INT 21 - Phar Lap 386/DOS-Extender - GET PROTECTED-MODE INTERRUPT VECTOR
AX = 2502h
CL = interrupt number
Return: CF clear
ES:EBX = CS:EIP of protected-mode interrupt handler
Note:   this function is also supported by FlashTek X-32VM
SeeAlso: AX=2504h,INT 31/AX=0204h

See also: 212503

212502 - Phar Lap 386/DOS-Extender - GET PROTECTED-MODE INTERRUPT VECTOR