> It's also a sad commentary on the state of CPU designs, where we now have GHz processors that can't sample the state of an IO pin in 200ns to save their life

> It's also a sad commentary on the state of CPU designs, where we now have GHz processors that can't sample the state of an IO pin in 200ns to save their life. Not really! It's much closer to a general purpose microprocessor than a microcontroller. How many desktop PCs can sample GPIO pins at all? Much less at some kind of rate that you find reasonable. You're going to use the parallel port? Sorry, that's about three layers of abstraction away from the actual processor. Complicated things are complicated and the beaglebone is a full, real computer. I think it's comparable to desktops around the turn of the century. I don't think a PIII could sample GPIO pins at 100MHz even if it had any, which it didn't.