Hi Einar,

A commonly used technique to toggle a bit into a byte is to XOR the original byte with a bit mask that has the position you want to flip set to 1. The rest of bits must be set to 0. Let't see an example of this arithmetic:

Take 1 (0000001) as your original number. Now, assuming that you want to toggle the bit 7, your bit mask will be 10000000 (bit 7 on and the others off). This is the result:

00000001 (1)
XOR
10000000 (128) <- this is always the bit mask to toggle the bit 7
--------
10000001 (129)

So, the code to make this work is something like this:

private byte FlipBit7(byte oldByte)
{
    byte bitMaskToFlipBit7 = 128;    // 10000000
    return oldByte ^= bitMaskToFlipBit7;
}

HTH.