INT 2F U - PCIBM PC LAN PROGRAM REDIR/REDIRIFS internal - ???
	AX = 0203h
Return: nothing???
Notes:	this function is called by the DOS 3.3+ PRINT.COM
	AX=0204h appears to be the opposite function
	these functions are supposedly used to signal opening and closing of
	  printers
SeeAlso: AX=0200h,AX=0204h