Int 21/AX=2507h

AX = 2507h
CL = interrupt number
DS:EDX = CS:EIP of protected-mode interrupt handler
EBX = CS:IP of real-mode interrupt handler

Return:
CF clear

Notes: Interrupts are disabled until both vectors have been modified. This function is also supported by FlashTek X-32VM

See Also: AX=2504h - AX=2505h