Used a "modem cable" (no, not *null*modem) to transfer data between my old A500 and fresh and new A4000D, because it was "shorter" than my null modem cable (though I could run it at >51600bps). Very stupid, because the Tx/Rx wires were not crossed and the power lines were routed. Fried the soldered CIA of the A4000 immediately. Very stupid.
