5 bit is what radio amateurs call RTTY ... 5 bit code is Baudot (as in Emile Baudot, the guy who invented it). It predates both ASCII and EBCDIC and was the standard for the wire services way back when they used real Teletypes connected by leased phone lines. But you're right - Baudot is the standard for radio teletype as well - hams are poor and they bought all the surplus TTY equipment from the wire services when they upgraded. Although these days there are many ham digital protocols based on ASCII, and most all hams have PCs. Not many actually use teletypes anymore... Bob WU6V