Welcome to the second part of Linux administration series of articles where we gonna take a look at short history of UNIX which was jump board for Linux. Further in article you are going to see rare pictures of Ken Thompson and Dennis Ritchie working on UNIX using PDP11, a robust computer developed back in 1970. Trough the article, we shall see a part on GNU/Linux naming controversy why GNU/Linux and not Linux operating system as wee shall see the opinion of Richard Stallman, founder of FSF and GNU.
Short history of UNIX
To understand the story of Linux, we must first take a look at UNIX (Uniplexed Information and Computing System) and it’s history. UNIX started back in 1969 (fifty years ago) at Bell Labs of AT&T. These guys have just withdrawn from project called MULTICS, which was designed to create an operating system so that a large computers can support thousands of users simultaneously. Two key software mind behind the UNICS were Ken Thompson and Dennis Ritchie who found a DEC PDP7 computer at Bell Lab to develop parts of UNIX (Esteve, 2007 : 23).
Figure 1: DEC PDP 7 computer used by Thompson and Ritchie in their UNIX development
Figure source: https://en.wikipedia.org/wiki/PDP-7
In short, PDP (Programmed Data Processor) was a computer developed by American computer company DEC (Digital Equipment Corporation) back in 1969. They were a robust computer featuring 18-bit architecture, 9.2 KB of RAM and use tape drive for storage. For Ritchie and Thompson, DEC PDP7 was important as it contained assembler required for them to write parts of UNIX. They will later move their UNIX development to DEC PDP11 which features a general-purpose register that made it much easier to program than previous models. It was on PDP11 that Dennis Ritchie developed and released it’s widely known C-programming language and first release of UNIX came out on PDP11 machine.
Figure 2: Dennis Rithcie and Ken Thompson working on UNIX using PDP11 computer
Figure source: https://en.wikipedia.org/wiki/Ken_Thompson
That same year, Thompson wrote a UNIX filesystem and in order to complete their first UNIX release, they purchased PDP11 computer feature in above image. Soon with the help of others, they develop text processor named Troff, a tool later used to develop UNIX man pages (Esteve, 2007 : 24).
In November 1971, Thompson published very first UNIX Programmers Manual. Second edition came out in June 1972 and UNIX reached up to 10 installation that same year. Then, in 1973 they organize very first operating system conference and after that various IT centres and Universities adopt UNIX and join in it’s development (Esteve, 2007 : 24).
One of the University to have obtained a UNIX license was the University of California at Berkeley, where Ken Thompson had studied. In 1975, Thompson returned to Berkeley as a teacher bringing with him the latest version of UNIX and start to teach students on UNIX and it’s development. Two recent graduates by name Chuck Haley and Bill Joy, join him and started to work on a UNIX development. Joy very quickly perfected an editor called EX, which later becomes well known VI, a full screen visual editor. Soon, they develop a BSD a Berkeley Software Distro (Esteve, 2007 : 25).
BSD was a major success so Joy later added new features to it’s vi editor such as handling text terminals in such way that the editor was independent of terminal where it was being used. The next thing was it’s architecture since UNIX run only on PDP, they expended it on Interdata and IBM machines. One of the feature they added to UNIX back in 1997 was a C compiler, developed by Dennis Ritchie. Later, they also added Bourne shell (written and named by America programmer Stephen R. Bourne), also known today as Bourne Again Shell or BASH. Later, that same year they added several BASH commands such as: find, cpio, expr, awk, make and others (Esteve, 2007 : 25).
Back in those years, AT&T soon realised that UNIX was a valuable commercial product so they come up with their own commercial license which prohibited it’s study as well as access to it’s source code. Everyone willing to participate in UNIX development were force to find other way around. Back in Amsterdam, Andrew Tanenbaum, famous author on computing science, decided to write his own UNIX like operating system which he called Minix, the same OS later used by Torvalds in writing his Linux kernel (Esteve, 2007 : 26).
Bill Joy, developer of BSD, soon transfer to the newly founded company SUN Microsystems where he completed BSD 4.2 edition, later used by the company in making their own Sun OS, known today as Solaris OS. Very soon other type of UNIX operating system appear such as IRIX OS which runs and powered SGI (Silicon Graphics International) workstation such as SGI Indigo.
Figure 3: SGI Octane 2 MIPS graphical workstation running IRIX 6.5
Figure source: https://picclick.com/Silicon-Graphics-Octane2-SGI-Octane-2-Great-283188155607.html
Believe or not, this are the most powerful PC’s/workstation developed back in 1970 and trough 1990 and later on. One such machine costed up to $1000 sometimes up ten of thousand dollars, depending on the power, hardware and performances they were running. Showed above is SGI Octane 2 MIPS graphical workstation used in 3D modeling and animation. It was direct replacement of SGI Indigo2 machines and it runs on IRIX 6.5 OS, but were way expensive and SGI soon discontinued it’s production in 2004. Overtime, the UNIX system split into several branches of which two stands out AT&T/UNIX System V and BSD(Esteve, 2007 : 26). Today, UNIX is own by Open Group, previously known as Open Software Foundation.
Is it Linux or GNU/Linux?
There is a still great debate on what is Linux and how to pronounce it, other words, why Linux is not operating system and why do we use the term GNU/Linux? To answer this question we need to go back to the year 1984 when Richard Stallman started it’s work on GNU operating system. Since GNU operating system was developed in unique philosophy regarding the freedom to share and redistribute the software to everyone else under the terms that all the changes you made to the software must be public and accessible to everyone else so they can contribute, the missing part was a kernel, the core of operating system.
Due to fact that Stallman needed the kernel to complete it’s GNU operating system, he started it’s work on HURD, a kernel for it’s system back in 1990. Next year, Torvalds published it’s Linux kernel and so Stallman completed it’s GNU/Linux operating system. To find answers on our questions, we must take a look inside of the GNU Manifesto, a document written by Stallman it self where he described what GNU is and how does GNU and Linux come together to form GNU/Linux.
Further more Stallman wrote the following:
Just as I explained earlier, Linux it self is just the kernel, the core of operating system. But in order to do something with it, it needs bunch of other tools, utilities, applications, graphic user interface such as GNOME, MATE, Unity, X.org server, and when we packed all this into single package, we get the working Linux distribution, otherwise known as GNU/Linux.
Stallman explained it’s main goal behind the GNU operating system as well as why it is important for GNU to be free? Here’s what he has written in his GNU manifesto regarding this.
So, here’s the following summary regarding the GNU operating system:
- GNU/Linux is open source and accessible to everyone. Meaning that you are no longer at the mercy of single company who will take your money in order to give you support.
- It’s source code is completely free and available to everyone.
- You can modify it and make each Linux distribution do the exact job you want.
- You can sale changes made in the source code under the rules of GNU/GPL license. Meaning, every single change you made in the source code must be available to public alongside with it’s GNU/GPL license.
Here’s what Richard Stallman has to say on freedom of sharing, modifying and sailing programs according to GNU/General Public License v1.0.
In his second paragraph of his GNU/GPL license v1.0, Stallman states that if you want to sell the modified software with your own changes or charge for your support, you can do so as long as you follow the following terms.
Historic Linux facts
Here are couple interesting historic Linux facts that you may not know. For instance, the oldest and very fist Linux distribution was MCC Interim Linux.
Down bellow is Yggdrasil Linux, a very fist distribution that uses term GNU in front it’s name. Check the rest of short information banner.
Regarding Yggdrasil Linux, one thing must be clear. First, it was released some 11. months later after the release of MCC Interim, the very first Linux distribution released on February 1992 by Manchester Computing Center at the University of Manchester in England. It costed up between $60 for it’s beta version while production release which features bunch of utilities and packed software, costed around $100. Further to note, it was the first Linux distribution that provided live cd mode.
Summary
- UNIX is operating system developed in 1969 by Ken Thompson and Dennis Ritchie on a DEC PDP 7/11 computer. It was multi-tasking, multi-user operating system adopted by various IT centres and Universities in USA at that time and is still in development today.
- Using UNIX, Andrew Tanenbaum, american computer programmer developed MINIX operating system in 1987, same operating system which was later used by Linus Torvalds in his development of Linux.
- One of the most famous UNIX-like operating system was IRIX which was used on SGI work station and servers (see references down bellow).
- Linux is a kernel developed by Linus Torvalds in 1991 and was later put together with Richard Stallman GNU operating system, a set of packages, utilities, applications and graphic user interface which together form a GNU/Linux distribution, known by others as Linux operating system.
- GNU/Linux operating system uses a unique license known as GNU/GPL – General Project License developed by Richard Stallman. It is available in three version being first one GNU/GPL v1.0 released in 1989, the same license later used by Linus Torvalds in his Linux kernel (see the references for other GNU/GPL licenses).
- GNU/Linux uses GNU Manifesto, document written by Richard Stallman in 1983 where he explained why the software should be open source and free and what are the benefits of free and open source software for users as well as business oriented customers. He also explained how you can make a money using the GNU operating system and it’s open source software (see the references).
- The very first Linux distribution was MCC Interim Linux released on February 1992 by Owen La Blanc at the Manchester Computing Center at the University of Manchester.
- First distribution to use the term GNU was Yggdrasil GNU/Linux/X, Linux distribution developed on 8. December 1992 by Yggdrasil Computing Inc. Among other things, it was a distribution which introduced very first live cd of it’s edition.
Bibliographic references
Esteve, Josep (2007)
[1] GNU Linux advanced administration
© Eureca Media, SL 2007 – 2019, Barcelon, p 23 – 26
On-line references
[1] Is it Linux or GNU/Linux?
https://www.linuxjournal.com/content/it-linux-or-gnulinux
[2] GNU Manifesto
https://www.gnu.org/gnu/manifesto.html
[3] Overview of GNU/GPL license v1.0
https://www.gnu.org/licenses/old-licenses/gpl-1.0.html
[4] MCC Interim Linux
https://en.wikipedia.org/wiki/MCC_Interim_Linux
[5] Yggdrasil GNU/Linux/X
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