When the 400 PPI PS/2 serial mouse is installed on the 9-pin serial
port as a serial mouse, it uses pins 2, 3, 4, 5, and 7 to communicate
with the serial port.
The other pins in the 9-pin connector are used when the PS/2 adapter
is connected to the mouse. Pin 8 of the built-in serial port, when set
to a logic zero, is 1 to 2 volts higher than the voltage that would be
present on an IBM-compatible serial port. When a logic 1 is present on
pin 8 and the mouse is connected to a 9-pin serial port, the mouse
cannot reset. This prevents the mouse from installing.
To work around this problem, do the following:
Use a 9- to 25-pin serial adapter to eliminate the signal
from pin 8. To do this, you need to purchase the adapter
from a local electronics store. This adapter has a 9-pin
female connector on one end and a 25-pin male connector
on the other end.
Once you have the adapter, perform the following steps:
• Attach the adapter you purchased to the built-in serial port of
• Attach the mouse to the 25- to 9-pin serial adapter that was
supplied with your mouse.
• Attach this adapter to the 9- to 25-pin adapter that you have
already attached to your computer.
The Maxir product included here is manufactured by a vendor independent
of Microsoft; we make no warranty, implied or otherwise, regarding this
product's performance or reliability.