Fun, but somewhat obscure, fact is that Intel MDS systems (their "Big blue box" for developing software of their microprocessors) used 0x55 (ASCII 'U') to set t

Fun, but somewhat obscure, fact is that Intel MDS systems (their "Big blue box" for developing software of their microprocessors) used 0x55 (ASCII 'U') to set the initial baud rate. When you turned them on they would read signal coming in on the console line, derive timing information from it and then set the baud rate and print out the greeting message.