BIOS / Int / Int 15 / 10/13


  INT 15 -  TopView  -  "GETBIT"  -  DEFINE  A  2ND-LEVEL INTERRUPT HANDLER

Input			Output
AX	10h	13h		AX
BX			Bit Mask	BX
CX				CX
DX				DX
ES:DI	FAR Service Routine			ES:DI

Bit Mask:       Bit mask indicating which bit was allocated
                0 if no more bits available