Teletype Model 33

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.

The Model 33 was one of the first products to employ the newly standardized ASCII character encoding method, which was first published in 1963. A companion Teletype Model 32 used the older, established five-bit Baudot code. Because of its low price and ASCII compatibility, the Model 33 was widely used, and the large quantity of teleprinters sold strongly influenced several de facto standards that developed during the 1960s.

The Model 33 originally cost about $1000 (equivalent to $11,000 today), much less than other teleprinters and computer terminals in the mid-1960s, such as the Friden Flexowriter and the IBM 1050. In 1976, a new Model 33 RO printer cost about $600 (equivalent to $3,000 today).

As Teletype Corporation realized the growing popularity of the Model 33, it began improving its most failure-prone components, gradually upgrading the original design from "light duty" to "standard duty", as promoted in its later advertising (see advertisement).