INT 21,5F AL=01 Set Redirection Mode (DOS 3.1+)

AH = 5F

AL = 01

BH = device redirection state

= 00 turn redirection off

= 01 turn redirection on

BL = redirection type

= 03 printer

= 04 disk drive

on return:

AX = error code if CF is set

- enables or disables disk or printer redirection

- local devices are used when redirection is off

- fails if file sharing is not loaded