INT 2F U - DOS 3.3+ internal - OPEN FILE
AX = 1226h
CL = access mode
DS:DX -> ASCIZ filename
SS = DOS DS (must be using a DOS internal stack)
Return: CF set on error
AL = error code (see INT 21/AH=59h)
CF clear if successful
AX = file handle
Notes:  can only be called from within DOS
equivalent to INT 21/AH=3Dh
SeeAlso: INT 21/AH=3Dh

See also: 2F1227

2F1226 - DOS 3.3+ internal - OPEN FILE