computer science

Research Unix

Research Unix 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 Research Unix rather than just read about it. In short: Research Unix refers to the early versions of the Unix operating system for DEC PDP-7, PDP-11, VAX, and Interdata 7/32 and 8/32 computers, developed in the Bell Labs Computing Sciences Research Center (CSRC). The term Research Unix first appeared in the Bell System Technical Journal (Vol. 57, No. 6, Part 2 July/August 1978) to distinguish it from other versions internal to Bell Labs (such as PWB/UNIX and MERT) whose…

Key takeaways

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

Reference excerpt

Research Unix refers to the early versions of the Unix operating system for DEC PDP-7, PDP-11, VAX, and Interdata 7/32 and 8/32 computers, developed in the Bell Labs Computing Sciences Research Center (CSRC). The term Research Unix first appeared in the Bell System Technical Journal (Vol. 57, No. 6, Part 2 July/August 1978) to distinguish it from other versions internal to Bell Labs (such as PWB/UNIX and MERT) whose code-base had diverged from the primary CSRC version. However, that term was little-used until Version 8 Unix (1985), but has been retroactively applied to earlier versions as well. Prior to V8, the operating system was most commonly called simply UNIX (in caps) or the UNIX Time-Sharing System. Ancient UNIX is any early release of the Unix code base prior to Unix System III, particularly the Research Unix releases prior to and including Version 7 (the base for UNIX/32V as well as later developments of AT&T Unix).

History AT&T licensed Version 5 to educational institutions, and Version 6 also to commercial sites. Schools paid $200 and others $20,000, discouraging most commercial use, but Version 6 was the most widely used version into the 1980s. Research Unix versions are often referred to by the edition of the manual that describes them, because early versions and the last few were never officially released outside of Bell Labs, and grew organically. So, the first Research Unix would be the First Edition, and the last the Tenth Edition. Another common way of referring to them is as "Version x Unix" or "Vx Unix", where x is the manual edition. All modern editions of Unix—excepting Unix-like implementations such as Coherent, Minix, and Linux—derive from the 7th Edition. Starting with the 8th Edition, versions of Research Unix had a close relationship to BSD. This began by using 4.1cBSD as the basis for the 8th Edition. In a Usenet post from 2000, Dennis Ritchie described these later versions of Research Unix as being closer to BSD than they were to UNIX System V, which also included some BSD code:

Research Unix 8th Edition started from (I think) BSD 4.1c, but with enormous amounts scooped out and replaced by our own stuff. This continued with 9th and 10th. The ordinary user command-set was, I guess, a bit more BSD-flavored than SysVish, but it was pretty eclectic.

Versions

Licensing After the publication of the Lions' book, work was undertaken to release earlier versions of the codebase. SCO first released the code under a limited educational license. Later, in January 2002, Caldera International (later to become SCO Group and made defunct) relicensed (but has not made available) several versions under the four-clause BSD license, up to and including Version 7 Unix (UNIX/32V). As of 2022, there has been no widespread use of the code, but it can be used on emulator systems, and Version 5 Unix runs on the Nintendo Game Boy Advance using the SIMH PDP-11 emulator. Version 6 Unix provides the basis for the MIT xv6 teaching system, which is an update of that version to ANSI C and the x86 or RISC-V platform. The BSD vi text editor is based on code from the ed line editor in those early Unixes. Therefore, "traditional" vi could not be distributed freely, and various work-alikes (such as nvi) were created. Now that the original code is no longer encumbered, the "traditional" vi has been adapted for modern Unix-like operating systems. SCO Group, Inc. was previously called Caldera International. As a result of the SCO Group, Inc. v. Novell, Inc. case, Novell, Inc. was found not to have transferred the copyrights of UNIX to SCO Group, Inc. Concerns have been raised regarding the validity of the Caldera license.

The Unix Heritage Society The Unix Heritage Society was founded by Warren Toomey. First edition Unix was restored to a usable state by a restoration team from the Unix Heritage Society in 2008. The restoration process started with paper listings of the source code which were in PDP-11 assembly language.

Legacy In 2002, Caldera International released Unix V1, V2, V3, V4, V5, V6, V7 on PDP-11 and Unix 32V on VAX as FOSS under a permissive BSD-like software license. In 2017, The Unix Heritage Society and Alcatel-Lucent USA Inc., on behalf of itself and Nokia Bell Laboratories, released V8, V9, and V10 under the condition that only non-commercial use was allowed, and that they would not assert copyright claims against such use.

See also History of Unix List of Unix systems

References

External links

UNIX Evolution (PostScript) by Ian F. Darwin and Geoffrey Collyer Unix heritage - More links and source code for some Research Unix versions The Evolution of the Unix Time-sharing System by Dennis M. Ritchie The Restoration of Early UNIX Artifacts by Warren Toomey, School of IT, Bond University Full Manual Pages documentation for Research Unix 8th Edition. List of new features in Research Unix 9th Edition. Emulator for running UNIX v9. Pamela Jones (August 23, 2003) Ancient UNIX Released Under What Terms?, Groklaw The Unix Heritage Society (TUHS), for the preservation and maintenance of historical UNIX systems code, disk images, and related at TUHS Unix First Edition Manual Pages Restoration of 1st Edition UNIX kernel sources from Bell Laboratories

Illustrations

Worked examples

Example 1 — a first encounter with Research Unix

Start with the simplest possible case. Write down what Research Unix 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 Research Unix 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 Research Unix 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 Research Unix

In research: Research Unix 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 Research Unix 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: Research Unix is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bell Labs Unices, Computing platforms, Discontinued operating systems, so understanding it makes those chapters shorter.
In everyday life: Look for Research Unix 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 Research Unix in 20 minutes

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

Frequently asked questions

What is Research Unix in simple terms?

Why does Research Unix 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 Research Unix?

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 Research Unix.