Evolution of Operating Systems
PHASE-1
GENESIS
Introduction
1. It started all in 1969 with
the development of UNIX ,which was originally developed at Bell
Laboratories as a private research project by a small group of people
(K. Thompson, Dennis M Ritchie, M. D. McIlroy,
J. F. Ossanna), starting in 1969 after
their lab withdrew from the MULTICS ?project. When Multics was
withdrawn Ken Thompson and Dennis Ritchie needed to rewrite an
operating system in order to play space travel on another smaller
machine (a DEC PDP-7 [Programmed Data Processor 4K memory for user
programs).So they started to develop an Operating system.. The goals
of the group were to design an operating system to satisfy the
following objectives:
(a) Simple
and elegant.
(b) Written
in a high level language rather than assembly language.
(c) Allow
re-use of code.
2. The
result was a system which a punning colleague called UNICS (Uniplexed
Information and Computing Service)-an ’emasculated Multics’ UNIX had
a relatively small amount of code written in assembly language (this
is called the kernel) and the remaining code for the operating system
was written in a high level language called C. But UNIX itself was
far more expensive. In quest of big money, the UNIX vendors priced it
high enough to ensure small PC users stayed away from it. The source
code of UNIX, once taught in universities courtesy of Bell Labs, was
now cautiously guarded and not published publicly. To add to the
frustration of PC users worldwide, the big players in the software
market failed to provide an efficient solution to this problem. A
solution seemed to appear in form of MINIX. It was written from
scratch by Andrew S. Tannenbaum, a Dutch
professor who wanted to teach his students the inner workings of a
real operating system. It was designed to run on the Intel 8086
microprocessors that had flooded the world market. As an operating
system, MINIX was not a superb one. But it had the advantage that the
source code was available. Anyone who happened to get the book
‘Operating System’ by Tannenbaum could get
hold of the 12,000 lines of code, written in C and assembly language.
3. For
the first time, an aspiring programmer or hacker could read the
source codes of the operating system, which to that time the software
vendors had guarded vigorously. In 1991, Linus Benedict Torvalds
was a second year student of Computer Science at the University of
Helsinki and a self-taught hacker was working on MINIX. But all that
was lacking was an operating system that could meet the demands of
the professionals. MINIX was good, but still it was simply an
operating system for the students, designed as a teaching tool rather
than an industry strength one. At that time, programmers worldwide
were greatly inspired by the GNU project by Richard Stallman,
a software movement to provide free and quality software. In the
early eighties, commercial software companies negotiated
stringent
nondisclosure agreements to protect their secrets. But Stallman had a
different vision. His idea was that unlike other products, software
should be free from restrictions against copying or modification in
order to make better and efficient computer programs. With his famous
1983 manifesto that declared the beginnings of the GNU project, he
started a movement to create and distribute softwares that conveyed
his philosophy (Incidentally, the name GNU is a recursive acronym
which actually stands for ‘GNU is Not Unix’). But to achieve this
dream of ultimately creating a free operating system, he needed to
create the tools first.
4. So,
beginning in 1984, Stallman started writing the GNU C Compiler (GCC),
an amazing feat for an individual programmer considered as one of the
most efficient and robust compilers ever created. By 1991, the GNU
project created a lot of the tools. The much awaited GNU C compiler
was available by then, but there was still no operating system. Even
MINIX had to be licensed.
5. Then
in August, 1991 Linus Trovalds uploaded his
code of his Kernel (Linux 0.01) on the university website and along
with GNU applications bash (1.08) and gcc
(1.40) this was called the GNU/Linux Operating System.
The codes were downloaded, tested, tweaked, and returned to
Linus. Linux 0.02 came in October 1991. And work went on. Soon more
than a hundred people joined the GNU/Linux camp. Then hundreds of
thousands. Powered by a good no. of programs from the GNU project,
GNU/Linux was ready for the actual showdown.
6. Linux
(the kernel) was licensed under GNU General Public License, thus
ensuring that the source codes will be free for all to copy, study
and to change. Soon, commercial vendors moved in. GNU/Linux itself
was, and is free. What the vendors did was to compile up various
software and gather them in a distributable format, more like the
other operating systems with which people were more familiar. Red Hat
, Caldera, Debian, and some other companies
gained substantial amount of response from the users worldwide. With
the new Graphical User Interfaces (like X-windows, KDE, GNOME)the
GNU/Linux distributions became very popular. Now there are more than
200 GNU/Linux variants available. The best thing about GNU/Linux
today is the fanatic following it commands. Whenever a new piece of
hardware is out, Linux kernel is tweaked to take advantage of it. It
has also been adapted for use in Alpha, Mac, PowerPC,
and even for palmtops, a feat which is hardly matched by any other
operating system. And it continues its journey into the new
millennium, with the same enthusiasm that started one fine day back
in 1991.
7. Proving
all the warning and prophecies of the skeptics wrong, Gnu/Linux has
completed a decade of development. Today, Gnu/Linux is one of the
fastest growing operating systems in the history. From a few
dedicated fanatics in 1991-92 to millions of general users at
present, it is certainly a remarkable journey. But what’s really
amazing is the continuously increasing band of developers spread
throughout the world who work with a fervent zeal to improve upon the
features of Gnu/Linux. The development effort is not, as many
closed-sourced advocates accuse, totally engulfed with chaos. A well
designed development model supervised by some maintainers is adopted.
Along with this, there are thousands of developers working to port
various applications to Gnu/Linux. With this added confidence, many
large and small businesses have adopted Gnu/Linux based servers and
workstations as an integral part of their offices.