computer science

Model V

Model V 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 Model V rather than just read about it. In short: The Model V was among the early electromechanical general purpose computers, designed by George Stibitz and built by Bell Telephone Laboratories and became operational in 1946. Only two machines were built: first one was installed at National Advisory Committee for Aeronautics (NACA, later NASA), the second (1947) at the US Army’s Ballistic Research Laboratory (BRL).

Key takeaways

Model V 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 Model V to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Model V from memory before moving on to harder problems.

Reference excerpt

The Model V was among the early electromechanical general purpose computers, designed by George Stibitz and built by Bell Telephone Laboratories and became operational in 1946. Only two machines were built: first one was installed at National Advisory Committee for Aeronautics (NACA, later NASA), the second (1947) at the US Army’s Ballistic Research Laboratory (BRL).

Construction Design was started in 1944. The tape-controlled (Harvard architecture) machine had two (design allowed for a total of six) processors ("computers") that could operate independently, an early form of multiprocessing. The Model V weighed about 10 short tons (9.1 t).

Significance Inspired Richard Hamming to investigate the automatic error-correction, which led to invention of Hamming codes One of the early electromechanical general purpose computers First American machine and first George Stibitz design to use floating-point arithmetic Had an early form of multiprocessing Had a very primitive form of an operating system, albeit in hardware. A separate hardware control unit existed to direct the sequence of computer operations.

Model VI Built and used internally by Bell Telephone Laboratories, operational in 1949. Simplified version of the Model V (only one processor, about half the relays) but with several improvements, including one of the earliest use of the microcode.

Bibliography Research, United States Office of Naval (1953). A survey of automatic digital computers. Models V and VI. Office of Naval Research, Dept. of the Navy. pp. 9–10 (in reader: 15–16). "The relay computers at Bell Labs : those were the machines, part 2". Datamation. The relay computers at Bell Labs : those were the machines, parts 1 and 2 | 102724647 | Computer History Museum. part 2: pp. 47, 49. May 1967. Irvine, M. M. (July 2001). "Early digital computers at Bell Telephone Laboratories". IEEE Annals of the History of Computing. 23 (3): 25–27. doi:10.1109/85.948904. ISSN 1058-6180. pdf Kaisler, Stephen H. (2016). "Chapter Three: Stibitz's Relay Computers". Birthing the Computer: From Relays to Vacuum Tubes. Cambridge Scholars Publishing. pp. 35–37. ISBN 9781443896313. "Г. – Bell Labs – Model V" [G. – Bell Labs – Model V]. oplib.ru (in Russian). Archived from the original on September 29, 2022. Retrieved 2017-10-11.

Further reading Alt, Franz L. (1948). "A Bell Telephone Laboratories' computing machine. I". Mathematics of Computation. 3 (21): 1–13. doi:10.1090/S0025-5718-1948-0023118-1. ISSN 0025-5718. Alt, Franz L. (1948). "A Bell Telephone Laboratories' computing machine. II". Mathematics of Computation. 3 (22): 69–84. doi:10.1090/S0025-5718-1948-0025271-2. ISSN 0025-5718. Tomash, Erwin (2008). "The Erwin Tomash Library on the History of Computing: An Annotated and Illustrated Catalog". www.cbi.umn.edu. CBI Hosted Publications. Image: Bell Labs Model V.drawing of Model V, description: A Chapter, pp. 36-37. Retrieved 2018-05-08. Andrews, Ernest G. (1949-09-01). "The Bell Computer, Model VI". Proceedings of a Second Symposium on Large-scale Digital Calculating Machinery: 20–31 (58–69). "Bell Laboratories Digital Computers". Bell Laboratories Record. www.americanradiohistory.com. XXXV (3): 81–84. Mar 1957. Ceruzzi, Paul E. (1983). "4. Number, Please - Computers at Bell Labs". Reckoners: The Prehistory of the Digital Computer, from Relays to the Stored Program Concept, 1935-1945. Greenwood Publishing Group, Incorporated. pp. 95–99. ISBN 9780313233821. Bullynck, Maarten (2015). "3. Bell Model V Calculator: Tapes and Controls". Programming men and machines. Changing organisation in the artillery computations at Aberdeen Proving Ground (1916-1946). pp. 9–12.

References

External links "Control Panel, Bell Telephone Laboratories Model 5 Computer". National Museum of American History.

Illustrations

Worked examples

Example 1 — a first encounter with Model V

Start with the simplest possible case. Write down what Model V 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 Model V 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 Model V 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 Model V

In research: Model V 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 Model V 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: Model V is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1940s computers, AT&T computers, Bell Labs, so understanding it makes those chapters shorter.
In everyday life: Look for Model V 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 Model V in 20 minutes

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

Frequently asked questions

What is Model V in simple terms?

Why does Model V 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 Model V?

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 Model V.