INT 60 - RIFS - CLIENT - UNMAP DRIVE                                            
	AX = 0003h
	BL = drive to unmap
Return: CF clear if successful
	CF set on error
SeeAlso: AX=0000h,AX=0002h,AX=0004h,INT 21/AX=5F04h,INT 21/AX=5F06h"STARLITE"