Computer Basic Information.

( Computer Information )

A computer is a machine which helps us to calculate, simulate and store different scenarios. For example, in order to write an e-mail, instead of paper and pen first we use a software (or program) called wordprocessor which helps us enter sentences through keyboard (Input), computer's screen (output) to read, and modem (output/input) to send it to a distant relative, friend, etc.

The mechanism to simulate a regular mail into an e-mail, gave us a very fast and much cheaper medium to communicate (not a simulation anymore). Same way, using computers we can simulate other things over which we do not have any control, for example weather, behaviour of atomic bomb, behaviour of a deadly virus, Earthquake, a innovative design for a new auto, airplane, machine, etc.

Any computer has five parts Input, Output, CPU, Memory, disk (storage) . Input is things like mouse, keyboard, modem. Output is computer screen, printer. CPU or central processing is brain of the computer which controls and execute all calculations, manipulations and output. Memory (RAM)is a temporary storage to be used by CPU when doing calculations, etc. Think of it as a scratch pad for CPU. Disk is permanent storage, on which all the software and data is stored.

When you turn on your computer, BIOS (or basic input output system) which resides on CMOS (complimentary Metal Oxide semiconductor,a type of chip) has small coded software written on it which tells CPU to read the next instruction from sector n of disk x. This next instruction loads the Operating System.

(Information Of Data-Base)

A database is a software which lets user to organize their data in an orderly fashion. For example consider a company which sells cookies, they have a database of which has tables (or records) of customers, types of cookies and orders. So when customer x orders n number of x type of cookies his orders is placed in table orders. There are several type of databases. Some which are simply text files with records, others which are complex with tables of information. A table of information means "an array of one type of records", for example "an array of customer names, addresses, phone numbers". A Relational database is in which there are relations among the tables, for example consider three tables with customer info, inventory info and orders info. The relations between these three tables define the relational database. So when a customer X from customer table orders Item Y from Inventory info it is put in Orders table, there are links in these tables (through primary keys, secondary and foreign keys such Social Security number, product number, order number, etc) which lets us do that and thus making it a relational database. Popular type of relational databases are Access for PCs on windows 95, Oracle, Sybase, Informix, for huge business environment (running Unix operating systems).

(Information Of Internet)

Internet is a bunch of computers connected to each other. It started out when about 10 computers running Unix operating systems serving US military were connected to each other and named ARPANET. Initially, users could only send an e-mail to each other, deploying UUCP (unix to unix copy using modems) method. Then more computers from universities were added to ARPANET and research individuals started sharing their notes over e-mail. Later came Usenet which was more or less a discussion forum. Then after tremendous innovations in hardware (networking), in 1992 came Web, or the software called web browser which could display pictures and text. REST is history. Some terms,

• HTML : is Hypertext markup language. All pages in Internet use HTML.
• Browser Is Piece Of Software To Browse Internet, I.E, Netscape,Internet Explorer.
• Router Is a Piece Of Hardware Which Connects LAN To Internet.
• Bridge Is a Piece Of Hardware Which Connects Two LAN'S.

Fourth Generation

Fourth Generation Computers
(1971-Present)

The 4th generation computers are marked by the usage of integrated circuits and microprocessors. As the years passed, computers became smaller and smaller, and their prices became lower and lower. Millions of components could be placed onto a single silicon chip. Computers became more efficient and more reliable, and they could perform more and more operations. They began to catch the eye of the general public, and soon more sophisticated software and equipment were designed. Networks became commonplace, and the whole world was connected by the Internet and by the World Wide Web.

1971: Intel 4004

The Intel 4004 is a 4-bit microprocessor. Microprocessors are integrated circuits that contain thousands and millions of transistors. The Intel 4004 is the essence of a general-purpose computer. It performed many input and output operations and was also able to read and respond to instructions stored in its memory. The microprocessor was able to group all the components of a computer, including the CPU, or central processing unit, the memory, and the input and output controls on a single chip. The Intel 4004 was first used on March 2, 1972 in the Pioneer 10 space probe.

1972: Intel 8008

In November of 1972, Intel came out with a new 8-bit processor, known as the Intel 8008.

1974: Intel 8080

The Intel 8080 is a re-engineered version of the Intel 8008. It had a larger and more versatile instruction set.

1975: Altair 8800

The Altair 8800 is often called the first personal computer. It was developed by Micro Instrumentation Telemetry Systems (MITS), a small company centered in Albuquerque, New Mexico. The Altair 8800 was sold as an electronic hobbyist kit for only $397. The Altair computers were of blue box-shaped machines with dimensions of 17 inches by 18 inches by 7 inches. They were very simple, and so in complex that they did not even have a keyboard or display. These computers did not even have enough memory to perform any useful tasks. The Altair 8800 used an Intel 8080 microprocessor and had switches on the front panel for input and rows of neon light bulbs for the output. These lights were known as light-emitting diodes, or LEDs. It is hard to believe, but it is the in-complexity of the Altair 8800 that helped to establish the personal computer industry. Because of its limitations, the Altair allowed for other companies to refine the computer and do develop more software.

One such example of software developed for the Altair 8800 is the development of a version of the programming language, BASIC, for this computer. BASIC was a popular programming language used by many minicomputers and other machines. It was simple and easy to develop. The BASIC programming language designed for the Altair was developed by Bill Gates and Paul Allen, the cofounders of the software giant, Microsoft. Microsoft was not the only company to develop programs and software for the Altair. In fact, more and more companies began entering the software business by developing software and peripherals for the Altair 8800. The personal computer soon became a business machine.

Third Generation

Third Generation Computers
(1964-1971)

The 3rd Generation Computers were generally much smaller in size than the 2nd and 1st generation computers. This is because these newer computers made us of integrated circuits and semiconductors (a type of material that had the properties of an insulator and a conductor). 3rd generation computers also contained operating systems, which acted as overseers to the performance of a computer and which allowed computers to run different programs at once. Another function of operating systems is to make sure everything is flowing smoothly inside the computer. The 3rd generation computers made the transition from transistors to integrated circuits and from punch cards to electronic computer systems.

1964-1965: IBM 360

The IBM 360 was introduced by IBM (duh!) in April of 1964, and was finally delivered in 1965. It was not actually a single computer, but was rather a family of six computers and their peripherals. These computers were all mutually compatible and all worked together. The first models of the IBM 360 used transistors, but later these computers made a transition from transistors to integrated circuits.

1965: PDP-8

The PDP-8 was a successor to the PDP-1. Because it was the first computer to successfully make use of integrated circuits, it was much smaller and cheaper compared to other computers available at the same time. When it first entered the minicomputer market, it sold for about $20,000. Five years later, this price was Reducing to only $3,000. The PDP-8 was Relatively simple in design-physically, logically, and electronically. It only had 4,096 words of memory, and its word length was only 12 bits. This machine became the first commercially successful minicomputer because of its reasonable cost, speed, and small size. Minicomputers are medium-sized computers that were much cheaper than the larger and bulkier mainframe computers.

1966: HP-2115

With the invention of the HP-2115, the company Hewlett Packard enters the computer business.

1969: UNIX

At the AT & T Bell Laboratories, programmers Kenneth Thompson and Dennis Ritchie developed a new type of operating system known as UNIX. UNIX is a multi-user operating system able to perform multiple tasks. In addition, UNIX is written in the C language, which allows it to be less machine-specific than other available operating systems. C was specifically designed for UNIX. Because UNIX used C, it was able to be used in any computer system. This was a big achievement at the time!

1970s: GUI

GUI (graphical user interface, pronounced gooey) was designed by the Xerox Corporation. GUI allowed users to be able to "point and click." In other words, the computer screen was designed to resemble a desktop. It had click-able folders, calculators, etc. which were represented by images known as icons. Users could click on these icons to move and manipulate the folders and other tools. GUI made using computers much easier and is currently found in modern-day computers.

Second Generation

Second Generation Computers
(1956-1963)

The computers built in the 1950s and 1960s are considered the 2nd generation computers. These computers make use of the transistors invented by Bell Telephone laboratories and they had many of the same components as the modern-day computer. For instance, 2nd generation computers typically had a printer, some sort of tape or disk storage, operating systems, stored programs, as well as some sort of memory. These computers were also generally more reliable and were solid in design.

1957: FORTRAN

FORTRAN, an acronym for Formula Translator was the first successful programming language. This language used words and sentences instead of the binary machine codes that had been commonplace in computers prior to the 1950s. FORTRAN could be read by ordinary people with no previous programming experience or knowledge, and it made it easier for computers to be programmed. FORTRAN was extremely useful in that given a single statement, many instructions would be produced. FORTAN created programs that were just as good as those produced by human programmers. Not only was it one of the most successful programming languages ever, but it also dominated many other languages for years.

1959: COBOL

COBOL, the Common Business Oriented Language, was invented in 1959. This is a business programming language that allowed for computer programs to be easily read.

1960: PDP-1

DEC, or the Digital Equipment Corporation was founded by Kenneth Olsen and Harland Anderson in 1957. In 1960, DEC introduced the Programmed Data Processor, or PDP-1. The PDP-1 was a mainframe computer famous for its low costs. Compared to other computers that generally cost more than $1 million dollars, at "only" about $120,000 the PDP-1 was considered really cheap! The PDP-1 could be sold at such a low price because it did not contain many advanced peripherals and software. In other computers, these advanced systems amounted to nearly 80% of the computers' cost.

1961: IBM 1400 Series

The IBM 1400 Series were a major breakthrough for IBM. The first computer in this series is the IBM 1401. The 1401 was a computer system that used transistors instead of the vacuum tubes found in previous IBM computers. The system contained many peripherals, which included, among others, a new high-speed printer. This printer could print 600 lines per minute! The total cost of an IBM 1401 was $150,000. 12,000 of these computers were produced.

1962: SpaceWar!

Space War is the first interactive computer game. It was developed by MIT students Slug Russell, Shag Graetz, and Alan Kotok for the PDP-1 computer. In this game, players must battle against enemy spaceships and face obstacles like the gravity of the sun. The players used primitive joysticks to maneuver their ships. SpaceWar has helped to inspired future video games.

Late 1960s: Integrated Circuit

Introduced in the 1960s simultaneously by Texas Instruments and by Fairchild Semi-Conductor, the integrated circuit combines many tiny transistors and other electrical components onto a small silicon chip. It replaced the need for individual transistors. Later, these integrated circuits were refined so that one small chip could contain thousands of transistors, as well as other similar components. As more and more components were squeezed into a small silicon chip, the size of computers gradually decreased.

Computer Generation

( First Generation Computers )

( 1940s - 1956s )

Generally, the computers built during the World War II era are known as the first generation computers. These are considered the first computers, and were extremely different from the computers we see today. Because the first generation computers were extremely difficult to program, they were designed for a specific task, and they never made it to the general market. These primitive computers relied on vacuum tubes and magnetic drums. Vacuum tubes process data by allowing the passage of electrons while magnetic drums use magnetic material to store data. The 1st generation computers were also extremely slow. However, despite their great number of downfalls, these computers have gradually evolved into computers, as we know them today.

1939-1942: Atanasoff-Barry Computer

The Atanasoff-Barry Computer (ABC) was the first electronic computer. It was developed by physics and mathematics professor John Atanasoff and his graduate student, Clifford Barry. This computer used the binary system found in modern computers and its method for storing data is quite similar to that of the modern computer. However, in 1942, Atanasoff was recruited to the Naval Ordnance Laboratory to help with war research, and the ABC was never properly put into working order.

1941: Z3

A German named Konrad Zuse invented the Z3, a computer used to design airplanes and missiles. It was the first program-controlled processor.

1943: Colossus

Built in December of 1943 in Bletchly Park (a research center a few miles north of London), Colossus is a computer specifically designed for code breaking. It was used by the British during World War II to break German coded messages.

1944: Harvard Mark I

Howard Aiken proposes the idea of a fully automatic computer in 1937. With the help of IBM, Aiken was able to develop the Mark I by 1944. The Mark I was about 50 feet wide and 8 feet tall, and it was able to handle 23 digit numbers. In addition to the four basic operations, addition, subtraction, multiplication, and division, the Mark I was also able to perform trigonometric and probability functions. To input data and instructions, the computer used paper tapes, which were merely toilet-paper-like rolls of punch cards. For output, the Mark I printed the results using two electric typewriters. The Mark I could perform simple addition problems in less than a second and simple multiplication problems in a second or so. However, for more complicated problems, the computer would require as long as a whole minute. The Mark I was known for being the first automatic computer. It used electromagnetic signals to move mechanical parts. Later, predecessors of the Mark I were introduced to the world, such as the Mark II and the Mark III.

1943-1946: ENIAC

In April of 1943, the building of the Electronic Numerical Integrator Analyzer and Computer (ENIAC) commenced. Developed by colleagues John Mauchley and J. Presper Eckert Junior and built at the University of Pennsylvania's Moore School of Electrical Engineering, ENIAC was the first general-purpose, all-electronic, programmable digital computer. It cost $400,000 to build and it occupied 50 feet by 30 feet of floor space. This humongous computer consisted of 18,000 vacuum tubes (used to process data), 70,000 resistors (used to resist the flow of electric current), 10,000 capacitors (the part of an electrical circuit used to store charge), 6,000 switches, and 1,500 relays (used to activate switches when changes in voltages occur). In addition, it weighed 30 tons and used up 160 kilowatts of electrical power. That's nearly enough to dim every single light in a city as big as Philadelphia! The initial purpose of the ENIAC was to compute the values for artillery range tables, but its first actual task was to make certain calculations for the construction of a hydrogen bomb.

The giant computer made use of plug boards, through which its instructions were entered, and it also made use of conditional branching. Conditional branching gave

the ENIAC flexibility, allowing it to execute instruction in different order based on value of the data.

The ENIAC also contained accumulators, special registers used to store data, and in addition the computer used a digital number system rather than the binary system used in modern

computers today. Furthermore, the computer operated at extremely fast speeds and had the capability to perform 5,000 operations per second.

Although the ENIAC was a major breakthrough in the computing world, it also had its problems. For one thing, once a certain task was completed, it would take days to reprogram the computer so that another task could be performed. Every time the computer was completed an operation, it had to be re-wired and its program had to be changed. Because of the great complexities of the ENIAC, this could take many hours, and even days. Another liability of the ENIAC was that because there were so many tubes and components, there were many potential sources of breakdowns. It had to be continuously serviced, and it usually spent one-third of its time down for maintenance.

The ENIAC was used from February 1946 until October 1955.

1945: EDVAC

John von Neumann (1903-1957), a mathematician and physicist at the Institute for Advanced Study in Princeton, played a key role in the development of the Electronic Discrete Variable Automatic Computer (EDVAC). The EDVAC was a successor to the ENIAC, and it had been designed to hopefully correct the weaknesses and problems of its predecessor. The EDVAC had a memory, which held the stored information and data. It was this stored memory that allowed for the EDVAC to be stopped and resumed at various times. The EDVAC also had a central processing unit (CPU), which can be found in many modern computers. The CPU of a computer is analogous to the brain of a person. Some of its duties include executing instructions and performing operations.

1944-1945: Plankalkul

Plankalkul ("Plan Calculus"), developed by Konrad Zuse, was the first real programming language. Plankalkul made use of structured data, in which the records in the database was, a mixture of alphabetic and numeric data. It also used conditional statements, which modified the execution of a program. However, Plankalkul was not generally known outside of Germany.

1947: Transistors

Transistors were first developed in 1947 by Bell Telephone laboratories. They replaced vacuum tubes, which were big, bulky, costly, and unreliable. Transistors are most often used to regulate the flow of an electrical current and to switch electricity on and off.

1948: SSEC

The Selective Sequence Electronic Calculator (SSEC) was developed by IBM. It occupied space 25 feet by 40

feet and used punch cards, punched tape, vacuum tubes, and relays. It could do 50 multiplications per second, but it was not successful because of its high cost. However, it was of some use. In 1969, it produced tables that were used to plot the course of the spaceship Apollo's flight to the moon.