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/// <summary>
/// This function reproduces an algorithm from the Williams Sound ROM, 
/// addresses 0xF503 to 0xF54F. It takes 7 byte parameters and one 
/// 16-bit parameter, and returns a list of sound values 0-255
/// sampled at 894750 samples per second
/// </summary>

public List<byte> Sound1(
	byte b1, byte b2, byte b3, byte b4, 
	byte b5, byte b6, byte b7, ushort u1
	)
{
    ushort count;   // internal counter
    byte c1, c2, t; // internal storage
    byte sound = 0; // current sound level
    var wave = new List<byte>();
    // copy the current sound value this many times into the output
    Action<int> dup = d =>
                            {
                                while (d-- > 0)
                                    wave.Add(sound);
                            };

    dup(8);
    sound = b7;
    do
    {
        dup(14);
        c1 = b1;
        c2 = b2;
        do
        {
            dup(4);
            count = u1;
            while (true)
            {
                dup(9);
                sound = (byte) ~sound;

                ushort t1 = (c1 != 0 ? c1 : (ushort)256);
                dup(Math.Min(count, t1)*14 - 6);
                if (count <= t1)
                    break;
                dup(12);
                count -= t1;

                sound = (byte) ~sound;

                ushort t2 = (c2 != 0 ? c2 : (ushort)256);
                dup(Math.Min(count, t2) * 14 - 3);
                if (count <= t2)
                    break;
                dup(10);
                count -= t2;
            }

            dup(15);

            if (sound < 128)
            {
                dup(2);
                sound = (byte)~sound;
            }

            dup(27);
            c1 += b3;
            c2 += b4;
        } while (c2 != b5);

        dup(7);
        if (b6 == 0) break;
        dup(11);
        b1 += b6;
    } while (b1 != 0);
    return wave;
}