C     .TITLE CLOCK
C
C  13 JUL 76 (013; PDH) CORRECT 'MARK' CALLING SEQUENCE
C  12 JUL 76 (009; PDH) DELETE FILE EVERY TIME WITH DRAW
C   7 JUL 76 - PAUL HENDERSON
C
C  A TASK TO SHOW A CLOCK FACE WITH SWEEP SECOND HAND, ON THE
C  VT15 SCOPE.  THIS WILL BE A LOW PRIORITY JOB, TO RUN CONTINUOUSLY.
C
      INTEGER IVECT(200),IDATE(6),IT(2),DUMMY(3)
      REAL PICT(4,3)
C
      COMMON /LIMITS/ XMIN,XMAX,YMIN,YMAX
      DATA PI/3.14159/,IT/1,2/,IFRST1/1/,IFRST2/101/
C
   1  CALL CLEAR
      XMIN = -20.
      XMAX =  20.
      YMIN = -20.
      YMAX =  20.
      PIBY30 = PI/30.
      PIBY6  = PI/6.
      PIBY2  = PI/2.
C
   2  CALL DATE (IDATE)
      THETAS = PIBY30*IDATE(6)
      THETAM = PIBY30*IDATE(5) + THETAS/60.
      THETAH = PIBY6 *IDATE(4) + THETAM/12.
C
      PICT(1,1) = COS (-THETAS+PIBY2)
      PICT(2,1) = SIN (-THETAS+PIBY2)
      PICT(3,1) = 20.*PICT(1,1)
      PICT(4,1) = 20.*PICT(2,1)
      PICT(1,2) = COS (-THETAM+PIBY2)
      PICT(2,2) = SIN (-THETAM+PIBY2)
      PICT(3,2) = 15.*PICT(1,2)
      PICT(4,2) = 15.*PICT(2,2)
      PICT(1,3) = COS (-THETAH+PIBY2)
      PICT(2,3) = SIN (-THETAH+PIBY2)
      PICT(3,3) = 10.*PICT(1,3)
      PICT(4,3) = 10.*PICT(2,3)
C
      CALL VECTOR (1,PICT,1,3,IVECT,IFRST1,LAST,7,1,.TRUE.)
      CALL DRAW (IVECT,IFRST2,0)
      CALL DRAW (IVECT,IFRST1,LAST)
      LAST   = IFRST1
      IFRST1 = IFRST2
      IFRST2 = LAST
      CALL MARK (IT,IEV)
      CALL WAITFR (IEV)
      GO TO 2
      END
