#define PI 4 * Atn(1)

' Constants for the audio format
Dim Shared As Integer SAMPLE_RATE = 44100
Dim Shared As Integer BITS_PER_SAMPLE = 16
Dim Shared As Integer NUM_CHANNELS = 1

' Generates a sine wave
Sub generateSineWave(buffer() As Short, frequency As Double)
    Dim As Double increment = 2.0 * PI * frequency / SAMPLE_RATE
    Dim As Double x = 0.0
    For i As Integer = 0 To Ubound(buffer)
        buffer(i) = (Sin(x) * 32767.0)
        x += increment
    Next i
End Sub

' Write the header of the .wav file
Sub writeWaveHeader(file As Integer, numSamples As Integer)
    ' Write the RIFF header
    Print #file, "RIFF";
    Put #file, , numSamples * 2 + 36  ' File size
    Print #file, "WAVE";

    Dim As Integer SB = 16, FA = 1
    ' Write the fmt sub-block
    Print #file, "fmt ";
    Put #file, , SB                 ' Size of the fmt sub-block
    Put #file, , FA                 ' Audio format (1 = PCM)
    Put #file, , NUM_CHANNELS       ' Number of channels
    Put #file, , SAMPLE_RATE        ' Sample rate
    Put #file, , SAMPLE_RATE * NUM_CHANNELS * BITS_PER_SAMPLE / 8   ' Byte rate
    Put #file, , NUM_CHANNELS * BITS_PER_SAMPLE / 8   ' Alineación de bloques
    Put #file, , BITS_PER_SAMPLE    ' Bits per sample

    ' Write the data sub-block
    Print #file, "data";
    Put #file, , numSamples * 2     ' Data size
End Sub

Dim As Integer file = Freefile
Open "output.wav" For Binary As #file

' Generates a 440 Hz sine wave for 5 seconds
Dim As Integer numSamples = SAMPLE_RATE * 5
Dim As Short buffer(numSamples - 1)
generateSineWave(buffer(), 440.0)

' Write the .wav file
writeWaveHeader(file, numSamples)
Put #file, , buffer()

Close #file