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Pocket computer

Pocket computer 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 Pocket computer rather than just read about it. In short: A pocket computer is a class of handheld computer characterized by very short displays (typically accommodating only one or a handful of lines of text) and calculator-style alphanumeric keypads. Pocket computers occupy a small footprint, allowing the unit to be comfortably stashed in one's pocket when on the go, and usually weigh less than 1 pound (0.45 kg).

Pocket computer — main illustration
Pocket computer — illustration

Key takeaways

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

Reference excerpt

A pocket computer is a class of handheld computer characterized by very short displays (typically accommodating only one or a handful of lines of text) and calculator-style alphanumeric keypads. Pocket computers occupy a small footprint, allowing the unit to be comfortably stashed in one's pocket when on the go, and usually weigh less than 1 pound (0.45 kg). Many feature a port for an expansion chassis, allowing the computers to be used with external peripherals. Pocket computers had their peak of popularity in the early 1980s, but sales quickly plateaued and declined in Western markets as consumers became aware of their limitations. In Japan, where they were invented, pocket computers maintained their popularity and continued to be used as teaching aids into the 21st century.

History

The first pocket computer was the Sharp PC-1211, introduced in March 1980 by Sharp Corporation and sold exclusively outside of the US market. Later in 1980, the PC-1211 was resold and rebranded by Tandy Corporation in the United States as the TRS-80 Pocket Computer (PC-1). The invention of the pocket computer was prefigured by pocketable programmable calculators, such as Hewlett-Packard's HP-65 in 1974. Within a couple of years of the PC-1211's release, many other manufacturers, including Hewlett-Packard, Panasonic, and Casio, announced their own pocket computers. Many pocket computers feature ports for an expansion chassis, allowing the computers to be used with external peripherals. Such peripherals include data cassettes, printers, plotters, and modems. Sharp's PC-1401, released in 1983, merged the scientific calculator and pocket computer for the first time through the addition of scientific calculation function buttons to the side. This served as the foundation for competing clone models by Casio and HP. Toward the end of the 1980s, a number of pocket computers were developed with larger screens capable of displaying both graphics and text. Pocket computers had a surge of popularity on their market introduction in the early 1980s. In 1983, however, sales of pocket computers dropped considerably; Radio Shack reported that they had shipped 40,000 units of their pocket computers in 1983, compared to 70,000 in 1982. According to InfoWorld, this drop was due to both ambiguous marketing and consumers becoming become aware of the limitations of pocket computers. Owing to their limited random-access memory (RAM), the extent of the built-in software of most early pocket computers was limited to a simple interpreter, usually for the BASIC and Fortran programing languages. The few aftermarket commercial software titles that were available for these pocket computers were very limited in scope and capability, due to the lack of RAM and limited screen real estate. This reduced their mass-market appeal, and by the mid-1980s the user-base of pocket computers comprised largely scientific engineers, surveyors, and technicians. Additionally, the diminutive keypads rendered touch typing impossible for almost all pocket computer users. Sales of pocket computers in the West had all but stalled by the late 1980s with the transition away from home computers to the IBM PC paradigm. In these Western markets they were succeeded by so-called handheld PCs, like the Poqet PC and the Atari Portfolio, which were both software-compatible with the IBM PC and featured more RAM. For those who did not need advanced programming capability, electronic organizers such as the Sharp Wizard proliferated in the 1990s among casual users and businesspeople. In Japan, however, pocket computers managed to stay popular into the early 21st century, finding use as a teaching aid in education. The last pocket computers manufactured by Sharp, the PC-G850 series, were released in 2001 and featured 24-column, 6-line dot-matrix LCDs while being powered by CMOS-based Z80-compatible processors.

See also Personal digital assistant Smartbook Ultra-mobile PC

References

External links

The Pocket Computer Museum List of pocket computer manufacturers at Epocalc.net

Illustrations

Pocket computer: Sharp PC-E500S pocket computer
Sharp PC-E500S pocket computer
Pocket computer: The Sharp PC-1211, the first pocket computer, in a travel case
The Sharp PC-1211, the first pocket computer, in a travel case

Worked examples

Example 1 — a first encounter with Pocket computer

Start with the simplest possible case. Write down what Pocket computer 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 Pocket computer 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 Pocket computer 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 Pocket computer

In research
Pocket computer 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 Pocket computer 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
Pocket computer is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer-related introductions in 1980, Japanese inventions, Pocket computers, so understanding it makes those chapters shorter.
In everyday life
Look for Pocket computer 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 Pocket computer in 20 minutes

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

Frequently asked questions

What is Pocket computer in simple terms?

A pocket computer is a class of handheld computer characterized by very short displays (typically accommodating only one or a handful of lines of text) and calculator-style alphanumeric keypads. Pocket computers occupy a small footprint, allowing the unit to be comfortably stashed in one's pocket w…

Why does Pocket computer 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 Pocket computer?

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 Pocket computer.

Tags

  • Computer-related introductions in 1980
  • Japanese inventions
  • Pocket computers

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