computer science

TK95

TK95 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 TK95 rather than just read about it. In short: The TK 95 microcomputer was a 1986 ZX Spectrum clone by Microdigital Eletrônica, a company located at São Paulo, Brazil. It was an evolution of the TK90X introduced the previous year.

Key takeaways

TK95 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 TK95 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of TK95 from memory before moving on to harder problems.

Reference excerpt

The TK 95 microcomputer was a 1986 ZX Spectrum clone by Microdigital Eletrônica, a company located at São Paulo, Brazil. It was an evolution of the TK90X introduced the previous year. The case was redesigned (copied from the Plus/4) and the keyboard was said to be "semi-professional" (according to the Brazilian manufacturer), with the addition of some Sinclair BASIC commands that did not exist in the ZX Spectrum's basic set (for user-defined characters – UDG), and better compatibility with the original ZX Spectrum (compared to the TK90X). Like the Spectrum, the machine had 48 kilobytes of RAM. Inside, it had the same processor: Z80A running at 3.58 MHz, a 16 KB ROM chip and some RAM chips (old dynamic rams 4116 and 4416). Microdigital did some reverse engineering to develop a chip with the functions of the original ULA from Sinclair/Ferranti. The modulator was tuned to VHF channel 3 and the TV system was PAL-M (60 Hz). The cassette interface ran at a faster speed than the Spectrum. Only two peripherals were released by Microdigital – a light pen interface and a parallel printer interface. Other companies in Brazil released clone versions of Interface 1 joysticks (Atari 2600-compatibles) and interfaces for 5¼" PC drives (360 KB). The games had questionable legality being close to copies of the originals and the fans of the ZX Spectrum computer in Brazil were counted in tens of thousands.

References

External links

(in Portuguese) – Clube do TK90X TK95 in Old-Computers ZEsarUX – ZX Second-Emulator And Released for UniX (GPL)

Illustrations

Worked examples

Example 1 — a first encounter with TK95

Start with the simplest possible case. Write down what TK95 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 TK95 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 TK95 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 TK95

In research: TK95 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 TK95 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: TK95 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer-related introductions in 1986, Computer hardware stubs, Goods manufactured in Brazil, so understanding it makes those chapters shorter.
In everyday life: Look for TK95 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 TK95 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what TK95 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 TK95 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is TK95 in simple terms?

The TK 95 microcomputer was a 1986 ZX Spectrum clone by Microdigital Eletrônica, a company located at São Paulo, Brazil. It was an evolution of the TK90X introduced the previous year.

Why does TK95 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 TK95?

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 TK95.