Reading single bytes from SerialPort synchronously?

Question

I'm attempting to read from a serial port a byte at a time. I've got the following code in my Console app:

// Open the serial port in 115200,8N1
using (SerialPort serialPort = new SerialPort("COM1", 115200,
                                              Parity.None, 8,
                                              StopBits.One))
{
    serialPort.Open();

    for (; ; )
    {
        int result = serialPort.ReadByte();
        if (result < 0)
            break;

        Console.WriteLine(result);
    }
}

I'm expecting this to loop round, dumping the bytes received to the screen (ignore for a moment that they'll be printed as integers; I'll deal with that later).

However, it just blocks on the ReadByte call and nothing happens.

I know that my serial device is working: if I use Tera Term, I see the data. If I use the DataReceived event, and call SerialPort.ReadExisting, then I can see the data.

However, I'm not bothered about performance (at least, not yet), and the protocol I'm implementing works better when dealt with synchronously.

So: what am I doing wrong? Why doesn't ReadByte return?