DVERIFY "myprogram"
    
    Good:   SEARCHING FOR O:myprogram       Bad:    SEARCHING FOR O:myprogram
            VERIFYING                               VERIFYING
            OK                                      ?VERIFY ERROR

ELLIPSE - Draw an ellipse on a graphic screen

    ELLIPSE x_center, y_center, x_radius, y_radius [,solid]

The ELLIPSE command will draw an ellipse with the given radii centered at (x center,y center) on the current graphic screen. The ellipse will be filled (i.e., a disc) if SOLID is non-zero.

        ELLIPSE 160,100,65,50

The above example will draw an ellipse in the center of a 320x200 pixel screen (160,100) having radii of (65,50) pixels. The aspect ratio of the screen may cause it to appear as an circle, however. See also the CIRCLE command.

ELSE - See IF/THEN/ELSE

END - Define the end of program execution

    END

The END statement terminates program execution. It does not close channels or files, and it does not clear any variables or reset any pointers. An END statement does not need to be put at the last line of a program.

The CONTinue command can-be-used to resume execution with the next statement following the END statement. See also the STOP command.

ENVELOPE - Define musical instrument envelopes

    ENVELOPE n, [,[atk] [,[dec] [,Csus].[,Crell [,[wf] [,Pw] ]]]]]
    
                 n ......Envelope number                (0-9)
                 atk ....Attack rate                    (0-15)
                 dec ....Decay rate                     (0-15)
                 sus ....Sustain rate                   (0-15)
                 rel ....Release rate                   (0-15)
                 wf .....Waveform:  0 = triangle
                                    1 = sawtootb
                                    2 = pulse (square)
                                    3 = noise
                                    4 = ring modulation
                 pw .....Pulse width                    (0-4096)

[*** THIS COMMAND IS SUBJECT TO CHANGE ***]

A parameter that is not specified will retain its current value. Pulse width applies to pulse waves (wf=2) only and is determined by the formula (pwout = pw/40.95 %), so that pw = 2048 produces a square wave and values of 0 or 4095 produce constant DC output. The C64DX initializes the ten (10) tune envelopes to:

                    n  A  D  S  R  wf  pw       instrument
                    ------------------------    -------------
        ENVELOPE    0, 0, 9, 0, 0, 2, 1536      piano
        ENVELOPE    1,12, 0,12, 0, 1            accordion
        ENVELOPE    2, 0, 0,15, 0, 0            calliope
        ENVELOPE    3, 0, 5, 5, 0, 3            drum
        ENVELOPE    4, 9, 4, 4, 0, 0            flute
        ENVELOPE    5, 0, 9, 2, 1, 1            guitar
        ENVELOPE    6, 0, 9, 0, 0, 2, 512       harpsichord
        ENVELOPE    7, 0, 9, 9, 0, 2, 2048      organ
        ENVELOPE    8, 8, 9, 4, 1, 2, 512       trumpet
        ENVELOPE    9, 0, 9, 0, 0, 0            xylophone