SUBROUTINE DIGIT
       COMMON /DATA/ DATA(2,600), NDATA, IFLAG, NDIMAX
       BYTE BUF(38), FILNAM(32)
       DATA FILNAM/32*0/
C
C......SUBROUTINE TO DIGITIZE DATA INPUT FROM HP7220 PLOTTER
C......CALLABLE FROM 'GRAF'
C
       DO 10 I=1, 600
       DATA (1,I)=0.0
       DATA (2,I)=0.0
   10  CONTINUE
C
C
       TYPE*,'WELCOME TO DIGIT.  TO DIGITIZE POINTS ON THE'
       TYPE*,'HP7220 PLOTTER MOVE PEN OR DIGITIZING SIGHT TO'
       TYPE*,'DESIRED POSITION AND PRESS RETURN.  TO EXIT'
       TYPE*,'INPUT LOOP PUSH "PEN UP" BUTTON ON PLOTTER'
       TYPE*,'AND PRESS RETURN.  YOU MAY BEGIN.'
       READ (5,110)          !WAIT FOR USER RESPONSE (CR)
       CALL XMT('PD;*')
       CALL REC ('OA;*',BUF,L)
       DECODE (L,20,BUF) IX,IY,IPSTAT
   20  FORMAT (2I9,I1)
       DATA(1,1)=IX
       DATA(2,1)=IY
       NDATA=1
C
C
       DO 50 I=2, 1000
       TYPE*,'NEXT POINT:'
       READ (5,110)          !WAIT FOR USER RESPONSE (CR)
       CALL REC('OA;*',BUF,L)
       DECODE (L,20,BUF) IX,IY,IPSTAT
       DATA (1,I)=IX
       DATA (2,I)=IY
       IF (IPSTAT.EQ.0) GOTO 80     !PEN UP; EXIT LOOP
       NDATA=NDATA+1
   50  CONTINUE
C
C
   80  CONTINUE
       WRITE (5,100)
  100  FORMAT (1X,'PLOT DATA ABSOLUTE: Y OR N ',$)
       READ (5,110) REPLY
  110  FORMAT (A1)
       IF (REPLY.EQ.'Y') GOTO 130
       IF (REPLY.EQ.'N') GOTO 200
       GOTO 80
C
C
  130  TYPE*,'INSERT PEN; PRESS RETURN IF TRUE.'
       READ (5,110)          !WAIT FOR USER RESPONSE
       CALL XMT('PU;*')
       IX=DATA(1,1)
       IY=DATA(2,1)
       ENCODE (22,140,BUF) IX,IY
       CALL XMT(BUF)
       CALL XMT('PD;*')
       DO 160 I=2,NDATA
       IX=INT(DATA(1,I))
       IY=INT(DATA(2,I))
       ENCODE (22,140,BUF) IX,IY
  140  FORMAT ('PA',I9,I9,';*')
       CALL XMT(BUF)
  160  CONTINUE
       
C
C
  200  WRITE (5,210)
  210  FORMAT (1X,'SAVE INPUT DATA: Y OR N ',$)
       READ (5,110) REPLY
       IF (REPLY.EQ.'Y') GOTO 250
       IF (REPLY.EQ.'N') GOTO 290
       GOTO 200
C
C
  250  WRITE (5,260)
  260  FORMAT (1X,'ENTER FILE NAME TO RECIEVE DATA: '$)
       READ (5,265) (FILNAM(I), I=1, 31)
  265  FORMAT (32A1)
       OPEN (UNIT=2, TYPE='NEW', NAME=FILNAM, ERR=300)
       WRITE (2,267) 
  267  FORMAT (1X,'DATA BEGINS NEXT LINE')
       DO 275 I=1, NDATA
       WRITE (2,273) DATA(1,I), DATA(2,I)
  273  FORMAT (2(1X,F12.3))
  275  CONTINUE
       CALL CLOSE(2)
  290  TYPE*,'EXITING DIGIT'
       RETURN
  300  TYPE*,'OPEN ERROR; TRY AGAIN'
       END