Thursday 17 May 2012

History Of Mac Os

Mac OS History


On January 24, 1984, Apple Computer, Inc. (now Apple Inc.) introduced the Macintosh personal computer, with the Macintosh 128K model, which came bundled with the Mac OS operating system, then known as the System Software. The Macintosh is often credited with popularizing the graphical user interface. The Mac OS has been pre-installed on almost every Macintosh computer ever sold. The operating system is also sold separately at Apple retail stores, and online. The original Mac OS was partially based on the Lisa OS, previously released by Apple for the Lisa computer in 1983 and, as part of an agreement allowing Xerox to buy shares in Apple at a favourable rate, it also used concepts from the Xerox PARC Xerox Alto which Steve Jobs and several other Macintosh team members had previewed.

    Early history


    The Macintosh project started in early 1979 with Jef Raskin, who envisioned an easy-to-use, low-cost computer for the average consumer. In September 1979, Raskin was given permission to start hiring for the project and was, in particular, looking for an engineer that could put together a prototype. Bill Atkinson, a member of the Apple Lisa team, introduced him to Burrell Smith, a service technician who had been hired earlier that year.
  In January 1981, Steve Jobs completely took over the Macintosh project. Jobs and a number of Apple engineers visited Xerox PARC in December 1979, three months after the Lisa and Macintosh projects had begun. After hearing about the pioneering GUI technology being developed at Xerox PARC from former Xerox employees like Raskin, Jobs negotiated a visit to see the Xerox Alto computer and Smalltalk development tools in exchange for Apple stock options. The final Lisa and Macintosh operating systems mostly used concepts from the Xerox Alto, but many elements of the graphical user interface were created by Apple including the menubar and pop-up menus.

    Unlike the IBM PC, which used 8 kB of system ROM for power-on self-test (POST) and basic input/output system (BIOS), the Mac ROM was significantly larger (64 kB) and held key OS code. Much of the original Mac ROM was coded by Andy Hertzfeld, a member of the original Macintosh team. He was able to conserve some of the precious ROM space by interleaving some of the assembly language code. In addition to coding the ROM, he also coded the kernel, the Macintosh Toolbox and some of the desktop accessories (DAs) as well. The icons of the operating system, which represented folders and application software were designed by Susan Kare, who later designed the icons for Microsoft Windows 3.0. Bruce Horn and Steve Capps wrote the Macintosh Finder as well as a number of Macintosh system utilities.

    Apple was very strong in advertising their newfound machine. After it was created, the company bought all 39 pages of advertisement space in the Newsweek magazine, 1984 November/December edition. Apple was so successful in its marketing for the Macintosh, that it quickly outshone its more sophisticated predecessor, the Lisa, in sales – so much so that Apple quickly developed a product called MacWorks which allowed the Lisa to emulate Macintosh system software through System 3, by which time it had been discontinued as the re-branded Macintosh XL. Many of Lisa's operating system advances would not appear in the Macintosh OS until System 7.

Wednesday 16 May 2012

History Of Linux

LINUX's History

Note: The following text was written by Linus on July 31 1992. It is a
   collection of various artifacts from the period in which Linux first
   began to take shape.
   This is just a sentimental journey into some of the first posts
   concerning linux, so you can happily press 'n' now if you actually
   thought you'd get anything technical.
From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
  Newsgroups: comp.os.minix
  Subject: Gcc-1.40 and a posix-question
  Date: 3 Jul 91 10:00:50 GMT

  Hello netlanders,

  Due to a project I'm working on (in minix), I'm interested in the posix
  standard definition. Could somebody please point me to a (preferably)
  machine-readable format of the latest posix rules? Ftp-sites would be

   The project was obviously linux, so by July 3rd I had started to think
   about actual user-level things: some of the device drivers were ready,
   and the harddisk actually worked. Not too much else.

  As an aside for all using gcc on minix - [ deleted ]

   Just a success-report on porting gcc-1.40 to minix using the 1.37
   version made by Alan W Black & co.

                Linus Torvalds

  PS. Could someone please try to finger me from overseas, as I've
  installed a "changing .plan" (made by your's truly), and I'm not certain
  it works from outside? It should report a new .plan every time.

History of Electricity

 History of Electricity

Starting With Mr. Edison and
Ben Franklin His Light
Many people think Benjamin In 1879, Thomas Edison
Franklin discovered electricity focused on inventing a
with his famous kite-flying practical light bulb, one that
experiments in 1752, but would last a long time before
electricity was not discovered burning out. The problem was
all at once. At first, electricity finding a strong material for
was associated with light. the filament, the small wire
People wanted a cheap inside the bulb that conducts
and safe way to light their electricity. Finally, Edison used
homes, and scientists thought ordinary cotton thread that
electricity might be a way. had been soaked in carbon.
                           This filament didn’t burn at
                            all—it became incandescent;
                             that is, it glowed.

Image courtesy of NOAA Photo Library
The Battery
Learning how to produce
and use electricity was not
easy. For a long time there
was no dependable source
of electricity for experiments.
Finally, in 1800, Alessandro
Volta, an Italian scientist, made
a great discovery. He soaked
paper in salt water, placed zinc
and copper on opposite sides
of the paper, and watched the
chemical reaction produce
an electric current. Volta had
created the first electric cell.
By connecting many of these Alessandro Volta
cells together, Volta was able
to “string a current” and create
a battery. It is in honor of Volta that we measure battery power
in volts. Finally, a safe and dependable source of electricity was
available, making it easy for scientists to study electricity.

A Current Began
An English scientist, Michael Faraday, was the first one to realize that
an electric current could be produced by passing a magnet through
a copper wire. It was an amazing discovery. Almost all the electricity
we use today is made with magnets and coils of copper wire in giant
power plants.
Both the electric generator and electric motor are based on this
principle. A generator converts motion energy into electricity. A
motor converts electrical energy into motion energy.
Image courtesy of U.S. Library of Congress
Thomas Edison in his lab in 1901.
The next challenge was developing an electrical system that could
provide people with a practical source of energy to power these new
lights. Edison wanted a way to make electricity both practical and
inexpensive. He designed and built the first electric power plant that
was able to produce electricity and carry it to people’s homes.
Edison’s Pearl Street Power Station started up its generator on
September 4, 1882, in New York City. About 85 customers in lower
Manhattan received enough power to light 5,000 lamps. His
customers paid a lot for their electricity, though. In today’s dollars,
the electricity cost $5.00 per kilowatt-hour! Today, electricity costs
about 12 cents per kilowatt-hour for residential customers, and
about 7 cents per kilowatt-hour for industry.

History of Coimbatore

History of Coimbatore

 A Trip down memory lane

Originally Coimbatore district  formed part of the Kongu country, the history of which dates back to the Sangam age. It is found that in early days the area was inhabited by the tribes, the most predominant among them being the Kosars who are reported to have had their headquaeters at Kosampathur  which probably later became the present Coimbatore.

However, tribal predominance did not last long as they were over-run by the Rashtra Kutas. From Rastrakutas the Region fell in to the hands of the cholas who were in prominence at the time of Raja Raja Chola. On the decline of Cholas the Kongun territory was occupied by the Chalukyas and then by the Pandyas and the cysalas.

Due to internal strife in the Pandyas Kingdom the Muslim rulers from Delhi happened to interfere. Thus the area fell into the hands of Madurai Sultanate from whom the Vijayanagar rulers wrestled for the region during 1377-78 after overthrowing the Madurai Nayaks.During the period of Muthu Veerappa Nayak and later during the period of Tirumal Nayak internal strife and intermittent wars ruined the kingdom.

 As a  consequence during the period of Tirumal Nayak,the Kongu region fell into the hands of the Mysore rulers from whom hyder Ali took over the area. However, consequents on the fall of Tippu Sultan of Mysore in 1799, the Kongu  region came to be ceded to the East India Company by the Maharaja of mysore who was restored to power by the East India Company after defeating Tippu Sultan. From then till 1947 when India attained Independence, the region remained under British control who initiated systematic revenue administration.   
In 1840, the areas were merged into one  and brought under one District Collector. During the time, Mr.H.S. GREAME, [I/C] from 20/10/1803 to 20/01/1805 was the Collector. In 1868, the Nilgiris District was bifurcated from the Coimbatore District. At the opening of the present century there were ten taluks in the district viz., Bhavani, Coimbatore, Dharapuram, Erode, Karur, Kollegal, Palladam, Pollachi, Sathyamangalam and Udumalaipettai. The name of Sathyamangalam taluk was subsequently changed as Gopichettipalaiyam.

Avinashi taluk was formed in the year Karur taluk happened to be transferred to Tiruchirappalli district. In 1927, some villages of Bhavani taluk together with a few village from Salem district were constituted into Mettur Area but very soon i.e, in 1929, this area was transferred to Salem district.

Again in the year 1956 considerable area of the district, viz., the whole of Kollegal taluk was transferred to Mysore State as part of the States Re-organisation Scheme. In 1975, Sathyamangalam sub-taluk was upgraded as a full fledged taluk.

History Of Unix

History Of Unix

Since it began to escape from AT&T's Bell Laboratories in the early 1970's, the success of the UNIX operating system has led to many different versions: recipients of the (at that time free) UNIX system code all began developing their own different versions in their own, different, ways for use and sale. Universities, research institutes, government bodies and computer companies all began using the powerful UNIX system to develop many of the technologies which today are part of a UNIX system.

Computer aided design, manufacturing control  systems, laboratory simulations, even the Internet itself, all began life with and because of UNIX systems. Today, without UNIX systems, the Internet would come to a screeching halt. Most telephone calls could not be made, electronic commerce would grind to a halt and there would have never been "Jurassic Park"!

By the late 1970's, a ripple effect had come into play. By now the under- and post-graduate students whose lab work had pioneered these new applications of technology were attaining management and decision-making positions inside the computer system suppliers and among its customers. And they wanted to continue using UNIX systems.

Soon all the large vendors, and many smaller ones, were marketing their own, diverging, versions of the UNIX system optimized for their own computer architectures and boasting many different strengths and features. Customers found that, although UNIX systems were available everywhere, they seldom were able to interwork or co-exist without significant investment of time and effort to make them work effectively. The trade mark UNIX was ubiquitous, but it was applied to a multitude of different, incompatible products.

Monday 14 May 2012

History Of Green Revolution

History and Development of the Green Revolution

 The beginnings of the Green Revolution are often attributed to Norman Borlaug, an American scientist interested in agriculture. In the 1940s, he began conducting research in Mexico and developed new disease resistance high-yield varieties of wheat. By combining Borlaug's wheat varieties with new mechanized agricultural technologies, Mexico was able to produce more wheat than was needed by its own citizens, leading to its becoming an exporter of wheat by the 1960s. Prior to the use of these varieties, the country was importing almost half of its wheat supply.

Due to the success of the Green Revolution in Mexico, its technologies spread worldwide in the 1950s and 1960s. The United States for instance, imported about half of its wheat in the 1940s but after using Green Revolution technologies, it became self-sufficient in the 1950s and became an exporter by the 1960s.

In order to continue using Green Revolution technologies to produce more food for a growing population worldwide, the Rockefeller Foundation and the Ford Foundation, as well as many government agencies around the world funded increased research. In 1963 with the help of this funding, Mexico formed an international research institution called The International Maize and Wheat Improvement Center.

Countries all over the world in turn benefited from the Green Revolution work conducted by Borlaug and this research institution. India for example was on the brink of mass famine in the early 1960s because of its rapidly growing population. Borlaug and the Ford Foundation then implemented research there and they developed a new variety of rice, IR8, that produced more grain per plant when grown with irrigation and fertilizers. Today, India is one of the world's leading rice producers and IR8 rice usage spread throughout Asia in the decades following the rice's development in India.

History of Vampires

History of Vampires 

The Evolution of Vampires

We currently live in a pop culture world that seems obsessed with vampires. From gothic vampire novels, to endless movies, television and art, the vampire archetype continues to grow in popularity and sophistication.

What is behind this seeming obsession with vampires, in our western culture? Why does this archeype endure? What does the vampire have, or do, that makes him/her so attractive and compelling? When did the transformation occur, from foul miscreant to suave tragic hero? Who is the vampire - really?
Vampire culture seems in stark contrast with the current technological age and advances in science. Starting out in the dim and obscure recesses of Eastern European folk tales and legends, the vampire has reached center stage in modern pop culture. From foul revenant of the grave, to super hero status within 100 years of evolution. Why?

The vampires of folk history were totally repugnant creatures. They were depicted as crude, foul smelling, reanimated corpses, with a single parasitic-like motivation for blood. They are never actually observed in their vampire state, by the living, but their existence is confirmed by circumstantial evidence within the surrounding community.

The evidence for the existence of a vampire was thought to include such things as the sudden deaths of citizenry and livestock, under unclear or questionable circumstances. Also indicative of vampirism, was the sudden onslought of mysterious disease symptoms, especially those causing pale skin coloration and slow physical wasting (like tuberculosis - which was rampant and contagious during the 19th century in Europe and the U.S.).

Sunday 13 May 2012

History Of Spiderman

Spiderman History and Profile

Spider-Man is the quintessential Marvel character. Although a super hero, he is spared none of the slings and arrows of ordinary life; he experiences difficulties with friends, family, sweethearts and employers. His powers enable him to do good, but not to improve his own lot in life, and it is his simple humanity, rather than his exotic talent, that has won him millions of enthusiastic fans. He is one super-hero who has not lost the common touch, and in fact he is frequently described as "your friendly neighborhood Spider-Man."

In his 1962 debut, Spider-Man took to fighting crime for a reason commonplace in comc books: he was motivated by the murder of a father figure, his Uncle Ben. Yet Spidey's driving force is guilt, not revenge; he must live forever with the knowledge that he could have prevented the killing if he had not been so self absorbed. Perhaps he suffers from a classic Oedipus complex; in any case he is certainly neurotic, forever agonizing over the choices that confront him when he attempts to do the right thing. Despite his best efforts, he is viewed with a touch of suspicion by those in authority, and is sometimes considered little more than a criminal himself.

Although nobody seems to understand him, Spider-Man has the spirit to be a joker as well as a tragic figure. He is quick with a quip, appreciates the irony of his endless predicaments, and relishes the chance to play tricks on people who never suspect that he and Peter Parker are one and the same.

As originally depicted by writer Stan Lee and artist Steve Ditko, Peter Parker was just a bit of a wimp. Bright, imaginative, but nonetheless an alienated adolescent, he might well have been a typical comic book reader. Although he has matured and gained in confidence over the years. Spidey is still all to human. He misses appointments, catches the flu when he needs to fight, forgets to put film in his camera and has trouble paying the rent. In short Spider-Man remains Everyman, "the super hero who could be you."

Spiderman Black McFarlane Costume
From 1982 to 1988, Spider-Man was seen around town in this black costume,but now he has returned to his true colors.

Spiderman Amazing Fantasy Caught in the web
The first Spider-Man story was originally intended as no more than a one-shot experiment, and almost didn't get into print at all. "Martin Goodman didn't want to publish it," recalls Stan Lee. Goodman was convinced that readers would find the subject of spiders distasteful.

Fortunately for all concerned, a comic book called Amazing Fantasy was about to be canceled due to faltering sales. "Nobody cares what you put in a book that's going to die," Lee says, "so I threw in Spider-Man. I featured him on the cover and then forgot about him." For the occasion the comic book reverted to its original title of Amazing Fantasy, an appropriate amendment since Spider-Man was to be the most important adolescent super hero in comics.

Spiderman Bust
Spider-Man was the hero and teenage helper rolled into one; he was his own sidekick. Marvel's first editor, Joe Simon, theorized that kid companions like Captain America's Bucky were important because they gave the protagonist someone to talk to; Spider-man talked to himself. In fact he has delivered more siloquies than Hamlet. In his first appearance he mused out loud but subsequently Lee adopted the device of the thought balloon with its characteristic bubbles. "I used those thought balloons to help the exposition," says Lee. "I could put interesting thoughts there that weren't necessarily about what ws happening in that particular panel - something to hold the reader's interest."

Batman History

Batman History

A family outing to the cinema ended in tragedy for young Bruce Wayne. Walking homeward, Bruce, his father, Thomas, and mother, Martha, accidentally ventured into Gotham City's notorious "Crime Alley" and were accosted by a mugger. Not content merely to rob the wealthy family, the hoodlum - whose identity was "never determined" - shot Dr. Thomas and Martha Wayne dead before fleeing into the darkness. As he knelt beside his parent's bodies, Bruce swore to avenge them. After the police arrived, Bruce was comforted by Dr. Leslie THompkins. Dr. Thompkins and Alfred Pennyworth helped arrange matters so that Gotham's Social Services would not take Bruce into care. In this way, both Dr. Thompkins and Alfred enabled Bruce to realize his dream of becoming a crusader against crime.

The Young Bruce Wayne
At age 14, Bruce embarked on a journey that took him to every continent as he sought to learn all the skills he would need to keep his vow. He studied criminology, forensics, and criminal psychology, and learned from manhunters and martial artists, mastering every fighting style. In time, Bruce forged himself into a living weapon to wage war on crime and injustice. On his return to Gotham, Bruce stalked street thugs as a plainclothes
vigilante. Beaten by the very people he intended to protect, he barely survived his first night out. As he sat bleeding in his study at Wayne Manor Bruce knew that he had to first strike fear in the hearts of his foes. Just then, a bat crashed through the study window, giving Bruce the inspiration he needed.

 Batman Begins
Establishing a secret headquarters in the caves beneath his mansion, Bruce became Batman, a Dark Knight to protect Gotham and its citizens from vice and villainy. Alfred Pennyworth remained his confidant, tending to injuries and offering sage advice - whether requested or not!

Batman became an urban legend, a cautionary tale that sent shivers through the city's underworld. This Caped Crusader found a friend in Captain James Gordon a Gotham cop who didn't approve of Batman's methods, but appreciated the results of his nightly crime fighting. Batman's Rogues Gallery grew to include a host of bizarre criminals, such as the Joker, Catwoman, Two-Face and the Penguin. As his enemies increased, help arrived in the form of another young boy left parentless by brutal crime.

history Of Mathematics

 history Of Mathematics

Arguably the most famous theorem in all of mathematics, the Pythagorean Theorem has an interesting history. Known to the Chinese and the Babylonians more than a millennium before Pythagoras lived, it is a "natural" result that has captivated mankind for 3000 years. More than 300 proofs are known today.

(The diagram to the left is that used by Euclid in his proof given 2300 years ago.)

Exploring the concepts, ideas, and results of mathematics is a fascinating topic. On the one hand some breakthroughs in mathematical thought we will study came as accidents, and on the other hand as consequences of attempts to solve some great open problem. For example, complex numbers arose in the study of the solution of cubic polynomials. At first distrusted and ultimately rejected by their discoverers, Tartaglia and Cardano, complex numbers were subsequently found to have monumental significance and applications.

In this course you will see firsthand many of the results that have made what mathematics is today and meet the mathematicians that created them. One particularly interesting attribute of these "builders" of mathematical structure is how clear they were about what to prove. Their results turn out to be just what is needed to establish other results sometimes in an unrelated area. What is difficult to understand for the ordinary mathematics students is just how brilliant these people were and how tenaciously they attacked problems. The personality of the greatest mathematicians span the gamut from personable and friendly to arrogant and rude.

Nonetheless, it is the mathematics that is important. For the most part we will focus on the subject itself.
How to pursue this course.