INT 21 - DR Multiuser DOS 5.0 - API

	AX = 4459h
	CL = function (see #04019 at INT E0"CP/M-86")
	DS,DX = parameters
Notes:	DR DOS 5.0 and Novell DOS 7 return CF set and AX=0001h
	this API is also available on INT E0
SeeAlso: AX=4452h,INT E0"CP/M-86"