Int 7F/AX=564Dh/BH=C1h

AX = 564Dh ('VM')
BH = C1h
BL = function (00h-1Bh)
00h ???
Return:
CF clear
AX = 0000h.
???

Return:
AX = FFFFh if invalid function
???

See Also: AX=4331h - AX=5658h