The Teletype Model 33 is an electromechanical teleprinter designed for light-duty office use. Teletype Corporation's Model 33 terminal, introduced in 1963, was one of the most popular terminals in the data communications industry until the late 1970s. Over a half-million 33s were made by 1975, and the 500,000th was plated with gold and placed on special exhibit. Another 100,000 were made in the next 18 months, and serial number 600,000, manufactured in the United States Bicentennial, was painted red, white and blue, and shown around the country.