Who Invented the Computer? Two Smiths, One Susan, and SABRE

Who Invented the Computer? This is the eighteenth installment in our ongoing series.


Airline ticketing tangles kicked off another evolution in computing technology.

In 1952 the de Havilland DH 106 Comet became the world's first commercial jet airliner. With the advent of jet airliners, the popularity of air travel increased. Unfortunately, so too did the complexity of synchronizing passenger demand with flight availability.


Booking a reservation was a convoluted, multi-step process not at all refined or improved by the touch of still-emerging computer technology. Rather, the process involved a giant Lazy Susan (essentially an enormous platter rotating on a turntable base), lots of index cards, and numerous people. Reservations typically required 90 minutes to complete.


A customer desiring to travel would phone a travel agent to tell them the day and time they wished to fly. The travel agent would then call an airline ticketing agent to see whether any seats were available on a particular flight.


The ticketing agent, seated at the aforementioned oversized lazy Susan would spin it around to locate the requested flight, pull the index card pertaining to that flight and, if a seat were available, check off a box. Then the ticketing agent would inform the travel agent, and return the card to its appointed slot on the giant lazy Susan.


If there were no open seats on a flight, then the ticketing agent would inform the travel agent, who in turn would call the customer, at which point the process would begin again. Slowing the process down even further was the fact that numerous ticketing agents would simultaneously be checking flights for other travel agents. With six or more ticketing agents spinning the lazy Susan around there was a strict rule that an agent could not pull more than one index card at time.


Cutting Down on Screw-ups


This physical hands-on process was both ridiculously time consuming and frequently inaccurate, as cards were occasionally misplaced or an agent inaccurately checked a sold seat. The problem would get even worse whenever a flight was near capacity.


As a result, too many flights were flying with empty or even double-booked seats. The situation was costing the airlines a great deal of money and a solution needed to be found. American Airlines was the first company to experiment with automating the reservation process. For a brief time, they utilized a Magnetronic Reservisor, an electromechanical machine that displayed 12 days of flights.


Operators could utilize the device to check seat availability and, if there were no seat available, offer an alternative flight. The Reservisor did help somewhat, but the entire process was still dependent on manual input from a dozen different people. As a result, the system remained error-prone as approximately eight percent of all reservations contained errors.


Smith and Smith


In 1953, C.R. Smith, president of American Airlines, was on a flight from Los Angeles to New York City. His seatmate happened to be Blair Smith, IBM's director of market development. During the flight, the two men began discussing challenges facing the airline industry, particularly the need for accurate and speedy reservations.


At the time, IBM was developing SAGE, a computerized air defense system for the Air Force. Blair Smith had been pondering possible commercial applications for SAGE and suggested that IBM could potentially tune up American Airlines' hopelessly buggy reservation process.


The companies eventually signed a formal agreement and, in 1959, for a development cost of $40 million, IBM produced the Semi-Automatic Business Environment Response system ("SABER").


Slicing Through the Paradigm


SABER was a revolutionary development for the travel industry. Approximately 1,500 Special Function Consoles located in 39 American Airlines offices scattered across Canada and the United States were linked through high-speed telephone lines to two powerful IBM 7090 mainframes housed in a specially designed data center located at Briarcliff Manor, N.Y.


Using a console, an operator (ticket agent) could gather accurate information about a flight in seconds. More importantly, the consoles enabled operators to be self-sufficient and completely independent of other operators when making a reservation.


Each console consisted of a keyboard and control buttons for the date, time, and number of seats requested. When a travel agent called to check seat availability, the console operator would type in the request and physically insert into the console a pre-punched card detailing flights between the originating and destination airports. A series of flashing lights would quickly indicate any open seats.


Better for Everyone


Airline ticketing tangles kicked off another evolution in computing technology.

American Airlines and their customers both benefitted from the new system. The airline saved money by ensuring that every seat on a flight was sold and eliminated the possibility of double-booking a seat. For the customer, SABER substantially reduced clerical errors when transmitting reservation information and cut the time to complete a reservation from 90 minutes to less than three minutes.


For marketing purposes, American Airlines changed the name from SABER to SABRE which stood for Semi-Automatic Business Research Environment. SABRE would go onto become the largest commercial computer system in the world. It operated in real time, handling almost 200,000 reservations per day.


Over the next two decades, SABRE would be adopted by every large airline. It would also undergo numerous upgrades until eventually being replaced by more powerful computerized network systems in the 1990s.


In spite of upgrades and improvements to SABRE, its original operating software remains as powerful today as in 1959, and is capable of completing 30,000 transactions per second. A number of large travel-related and business entities such as Travelocity, Expedia, AMTRAK, the Chicago Options Exchange, and the 9-1-1 emergency system for New York State continue to use the software.


Would you like more insight into the history of hacking? Check out Calvin's other articles about historical hackery:
About the Author
Calvin Harper

Calvin Harper is a writer, editor, and publisher who has covered a variety of topics across more than two decades in media. Calvin is a former GoCertify associate editor.