computer science

Portal (computer)

Portal (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 Portal (computer) rather than just read about it. In short: Portal R2E CCMC was a portable microcomputer designed and marketed by the Réalisation et Études électroniques department of the French firm R2E Micral, and officially appeared in September 1980 at the Sicob show in Paris. Osborne 1, the first commercially successful portable computer, was only released eight months later, on 3 April 1981.

Key takeaways

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

Reference excerpt

Portal R2E CCMC was a portable microcomputer designed and marketed by the Réalisation et Études électroniques department of the French firm R2E Micral, and officially appeared in September 1980 at the Sicob show in Paris. Osborne 1, the first commercially successful portable computer, was only released eight months later, on 3 April 1981. The machine was designed with a focus on payroll and accounting. Several hundred Portal computers were sold between 1980 and 1983. Surviving machines are extremely rare. No museum has a Portal, and only two are in private collections. The company R2E Micral is also known to have designed "the earliest commercial, non-kit computer based on a microprocessor", the Micral N. One of these machines was sold for 62,000 euros to Paul G. Allen, the co-founder of Microsoft (with Bill Gates), by the auctioneer Rouillac on June 11, 2017, for Allen's Seattle museum, Living Computers: Museum + Labs.

Specifications The Portal was based on an Intel 8085 processor, 8-bit, clocked at 2 MHz. It was equipped with 64 kB of main RAM, a keyboard with 58 alphanumeric keys and 11 numeric keys (in separate blocks), a LED 32-character one-line screen, a floppy disk (capacity - 140000 characters), a thermal printer (speed - 28 characters/second), an asynchronous channel, a synchronous channel, and a 220-volt power supply. The machine required access to mains power. It came with two operating systems: Prologue and Basic Assembly Language (BAL). Designed for an operating temperature of 15 °C to 35 °C, it weighed 12 kg and its dimensions were 45 × 45 × 15 cm.

Illustrations

Worked examples

Example 1 — a first encounter with Portal (computer)

Start with the simplest possible case. Write down what Portal (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 Portal (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 Portal (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 Portal (computer)

In research: Portal (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 Portal (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: Portal (computer) is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1980 establishments in France, 1983 disestablishments in France, Computer-related introductions in 1980, so understanding it makes those chapters shorter.
In everyday life: Look for Portal (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 Portal (computer) in 20 minutes

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

Frequently asked questions

What is Portal (computer) in simple terms?

Why does Portal (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 Portal (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 Portal (computer).