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Traf-O-Data

Traf-O-Data is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Traf-O-Data rather than just read about it. In short: Traf-O-Data was a business partnership between Bill Gates, Paul Allen and Paul Gilbert that existed in the 1970s. The objective was to read the raw data from roadway traffic counters and create reports for traffic engineers.

Traf-O-Data — main illustration
Traf-O-Data — illustration

Key takeaways

  • Traf-O-Data belongs to computer science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Traf-O-Data to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Traf-O-Data from memory before moving on to harder problems.

Reference excerpt

Traf-O-Data was a business partnership between Bill Gates, Paul Allen and Paul Gilbert that existed in the 1970s. The objective was to read the raw data from roadway traffic counters and create reports for traffic engineers. The company had only modest success but the experience was instrumental in the creation of Microsoft Corporation a few years later.

History

In the 1970s, traffic counts were mechanically recorded on a roll of paper tape. The time and number of axles were punched as a 16 bit pattern into the paper. Bill Gates and Paul Allen were high school students at Lakeside School in Seattle. The Lakeside Programmers Group got free time on various computers in exchange for writing computer programs. Gates and Allen thought they could process the traffic data cheaper and faster than the local companies by building a computer that could process all the traffic tapes using the Intel 8008 processor. The goal was to sell such machines to states and local governments as a time and cost-saving tool. Since Gates and Allen did not know how to build a computer capable of processing data on paper tapes, they recruited Paul Gilbert to help build a prototype that can manually read the hole-patterns in the paper tape and transcribe the data onto computer cards. Gilbert became the third partner. Gates then used a computer at the University of Washington to produce the traffic flow chart. This was the beginning of Traf-O-Data.

Hardware

The next step was to build a device to read the traffic tapes directly and eliminate the tedious manual work. The Intel 8008 microprocessor was announced in 1972 and they realized it could read the tapes and process the data. Allen had graduated and was enrolled at Washington State University. Since neither Gates nor Allen had any hardware design experience, they were initially stumped. Gates and Allen had a friend, Paul Wennberg, who, like them, loitered at Control Data Corporation near the University of Washington, cadging open time on the mainframe computer. Wennberg, later the founder of the Triakis Corporation, was an electrical engineering student at the University of Washington. Over the course of events Gates and Allen mentioned they were looking for somebody to build them a computer for free. They needed somebody good enough to build a computer from parts and the diagrams found in a computer magazine. Wennberg talked to his friend, Wes Prichard, who suggested to Wennberg that Gates and Allen head over to the UW Physics building, now known as Mary Gates Hall, to talk to Paul Gilbert, another electrical engineering student, who worked in the high-energy tracking laboratory. It was there that Paul Gilbert was approached by the duo to become a partner in Traf-O-Data. In that year, Gilbert built the working microcomputer. Miles Gilbert, Paul Gilbert's brother, a graphic designer and draftsman, helped the fledgling company by designing the company's logo. Gates and Allen started writing the software. To test the software while the computer was being designed, Paul Allen wrote a computer program on WSU's PDP-10 that would emulate the 8008 microprocessor. Although the plan had been to manufacture and sell the machines:

"... when the guy from the County that Seattle's in came to see it, it didn't work. We ended up being okay successful, not seriously successful ... just by processing the tapes. At first, that was a very manual process. Then we used this prototype machine that we built to do that. So, we made a little bit of money and had some fun with it." Later, the State of Washington offered free traffic processing services to cities, ending the need for private contractors, and all three principals moved on to other projects. The real contribution of Traf-O-Data was the experience that Gates and Allen gained, skills they used to write Altair BASIC for the MITS Altair 8800 computer:

"Even though Traf-O-Data wasn't a roaring success, it was seminal in preparing us to make Microsoft's first product a couple of years later. We taught ourselves to simulate how microprocessors work, using DEC computers, so we could develop software even before our machine was built."

References

Illustrations

Traf-O-Data illustration
Traf-O-Data: Business card showing the names of Gates, Allen, and Gilbert from the New Mexico Museum of Natural History and Science
Business card showing the names of Gates, Allen, and Gilbert from the New Mexico Museum of Natural History and Science
Traf-O-Data: Traf-O-Data 8008 computer with a tape reader
Traf-O-Data 8008 computer with a tape reader

Worked examples

Example 1 — a first encounter with Traf-O-Data

Start with the simplest possible case. Write down what Traf-O-Data claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Traf-O-Data before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Traf-O-Data ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Traf-O-Data

In research
Traf-O-Data appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Traf-O-Data in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Traf-O-Data is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1972 establishments in Washington (state), 1975 disestablishments in Washington (state), Bill Gates, so understanding it makes those chapters shorter.
In everyday life
Look for Traf-O-Data outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Traf-O-Data in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Traf-O-Data means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Traf-O-Data out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Traf-O-Data in simple terms?

Traf-O-Data was a business partnership between Bill Gates, Paul Allen and Paul Gilbert that existed in the 1970s. The objective was to read the raw data from roadway traffic counters and create reports for traffic engineers.

Why does Traf-O-Data matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Traf-O-Data?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Traf-O-Data.

Tags

  • 1972 establishments in Washington (state)
  • 1975 disestablishments in Washington (state)
  • Bill Gates
  • Computer companies disestablished in 1975
  • Computer companies established in 1972
  • Defunct companies based in Seattle
  • Defunct computer companies of the United States
  • Defunct computer hardware companies
  • Transport companies disestablished in 1975
  • Transport companies established in 1972
  • Transportation engineering

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