replicator
• ThinkPad Port Replicator with Advanced EtherJet
• SelectaBase Model I
• SelectaBase 600
• SelectaBase 770
• ThinkPad MultiPort
• ThinkPad MultiPort II
• ThinkPad Dock I (3545)
• ThinkPad Dock II (3546)
• ThinkPad Port Replicator Model 1
• ThinkPad Port Replicator Model 2