INT 21,5F AL=00 Get Redirection Mode (DOS 3.1+)

AH = 5F

AL = 00

BL = redirection type

= 03 printer

= 04 disk drive

on return:

AX = error code if CF is set

BH = device redirection state

= 00 redirection off

= 01 redirection on

- determines if disk or printer redirection is enabled

- fails if file sharing is not loaded