INT 21 - DOS 3.1+ network - GET REDIRECTION MODE
AX = 5F00h
BL = redirection type
03h printer
04h disk drive
Return: CF set on error
AX = error code (see AH=59h)
CF clear if successful
BH = redirection state
00h off
01h on
Note:   calls INT 2F/AX=111Eh with AX on top of the stack
SeeAlso: INT 2F/AX=111Eh

See also: 215F01

215F00 - DOS 3.1+ network - GET REDIRECTION MODE