Differences Among Mouse Functions 12, 20, and 24

• Microsoft Mouse Driver for MS-DOS, versions 6.x, 7.x, 8.x, and 9.0

SUMMARY

Mouse Function 12 is used to replace an existing interrupt subroutine address and call mask with the address and call mask of a new user-defined subroutine.

Mouse Function 20 is similar to Function 12, and is used to replace an existing interrupt subroutine address and call mask with the address and call mask of a new user-defined interrupt subroutine. Unlike Function 12, Function 20 returns the subroutine address and call mask to the calling program so that they may be restored. Microsoft recommends that you use Function 20 or Function 24 instead of Function 12.

With Mouse Function 24 you can define up to three individual interrupt subroutine addresses and call masks. Subroutines defined by Function 24 can be activated only by a combination of a mouse action (button press, mouse motion) and a SHIFT, CTRL, or ALT key press.