Logitech Pointing Device Hardware Information
Product Support Document # 1410

The following are the pin-outs for  Logitech mice as documented in the 
Logitech Mouse Technical Reference and Programming Guide.  Note that the 
wire colors are provided only for the bus mouse.  Wire colors are not 
available for serial or pix-port mice.

PS/2 (PIX) Mouse

The mouse cable assembly has a six pin miniature circular (mini-DIN) plug 
for attaching to the host.

Pin	Wire Name
1	DATA
2	Reserved
3	Ground
4	+5V Supply
5	CLK
6	Reserved
Shield	Chassis

Bi-directional transmission is controlled by the CLK and DATA lines.  Both 
are fed by an open collector device which lets either host or mouse force 
the line to "0".  During non-transmission, CLK is at "1" and  DATA can be 
at "0" or "1".

The host can inhibit mouse transmission by forcing CLK to "0".  If the 
host inhibits the mouse while it is transmitting, the byte must be 
retransmitted (if the inhibit state arrived before the 11th clock).