On Sat, 21 Feb 2009 02:02:45 -0800 (PST), HDI
wrote:

Hi,

I want to experiment with an old computer but the manual of the
motherboard isn't so good.

It's an EXP8661 motherbord, you can see the layout at:
http://stason.org/TULARC/pc/motherbo...m-EXP8661.html.

So the MS1 is the ps/2 mouse connector were I have the put in my
counter. The connector on the motherboard has 4 pins and the counter
has 5 holes and one of them hasn't got a wire. So it's like no wire,
yellow one, blue one, red one, green one.

Can anyone help me connecting it?
BTW: can I do something wrong by connecting it wrong?

I don't recall, if I ever knew, what the typical color
coding for a PS2 port dongle was. You have vcc (power),
ground, data, and clock lines.

With a multimeter you can determine which pin is power by 5V
when the system is on (meter ground being system ground
anywhere). With the meter the ground pin will have
practically zero resistance to case ground. With data and
clock, if you get them reversed it won't work, just switch
the two around and try again.

Similar for the dongle itself, by looking at a pinout for a
PS2 port, you can use the meter to check continuity to
confirm which pins in the socket each connector pin
corresponds to.