computer science

ISO 1745

ISO 1745 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 ISO 1745 rather than just read about it. In short: ISO 1745:1975 Information processing – Basic mode control procedures for data communication systems is an early ISO standard defining a Telex-oriented communications protocol that used the non-printable ASCII transmission control characters SOH (Start of Heading), STX (Start of Text), ETX (End of Text), EOT (End of Transmission), ENQ (Enquiry), ACK (Acknowledge), DLE (Data Link Escape), NAK (Negative Acknowledge), S…

Key takeaways

ISO 1745 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 ISO 1745 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of ISO 1745 from memory before moving on to harder problems.

Reference excerpt

ISO 1745:1975 Information processing – Basic mode control procedures for data communication systems is an early ISO standard defining a Telex-oriented communications protocol that used the non-printable ASCII transmission control characters SOH (Start of Heading), STX (Start of Text), ETX (End of Text), EOT (End of Transmission), ENQ (Enquiry), ACK (Acknowledge), DLE (Data Link Escape), NAK (Negative Acknowledge), SYN (Synchronous Idle), and ETB (End of Transmission Block). It also defines a serial data format, consisting of a start bit, 7 bit ASCII (least significant bit first), a parity bit (even for asynchronous networks, odd for synchronous networks), and a stop bit. The text of ISO 1745:1975 is not currently freely available, but the corresponding ECMA version is. The protocol it defines seems to now be little used.

References

Worked examples

Example 1 — a first encounter with ISO 1745

Start with the simplest possible case. Write down what ISO 1745 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 ISO 1745 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 ISO 1745 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 ISO 1745

In research: ISO 1745 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 ISO 1745 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: ISO 1745 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computing stubs, Ecma standards, ISO standards, so understanding it makes those chapters shorter.
In everyday life: Look for ISO 1745 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 ISO 1745 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what ISO 1745 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 ISO 1745 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is ISO 1745 in simple terms?

Why does ISO 1745 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 ISO 1745?

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 ISO 1745.