Function 24: Set Alternate Subroutine Call Mask and Address (35365)

The information in this article applies to:
    Microsoft Mouse driver for MS-DOS 9.0
    Microsoft Mouse driver for MS-DOS 6.x
    Microsoft Mouse driver for MS-DOS 7.x
    Microsoft Mouse driver for MS-DOS 8.x

This article was previously published under Q35365


Function 24 sets the interrupt call mask and user subroutine address for mouse hardware interrupts. Subroutine calls using Function 24 allow the called routine to be reentrant; that is, the subroutine called can itself make interrupt calls.
Input                             Output

AX = 24                           AX = error status (-1 if error
CX = user interrupt call mask
ES:DX = user subroutine address

Mask Bit                          Condition

0                                 Cursor position changes
1                                 Left button pressed
2                                 Left button released
3                                 Right button pressed
4                                 Right button released
5                                 SHIFT key pressed with button
6                                 CTRL key pressed with button
7                                 ALT key pressed with button
8-15                              Not used
Note: One of at least bits 5,6,7 must be set in order for this function to work properly.

Modification Type: Major Last Reviewed: 9/24/2003
Keywords: KB35365