Radioteletype (
RTTY) is a
telecommunications system consisting originally of two or more
electromechanical teleprinters in different locations connected by
radio rather than a wired link. These machines were later superseded by
personal computers (PCs) running
software to emulate teleprinters. Radioteletype evolved from earlier landline teleprinter operations that began in the mid-1800s. The US Navy Department successfully tested printing telegraphy between an airplane and ground radio station in 1922. Later that year, the Radio Corporation of America successfully tested printing telegraphy via their
Chatham, Massachusetts, radio station to the R.M.S. Majestic. Commercial RTTY systems were in active service between
San Francisco and
Honolulu as early as April 1932 and between San Francisco and
New York City by 1934. The US military used radioteletype in the 1930s and expanded this usage during World War II. From the 1980s, teleprinters were replaced by computers running teleprinter emulation software.