SUBROUTINE  PLTMS (X,Y,S)

C     [MARGIN SUPPRESSED]
C     PLTMS (X,Y,S) MOVES THE PEN TO THE POINT (X,Y) ON AN 8-1/2" X 11"
C     SHEET.  HOWEVER, A BORDER IS MAINTAINED 1" FROM THE EDGE, BEYOND
C     WHICH NO PEN MOVEMENT IS PERMITTED. LINEAR INTERPOLATION IS USED
C     TO OBTAIN AN ACCURATE INTERSECTION OF ANY LINE SEGMENT WHITH THIS
C     MARGIN. IF S=.TRUE. THE PEN IS MOVED IN THE LOWERED POSITION,
C     OTHERWISE THE NEW PEN POSITION IS MERELY NOTED AS (X0,Y0). NULL
C     INTERVALS ARE INVISIBLE, SO THE PEN IS NOT RAISED OR LOWERED EVEN
C     THOUGH THIS MOVEMENT HAS BEEN CALLED FOR.
C     [15-MAY-74]

      LOGICAL*1    S,S0,P0,P1,Q,EQ

      EQ(X,Y)=ABS(X-Y).LE.(1.0E-5)

      IF (S) GO TO 20
   10 S0=.TRUE.
   11 X0=X
      Y0=Y
      RETURN
   20 IF (EQ(X,X0).AND.EQ(Y,Y0)) GO TO 10
      X1=X
      Y1=Y
      CALL PLTMT (X0,Y0,P0,X1,Y1,P1,Q)
      IF (.NOT.Q) GO TO 10
      IF (S0.OR.P0) CALL PLOT (Y0,-X0,3)
      CALL PLOT  (Y1,-X1,2)
      S0=P1
      GO TO 11

      END