Connecting externel laptop keyboard

Do you have a question? Post it now! No Registration Necessary.  Now with pictures!

Threaded View
i have an IBM thinkpad 600e and the integral keyboard sometimes doesn't
work.  i'm not too fussed about this because it its only intermittent
and with certain keys, but i'd like to be able to hook up an externel
keyboard when at my desk.  But if I plug in a keyboard to the ps/2 port
i don't get anything - not even the caps lock light works.  How can I
get my keyboard working.?

Re: Connecting externel laptop keyboard

Quoted text here. Click to load it

It's always been a mystery why, when they were defining the PS/2
keyboard and mouse standards, IBM chose to do it exactly the way
they did.  The two connectors could easily have been made to be
interchangable - there are even spare pins on the connector that
could have been used, but for some reason they went for two physically
interchangable but incompatible ports.

The PS/2 port on most notebooks, including the TP600 series, is
wired as a mouse port.  The rationale for this is most people can
tolerate laptop keyboards better than they can laptop mouse
substitutes.  The keyboard signals are present, but on non-standard
pins so to get at them you need an adapter whoch usually takes the
form of a Y/splitter cable that provides both keyboard and mouse
sockets.  These adapters are readily available on the Internet but
in my experience slightly too obscure for local computer stores to
stock.  If you're in a hurry and fancy making your own the wiring
is as follows:

    Computer    Mouse     Keyboard
     (plug)    (socket)   (socket)

    Pin 1      NC         Pin 2
    Pin 2      Pin 2      NC
    Pin 3      Pin 3      Pin 3
    Pin 4      Pin 4      Pin 4
    Pin 5      Pin 5      NC
    Pin 6      NC         Pin 5

Andrew Smallshaw

Re: Connecting externel laptop keyboard

Quoted text here. Click to load it

Just plug in a USB keyboard and don't worry about the ps/2 port!

Posted via a free Usenet account from

Site Timeline