RTTY is short for Radio Teletype.

Originally associated with a large, floor-standing machine that was a cousin to a typewriter, and which clacked incessantly as it received and printed messages, RTTY has evolved to another computer-based mode of communications. As in other modes, there is software readily available on the internet and little equipment needed beyond a standard transmitter, a computer and an interface.



Much more info here:
»www.southgatearc.org/data/rtty/
here:
»www.dxzone.com/cgi-bin/d ··· ID=13022
and here:
»www.athensarc.org/digita ··· odes.asp