EVOLUTION OF COMPUTER
In its most basic form a computer is any device which aids humans in performing various kinds of computations or calculations. In that respect the earliest computer was the abacus, used to perform basic arithmetic operations.
Every computer supports some form of input, processing, and output. This is less obvious on a primitive device such as the abacus where input, output and processing are simply the act of moving the pebbles into new positions, seeing the changed positions, and counting. Regardless, this is what computing is all about, in a nutshell. We input information, the computer processes it according to its basic logic or the program currently running, and outputs the results.
Modern computers do this electronically, which enables them to perform a vastly greater number of calculations or computations in less time. Despite the fact that we currently use computers to process images, sound, text and other non-numerical forms of data, all of it depends on nothing more than basic numerical calculations. Graphics, sound etc. are merely abstractions of the numbers being crunched within the machine; in digital computers these are the ones and zeros, representing electrical on and off states, and endless combinations of those. In other words every image, every sound, and every word have a corresponding binary code.
While abacus may have technically been the first computer most people today associate the word “computer” with electronic computers which were invented in the last century, and have evolved into modern computers we know of today.
ENIAC
First Generation Computers (1940s – 1950s)
First electronic computers used vacuum tubes, and they were huge and complex. The first general purpose electronic computer was the ENIAC (Electronic Numerical Integrator And Computer). It was digital, although it didn’t operate with binary code, and was reprogrammable to solve a complete range of computing problems. It was programmed using plugboards and switches, supporting input from an IBM card reader, and output to an IBM card punch. It took up 167 square meters, weighed 27 tons, and consuming 150 kilowatts of power. It used thousands of vacuum tubes, crystal diodes, relays, resistors, and capacitors.
The first non-general purpose computer was ABC (Atanasoff–Berry Computer), and other similar computers of this era included german Z3, ten British Colossus computers, LEO, Harvard Mark I, and UNIVAC.
IBM 1401
Second Generation Computers (1955 – 1960)
The second generation of computers came about thanks to the invention of the transistor, which then started replacing vacuum tubes in computer design. Transistor computers consumed far less power, produced far less heat, and were much smaller compared to the first generation, albeit still big by today’s standards.
The first transistor computer was created at the University of Manchester in 1953. The most popular of transistor computers was IBM 1401. IBM also created the first disk drive in 1956, the IBM 350 RAMAC.
Third Generation Computers (1960s)
IBM System/360
The invention of the integrated circuits (ICs), also known as microchips, paved the way for computers as we know them today. Making circuits out of single pieces of silicon, which is a semiconductor, allowed them to be much smaller and more practical to produce. This also started the ongoing process of integrating an ever larger number of transistors onto a single microchip. During the sixties microchips started making their way into computers, but the process was gradual, and second generation of computers still held on.
First appeared minicomputers, first of which were still based on non-microchip transistors, and later versions of which were hybrids, being based on both transistors and microchips, such as IBM’s System/360. They were much smaller, and cheaper than first and second generation of computers, also known as mainframes. Minicomputers can be seen as a bridge between mainframes and microcomputers, which came later as the proliferation of microchips in computers grew.
Fourth Generation Computers (1971 – present)
First microchips-based central processing units consisted of multiple microchips for different CPU components. The drive for ever greater integration and miniaturization led towards single-chip CPUs, where all of the necessary CPU components were put onto a single microchip, called a microprocessor. The first single-chip CPU, or a microprocessor, was Intel 4004.
The advent of the microprocessor spawned the evolution of the microcomputers, the kind that would eventually become personal computers that we are familiar with today.
First Generation of Microcomputers (1971 – 1976)
Altair 8800
First microcomputers were a weird bunch. They often came in kits, and many were essentially just boxes with lights and switches, usable only to engineers and hobbyists whom could understand binary code. Some, however, did come with a keyboard and/or a monitor, bearing somewhat more resemblance to modern computers.
It is arguable which of the early microcomputers could be called a first. CTC Datapoint 2200 is one candidate, although it actually didn’t contain a microprocessor (being based on a multi-chip CPU design instead), and wasn’t meant to be a standalone computer, but merely a terminal for the mainframes. The reason some might consider it a first microcomputer is because it could be used as a de-facto standalone computer, it was small enough, and its multi-chip CPU architecture actually became a basis for the x86 architecture later used in IBM PC and its descendants. Plus, it even came with a keyboard and a monitor, an exception in those days.
However, if we are looking for the first microcomputer that came with a proper microprocessor, was meant to be a standalone computer, and didn’t come as a kit then it would be Micral N, which used Intel 8008 microprocessor.
Popular early microcomputers which did come in kits include MOS Technology KIM-1, Altair 8800, and Apple I. Altair 8800 in particular spawned a large following among the hobbyists, and is considered the spark that started the microcomputer revolution, as these hobbyists went on to found companies centered around personal computing, such as Microsoft, and Apple.
Second Generation Microcomputers (1977 – present)
As microcomputers continued to evolve they became easier to operate, making them accessible to a larger audience. They typically came with a keyboard and a monitor, or could be easily connected to a TV, and they supported visual representation of text and numbers on the screen.
In other words, lights and switches were replaced by screens and keyboards, and the necessity to understand binary code was diminished as they increasingly came with programs that could be used by issuing more easily understandable commands. Famous early examples of such computers include Commodore PET, Apple II, and in the 80s the IBM PC.
The nature of the underlying electronic components didn’t change between these computers and modern computers we know of today, but what did change was the number of circuits that could be put onto a single microchip. Intel’s co-founder Gordon Moore predicted the doubling of the number of transistor on a single chip every two years, which became known as “Moore’s Law”, and this trend has roughly held for over 30 years thanks to advancing manufacturing processes and microprocessor designs.
The consequence was a predictable exponential increase in processing power that could be put into a smaller package, which had a direct effect on the possible form factors as well as applications of modern computers, which is what most of the forthcoming paradigm shifting innovations in computing were about.
Graphical User Interface (GUI)
Possibly the most significant of those shifts was the invention of the graphical user interface, and the mouse as a way of controlling it. Doug Engelbart and his team at the Stanford Research Lab developed the first mouse, and a graphical user interface, demonstrated in 1968. They were just a few years short of the beginning of the personal computer revolution sparked by the Altair 8800 so their idea didn’t take hold.
Instead it was picked up and improved upon by researchers at the Xerox PARC research center, which in 1973 developed Xerox Alto, the first computer with a mouse-driven GUI. It never became a commercial product, however, as Xerox management wasn’t ready to dive into the computer market and didn’t see the potential of what they had early enough.
It took Steve Jobs negotiating a stocks deal with Xerox in exchange for a tour of their research center to finally bring the user friendly graphical user interface, as well as the mouse, to the masses. Steve Jobs was shown what Xerox PARC team had developed, and directed Apple to improve upon it. In 1984 Apple introduced the Macintosh, the first mass-market computer with a graphical user interface and a mouse.
Microsoft later caught on and produced Windows, and the historic competition between the two companies started, resulting in improvements to the graphical user interface to this day.
Meanwhile IBM was dominating the PC market with their IBM PC, and Microsoft was riding on their coat tails by being the one to produce and sell the operating system for the IBM PC known as “DOS” or “Disk Operating System”. Macintosh, with its graphical user interface, was meant to dislodge IBM’s dominance, but Microsoft made this more difficult with their PC-compatible Windows operating system with its own GUI.
Portable Computers
As it turned out the idea of a laptop-like portable computer existed even before it was possible to create one, and it was developed at Xerox PARC by Alan Kay whom called it the Dynabook and intended it for children. The first portable computer that was created was the Xerox Notetaker, but only 10 were produced.
The first laptop that was commercialized was Osborne 1 in 1981, with a small 5″ CRT monitor and a keyboard that sits inside of the lid when closed. It ran CP/M (the OS that Microsoft bought and based DOS on). Later portable computers included Bondwell 2 released in 1985, also running CP/M, which was among the first with a hinge-mounted LCD display. Compaq Portable was the first IBM PC compatible computer, and it ran MS-DOS, but was less portable than Bondwell 2. Other examples of early portable computers included Epson HX-20, GRiD compass, Dulmont Magnum, Kyotronic 85, Commodore SX-64, IBM PC Convertible, Toshiba T1100, T1000, and T1200 etc.
The first portable computers which resemble modern laptops in features were Apple’s Powerbooks, which first introduced a built-in trackball, and later a trackpad and optional color LCD screens. IBM’s ThinkPad was largely inspired by Powerbook’s design, and the evolution of the two led to laptops and notebook computers as we know them. Powerbooks were eventually replaced by modern MacBook Pro’s.
Of course, much of the evolution of portable computers was enabled by the evolution of microprocessors, LCD displays, battery technology and so on. This evolution ultimately allowed computers even smaller and more portable than laptops, such as PDAs, tablets, and smartphones.
COMPUTER SYSTEM
A computer system has four main components: the arithmetic logic unit (ALU), the control unit, the memory, and the input and output devices (collectively termed I/O). These parts are interconnected by buses, often made of groups of wires.
Inside each of these parts are thousands to trillions of small electrical circuits which can be turned off or on by means of an electronic switch. Each circuit represents a bit (binary digit) of information so that when the circuit is on it represents a “1”, and when off it represents a “0” (in positive logic representation). The circuits are arranged in logic gates so that one or more of the circuits may control the state of one or more of the other circuits.
The control unit, ALU, registers, and basic I/O (and often other hardware closely linked with these) are collectively known as a central processing unit (CPU). Early CPUs were composed of many separate components but since the mid-1970s CPUs have typically been constructed on a single integrated circuit called a microprocessor.
INPUT DEVICE
In computing, an input device is any peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system such as acomputer or other information appliance. Examples of input devices include keyboards, mice, scanners, digital cameras and joysticks.
CPU
A central processing unit (CPU), also referred to as a central processor unit,is the hardware within a computer that carries out theinstructions of a computer program by performing the basic arithmetical, logical, and input/output operations of the system. The term has been in use in the computer industry at least since the early 1960s. The form, design, and implementation of CPUs have changed over the course of their history, but their fundamental operation remains much the same.
A computer can have more than one CPU; this is called multiprocessing. Some integrated circuits (ICs) can contain multiple CPUs on a single chip; those ICs are called multi-core processors.
Two typical components of a CPU are the arithmetic logic unit (ALU), which performs arithmetic and logical operations, and the control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.
Not all computational systems rely on a central processing unit. An array processor or vector processor has multiple parallel computing elements, with no one unit considered the "center". In the distributed computing model, problems are solved by a distributed interconnected set of processors.
The abbreviation CPU is sometimes used incorrectly by people who are not computer specialists to refer to the cased main part of adesktop computer containing the motherboard, processor, disk drives, etc., i.e., not the display monitor or keyboard
OUTPUT DEVICES
An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as acomputer) which converts the electronically generated information into human-readable form
COMPUTER NETWORK
A computer network (or data network) is a telecommunications network that allows computers to exchange data. The physical connection between networked computing devices is established using either cable media or wireless media. The best-known computer network is theInternet.
Network devices that originate, route and terminate the data are called network nodes.[1] Nodes can include hosts such as servers andpersonal computers, as well as networking hardware. Two devices are said to be networked when a process in one device is able to exchange information with a process in another device.
Computer networks support applications such as access to the World Wide Web, shared use of application and storage servers, printers, and fax machines, and use of email and instant messaging applications. The remainder of this article discusses local area networktechnologies and classifies them according to the following characteristics: the physical media used to transmit signals, thecommunications protocols used to organize network traffic, along with the network's size, its topology and its organizational intent.
-A computer network consist of a collection of computer,printers and other equipment that is connected together so that they can communicate with each other. Every network has a strategy or a way of coordinating the sharing of the information and resource. the most common network strategies are terminal,peer to peer and client. in this system processing power is centralized in one larger computer,usually the mainframe. the nodes connected to this host computer are terminals with little or no processing capability. Most airline reservation systems are terminal systems.
~>LOCAL AREA NETWORKS(LAN)
~>METROPOLITAN AREA NETWORK(MAN)
~>WIDE AREA NETWORK(WAN)
STANDALONE COMPUTER
Stand-alone computer - is one which does not communicate with any other computer. All its applications and resources are available on the same computer.
NETWORK COMPUTER
Network computer - is one which communicates with other computers. It can share resources like disk drives, printers and files
Some of the advantages of computer networks are speed, which enables users to share and transfer files within the same network and save time, while maintaining the confidentiality of the file. Sensitive files and software can be transferred on a network that is password protected to restrict access to unauthorised users.
OPERATING SYSTEM
An operating system (OS) is a collection of software that manages computer hardware resources and provides common services forcomputer programs. The operating system is a vital component of the system software in a computer system. Application programs usually require an operating system to function.
Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting for cost allocation of processor time, mass storage, printing, and other resources.
For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware,[1][2] although the application code is usually executed directly by the hardware and will frequently make a system call to an OS function or be interrupted by it. Operating systems can be found on almost any device that contains a computer—from cellular phones and video game consoles to supercomputers and web servers.
Examples of popular modern operating systems include Android, BSD, iOS, GNU/Linux, OS X, QNX, Microsoft Windows,[3] Windows Phone, and IBM z/OS. All these, except Windows and z/OS, share roots in UNIX.
START UP COMPUTER
- Connect the computer's Power lead or AC adapter into the CPU unit or laptop and use a wall outlet to plug the cord in. Most laptops and portable computers run on battery and does not require an outlet to be operated.
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- Find and press the "on switch" on the top of you HP Computer or near the screen on the laptop.
Wait for the computer to boot up. A screen will come up, as this is the initial "boot up" screen.
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Wait until everything is loaded. The more programs that is set to load when the computer is started, the longer it will take. You may not want to attempt to start up programs or open files right away, as this creates more work for the computer.
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