Taken from interrup.n

INT AH AL			Description
 33 00 00 MS MOUSE - RESET DRIVER AND READ STATUS
 33 00 01 MS MOUSE v1.0+ - SHOW MOUSE CURSOR
 33 00 02 MS MOUSE v1.0+ - HIDE MOUSE CURSOR
 33 00 03 MS MOUSE v1.0+ - RETURN POSITION AND BUTTON STATUS
 33 00 04 MS MOUSE v1.0+ - POSITION MOUSE CURSOR
 33 00 05 MS MOUSE v1.0+ - RETURN BUTTON PRESS DATA
 33 00 06 MS MOUSE v1.0+ - RETURN BUTTON RELEASE DATA
 33 00 07 MS MOUSE v1.0+ - DEFINE HORIZONTAL CURSOR RANGE
 33 00 08 MS MOUSE v1.0+ - DEFINE VERTICAL CURSOR RANGE
 33 00 09 MS MOUSE v3.0+ - DEFINE GRAPHICS CURSOR
 33 00 0A MS MOUSE v3.0+ - DEFINE TEXT CURSOR
 33 00 0B MS MOUSE v1.0+ - READ MOTION COUNTERS
 33 00 0C MS MOUSE v1.0+ - DEFINE INTERRUPT SUBROUTINE PARAMETERS
 33 00 0D MS MOUSE v1.0+ - LIGHT PEN EMULATION ON
 33 00 0E MS MOUSE v1.0+ - LIGHT PEN EMULATION OFF
 33 00 0F MS MOUSE v1.0+ - DEFINE MICKEY/PIXEL RATIO
 33 00 10 MS MOUSE v1.0+ - DEFINE SCREEN REGION FOR UPDATING
 33 00 10 Genius MOUSE - DEFINE SCREEN REGION FOR UPDATING

 33 00 11 Genius Mouse 9.06 - GET NUMBER OF BUTTONS
 ' Returns: OutregsX.AX = &H574D if Mouse Wheel present.

 ' function call is 0-based. mouse pixel is 8x8.
 Call Mouse.Function2(7,0,0,632) ' 80 columns
 Call Mouse.Function2(8,0,0,192) ' 25 rows
 Call Mouse.Function2(8,0,0,336) ' 43 rows
 Call Mouse.Function2(8,0,0,392) ' 50 rows
