Int 15H [PS/2] Function C2H (194) Subfunction 07H Set pointing device handler address

Notifies the ROM BIOS pointing device driver of the address for a routine to be called each time pointing device data is available.

Call with:

AH = C2H

AL = 07H

ES:BX = segment:offset of user routine

Returns:

If function successful

Carry flag = clear

If function unsuccessful

Carry flag = set

AH = status (see Int 15H Function C2H Subfunction 00H)

Notes:

The user's handler for pointing device data is entered via a far call with four parameters on the stack:

SS:SP+0AH status SS:SP+08H x coordinate SS:SP+06H y coordinate SS:SP+04H z coordinate (always 0)

The handler must exit via a far return without removing the parameters from the stack.

The status parameter passed to the user's handler is interpreted as follows:

Bit(s) Significance (if set) 0 left button pressed 1 right button pressed 2—3 reserved 4 sign of x data is negative 5 sign of y data is negative 6 x data has overflowed 7 y data has overflowed 8—15 reserved