Q44126: Finding the COM1: Serial Port on a PC/XT/AT Machine

Article: Q44126
Product(s): See article
Version(s): 1.00   | 1.00
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | | mspl13_basic
Last Modified: 31-AUG-1989

When connecting the Microsoft Mouse serial interface cable to your
computer, you must first determine the location of the serial port.

On a PC- or XT-class computer, the serial port is normally the male,
25-pin, D-shaped connection in the back of the machine.

On an AT-class computer, the serial connection is normally the male,
9-pin, D-shaped connection on the back of the computer.

There are exceptions, but these descriptions are a good rule of thumb.

Note: If the machine has only one serial port, it should be set up as
COM1: using IRQ4. If the serial port is set up as COM2: and it is the
only serial port in the machine, the Microsoft Mouse driver might
install, but the mouse might not function properly.

COM3: and COM4: is not supported by the mouse driver.