Teletype Corporation

Lore & Background

The Teletype Corporation had its roots in the Morkrum Company, formed in 1906 by combining the Morton and Krum names. In 1902, electrical engineer Frank Pearne approached Joy Morton seeking sponsorship for research into a printing telegraph system; Joy Morton consulted mechanical engineer Charles Krum, who set up a laboratory in the attic of Western Cold Storage. Pearne left after a year—the Pearne family disputes that he lost interest, saying Morton did not pay him enough to support his family—and Krum continued the work. In 1908 a working teleprinter, the Morkrum Printing Telegraph, was field tested with the Alton Railroad. In 1910 the first commercial teletypewriter system was installed on Postal Telegraph Company lines between Boston and New York City using the 'Blue Code Version.' In 1925 the Morkrum Company merged with the Kleinschmidt Electric Company to form Morkrum-Kleinschmidt, which changed its name to Teletype Corporation in December 1928. In 1930 AT&T purchased the company for $30,000,000 in stock, making it a Western Electric subsidiary. Howard Krum stayed on as a consultant; Sterling Morton became head of the family's salt business. In 1974 the Little Rock plant went on strike with its 1400 IBEW members over benefits and pay; a ratified contract was agreed on September 3, 1974, subject to ratification at the Arkansas plant.

Reader's Guide

The Teletype Corporation's significance lies in its role as a primary supplier of teleprinter equipment for decades, particularly to the U.S. military and news wire services. The Model 15, introduced in 1930, became the mainstay of U.S. military communications in World War II and remained in production until 1963—a 33-year run—with approximately 200,000 units built. Its production was extended because Teletype built so many factories for the Model 15 during the war that mass production remained economical even after the Model 28 was scheduled to replace it in the mid-1940s. The Model 15, especially in its receive-only configuration, was the classic 'news Teletype' until the 1950s. The company continued until January 8, 1982, the date of settlement of United States v. AT&T, when Western Electric was absorbed into AT&T as AT&T Technologies and Teletype became AT&T Teletype. The last vestiges of the Teletype Corporation ceased in 1990.

Did You Know?

• The Teletype Corporation name came from the trademark equipment of the Morkrum-Kleinschmidt Company when it changed its name in 1928.
• The Model 15 teleprinter remained in production for 33 years, from 1930 to 1963.
• Howard Krum developed and patented the start-stop synchronizing method for code telegraph systems, making practical teleprinters possible.
• The first commercial teletypewriter system was installed in 1910 between Boston and New York City using the 'Blue Code Version' of the Morkrum Printing Telegraph.

Light-Duty by Design: Engineering for the Small Office

The Model 33 was conceived with a specific operational envelope in mind: a compact machine for a small office, capable of handling roughly two hours of daily use. This design brief shaped nearly every engineering decision. Rather than the heat-treated, hardened components found in Teletype's earlier, more rugged teleprinters, the 33 relied on die-cast metal bases, self-tapping screws, and parts that simply snapped together without bolting. Adjustments that required turning screws on previous models were instead accomplished by bending metal bars and levers. A single electric motor at the rear of the mechanism powered everything mechanically, running continuously whenever the unit was plugged in and producing a characteristic hum and slight rattle that intensified during printing or tape operations. A small mechanical bell, triggered by the Control-G character code, could draw attention when needed. The finished machine, including its stand and paper, weighed 75 pounds and stood 34 inches tall. Originally designed for the United States Navy, it was introduced commercially in 1963 at roughly $1,000—far below rivals like the Friden Flexowriter or the IBM 1050.

ASCII, Affordability, and a Half-Million Milestone

When Teletype Corporation launched the Model 33 in 1963, it arrived alongside a pivotal moment in data communications: the first publication of the standardized ASCII character encoding. The 33 was among the earliest products to adopt this new scheme, while its companion Model 32 continued using the older five-bit Baudot code. This combination of ASCII compatibility and a price point well under competing terminals made the 33 a natural choice for offices and data centers alike. The machine came in three configurations: the ASR with a built-in eight-hole punched tape reader and punch, the KSR with a keyboard but no tape hardware, and the RO, a receive-only unit lacking both keyboard and tape mechanisms. By 1975, more than 500,000 units had been produced; the 500,000th was plated in gold and placed on special display. Another 100,000 rolled off the line in the following eighteen months, and serial number 600,000—manufactured during the United States Bicentennial—was painted red, white, and blue and toured the country. The sheer volume of these machines helped cement several de facto industry standards during the 1960s.

From 'Model 33 ASR' to 'tty': A Naming Legacy

The way the Model 33 is named in technical documentation tells a story about how computer culture absorbed and reshaped industrial hardware. Teletype Corporation itself called the tape-equipped version the 'Model 33 ASR,' but the shorter 'ASR-33' quickly became the term favored by computer users. The earliest known instance of this reversed convention appears in Digital Equipment Corporation's September 1963 PDP-4 brochure, which referred to a Teletype Model 28 KSR as a 'KSR-28.' DEC's practice of pairing letters with numerals was extended to other Teletype equipment in later documents, and the convention spread as other manufacturers—such as Micro Instrumentation and Telemetry Systems—adopted it in their own marketing materials. Beyond the model designation, the trigram 'tty' emerged as a widely used informal shorthand for Teletype, often designating the primary text input and output device on early computer systems. That abbreviation persists today in ham radio communities and among the hearing-impaired, where it refers to text-based assistive communication devices.

The Glass TTY and the End of the Line

The Model 33's dominance in data communications was ultimately challenged not by another electromechanical printer but by the arrival of video terminals. Early CRT-based units like the Tektronix 4010, available from 1970, initially cost around $10,000—far more than a teleprinter. But integrated circuits and semiconductor memory drove those prices down rapidly through the 1970s. Low-cost 'dumb terminals' such as the ADM-3 (1975) began undercutting the Teletype market, often nicknamed 'glass Teletypes' or 'glass TTYs' as a nod to their paper-printing predecessors. More capable models like the DEC VT52 (1975), the ADM-3A (1976), and the VT100 (1978) communicated far faster than any electromechanical printer and supported full-screen text editors without generating reams of paper. Even within the teleprinter category, DEC's DECwriter series introduced meaningful competition. Falling sales led Teletype Corporation to shut down Model 33 production in 1981. A few lingered in service; one in Australia remained connected to a phase ionosonde for ionospheric research until 1984. A malfunctioning Teletype even served as a plot point in the 1971 film The Andromeda Strain.