C SPIROGRAPH PLOT PROGRAM 10 WRITE(4,100) 100 FORMAT(1X,"ENTER FIXED CIRCLE RADIUS") READ(4,110) R1 110 FORMAT(I6) WRITE(4,120) 120 FORMAT(1X,"ENTER MOVING CIRCLE RADIUS") READ(4,110) R2 WRITE(4,140) 140 FORMAT(1X,"ENTER PEN OFFSET") READ(4,110) P WRITE(4,160) 160 FORMAT(1X,"0 = MOVING INSIDE, 1 = MOVING OUTSIDE") READ(4,110) ITYPE THETA=0 IASK=500 CALL PLOTS(.005*512/7.5,0) IPEN=3 IF (ITYPE .GT. 0) GO TO 450 DO 420 I=1,50000 PHI=(R1-R2)/R2*THETA X=(R1-R2)*COS(THETA)+P*COS(PHI) Y=(R1-R2)*SIN(THETA)-P*SIN(PHI) CALL XYPLOT(X,Y,IPEN) IPEN=2 THETA=THETA+.1 420 CONTINUE GO TO 10 450 DO 460 I=1,50000 PHI=(R1+R2)/R2*THETA X=(R1+R2)*COS(THETA)-P*COS(PHI) Y=(R1+R2)*SIN(THETA)-P*SIN(PHI) CALL XYPLOT(X,Y,IPEN) IPEN=2 THETA=THETA+.1 460 CONTINUE GO TO 10 600 END