INTRODUCTION TO COMPUTERS
" A Computer is a machine which which accepts data ( unprocessed) through its input devices, processes it as per the instruction stored or given and displays information (processed data)through an output device"
The first use of the word "computer" was recorded in 1613, referring to a person who carried out calculations, or computations, and the word continued with the same meaning until the middle of the 20th century. From the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations.
GENERAL FEATURES
1) SPEED
A Computer works one step at a time .it can add and subs tract numbers, compare letter to determine alphabetic sequence, and move and copy numbers and letters. There is nothing profound in these operations.The speed of the computer is more significant. The time required for the computers to execute such basic operations such as adding and subtracting numerical value varies from a few microseconds (millionths of a second ) for small machine to 80 nanosecond ( billionths of a second ) or even less for large ones.
2) STORAGE
The speed with which computers can process large quantities of information has led to the generation of new information to vast scale , In other words, the computers has compounded the information 'explosion' . In computer the internal memory of the CPU can store only limited data, therefore to store more amounts of data an auxiliary or secondary storage devices are used.
3) ACCURACY
Being a machine, computer works very accurately. the circuits in the computer have no mechanical parts to wear and malfunctioning. performing their thousands operations every second, these circuits can run error less for days at a time. if the input data entering the computer i correct and if the programs of instructions are reliable then we can expect that the computer generally Will produce accurate output. "computer errors " can usually be traced to incorrect input data or unreliable program both caused by users an not by the computer.
4) VERSATILITY
Now a days computer are used for varied application, right from writing letter, preparing bills, presentations, payroll, accounting,statements, designing logo, advertisement etc. all this can be done using program made for that particular task. In short computers are developed to perform any task provided the task is divided into logical steps.
5) DILIGENCE
Human beings are prone to make mistakes if the same type of job is to be done more times. but computer can do the same job even billion times without getting tired,because it is a machine. Being a machine, computer does not suffer from the human trades and lack of concentration . if millions of calculations are to be performed, it will perform million of operation with exactly the same accuracy and the speed as the first one.
GENERATION OF COMPUTERS
The history of computer development is often referred to in reference to the different generations of computing devices. Each generation of computer is characterised by a major technological development that fundamentally changed the way computers operate, resulting in increasingly smaller,cheaper,more powerful and more efficient and reliable devices.
1) FIRST GENERATION -1940 -1956 : VACUUM TUBES
The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. A magnetic drum,also referred to as drum, is a metal cylinder coated with magnetic iron-oxide material on which data and programs can be stored. Magnetic drums were once use das a primary storage device but have since been implemented as auxiliary storage devices.
The tracks on a magnetic drum are assigned to channels located around the circumference of the drum, forming adjacent circular bands that wind around the drum. A single drum can have up to 200 tracks. As the drum rotates at a speed of up to 3,000 rpm, the device's read/write heads deposit magnetised spots on the drum during the write operation and sense these spots during a read operation. This action is similar to that of a magnetic tape or disk drive.
2) SECOND GENERATION -1956-1963: TRANSISTORS
Transistors replaced vacuum tubes and ushered in the second generation computer. Transistor is a device composed of semiconductor material that amplifies a signal or opens or closes a circuit. Invented in 1947 at Bell Labs, transistors have become the key ingredient of all digital circuits, including computers. Today's latest microprocessor contains tens of millions of microscopic transistors.
Prior to the invention of transistors, digital circuits were composed of vacuum tubes, which had many disadvantages. They were much larger, required more energy, dissipated more heat, and were more prone to failures. It's safe to say that without the invention of transistors, computing as we know it today would not be possible.
The transistor was invented in 1947 but did not see widespread use in computers until the late 50s. The transistor was far superior to the vacuum tube,allowing computers to become smaller, faster, cheaper,more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.
3) THIRD GENERATION -1964-1971: INTEGRATED CIRCUITS
The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturised and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.
Silicon is the basic material used to make computer chips, transistors, silicon diodes and other electronic circuits and switching devices because its atomic structure makes the element an ideal semiconductor. Silicon is commonly doped, or mixed,with other elements, such as boron, phosphorous and arsenic, to alter its conductive properties.
A chip is a small piece of semi conducting material(usually silicon) on which an integrated circuit is embedded. A typical chip is less than ¼-square inches and can contain millions of electronic components(transistors). Computers consist of many chips placed on electronic boards called printed circuit boards. There are different types of chips. For example, CPU chips (also called microprocessors) contain an entire processing unit, whereas memory chips contain blank memory.
4) FOURTH GENERATION -1971-PRESENT : MICROPROCESSORS
The microprocessor brought the fourth generation of computers, as thousands of integrated circuits we rebuilt onto a single silicon chip. A silicon chip that contains a CPU. In the world of personal computers,the terms microprocessor and CPU are used interchangeably. At the heart of all personal computers and most workstations sits a microprocessor. Microprocessors also control the logic of almost all digital devices, from clock radios to fuel-injection systems for automobiles.
Three basic characteristics differentiate microprocessors:
- Instruction Set: The set of instructions that the microprocessor can execute.
- Banwidth: The number of bits processed in a single instruction.
- Clock Speed: Given in megahertz (MHz), the clock speed determines how many instructions per second the processor can execute.
5) FIFTH GENERATION- PRESENT AND BEYOND:ARTIFICIAL INTELLIGENCE
Fifth generation computing devices, based on artificial intelligence, are still in development,though there are some applications, such as voice recognition, that are being used today.
Artificial Intelligence is the branch of computer science concerned with making computers behave like humans. The term was coined in 1956 by John McCarthy at the Massachusetts Institute of Technology. Artificial intelligence includes:
- Games Playing: programming computers to play games such as chess and checkers
- Expert Systems: programming computers to make decisions in real-life situations (for example, some expert systems help doctors diagnose diseases based on symptoms)
- Natural Language: programming computers to understand natural human language
- Neural Networks: Systems that simulate intelligence by attempting to reproduce the types of physical connections that occur in animal brains
- Robotics: programming computers to see and hear and react to other sensory stimuli
TYPES OF COMPUTER
Computers can be classified based on their principles of operation or on their configuration. By configuration, we mean the size, speed of doing computation and storage capacity of a computer.
Types of Computers based on Principles of Operation
There are three different types of computers according to the principles of operation. Those three types of computers are
·
Analog Computers
· Digital Computers
· Hybrid Computers
Analog Computers
Analog Computer is a computing device that works on continuous range of values. The results given by the analog computers will only be approximate since they deal with quantities that vary continuously. It generally deals with physical variables such as voltage, pressure, temperature, speed, etc.
DIGITAL COMPUTERS
On the other hand a digital computer operates on digital data such as numbers. It uses binary number system in which there are only two digits 0 and 1. Each one is called a bit.
The digital computer is designed using digital circuits in which there are two levels for an input or output signal. These two levels are known as logic 0 and logic 1. Digital Computers can give more accurate and faster results.
Digital computer is well suited for solving complex problems in engineering and technology. Hence digital computers have an increasing use in the field of design, research and data processing.
Based on the purpose, Digital computers can be further classified as,
· General Purpose Computers
· Special Purpose Computers
Special purpose computer is one that is built for a specific application. General purpose computers are used for any type of applications. They can store different programs and do the jobs as per the instructions specified on those programs. Most of the computers that we see today, are general purpose computers.
Hybrid Computers
A hybrid computer combines the desirable features of analog and digital computers. It is mostly used for automatic operations of complicated physical processes and machines. Now-a-days analog-to-digital and digital-to-analog converters are used for transforming the data into suitable form for either type of computation.
For example, in hospital’s ICU, analog devices might measure the patients temperature, blood pressure and other vital signs. These measurements which are in analog might then be converted into numbers and supplied to digital components in the system. These components are used to monitor the patient’s vital sign and send signals if any abnormal readings are detected. Hybrid computers are mainly used for specialised tasks.
Types of Computers based on Configuration
There are four different types of computers when we classify them based on their performance and capacity. The four types are
· Super Computers · Mainframe Computers
· Mini Computers
· Micro Computers
Super Computers
When we talk about types of computers, the first type that comes to our mind would be Super computers. They are the best in terms of processing capacity and also the most expensive ones. These computers can process billions of instructions per second. Normally, they will be used for applications which require intensive numerical computations such as stock analysis, weather forecasting etc. Other uses of supercomputers are scientific simulations, (animated) graphics, fluid dynamic calculations, nuclear energy research, electronic design, and analysis of geological data (e.g. in petrochemical prospecting). Perhaps the best known super computer manufacturer is Cray Research. Some of the "traditional" companies which produce super computers are Cray, IBM and Hewlett-Packard.
As of July 2009, the IBM Roadrunner, located at Los Alamos National Laboratory, is the fastest super computer in the world.
If you want to know more advanced details about super computers, refer to Supercomputers
Mainframe Computers
Mainframe computers can also process data at very high speeds vi.e., hundreds of million instructions per second and they are also quite expensive. Normally, they are used in banking, airlines and railways etc for their applications.
Mini Computers
Mini computers are lower to mainframe computers in terms of speed and storage capacity. They are also less expensive than mainframe computers. Some of the features of mainframes will not be available in mini computers. Hence, their performance also will be less than that of mainframes.
Micro Computers
The invention of microprocessor (single chip CPU) gave birth to the much cheaper micro computers. They are further classified into
· Desktop Computers
· Laptop Computers
· Handheld Computers(PDAs)
Desktop Computers
Today the Desktop computers are the most popular computer systems.These desktop computers are also known as personal computers or simply PCs. They are usually easier to use and more affordable. They are normally intended for individual users for their word processing and other small application requirements.
Laptop Computers
Laptop computers are portable computers. They are lightweight computers with a thin screen. They are also called as notebook computers because of their small size. They can operate on batteries and hence are very popular with travellers. The screen folds down onto the keyboard when not in use.
Handheld Computers
Handheld computers or Personal Digital Assistants (PDAs) are pen-based and also battery-powered. They are small and can be carried anywhere. They use a pen like stylus and accept handwritten input directly on the screen. They are not as powerful as desktops or laptops but they are used for scheduling appointments,storing addresses and playing games. They have touch screens which we use with a finger or a stylus.
WORKSTATIONS
A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems. The term workstation has also been used to refer to a mainframe computer terminal or a PC connected to a network.
Both being microcomputers, workstations had offered higher performance than desktop computers, especially with respect to CPU and graphics, memory capacity, and multitasking capability. They are optimised for the visualisation and manipulation of different types of complex data such as 3D mechanical design, engineering simulation (e.g. computational fluid dynamics), animation and rendering of images, and mathematical plots. Typically, consoles consist of a high resolution display, a keyboard and a mouse at a minimum, but also offer multiple displays, graphics tablets, 3D mice (devices for manipulating 3D objects and navigating scenes), etc. Workstations are the first segment of the computer market to present advanced accessories and collaboration tools.
COMPUTER APPLICATION
Computers have their application or utility everywhere. We find their applications in almost every sphere of life–particularly in fields where computations are required to be done at a very fast speed and where data is so complicated that the human brain finds it difficult to cope up with.
As you must be aware, computer now-a-days are being used almost in every department to do the work at a greater speed and accuracy. They can keep the record of all the employees and prepare their pay bill in a matter of minutes every month. They can keep automatic checks on the stock of a particular item.
DATA PROCESSING AND INFORMATION PROCESSING
The Word data and information is used interchangeably ,but there is thin line, which differentiates data from the information.( E.g 2+2 = 4 here 2+2 represents the dta and 4 represents the information. if this 4 is used further for calculating percentage then this 4 becomes data and percentage is the information.)
DATA
It is a collection of facts and figures, which are yet to be organised in a proper manner, so that you can further process it and get information of your requirement.therefore it is very important to process data in a proper and percentage is the information)
INFORMATION
Processed data is called as information.
1) EDUCATION
Computers have proved to be excellent teachers. They can possess the knowledge given to them by the experts and teach you with all the patience in the world. You may like to repeat a lesson hundred times, go ahead, you may get tired but the computer will keep on teaching you. Computer based instructions (CBI) and Computer Aided Learning (CAL) are common tools used for teaching. Computer based encyclopedia such as Britannica provide you enormous amount of information on anything.
2) Entertainment
Computers are also great entertainers. Many computer games are available which are like the traditional games like chess, football, cricket, etc. Dungeons and dragons provide the opportunity to test your memory and ability to think. Other games like Briano and Volcano test your knowledge.
3) Transportation
Today computers have made it possible for planes to land in foggy and stormy atmosphere also. The aircraft has a variety of sensors, which measure the plane’s altitude, position, speed, height and direction. Computer use all this information to keep the plane flying in the right direction. In fact, the Auto–pilot feature has made the work of pilot much easy.
4) Industry
Computers are finding their greatest use in factories and industries of all kinds. They have taken over the work ranging from monotonous and risky jobs like welding to highly complex jobs such as process control. Drills, saws and entire assembly lines can be computerised. Moreover, quality control tests and the manufacturing of products, which require a lot of refinement, are done with the help of computers. Not only this, Thermal Power Plants, Oil refineries and chemical industries fully depend on
computerised control systems because in such industries the lag between two major events may be just a fraction of a second.
5) HEALTH
As technology has advanced medicine, computers have become a bigger and bigger part of the health care field. Whether it's databases used to keep patient files, or computers being used to help doctor's interface with more advanced scanning equipment, the importance of computer technology is steadily increasing.
6) OFFICE AUTOMATION
Every office wheather it is a small scale or large scale office uses computer for various business functions such as inventory, accounting , payroll etc. and also use it for communication purpose such as making presentation for marketing and sales personnel,writing promotional letters to customers,etc. prepare annual or quarterly budget for various departments in office and so on.
CONFIGURATION OF LENOVO IDEAPAD (Z580)
The Lenovo IdeaPad Z580's brushed metallic gray aluminum lid has a matte finish that repels most fingerprints. The lid is also adorned with a slightly raised Lenovo logo, inscribed in textured silver. It's a handsome but not every exciting look. (For a little more flair we suggest opting for the white or red lid.)
Lenovo continues the brushed chrome motif on the interior of the Z580, keeping the classic mien consistent. The keyboard rests in a recessed area, below a strip of speakers running across the top edge. A textured silver power button sits on the top left corner of the deck, beside Lenovo's tiny OneKey Recovery button.
Five white touch-sensitive LED buttons line the top of the deck: volume up, volume down and mute, as well as dedicated buttons to launch a thermal manager and OneKey Theater, Lenovo's proprietary app that improves picture quality for video playback.
Measuring 14.8 x 9.8 x 1.3-1.4 inches and weighing 5.2 pounds, it is lighter than the VAIO E15 (5.4 pounds) but not as slim. The Sony has a profile that tapers from 1 to 1.32 inches. We had no issues moving the laptop from room to room, but we did start to feel the weight of the load after carrying the notebook a while.
Display
The Z580's 15.6-inch HD 1366 x 768 display delivered a satisfying amount of detail on text-heavy websites such as NYTimes.com and CNN.com. We fired up an HD trailer of "The Dark Knight Rises" on YouTube, and the specks of light comprising the backdrop of nocturnal Gotham City glowed brightly, lending an ominous (and effective) look to the scene. Unfortunately, viewing angles weren't the best on the Z580, as two people flanking a person right in front of the computer couldn't view the images on the display clearly. The Z580 doesn't sport the brightest screen, either, measuring 181 lux on our light meter. Though that's 40 points higher than the VAIO E15's 141 lux display, but well below the category average of 255 lux.
However, Lenovo does include a nice additional feature in the OneKey Theater button, which let us switch between Normal, Movie and Intelligent mode. (The third option promises to automatically switch between the first two.) When we toggled from Normal to Movie mode, we saw more vibrant colors and the edges of objects became smoother.
Audio
The Z580's audio easily filled a large room, Thanks in part to Dolby's Home Theater v4 technology. Sound quality remained clear and accurate, and the inclusion of Dolby's optimized presets for Music, Movies and Games are a definite plus. We also created our own custom presets using the feature.
The speakers served up the acoustic riffs of Train's "Drive By" with satisfying clarity, with the lead singer's bright vocal crooning adding verve to the easy-moving melody. However, the electro house song "Bangarang" by Skrillex didn't fare so well. The characteristic wobble on the bass-heavy song ended up sounding pretty tinny instead of rich.
Keyboard and Touchpad
The Z580 features a black matte island-style keyboard with generous spacing between large, flat keys. This is known as Lenovo's AccuType keyboard, which boasts "smile-shaped" keys with good tactile feedback. However, we did have one design quibble: The right Shift key is rather undersized, which caused us to make more typing errors than we normally would. On the plus side, you get a dedicated number pad on the right side.
The IdeaPad V580's touchpad is pretty roomy (4.2 x 2.8 inches) and sports a nice non-slip surface. Multi-touch gestures worked quite well. Pinch-to-zoom and rotate both registered instantaneously, and three-finger flicks were fast and responsive, too. However, the integrated mouse buttons felt a bit mushy.
Heat
After watching a full-screen video on Hulu for 15 minutes, the touchpad and space between the G and H keys registered a cool 81 degrees Fahrenheit, while the underside measured 88 degrees. That's well below the 95-degree threshold we deem uncomfortable. In fact, we watched a couple of "Mad Men" episodes with the Z580 on our lap for over an hour without any issues.
Webcam
Overall, the 1-MP camera on the Z580 delivered sharp images. Natural lighting showed off more accurate colors compared to fluorescent lighting, which washed out the picture. The integrated webcam pairs up with CyberLink YouCam 3 software to capture stills and video at 1280 x 720 resolution.
We used the webcam to talk to a friend using the included ooVoo video chat app. We also added another layer of security using Lenovo VeriFace 4.0. This face-recognition software helped us quickly create a profile.
Ports
The right side of the Z580 houses a couple of USB 2.0 ports separated by an optical drive sitting between them, a jack for the AC adapter and a combination headphone/microphone jack. On the left front lip of the notebook, you'll find a 5-in-1 card slot. A pair of USB 3.0 ports, HDMI, Ethernet and VGA are located on the notebook's left side. Performance
You can expect solid performance from Intel's third-generation Ivy Bridge processors, and the IdeaPad Z580 is no exception. Equipped with a 2.5-GHz Intel i5-3210M CPU, 6GB of RAM, a 750GB 5,400-rpm hard drive and an Intel HD 4000 GPU, the Z580 handled multiple computing tasks without a hitch. In real-world testing, we simultaneously opened 11 tabs on Google Chrome, streamed a TV show on Netflix and chatted on ooVoo. The Z580 never stuttered or skipped a beat.
The notebook also did well on the PCMark07 benchmark test, posting a score of 2,685, well above the 2,397 mainstream category average. The Sony VAIO E15, which has the same processor and 6GB of RAM, scored a slightly lower 2,452.
Aided by Lenovo's RapidBoot feature, which the company claims will let you start 40 percent faster than a typical Windows 7 computer, the Z580 booted the 64-bit version of Windows 7 Home Premium in 44 seconds, 11 seconds faster than the average. By comparison, the E15 booted in 50 seconds.
The Z580 duplicated 5GB worth of mixed media files in 3 minutes and 1 second for a rate of 26.6 MBps. That's 9.5 MBps below the 36.1MBps category average, but still better than the VAIO E15 (23 MBps).
On the OpenOffice Test, the Z580 took 5 minutes and 1 second to match 20,000 names to their corresponding addresses. That's 1:16 faster than the 6:17 mainstream category average. However, the VAIO E15 finished the same task in 4:48.
Graphics
The Z580 features Intel HD Graphics 4000 GPU graphics, which is good enough to play mainstream games but not the most taxing 3D titles. On the "World of Warcraft" test, the Z580 delivered a frame rate of 64 fps on Good at 1366 x 768, placing it well above the 50 fps category average. We cranked the game to maximum, and the frame rate dropped to 24 fps, only a tad short of the 26 fps mainstream average. By comparison, the E15 served up 56 fps and 23 fps at the same settings This notebook scored 639 on the synthetic 3DMark11 benchmark. That's 358 points below the mainstream category average, but on a par with the VAIO E15, which notched 643 points.
Battery Life
During the LAPTOP Battery Test, which involves continuous Web surfing over Wi-Fi, the Z580 lasted 5 hours and 19 minutes. That's slightly below the category average for mainstream notebooks (5:24), but it still bests the VAIO E15's staying power (4:34). Software and Warranty
Lenovo packs the IdeaPad Z580 with a robust suite of proprietary apps and utilities. Lenovo DirectShare allows you to sync files, Outlook emails and browser bookmarks between notebooks, even without connecting to the Internet. As mentioned, OneKey Theater optimizes the notebook for movie viewing, while Lenovo's OneKey Recovery is used for backup and storage.
Other native software on the Z580 include ReadyComm for advanced networking and Internet connection management; Energy Management for getting the most out of your battery life; Thermal Management System (pictured) that regulates fan speed and noise; and Veriface, which adds a layer of security via facial recognition.
In terms of pre-loaded software, the Z580 came with Windows Live, Adobe Reader X, ooVoo (pictured), and a trial of McAfee AntiVirus software. The notebook also ships with Microsoft Office Starter 2010, where users can either purchase Office 2010 offline or off the shelf to unlock the software. Or they can simply use Microsoft Office Starter 2010 for free.
The Lenovo Z580 comes with a standard one-year warranty on parts and labor. See how Lenovo fared in our Best and Worst Brands Report.
Configurations
A quick look inside our $679 review unit of the Lenovo IdeaPad Z580 (this particular configuration is available through Amazon) reveals a 2.5-GHz Intel i5-3210M processor, 6GB of RAM, a 750GB 5,400-rpm hard drive and an Intel HD Graphics 4000 GPU. The $559 base model has identical specs as our review model but is powered by a second-generation 2.5-GHz Intel Core i5-2450M processor.
Verdict
The Lenovo IdeaPad Z580 is a capable Multimedia laptop that combines solid construction, impressive sound and strong overall performance. At $679, this notebook is reasonably priced, though the design feels a bit chunky. Consumers for whom a multimedia-focused suite of apps is a priority will want to check out the sleeker Sony VAIO E15 ($699), but the Z580 lasts longer on a charge and has a better keyboard. Overall, the IdeaPad Z580 is a very good value.
BY : SANGEETHA CHOUDHARY
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