Beaglebone Black with RS232 Cape

I’ve recently bought a Beaglebone Black (BBB) and an RS232 cape (BB-BONE-SERL-03). Mine is revision A1 (important to know which, see later). At the time of writing this and at the time I bought it, I did not realise that the cape was not yet supported in the Angstrom release. Because of the move to …