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TRW Vidar

TRW Vidar is a 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 TRW Vidar rather than just read about it. In short: TRW Vidar was an American telecommunications company, owned by TRW Inc., that made digital telephone switches from the mid-1970s to the early 1980s. They were the first, or one of the first, companies to make such a switch.

Key takeaways

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

Reference excerpt

TRW Vidar was an American telecommunications company, owned by TRW Inc., that made digital telephone switches from the mid-1970s to the early 1980s. They were the first, or one of the first, companies to make such a switch. Before being acquired by TRW Inc., they were known as Vidar Corporation and later, after a buyout, they were known as American Digital Switching.

History

Vidar Corporation Vidar Corporation was founded in 1959 and was headquartered in Mountain View, California. Its initial business focus was making solid-state electronics and related instruments for automatic control systems. By 1960 it was filing patent applications in the electronic instrumentation area. Its product line included temperature gauges and strain gauges. By the mid-1960s it had added a manufacturing facility, in San Luis Obispo, California. Vidar Corporation frequently hired engineering graduates from Stanford University. During the 1960s, Vidar's products used analog circuitry, but they were beginning the switch to digital elements. By the late 1960s, Vidar was focused on making telecommunications equipment as well as components for data processing. Vidar Corporation was acquired by Continental Telephone Corporation in May 1970 for around $20 million. The Vidar subsidiary continued to focus on making telecommunications equipment. It had positive results in 1973, with profits of over $4 million on revenues of over $38 million, but in 1974 revenues fell sharply to $21 million and the subsidiary lost over $4 million.

TRW Vidar The Vidar division was acquired from Continental Telephone by TRW, Inc., a large conglomerate in a number of businesses, in May 1975 for $14 million. At that point it became known as TRW Vidar; they additionally had offices in Sunnyvale, California, which after a while became their headquarters. Organizationally, TRW Vidar was part of the larger TRW Electronics organization. TRW Vidar's first product was the IMA2 switch. It then produced the ITS-5 switch, which met the Class-5 telephone switch requirements, the ITS-4 switch, which met the Class-4 telephone switch requirements, and the ITS-4/5 switch, which included both functionalities. The market for the TRW Vidar switches was independent telephone companies, and among the more prominent users of the switch were GTE and United Telephone as well as Continental Telephone. Computationally, the control processing for the TRW Vidar ITS switches was done by two Intel 8080 microprocessors, in a high use/low use, fault-tolerant configuration. According to recollections published in the Embedded Muse newsletter, the control code was written in the C programming language and cross-compiled to the 8080 from a PDP-11 minicomputer running Version 6 Unix. According to a 1989 Orlando Sentinel story, TRW Vidar "installed the industry's first digital switch in 1976." TRW Vidar declared, in the January 1978 issue of SIGNAL Magazine, "The IMA2, TRW Vidar's all solid-state switch, in service since March 1976, is the first system in North America to operate integrated digital T-carrier transmission with digital switching." However, according to the website Telephone World, TRW Vidar "produced and demonstrated the first digital central office switch" but were beaten to an actual installation of a commercial production digital switch by Northern Telecom and its DMS-10, and the first commercial installations of TRW Vidar switches did not happen until 1978. Still another account is presented in the 1982 book Digital Telephony by industry author John Bellamy, which states that TRW Vidar's IMA2 was the first digital toll switch in operation but that the first digital end office switch was one from Stromberg-Carlson. In any case, TRW Vidar was certainly one of the first companies to produce a working digital switch for use in central offices. By 1982 there were stresses within the telephony industry due to the breakup of the Bell System and the early 1980s recession in the United States. The Vidar business was characterized by large development and start-up costs and a low near-term size of the independent companies market. Moreover, the Vidar unit did not fit into TRW's strategic plans. Accordingly, TRW Vidar withdrew from active engagement in the digital switch marketplace. In the view of several executives involved with TRW Vidar, the TRW parent never really understood what they had at the time. One such executive left TRW in 1979 and, partly inspired by the difficulties he saw TRW going through, co-founded The Santa Cruz Operation (SCO), which became the leading company providing the Unix operating system on Intel commodity hardware. As a result, some have considered SCO to have been an offshoot of TRW Vidar. The CEO of TRW Vidar offered to buy out the company almost as soon as it withdrew from the digital switch market. The Vidar switch continued to be used by independent telephone companies for the next several years, however, although those companies were concerned about the level of servicing and support the switch would receive from TRW.

American Digital Switching In 1989, a buyout actually took place. American Digital Switching came into creation as the result of a joint management-and-customer buyout of the Vidar switch business from TRW. This kind of buyout was unusual; the new firm, headquartered in Melbourne, Florida, was owned by three co-founding former employees of TRW Vidor, an investment firm, and some twenty-four different independent telephone companies. The new company's main product was developed as the Centura 2000 switch. In 1996, American Digital Switching was acquired by Symetrics Industries, Inc. and began operating as a subsidiary of Symetrics. At that point American Digital Switching was described as "a provider of central-office digital switching systems and support services to telephone companies in rural communities." By the late 1990s, sales of the Centura 2000 switch were not growing. The American Digital Switching subsidiary was still in business as of the year 2000. But by 2001 they were not, and what property American Digital Switching had remaining was put up at a Brevard County, Florida auction.

See also List of telephone switches

References

Further reading A. Joel, "Digital Switching – How It Has Developed", in IEEE Transactions on Communications, vol. 27, no. 7, pp. 948–959, July 1979, doi: 10.1109/TCOM.1979.1094511.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with TRW Vidar

Start with the simplest possible case. Write down what TRW Vidar claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In 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 TRW Vidar 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 TRW Vidar 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 TRW Vidar

In research
TRW Vidar appears in 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 TRW Vidar 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
TRW Vidar is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1959 establishments in California, 2001 disestablishments in Florida, Companies based in Brevard County, Florida, so understanding it makes those chapters shorter.
In everyday life
Look for TRW Vidar 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 TRW Vidar in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what TRW Vidar 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 TRW Vidar out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is TRW Vidar in simple terms?

TRW Vidar was an American telecommunications company, owned by TRW Inc., that made digital telephone switches from the mid-1970s to the early 1980s. They were the first, or one of the first, companies to make such a switch.

Why does TRW Vidar matter?

Because it connects several 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 TRW Vidar?

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 TRW Vidar.

Tags

  • 1959 establishments in California
  • 2001 disestablishments in Florida
  • Companies based in Brevard County, Florida
  • Companies based in Mountain View, California
  • Companies based in Sunnyvale, California
  • Defunct telecommunications companies of the United States
  • TRW Inc.
  • Telecommunications equipment vendors

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