science

NCR VRX

NCR VRX is a 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 NCR VRX rather than just read about it. In short: VRX is an acronym for Virtual Resource eXecutive, a proprietary operating system on the NCR Criterion series, and later the V-8000 series of mainframe computers manufactured by NCR Corporation during the 1970s and 1980s. It replaced the B3 Operating System originally distributed with the Century series, and inherited many of the features of the B4 Operating System from the high-end of the NCR Century series of compu…

Key takeaways

NCR VRX belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NCR VRX to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NCR VRX from memory before moving on to harder problems.

Reference excerpt

VRX is an acronym for Virtual Resource eXecutive, a proprietary operating system on the NCR Criterion series, and later the V-8000 series of mainframe computers manufactured by NCR Corporation during the 1970s and 1980s. It replaced the B3 Operating System originally distributed with the Century series, and inherited many of the features of the B4 Operating System from the high-end of the NCR Century series of computers. VRX was upgraded in the late 1980s and 1990s to become VRX/E for use on the NCR 9800 (Criterion) series of computers. Edward D. Scott managed the development team of 150 software engineers who developed VRX and James J "JJ" Whelan was the software architect responsible for technical oversight and the overall architecture of VRX. Tom Tang was the Director of Engineering at NCR responsible for development of the entire Criterion family of computers. This product line achieved over $1B in revenue and $300M in profits for NCR. VRX was shipped to its first customers, on a trial basis, in 1977. Customer sites included the United Farm Workers labor union, who in 1982 were running an NCR 8555 mainframe running VRX. VRX was NCR's response to IBM's MVS virtual storage operating system and was NCR's first virtual storage system. It was based on a segmented page architecture provided in the Criterion architecture. The Criterion series provided a virtual machine architecture which allowed different machine architectures running under the same operating system. The initial offering provided a Century virtual machine which was instruction compatible with the Century series and a COBOL virtual machine designed to optimize programs written in COBOL. Switching between virtual machines was provided by a virtual machine indicator in the subroutine call mechanism. This allowed programs written in one virtual machine to use subroutines written for another. The same mechanism was used to enter an "executive" state used for operating system functions and a "privileged system" state used for direct access to hardware.

References

Worked examples

Example 1 — a first encounter with NCR VRX

Start with the simplest possible case. Write down what NCR VRX claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In 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 NCR VRX 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 NCR VRX 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 NCR VRX

In research: NCR VRX appears in 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 NCR VRX 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: NCR VRX is common in secondary-school and first-year university syllabi. It links to neighbouring topics NCR Corporation products, Operating system stubs, Proprietary operating systems, so understanding it makes those chapters shorter.
In everyday life: Look for NCR VRX 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study NCR VRX in 20 minutes

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

Frequently asked questions

What is NCR VRX in simple terms?

Why does NCR VRX matter?

Because it connects several 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 NCR VRX?

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 NCR VRX.