Mathgraphics:
 GOSUB INITIALIZE
 ' REPEAT UNTIL THE USER PRESSES A KEY.
 WHILE INKEY$=""
 ' MODULE 1: RightOvals
 R1=150
 R2=25
 
 R3=25
 R4=85
 INC=PI/64
 FOR THETA=0 TO 2*TWOPI STEP INC
 
 X1=FNPOLARX(R1,THETA)
 Y1=FNPOLARY(R2,THETA)
 X2=FNPOLARX(R3,THETA+PI)
 Y2=FNPOLARY(R4,THETA+PI)
 LINE(X2,Y2)-(X1,Y1),INT(RND*31)+1
 NEXT
 PAUSE
 ' MODULE 2: SideOvals---
 'SAME THING, ONLY DIFFERENT.
 R1=150
 R2=35
 R3=65
 R4=85
 INC=PI/64
 OFFSET=PI/3
 FOR THETA=0 TO 3*TWOPI STEP INC
 X1=FNPOLARX(R1,THETA)
 Y1=FNPOLARY(R2,THETA)
 X2=FNPOLARX(R3,THETA+OFFSET)
 Y2=FNPOLARY(R4,THETA)
 LINE(X1,Y1)-(X2,Y2),INT(RND*31)+1
 NEXT
 PAUSE
 ' MODULE 3: TWISTEDBAND
 ' YET ANOTHER VARIATION ON THE DOUBLE OVAL THEME.
 R1=150
 R2=35
 R3=65
 R4=85
 INC=PI/64
 OFFSET=PI/3
 FOR THETA=0 TO 3*TWOPI STEP INC
 X1=FNPOLARX(R1,THETA)
 Y1=FNPOLARY(R2,THETA)
 X2=FNPOLARX(R3,THETA)
 Y2=FNPOLARY(R4,THETA+OFFSET)
 LINE(X1,Y1)-(X2,Y2),INT(RND*31)+1
 NEXT
 PAUSE
 'MODULE 4:MULTILOBE
 R1=100
 INC=PI/128
 LOBES=4
 FOR THETA=0 TO 2*TWOPI STEP INC
 R2=R1*SIN(LOBES*THETA)
 X1=FNPOLARX(R2,THETA)
 Y1=FNPOLARY(R2,THETA)
 LINE (XCENTER,YCENTER)-(X1,Y1),INT(RND*31)+1
 NEXT
 PAUSE
 ' MODULE 5: SPIRALCONE
 R1=100
 R2=85
 INC=PI/160
 LOBES=3
 FOR THETA=0 TO 2*TWOPI STEP INC
 X1=FNPOLARX(R1,THETA*LOBES)
 Y1=FNPOLARY(R2,THETA)
 LINE (XCENTER,YCENTER)-(X1,Y1),INT(RND*31)+1
 NEXT
 PAUSE
 ' MODULE 6: SIDESPIRAL CONE
 R1=130
 R2=80
 INC=PI/160
 LOBES=3
 FOR THETA=0 TO 2*TWOPI STEP INC
 X1=FNPOLARX(R1,THETA)
 Y1=FNPOLARY(R2,THETA*LOBES)
 LINE (XCENTER,YCENTER)-(X1,Y1),INT(RND*31)+1
 NEXT
 PAUSE
 ' MODULE 7:CIRCLES
 R1=115
 R2=85
 R3=40
 R4=45
 INC1=PI/3
 INC2=PI/20
 FOR THETA1=0 TO TWOPI STEP INC1
 FOR THETA2=0 TO TWOPI STEP INC2
 
 X1=FNPOLARX(R1,THETA2)
 Y1=FNPOLARY(R2,THETA2)
 X2=FNPOLARX(R3,THETA1)
 Y2=FNPOLARY(R4,THETA1)
 LINE (X1,Y1)-(X2,Y2),INT(RND*31)+1
 NEXT
 NEXT
 PAUSE
 ' MODULE 8: SPIKES
 R1=115
 R2=85
 R3=40
 R4=45
 INC1=PI/3
 INC2=PI/18
 FOR THETA1=0 TO TWOPI STEP INC1
 FOR THETA2=0 TO TWOPI STEP INC2
 
 X1=FNPOLARX(R1,THETA2)
 Y1=FNPOLARY(R2,THETA1)
 X2=FNPOLARX(R3,THETA1)
 Y2=FNPOLARY(R4,THETA2)
 LINE (X1,Y1)-(X2,Y2),INT(RND*31)+1
 NEXT
 NEXT
 PAUSE
 WEND
 ' SHUT EVERYTHING DOWN AND QUIT.
 
 WINDOW CLOSE 2
 
 SCREEN CLOSE 2
 WINDOW OUTPUT 1
 END
 
 SUB PAUSE STATIC
 FOR DELAY=1 TO 5000
 NEXT
 CLS
 END SUB
 
 INITIALIZE:
 ' SET UP A 32 COLOR LOW-RES SCREEN.
 SCREEN 2,320,200,5,1
 WINDOW 2,"AmigaBasic Graphics",(0,0)-(297,185),23,2
 CLS
 ' COLOR 0 (background) is black.
 PALETTE 0,0,0,0
 ' SET UP OTHER 31 COLORS AS RANDOM COMBINATIONS.
 FOR L=1 TO 31
 
 PALETTE L,RND,RND,RND
 NEXT
 ' KEEP THE RANDOM SEQUENCE RANDOM.
 RANDOMIZE TIMER
 ' DEFINE CONSTANTS.
 PI=3.14159
 
 TWOPI=2*PI
 XCENTER=151
 YCENTER=93
 'DEFINE POLAR TO CARTESIAN CONVERSION FUNCTIONS.
 DEF FNPOLARX(R,THETA)=R*COS(THETA)+XCENTER
 DEF FNPOLARY(R,THETA)=R*SIN(THETA)+YCENTER
 RETURN