This function retrieves the current status of a LDAn device:

 	Function:	IO$_LD_CONTROL

 	Method 1 (old):

 	P1 = address of buffer which receives the device- or filename
 	     currently connected
 	P2 = size of buffer which receives the device- or filename
 	P3 = address of 3 word buffer which receives the file-id of the
 	     connected file
 	P4 = Address of buffer to receive start lbn (for lbn mapping)
 	P5 = Address of buffer to receive end lbn (for lbn mapping)
 	P6 = Subfunction: LDIO$K_GET_CONNECTION

 	Method 2 (new, preferred):

 	P1 = address of itemlist describing the connection
 	P6 = Subfunction: LDIO$K_GET_CONNECTION |LDIO$M_ITEMLIST

 	The itemlist consist of entries like this:

         BUFLEN  (word)     - Length of buffer
         ITEM    (word)     - Item description:
 			     LDITM$K_EXTENDSIZE
 			     LDITM$K_EXTENDLIMIT
 			     LDITM$K_DEVICENAME
 			     LDITM$K_FILEID
 			     LDITM$K_STARTLBN
 			     LDITM$K_ENDLBN
 			     LDITM$K_FLAGS
         ADDR (longword)    - Pointer to buffer
         RLENGTH (longword) - Returned data length

 	IOSB word 0 = status
 	     word 1 = number of characters transferred
 	     longword 1 = status flag bit 0 : 0 = disconnected
 	                                      1 = connected
 	                              bit 1 : 0 = normal connection
 	                                      1 = replaced drive
 	                              bit 2 : 0 = normal connection
 	                                      1 = replaced to DECRAM disk
 	                              bit 3 : 0 = normal access
 	                                      1 = write protected
 	                              bit 4 : 0 = local access
 	                                      1 = shared access
 	                              bit 8 : 0 = normal timing
 	                                      1 = accurate timing
 	                              bit 9 : 0 = normal trace
 	                                      1 = FDT trace active
 	                              bit 10: 0 = normal connection
 	                                      1 = LBN mapping used

 	The buffer specified in the P1 parameter is only valid when
 	the unit is connected (IOSB longword 1 bit 0 set).
 	If a buffersize of 0 is specified only the status is returned.
 	The itemlist consist of entries like this:

 	Errors returned:

 	SS$_ACCVIO	Buffer can not be written
 	SS$_DEVINACT	Device not connected
 	SS$_NORMAL	Successful completion