PROGRAM THREED
C
C  3 DIMENSIONAL PLOTTING PROGRAM
C
	DIMENSION P(50),ZZ(100)

	INTEGER H,V,STEP

	H(X,Y) = 0.5+(140+10*Y)*(1+X)+75*(1-Y)
	V(Z,Y) = 200.5+(112+8*Y)*(1+Z)-40*(1-Y)
	F(X,Y) = 

	STEP=32
	STEP2=STEP/2

	CALL PLOT(-3)


	CALL PLOT(H(-1.,1.),V(F(-1.,1.),1.),0)

	DO 1 J=0,STEP

	  X=-1+J/FLOAT(STEP2)
	  CALL PLOT(H(X,1.),V(F(X,1.),1.),2)
	  ZZ(J+1)=F(X,1.)

1	CONTINUE


	OY=1
	DO 10 I=1,STEP


	  Y=1-I/FLOAT(STEP2)

	  CALL PLOT(H(-1.,OY),V(ZZ(1),OY),0)	  
	  ZZ(1)=F(-1.,Y)
	  CALL PLOT(H(-1.,Y),V(ZZ(1),Y),2)
	  OX=-1

	  DO 20 J=1,STEP

	    X=-1+J/FLOAT(STEP2)
	    CALL PLOT(H(X,OY),V(ZZ(J+1),OY),0)
	    ZZ(J+1)=F(X,Y)
	    CALL PLOT(H(X,Y),V(ZZ(J+1),Y),2)
	    CALL PLOT(H(OX,Y),V(ZZ(J),Y),2)
	    OX=X

20	  CONTINUE

	  OY = Y

10	CONTINUE

	CALL PLOT(-2)



	END