LPC1768 tiny terminal emulator

That does not necessarily follow. It could, for example, be connected to another port which is using the same trick - this fails the "what if everyone did it?" test. It could even be connected to itself. I ran into such a port once; I shorted pins 2 and 3, got no echo, and concluded the hardware was broken...which it was, I suppose, just not in the way I thought. In short, please don't do this. Or, at the very least, provide an easy way to disable this "feature". Especially for a device whose very raison d'etre is driving a serial port; it is unlikely to spend much time powered up but with no desire to use the serial port, so there's not much to be saved by such a trick. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mouse at rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B