DECLARE FUNCTION radiansof! (radians!)
DECLARE FUNCTION degreesof! (radians!)
SCREEN 12
red = 1
blue = 1
green = 1
white = 1
runfirst = 1

DO

IF runfirst = 0 THEN DO: a$ = INKEY$: LOOP WHILE a$ = ""
runfirst = 0
IF a$ = CHR$(27) THEN END
CLS
'12,9,10
COLOR 12: PRINT "Press A to enable/disable plain 180 phase shift"
COLOR 9: PRINT "Press B to enable/disable simple stretched 180 shift"
COLOR 10: PRINT "Press C to enable/disable complex stretched 180 shift (Smooth)"
COLOR 7: PRINT "Press D to enable/disable Zero-Line"
COLOR 1: PRINT "Escape to exit"

COLOR 7: PRINT "Horizontal gray line is zero crossing point."
PRINT "Vertical gray lines are the active points of the wave, where sampling"
PRINT "determines the phase. (Where our data bits are  recovered.)"
a$ = UCASE$(a$)
IF a$ = "A" THEN IF red = 1 THEN red = 0 ELSE red = 1
IF a$ = "B" THEN IF blue = 1 THEN blue = 0 ELSE blue = 1
IF a$ = "C" THEN IF green = 1 THEN green = 0 ELSE green = 1
IF a$ = "D" THEN IF white = 1 THEN white = 0 ELSE white = 1
xs = 2  'xstep
ys = 100        'yscale (size, pixels)

IF white = 1 THEN
COLOR 7
LINE (0, 240)-(650, 240)
FOR n = 0 TO 640 STEP 143.5
LINE (n, 240 - 100)-(n, 240 + 100)
'LINE (n + 143 / 2, 240 - 100)-(n + 143 / 2, 240 + 100), 5
NEXT
END IF

IF red = 1 THEN
COLOR 12
PSET (0, 240)
yy = 0: xx = 0
fancy = 0
x = 0
deg = 0
DO
IF fancy = 1 THEN
deg = deg + 5
ELSE
deg = deg + 5
END IF
WHILE deg > 360
deg = deg - 360
WEND
yy = y
y = SIN(radiansof(deg)) * ys
LINE (xx, 240 - yy)-(x, 240 - y)
IF deg = 180 AND fancy = 1 THEN fancy = 3: deg = deg + 180
IF deg = 360 AND fancy = 0 THEN fancy = 1
xx = x
x = x + xs
LOOP WHILE x < 640

END IF


IF blue = 1 THEN

COLOR 9
xx = 0: yy = 240
PSET (0, 240)
fancy = 0
x = 0
deg = 0
DO
IF fancy = 1 THEN
deg = deg + 2.5
ELSE
deg = deg + 5
END IF
WHILE deg > 360
deg = deg - 360
WEND
yy = y
y = SIN(radiansof(deg)) * ys
LINE (xx, 240 - yy)-(x, 240 - y)
IF deg = 180 AND fancy = 1 THEN fancy = 3
IF deg = 360 AND fancy = 0 THEN fancy = 1
xx = x
x = x + xs
LOOP WHILE x < 640
END IF

IF green = 1 THEN
COLOR 10
xx = 0: yy = 240
PSET (0, 240)
fancy = 0
x = 0
deg = 0
DO
IF fancy = 1 THEN
deg = deg + 5 - (3.38 * SIN(radiansof(deg)))
ELSE
deg = deg + 5
END IF
WHILE deg > 360
deg = deg - 360
WEND
yy = y
y = SIN(radiansof(deg)) * ys
LINE (xx, 240 - yy)-(x, 240 - y)
IF deg > 180 AND fancy = 1 THEN fancy = 3
IF deg = 360 AND fancy = 0 THEN fancy = 1
xx = x
x = x + xs
LOOP WHILE x < 640
END IF


COLOR 7

LOOP WHILE a$ <> CHR$(27)
END

FUNCTION radiansof (radians)


                 
radiansof = radians * (3.141592654# / 180)
END FUNCTION