I/O Addresses for the Microsoft Mouse

ID: Q68110

The information in this article applies to:

Microsoft Mouse Driver for MS-DOS, versions 6.x, 7.x, and 8.x
Microsoft Mouse version 1.0

SUMMARY

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. This information applies to the Microsoft Mouse for MS-DOS systems.

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

MORE INFORMATION

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.

Additional query words:

Keywords :
Version : 6.x 7.x 8.x
Platform : MS-DOS
Issue type :