Int 33 Fn 000C  - Ms Mouse V1.0+ - Define Interrupt Subroutine Parameters  [M]

   AX = 000Ch
   CX = call mask (see #2842)
   ES:DX -> FAR routine (see #2843)

See Also: AX=0018h

Bitfields for mouse call mask:
Bit(s) Description (Table 2842)
 0 call if mouse moves
 1 call if left button pressed
 2 call if left button released
 3 call if right button pressed
 4 call if right button released
 5 call if middle button pressed (Mouse Systems/Logitech/Genius mouse)
 6 call if middle button released (Mouse Systems/Logitech/Genius mouse)
 7-15  unused

Note:  some versions of the Microsoft documentation incorrectly state that CX
     bit 0 means call if mouse cursor moves

(Table 2843)
Values interrupt routine is called with:
   AX = condition mask (same bit assignments as call mask)
   BX = button state
   CX = cursor column
   DX = cursor row
   SI = horizontal mickey count
   DI = vertical mickey count

Notes: some versions of the Microsoft documentation erroneously swap the
     meanings of SI and DI
   in text modes, the row and column will be reported as a multiple of
     the character cell size, typically 8x8 pixels