This will make a straight beep, that will play for two seconds:

SOUND 1, 4000, 32

And now for something completely different, a hysterical vibrato!

SOUND 1, 5000, 32, 2, 3000, 800, 1

To add an envelope to the sound, you use what you know on the PLAY command, and add the SOUND command immediatly before. Make sure you trigger them on the same voice.

Both the SOUND command and the PLAY command (in combination with the ENVELOPE command and the T synthesize control character) allows you to control the waveform that is being used. When combining them, PLAY decides, not SOUND. Type in this in your Commodore 128. You might want to reset your machine first, to set all parameters to default.

10 SOUND 1, 5000, 32, 2, 3000, 800, 1
20 PLAY "V1T5C"

Cool, right? Click here to listen.

Dim I(10) As Integer
Console.WriteLine(I.Length)
Dim J(I.Length - 1) As Integer
Console.Write(J.Length)

This will give the output 11 and 11. The array named I has 11 elements because the last index (10) is given when the array is created. The array named J has 11 elements bacause Length (11) – 1 equals 10, and a 0-based array with last element 10 gives you 11 elements. Confusing.

Sub DoSomething(X() As Foo)
   Console.WriteLine(X.Length)
End Sub

What I’m showing here is true for single variables too, but I am showing this using arrays. This cannot be called using an Integer array as follows:

DoSomething({1, 2, 3})

Adding a Integer constructor to the Foo class does not help. However, you can add a widening operator to the Foo class, and define how an implicit conversion is done, like so:

Public Class Foo

   Private mX As Integer

   Public Sub New(X As Integer)
      Me.mX = X
   End Sub

   Shared Widening Operator CType(X As Integer) As Foo
      Return New Foo(X)
   End Operator

End Class

Now, both the above method call is accepted. And because this also works on arrays, this simple line constructs three Foo objects:

Dim X() As Foo = {4, 5, 6}

The equivalent with a single (non arrayed) object would look like this:

Dim Y As Foo = 7

The opposite to Widening is called Narrowing and is used to define explicit type casts.

Thanks, Klas Dahlén!

TEMPO lets you control playback speed. The slowest is 1 and the fastest is 255.

ENVELOPE lets you modify the ten predefined instruments. You set the instruments using the T control character (0 to 9). The arguments are:

- The instrument you want to overwrite (0 to 9)
- Attack rate (0 to 15)
- Decay rate (0 to 15)
- Sustain level (0 to 15)
- Release rate (0 to 15)
- Waveform (0=triangle, 1=sawtooth, 2=square with adjustable pulse width, 3=noise, 4=ring modulation)
- Pulse width (0 to 4095) – only relevant if waveform is set to 2.

This program creates 5 similar instruments that differ in pulse width, and uses them in a simple riff.

10 ENVELOPE 0,0,5,0,0,2,100
20 ENVELOPE 1,0,5,0,0,2,300
30 ENVELOPE 2,0,5,0,0,2,500
40 ENVELOPE 3,0,5,0,0,2,700
50 ENVELOPE 4,0,5,0,0,2,900
60 TEMPO 40
70 PLAY "V1O2Q"
80 FOR I=1 TO 2
90 PLAY "T0CCT1CCT2CCT3CCT4CCT3CCT2CCT1CC"
100 NEXT

Click here to listen.

Chopra is an pseudo scientist and a magical healer who uses (or missuses) scientific buzzwords to make his mumbo jumbo sound plausible. Now, guess who Microsoft hires to inspire their partners in this years world wide partner conference? The charlatan himself! Money well spent? It’s a shame, Microsoft!

(Thanks Jesper Johag.)

PLAY "V1O1 CDE O2 CDE V2 CDE"

T (0 to 9) lets you chose from 10 predefined envelopes. The predefined envelopes emulates different instruments (0 is piano, 1 is accordion and so on). Envelopes differ in attack rate, decay rate, sustain level, release rate and waveform. This song uses a harpsichord bass (T6), a drum (T3) and some xylophone (T9).

10 FOR I=1 TO 4
20 PLAY "V1O2T6QCCT3O5CO2T6C"
30 PLAY "V2O5T9CV3G"
40 NEXT

U (0 to 15) controls the volume, but not on the next note, but also on any playing note. This will therefore play both C notes using volume 2.

PLAY "U15 C U2 C"

Finally, X (0 or 1) is used to turn the frequency filter on (1) or off (0).