C 	PROGRAM:  FILESPEC.SUB   FILE SPECIFICATIONS
C
	SUBROUTINE  FILESPEC(CMDLINE,CMDPTR,CMDLEN,PARAM,FSLEN,
     *                       FNAME,IO,ERRCODE)
C
	BYTE
     *		CMDLINE(80),		!COMMAND LINE
     *		FNAME(24),		!FILE NAME
     *		SWITCHES(40),	        !SWITCHES
     *		DEVICES(20),		!DEVICE CODES
     *		ERROR			!
C
	INTEGER
     *		ERRCODE,		!FTP ERROR CODE
     *		CMDPTR,		        !POINTER TO COMMAND LINE
     *		CMDLEN,		        !LENGTH OF COMMAND LINE
     *		FSLEN,		        !
     *		IO,			! 1 => OUTPUT SIDE,  2 => INPUT SIDE
     *		SCAN,		        !OPTION LENGTH SCAN ROUTINE
     *		DEVCODES(10),		!
     *		DC,			!
     *		PARAM(2,20)		!SWITCH VALVES
C
C
	COMMON  /CODES/SWITCHES,DEVICES
	DATA  DEVCODES/0,-1,-1,-2,-2,-2,4*0/,DC/10/
C
C THE PURPOSE OF THIS ROUTINE IS TO OBTAIN THE FILE NAME, AND 
C CHECK FOR DEVICE BY LOOKING AT THE CHARACTER THAT STOPPED THE
C FSLEN SCAN.  IF IT IS A ":" THEN GET DEVICE CODE.
C
	ERRCODE=0
	KPTR=1
C
C SEE IF A DEVICE SPECIFICATION IS PRESENT
C
	J=INDEX(CMDLINE(CMDPTR),':',1,1)
	IF(J .GT. 0 .AND. J .LE. FSLEN)GOTO 110	!DEVICE SPEC PRESENT
C
C NO DEVICE SPEC.   ASSUME SY:
C
	CALL SCOPY(FNAME,'SY:',ERROR)
	KPTR=4
110	CONTINUE
C
C TRANSFER FILE SPEC AND NAME
C
	CALL SUBSTR(FNAME(KPTR),CMDLINE,CMDPTR,FSLEN,ERROR)
C
C DETERMINE DEVICE TYPE
C
	IDEV=INDEX(DEVICES,FNAME,2,2)
	IF(IDEV .NE. 0) GO TO 210
	ERRCODE=5			! UNKNOWN DEVICE TYPE
	RETURN
C
210	IDEV=(IDEV+1)/2
	PARAM(IO,DC)=DEVCODES(IDEV)
	IF(DEVCODES(IDEV) .LT. 0) GO TO 300
C
C ELSE, GET TAPE UNIT #
C
	PARAM(IO,DC)= FNAME(3)-'0'+1
	J = PARAM(IO,DC)
	IF(J .GE. 0 .AND. J .LE. 3)GOTO 300
	ERRCODE = 16
	CMDPTR = CMDPTR + 2
	RETURN

 300	CONTINUE
	CMDPTR = CMDPTR + FSLEN
	RETURN
	END