Whirlwind sage sabre

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Whirlwind - SAGE - SABRE

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MITRE Corporation

TPF: IBM's Unknown Operating System

(unpublished book circa 1988)

Campbell-Kelly, Aspray : chapter 7

The Whirlwind Computer

Whirlwind began as an analog computer developed at Massachusetts Institute of Technology (MIT) in the 1940s as part of a project studying aircraft stability problems for the U.S. Navy.

A digital Whirlwind was built between 1945 and 1952 by MIT's Digital Computer Laboratory.

The [digital ] system was first demonstrated on April 20th, 1951.

It is among the five biggest computers in history.

It contained 4500 vacuum tubes and ate up 3100 square feet of floor space.

It was the first digital computer

capable of displaying real time text and graphics on a video terminal, which at this time was a large oscilloscope screen.

to use Core Memory for RAM

It was ultimately adopted by the U.S. Air Force for use in the

SAGE (Semi-Automatic Ground Environment) air defense system,

which became operational in 1958 .....

The last of the Whirlwind-based SAGE computers was shut down in 1983, giving the Whirlwind a record for practical operational longevity among digital computers.

========== From WIKIPEDIA
During World War II the US Navy approached MIT about the possibility of creating a computer to drive a flight simulator for training bomber crews.

They envisioned a fairly simple system in which the computer would continually update a simulated instrument panel based on control inputs from the pilots.

Unlike older systems like the Link Trainer, the system they envisioned would have a considerably more realistic aerodynamics model that could be adapted to any type of plane.

A short study by the MIT Servomechanisms Laboratory concluded that such a system was certainly possible.

The Navy decided to fund development under Project Whirlwind, and the lab placed Jay Forrester in charge of the project.

They soon built a large analog computer for the task, but found that it was inaccurate and inflexible.

Solving these problems would require a much larger system, perhaps one so large as to be impossible to construct.

In 1945 Jerry Crawford, another member of the MIT team, saw a demonstration of ENIAC and suggested that a digital computer was the solution. ..........

Up until this point all computers constructed were dedicated to single tasks, run in batch mode. ....

This was not appropriate for the Whirlwind system, which needed to operate continually on an ever-changing series of inputs.

Speed became a major issue, whereas with other systems it simply meant waiting longer for the printout, with Whirlwind it meant seriously limiting the amount of complexity the simulation could include.
Design and construction

By 1947, Forrester and Everett completed the design of a high-speed stored-program computer for this task.

Most computers of the era operated in bit-serial mode, using single-bit arithmetic and feeding in large words, often 48 or 60 bits in size, one bit at a time.

This was simply not fast enough for their purposes, so Whirlwind included sixteen such math units, operating on a complete 16-bit word every cycle in bit-parallel mode. Ignoring memory speed, Whirlwind was essentially sixteen times as fast as other machines.

Today almost all machines work in this fashion, albeit with larger 32- or 64-bit words.

The word size was selected after some deliberation.

The machine worked by passing in a single address with almost every instruction, thereby reducing the amount of memory accesses.

For operations with two operands, adding for instance, the "other" operand was assumed to be the last one loaded.

Whirlwind operated much like a reverse Polish notation calculator in this respect; except there was no operand stack, only an accumulator.

The designers felt that 2000 words of memory would be the minimum usable amount, requiring 11 bits to represent an address, and that 16 to 32 instructions would be the minimum for another 5 bits -- and so it was 16-bits.

Nevertheless the small word size led John von Neumann to conclude the machine would be worthless.

Construction of the machine started the next year, an effort that employed 175 people including 70 engineers and technicians.

Whirlwind took 3 years to build and first went online on April 20, 1951.

The project's budget was $1 million a year, and after three years the Navy had already lost interest.

However it was around this time that the USSR detonated their first atomic bomb, and the USAF picked up the work under Project Claude.

====> SAGE

The core of the machine

Speed of the original design: 20 KIPS

Thousands (not 1024s) of Instructions Per Second. Usage: rare.

too slow ..... most of the problem was attributed to the Williams-Kilburn

used for main memory of 256 words.

Forrester started looking at replacements, first using magnetic tape formed into spirals, and eventually creating core memory.

Speed was roughly doubled (40 KIPS) as a result ....

the Whirlwind became the fastest computer of its time. ...........

The new core-based machine was fast enough for use in SAGE, and an industrial effort was started in order to mass-produce the computers.

RCA was a front-runner, but IBM was eventually selected instead.
They started production in 1957, along with a massive construction project to build the buildings, power and communications network needed to feed the SAGE systems with data.

What came of the Whirlwind?
Whirlwind II ran in a support role for SAGE until June 30, 1959.

A member of the project team, Bill Wolf, then rented the machine for a dollar a year until the late 1970's.

At that point it was taken over by Ken Olsen, who kept it for a while before transferring it to the Smithsonian.

An effort was also started to convert the Whirlwind design to a transistorized form, led by Ken Olsen and known as the TX-0. TX-0 was very successful and plans were made to make an even larger version known as TX-1. However this project was far too ambitious .....

Even this version proved troublesome, and Olsen left to start DEC.

DEC's PDP-1 was essentially a collection of TX-0 and TX-2 concepts in a smaller package.

============ FROM MITRE Corp.

Semi-Automatic Ground Environment (SAGE)

In the 1950's MITRE's founders played a key role in the development of the Semi-Automatic Ground Environment (SAGE) system, the first major

real-time, computer-based command and control system.

Designed as a new air defense system to protect the United States from long-range bombers and other weapons, the SAGE system sent information from geographically dispersed radars over telephone lines and gathered it at a central location for processing by a newly designed, large-scale digital computer.

As the system evolved, SAGE broke new ground in :

radar, communications, computer, information display,

and computer programming technologies.

Developing a system of SAGE's size required a novel organization that could examine all facets of the problem without regard to the traditional boundaries between the military, industry and academia.

In 1958, in response to this need, The MITRE Corporation was formed out of the Computer System Division of the Massachusetts Institute of Technology (MIT) Lincoln Laboratories.

Much of MITRE's initial work focused on the software development of SAGE's digital computer system, radar surveillance, communications, and weapons integration. ..........

però altrove si dice che il sw venne affidato a RAND

The SAGE system was fully deployed in 1963;

the 24 SAGE Direction Centers and three SAGE Combat Centers were spread throughout the U.S. Each was linked by long-distance telephone lines to more than 100 interoperating air defense elements, requiring system integration on a scale previously unimagined.

At the heart of each center was a new large-scale digital computer that had evolved from MIT's experimental Whirlwind computer...

In spite of this complexity, remarkable for its time, SAGE exceeded virtually all the original stringent requirements, and was continuously in operation for more than 25 years. ..........

In addition, MITRE's SAGE work was directly applicable to another important mission: air traffic control. ....

SAGE: The System in Action see http://www.mitre.org/about/sage.html

SAGE [ and Whirlwind ]: Impact on the Computers of Today
SAGE had a fundamental impact on the development of computers and the computer industry.

Key to the success of SAGE was the development of a production version of MIT's prototype Whirlwind computer.

A little known company called IBM won the contract to design and build the Whirlwind II, otherwise known as AN/FSQ-7, ...

When complete, the AN/FSQ-7 weighed 250 tons, and required a 3,000kW power supply and over 49,000 vacuum tubes.

When SAGE became fully operational, it relied on 24 AN/FSQ-7s; they remained in service until the Air Force ended the SAGE program in 1983.

Looking back ... the origins of many key computer innovations are readily apparent.

  • SAGE's use of telephone lines to communicate from computer to computer and computer to radar ...

  • Bob Everett's invention of the light gun is often referred to as one of the precursor's to today's computer mouse.

  • Whirlwind's control program, the largest real-time computer program written at that time, spawned a new profession, software development engineers and programmers.

Many other computer breakthroughs such as magnetic-core storage, modular design, interactive graphic displays, on-line common databases, and continuous and reliable operation can also be traced to the development of Whirlwind.

In addition, software innovations like the ability to accommodate multiple, simultaneous users, the use of advanced data system structures, structured program modules, and global data definitions grew out of SAGE's development.

confronto con Time Sharing ?????

SABRE From : TPF: IBM's Unknown Operating System
IBM Transaction Processing Facility (TPF)

TPF is the world's undisputed leader in online high volume transaction processing ....

To really understand the origins and development of the system we now call TPF we must take a trip back in time to circa 1940.

We will visit a main ticket office of American Airlines in Little Rock Arkansas, a growing company with growing ambitions.

Here the basic control of flight reservation was a large card index around which eight or so clerks would sort through the index cards for the flight being requested.

They each knew the number of seats for the type of aircraft being used and by counting tally marks on the flight card they could tell if any seats were left and give you your 'yes' or 'no' over the telephone.

If your reservation was being made through another office it might take 2 1/2 to 3 hours to reach the revolving card index via a teletypewriter network and some clerical personnel.

In some of the medium sized offices it was necessary to use binoculars to view critical information posted on large availability status boards in the agents area.

The absence of a red tag indicated that at least one seat was available on that flight.

If more than one seat was needed a phone call to the back room might give you the availability which was again kept on three-by-five index cards according to flight number.

By 1955 some automation had begun to creep into larger offices and American's first automatic equipment, the Magnetronic Reservisor, provided remote controls so that the agents could search a memory drum and determine whether or not seats were available.

Now within a few seconds agents could check availabilities but the posting of the passengers name, telephone number and other information created a terrific paperwork headache.

It was still necessary to record the passenger data on the ever present three-by-five cards and a constant river of paper still wound its way on conveyor belts to find its place in the back room.

For every agent on the telephone another was required in the back to do the housekeeping.

It was a system and it worked
but as it grew, adding another clerk no longer was the answer ....

New solutions were found but .... never a total system capable of keeping pace with the service that was gobbling up transportation time and reducing days to hours and hours to minutes.

If ever there was a problem crying out for a computer solution it was this one ....

The story goes that American Airlines' then President, C.R. Smith,....

had the occasion to be seated next to an IBM Sales and Marketing Representative called, coincidentally, Blair Smith. ......

It was a mere 30 days later that IBM responded to American with a proposal to make a study of the airline's problems and it was 1957 by the time the direction was firmed up and formal agreements reached.

American Airlines appointed technical and functional representatives to work with an IBM staff of 75 and the

SABER (Semi Automatic Business Environment Research)

project was born.

In March of 1959 the initial program was proposed and one AA executive commented years later

It was the best damn research and development effort on the part of any company I've ever seen.

..... it was an entirely new concept which, it is said,

spawned [ diede origine a ] IBM's 360 computer systems.

The SABER name was later changed to the name more familiar to us today: SABRE.

The system was actually implemented in 1962 and reportedly cost $30 million.

altrove ho trovato: $150 millioni ed un jet costava $4.5 millioni

Initially the hardware it ran on was an IBM 7090 processor, a second generation computer using disk files and specialized terminals developed for the airline reservation function.

Also developed during this project were some innovations in communications technology, namely the concepts of line concentration and of medium and low speed data sets.

Also the use of a front-end-processor, development and improvement of large capacity rotating storage media (disk drives), fast direct access techniques for data stored on disk drives and the techniques of writing relocatable and reentrant code.

Two other systems which built on the experience gained in the SABER project were also developed in conjunction with IBM:

  • Deltamatic system for Delta Airlines, using IBM 7074

  • Panamac developed with Pan-American Airlines, using IBM 7080

Both of these systems were implemented in 1963 and the only fundamental differences were in their respective sizes.

This was important becaure since much of the system code at the time had to be hardware specific this meant that although the systems were based on the same design there were some significant differences in the code within them.

In 1964 IBM made two important announcements.

One, ... was the introduction of the System/360 (S/360) line of computers

and the other was the start of the development of

PARS (Programmed Airline Reservation System).


By 1968 IBM had developed PARS and released it as a product.

At this stage there was still no separation of function between Applications and Systems software.

  • application processing : booking seats, availability etc

  • system functions: accessing the database, restarting the system.

It was not until 1969 that IBM managed to pry apart the previously interwoven systems and applications portions of the PARS system.

The Applications portion of the new package was christened APPS

and the Systems portion became ACP (Airline Control Program) the forerunner of TPF.


This marked another turning point for the software [ ACP/TPF],

now it was IBM's 'official' belief that applications other than the airlines could and would benefit from its use.

To be fair it was probably more like the recognition that many other businesses were actually using ACP/TPF than a conscious decision on IBM's part to market it that way.

Already such companies as American Express, New York City Police, AVIS, GMAC, Federal Express, Western Bank Corporation, Bank of America and several consumer lending companies were ACP/TPF customers alongside the major airlines of the world (with the exception of Aeroflot, the world's largest, although even they may become TPF users before long, 'glasnost' strikes again...).

What follows is how Sabre themselves describe their history, taken from their website http://www.sabre.com

For more than 40 years, Sabre has been developing innovations and transforming the business of travel.

From the original Sabre® computer reservations system in the 1960s .....


The first Sabre system is installed in 1960 on two IBM 7090 computers located in a specially-designed computer center ....

The system.... processes 84 000 telephone calls per day.

initial research, development and installation investment:

400 man-years of effort at a development cost of almost $40 million.

[e cosi' abbiamo una terza stima del costo !!??]

The final Sabre system cutover [ ??? ] is complete in 1964.

The telecommunications network of the system extends from coast to coast in the United States. It is the largest, private real-time data processing system, second only to the U.S. government. .....

the system saves American Airlines 30% on its investments in staff alone,

and delivers an error rate of less than 1%, creating a competitive edge that will last for the next five to seven years.


In 1972, the Sabre system is upgraded to IBM 360s and moved to a new consolidated computer center in Tulsa, Oklahoma, designed to house all of American Airlines' data processing facilities.

The upgrade and move to Tulsa are completed with a total of 15 minutes' interruption of services to the airline's agents.

The Sabre system is installed in a travel agency for the first time in 1976. By year's end, the system is installed in 130 locations. .....

The Sabre system stores 1 million fares in 1978.



Bargain Findersm pricing is introduced in 1984 via the Sabre system.

This low-fare search capability automatically advises which class of service is the least expensive for the flights booked - a service unmatched in the industry.

1985 The introduction of easySabre® allows consumers using personal computers to tap into the Sabre system via computer online services to access airline, hotel and car rental reservations.


1988 Sabre begins providing software, consulting and systems management services to other airlines in areas such as revenue accounting, yield management and crew scheduling.

1988 The Sabre system stores 36 million fares which can be combined to create over 1 billion fare options.



In 1994 Sabre and SNCF (French National Railroad) install the RESARAIL™ rail reservations and distribution system for the TGV network.

The system is subsequently extended to the English Channel Tunnel.

Sabre Y2K work begins in 1995 which involves checking more than 200 million lines of software code, confirming proper interfaces with more than 600 suppliers, providing new software to more than 40,000 travel agents, and testing more than 1,200 hardware and software systems.

Sabre becomes a separate legal entity .... in July of 1996 .....

Also in 1996, Travelocity.com ... the first site to offer travel reservations and comprehensive destination and event information on the Internet.


Sabre completes the largest system migration ever in the airline industry, when 200 US Airways systems are shut down and shifted to Sabre systems.

Sabre launches Best Fare Finder pricing in April, 1999 - an industry-first software product that searches for flights based on specific fares.

Sabre® Virtually There™, a Web-based system that provides travelers with up-to-the minute itinerary and destination information via the Internet is introduced in November, 1999.

Sabre® Sales Manager is also launched in 1999. A software solution that enables airlines to deliver customized marketing messages to travelers.



In November, Sabre introduced Sabre® Aerodynamic Traveler™,

a new suite of passenger processing applications

designed to expedite the airline check-in process ....



Sabre® RovingAgent™ wireless passenger check-in system.

This product lets airline gate agents use a hand-held device to make seat assignments, print boardin passes and bag tags, issue vouchers and handle other routine tasks.

The system makes it simple for airlines to re-accommodate passengers who have missed connecting flights.

Sabre® Wireless Check-In System.

This product uses voiceprint technology

to let travelers check in for flights using their wireless phones.

A bar-coded boarding pass is then transmitted directly to the traveler's wireless phone screen.

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