60 Y = 5: REM  SET STARTING POSITION OF UP-AND-DOWN VARIABLE
 240  REM SET S TO ADDRESS OF SPEAKER
 260 S =  - 16336
 280  REM SET TEXT MODE
 300  TEXT : HOME
 310  PRINT "TO SELECT A COLOR FOR"
 320  PRINT "THE BOUNCING BALL, FIRST TYPE"
 330  PRINT "IN ANY NUMBER FROM 1 TO 15."
 340  PRINT "THEN PRESS THE KEY LABELLED RETURN.": PRINT
 350  INPUT "WHAT COLOR WOULD YOU LIKE THE BALL TO BE (1-15)?";HUE$
 352  REM  IS ENTRY A NUMBER?
 354 HUE =  VAL (HUE$): REM VALUE OF HUE$ BECOMES NUMERIC VARIABLE
 356  IF HUE > 999999 OR HUE < .01 THEN  GOTO 300: REM  INPUT MESSAGE WILL REAPPEAR
 358 HUE$ =  STR$ (HUE): REM  HUE CHANGED BACK INTO STRING HUE$
 370  REM IS HUE OF BALL IN RANGE?
 380  IF HUE > 0 AND HUE < 16 THEN 400
 390  HOME : PRINT "THAT WASN'T BETWEEN 1 AND 15!": PRINT
 395  GOTO 310
 400  GR : REM  SET COLOR GRAPHICS AREA
 420  HOME : REM CLEAR TEXT AREA
 440 X = 0: REM  SET STARTING POSITION OF BACK-AND-FORTH VARIABLE
 460 Y = 5: REM  SET STARTING POSITION OF UP-AND-DOWN VARIABLE
 480 XV = 2: REM SET X VELOCITY
 500 YV = 1: REM SET Y VELOCITY
 520  REM CALCULATE NEW POSITION
 540 NX = X + XV:NY = Y + YV
 560  REM IF BALL EXCEEDS SCREEN EDGE, THEN BOUNCE
 580  IF NX > 39 THEN NX = 39:XV =  - XV: FOR B = 1 TO 5:BOUNCE =  PEEK (S) +  PEEK (S) +  PEEK (S): NEXT B
 600  IF NX < 0 THEN NX = 0:XV =  - XV: FOR B = 1 TO 5:BOUNCE =  PEEK (S) +  PEEK (S) +  PEEK (S): NEXT B
 620  IF NY > 39 THEN NY = 39:YV =  - YV: FOR B = 1 TO 5:BOUNCE =  PEEK ( S) +  PEEK (S) +  PEEK (S): NEXT B
 640  IF NY < 0 THEN NY = 0:YV =  - YV: FOR B = 1 TO 5:BOUNCE =  PEEK (S) +  PEEK (S) +  PEEK (S): NEXT B
 660  REM PLOT NEW POSITION
 680  COLOR= HUE: PLOT NX,NY
 700  REM ERASE OLD POSITION
 720  COLOR= 0: PLOT X,Y
 740  REM SAVE CURRENT POSITION
 760 X = NX:Y = NY
 780  GOTO 540