z = .01: a = 0: b = 0: D = 1: E = 1: m = 0: n = 0: Y = 0: X = 0: T = 150: P = 1
CLS
SCREEN 11
DO

SELECT CASE INKEY$

    CASE IS = "q": END
    CASE IS = "a": D = D - .001
    CASE IS = "s": D = D + .001
    CASE IS = "d": E = E - .001
    CASE IS = "f": E = E + .001
    CASE IS = " ": CLS
    CASE IS = "h": T = T + 10
    CASE IS = "g": T = T - 10
    CASE IS = "j": z = z + .0001
    CASE IS = "k": z = z - .0001
    CASE IS = "w": m = m - .001: a = a + m
    CASE IS = "e": m = m + .001: a = a + m
    CASE IS = "r": n = n - .001: b = b + n
    CASE IS = "t": n = n + .001: b = b + n
    CASE IS = "p": P = 1
    END SELECT

IF T > 200 THEN : T = 200
IF T < -200 THEN : T = -200

IF P = 1 THEN
LOCATE 1, 1:  PRINT "                                                                                "
LOCATE 2, 13: PRINT "X = M * SIN(D * A) Y = T * SIN(E * B) Function Grapher"
LOCATE 4, 24: PRINT "VERSION 2.0 *** By Nicholas Erho"
LOCATE 6, 6: PRINT "******************************************************************"
LOCATE 7, 6: PRINT "* Please note: Its important that you make sure CAPS LOCK if OFF *"
LOCATE 8, 6: PRINT "******************************************************************"
LOCATE 10, 1: PRINT "********************************************************************************"
LOCATE 11, 1: PRINT "*    KEY    *                            FUNCTION                              *"
LOCATE 12, 1: PRINT "********************************************************************************"
LOCATE 13, 1: PRINT "*  S and A  *        Increase and Decrease the X axis wave fequency            *"
LOCATE 14, 1: PRINT "*  A and F  *        Increase and Decrease the Y axis wave fequency            *"
LOCATE 15, 1: PRINT "*  W and E  *        Increase and Decrease the X axis wave phase               *"
LOCATE 16, 1: PRINT "*  T and R  *        Increase and Decrease the Y axis wave phase               *"
LOCATE 17, 1: PRINT "*  H and G  *        Increase and Decrease the graph size                      *"
LOCATE 18, 1: PRINT "*  J and K  *        Increase and Decrease the speed of the graph              *"
LOCATE 19, 1: PRINT "*  SPACEBAR *        Clears the screen                                         *"
LOCATE 20, 1: PRINT "*     P     *        View help text (this screen)                              *"
LOCATE 21, 1: PRINT "*     Q     *        Quit                                                      *"
LOCATE 22, 1: PRINT "********************************************************************************"
LOCATE 24, 26: PRINT "****************************"
LOCATE 25, 26: PRINT "* Press Any Key to Proceed *"
LOCATE 26, 26: PRINT "****************************"
SLEEP
P = 0: CLS
END IF
LOCATE 1, 3: PRINT "X Fequency ="; D: LOCATE 1, 32: PRINT "Y Fequency ="; E: LOCATE 1, 61: PRINT "GRAPH SIZE:"; T
LOCATE 2, 3: PRINT "X Wave Phase:"; m: LOCATE 2, 32: PRINT "Y Wave Phase:"; n: LOCATE 2, 61: PRINT "SPEED:"; z
a = a + z: b = b + z
X = T * SIN(D * a) + 320
Y = T * SIN(E * b) + 256
PSET (X, Y)
LOOP