Article: Q68110
Product(s): See article
Version(s): 1.00
Operating System(s): MS-DOS
Keyword(s): ENDUSER | | mspl13_basic
Last Modified: 10-FEB-1991
The following are the ranges in which an I/O (Input/Output) port
assignment may occur for the Microsoft Mouse. The ranges are given in
hexadecimal numbers, and the serial communications port assignments
conform to the IBM standard I/O address range assignments for PCs and
PS/2s.
SERIAL MOUSE
------------
Port Assignments Address Ranges
---------------- --------------
COM1 3F8H-3FFH
COM2 2F8H-2FFH
BUS MOUSE (BUS INTERFACE BOARD SETTINGS)
----------------------------------------
Primary Inport Range
--------------------
23CH-23FH
Secondary Inport Range
----------------------
238H-23BH
An I/O port acts as a doorway through which information travels.
Information may originate from the CPU, travel over data and address
buses, pass through the I/O port, and finally reach a peripheral
device such as the mouse. Although the CPU recognizes various ports
through 16-bit port numbers that range from 00H through FFFFH, the
port address is not actually an address found in main memory. A port
assignment is a memory location separate from a (main) memory address
that is associated with that particular I/O port.
No other peripheral device, such as a modem or printer, may share the
same I/O address with the mouse or the mouse may not function
correctly.