Technology

Oneplus 7T pro

2019-11-03T22:00:00.000-08:00

OnePlus 7T Pro smartphone was launched on 10th October 2019. The phone comes with a 6.67-inch touchscreen display with a resolution of 1440x3120 pixels at a pixel density of 516 pixels per inch (ppi) and an aspect ratio of 19.5:9.

OnePlus 7T Pro is powered by an octa-core Qualcomm Snapdragon 855 Plus processor. It comes with 8GB of RAM. The OnePlus 7T Pro runs Android 10 and is powered by a 4085mAh non-removable battery. The OnePlus 7T Pro supports proprietary fast charging.

As far as the cameras are concerned, the OnePlus 7T Pro on the rear packs a 48-megapixel primary camera with an f/1.6 aperture and a pixel size of 0.8-micron; a second 16-megapixel camera with an f/2.2 aperture and a third 8-megapixel camera with an f/2.4 aperture and a pixel size of 1.0-micron. The rear camera setup has autofocus. It sports a 16-megapixel camera on the front for selfies, with an f/2.0 aperture and a pixel size of 1.0-micron.

The OnePlus 7T Pro runs OxygenOS 10.0 based on Android 10 and packs 256GB of inbuilt storage. The OnePlus 7T Pro is a dual-SIM (GSM and GSM) smartphone that accepts Nano-SIM and Nano-SIM cards.

Connectivity options on the OnePlus 7T Pro include Wi-Fi 802.11 a/b/g/n/ac, GPS, Bluetooth v5.00, NFC, USB OTG, USB Type-C, 3G, and 4G (with support for Band 40 used by some LTE networks in India) with active 4G on both SIM cards. Sensors on the phone include accelerometer, ambient light sensor, compass/ magnetometer, gyroscope, proximity sensor, and fingerprint sensor. The OnePlus 7T Pro supports face unlock.

The OnePlus 7T Pro measures 162.60 x 75.90 x 8.80mm (height x width x thickness) and weighs 206.00 grams. It was launched in Haze Blue colour. It bears a glass body.

As of 4th November 2019, OnePlus 7T Pro price in India starts at Rs. 53,990.

iPhone x review and specifications

2017-09-18T23:09:00.001-07:00

The iPhone X is one in every of the foremost exciting phones free this decade – however not as a result of it offers something notably innovative or new.

It’s exciting as a result of it’s the foremost radical design of AN iPhone nevertheless, fastening along variety of key trends within the business and adding in a very level of polish that may attract legions of Apple fans to upgrade, and pay another number of years within the iCycle.

But this transformation doesn’t return low-cost, and nor can it attractiveness to people who get pleasure from a degree of continuity in their upgrades. this can be a brand new manner of interacting together with your iPhone, how that permits you to get pleasure from a lot of of iOS at anybody time, and alters the manner you employ apps with the hyperbolic screen size.

Screen, Screen and more Screen

Right, let’s get all the way down to the new stuff, and after you pull this phone out on the train you'll be able to make certain of 1 thing: it's entirely totally different to something that’s precede from Apple.

It’s rare that we tend to see Apple jumping on a trend this early, however 2017 has been the year once the edge has begun to disappear from the smartphone, and also the iPhone X has jumped decidedly aboard that train.

Apart from the Essential Phone, the new iPhone seems like one among the least-bezelled phones on the market. The lip on the highest of the five.8-inch screen is that the solely factor that gets within the manner of you and also thenew package, with the impact rather beautiful.

Sat next to last year’s iPhone seven, the iPhone X may be a fully totally different device. The impact of the broader and fuller screen goes to actually impress, particularly if you’ve not command the Samsung Galaxy S8, that compasses a similar show.

It's arduous to magnify however lovely this screen is – and that is not exaggeration brought on by extreme fatigue. It's deep, wealthy and swish, and attracts level with Samsung within the quality stakes simply.

However, what’s completely different here is that the screen on the iPhone X extends right to rock bottom of the device, with the physical home button obscurity in view.

That’s planning to be one among the most important changes for any Apple fans probing for continuity in their iPhone expertise, as they’ll have to be compelled to alter the method they run through their phone.

The resolution of the screen has – fortunately – been upgraded from the iPhone seven, because the sub-HD component count wasn’t very one thing Apple might hope to urge away with in 2017 within the face of such robust competition from the remainder of the trade.

Apple’s users don’t wish to maneuver far from its scheme, however if sure specs area aren’t met lately then envy willdevelop once phones are shown off at the bar – therefore the iPhone X has been upgraded to match its rivals, with a resolution of 2436 x 1125 on the new Super membrane HD show.

The only reason the constituent count required to be upgraded was that there’s a particular boost to be had with the cheater screens that produces apps look higher and web-browsing a additional stunning expertise – and with Apple charging the maximum amount because it is for this phone, it required to bring an improved screen.

But what the Cupertino whole has continually been sensible at is creating the expertise sensible without fear an excessive amount of regarding the specification list – that is why the very fact that previous iPhones didn’t have the sharpest screens didn’t hurt it.

The digital display screens had an honest distinction magnitude relation and were colourful and bright – qualities that ar as partaking as chucking in a very load additional pixels.

But the move to the OLED show within the iPhone X has positively brought associate degree upgrade, with the blacks deeper, the colours richer and, well, the result simply sensible.

The Samsung Galaxy Note 8 has been dubbed the most effective show on the market – and currently Apple is victimisation a similar technology in its iPhones.

The overall mixture of technology is nice, and very brings a few special-looking iPhone, instead of Apple rehashing a similar tired style once more.

Better Design

The new iPhone X is definitely, simply the best-looking phone Apple's ever created. we tend to were fans of the economic style that publicised the arrival of the iPhone four, and therefore the ee lines of the iPhone six.

But it seems like the new phone takes all of these concepts and smashes them into the longer term. If there is one issue that is pervaded the iPhone age of Apple it is the laser-focused thinking on style, and therefore the iPhone X takes that on.

The rear that is currently glass, does not feel as premium because the almost-ceramic metal of previous models, however it still feels solid and secure within the hand. The sides are not sharp, instead folding into the palm in an exceedingly means that is pleasant to carry.

It's a flash phone in addition – which glass will like to suck up a fingerprint.

If you have used any of the iPhone and vary, you will get on instantly with this telephone set. It's got a much bigger screen than the other iPhone, and nevertheless it's smaller than the iPhone 7 and.

That doesn't mean it is simple to urge your fingers across the show to achieve all the weather, and there is nearly a sense that you are going to stay touching the show with each flick of a digit.

But in observe it sits within the hand simply fine, and you are able to move with most functions well. There is positively a collection of gestures that you've got to use 2 hands, therefore we'd positively still reason this device as a phablet, instead of a 'standard' phone just like the iPhone 7.

Face ID

The big modification to the iPhone combine this year – for the flagship model anyway – is that the loss of bit ID so as to create means for Face ID, the flexibility to open your phone simply by observing it.

This is a daring move from Apple, as it isn't a {technique} that we've ever been a devotee of – we've found that previous handsets looking forward to similar tech are often duped by a photograph of the user, that is not the hardest issue within the world to urge hold of.

Apple's methodology of taking in many totally different face angles, very like after you got to position your finger round the detector to line up bit ID, makes lots a lot of sense, and Apple is predictably claiming that this is often one among the foremost secure styles of this technology out there.

We've not been ready to strive it call at the demo space, however this is often actually one thing we wish to check to visualize if it is a worthy replacement for bit ID.

The demo we tend to were shown was slightly worrying, though. Within the demo on stage the primary phone failing, and once it absolutely was shown to USA the person connected to the phone unbroken has to show the show off and on once more to activate the system.

When control at the proper distance, it worked well and quickly, however we tend to saw lots of lost unlocks in our time with the phone. Apparently it's going to learn your face as time goes on, however this is often one thing we actually got to check intent on check that it is easy to urge into your phone.

It's cool that the phone can solely activate after you cross-check the screen, showing it is aware of you; however the accuracy must be tip prime.

New Cameras

Usually at this time we're talking concerning the camera on the new iPhone and its ability to focus quicker, or take higher low-light shots, or concerning another new feature meaning you'll embarrass your kids within the future with a lot of clarity.

While there are a unit upgrades this point around – a camera lens like that introduced on the iPhone seven and is enclosed, moreover as optical image stabilization for each sensor thus you've a clearer and brighter image whichever mode you are in – its depth sensing that steals the show.

The camera on the rear is fastened on vertically, instead of horizontally, showing that Apple desires you to carry the phone in landscape instead of portrait mode. This can be conjointly on account of the front True Depth camera that takes up most house and is required for Face ID.

AR wasn't very shown off at the event, though we tend to did undertake some games that were fast and very cool to appear at, with the table taking the place of the podium terribly quickly.

With Apple's ARKit and Google's new ARCore, there is not any doubt that consecutive massive contest goes to be within the AR house, with developers having a full new (real) world to play with as a result – and it's attention-grabbing to ascertain Apple go thus early into this house.

The front-facing camera is great at sensing your surroundings and your face, and therefore the ability to map a mask, or rework you into associate degree animated emoji (called Animoji) is genuinely joy-filling.

We can't justify it, however there is one thing superb concerning having the ability to form associate degree on-screen pig frown, or being reworked into a photograph.

The camera itself felt fine, terribly kind of like previous iterations – in brief, this was all concerning having the ability to sense the environment instead of taking higher photos, that was attention-grabbing.

However, the machine learning within ought to be able to higher total what you are snapping and alter the settings to match – and therefore the Portrait Lighting, that showing intelligence learns what's the topic and what is not, and might alter the result of the exposure consequently, is actually beautiful as a feature.

New version of iOS

Pumping at the heart of the iPhone X is that the new A11 Bionic chipset, designed to handle the work the new iPhone is asking thereon for.

The new engine is capable of powering the extra pixels that are unfold around the front of the iPhone X, equally as handling the huge power the AR device is posing for – and on high of that there’s the ultimate improvement in overall performance, and better graphical performance.

This equates to higher battery life, owing to the 10-nanometer manufacturing methodology Apple is rumored to possess used for its new chipset, allowing it to create things lots of economical then enabling it to either crank up the flexibility or improve battery life – or balance the two.

The new chip permits for higher image focusing, higher face unlocking and comprehensive power enhancements – typically this can be often apparently the world's most powerful phone, that it'll have to be compelled to incline the amount of functions it's got, and conjointly the amount of pixels it's to run.

More Power

Pumping at the guts of the iPhone X is that the new A11 Bionic chipset, designed to handle the work the new iPhone is asking on that for.

The new engine is capable of powering the additional pixels that are unfold round the front of the iPhone X, similarly as handling the massive power the AR device is asking for – and on high of that there’s the final improvement in overall performance, and higher graphical performance.

This equates to higher battery life, because of the 10-nanometer producing method Apple is reported to possess used for its new chipset, permitting it to form things a lot of economical and so sanctioning it to either crank up the ability or improve battery life – or balance the 2.

The new chip permits for higher image focusing, higher face unlocking and all-around power enhancements – this is often apparently the world's most powerful phone, that it will need to incline the number of functions it's got, and also the quantity of pixels it's to run.

iOS 10.2 is now available

2016-12-13T01:58:00.001-08:00

On holy day of obligation Apple started the beta testing amount for iOS 10.2, and today, very little over one month later, the ultimate unharness is up for grabs. iOS 10.2 is offered to all or any supported devices, therefore if you've got one in all those expect to examine the update notification terribly shortly (if you haven't already). you'll be able to conjointly install the new unharness via iTunes.

iOS 10.2 introduces quite one hundred new emoji and new wallpapers and iMessage screen effects. It conjointly marks the debut of Apple's new TV app (US-only for now), meant to assist Apple TV house owners simply notice things to observe, and examine their purchased movies and television shows from multiple services. The Emergency SOS feature can contact emergency services after you press the ability button 5 times, whereas the Music app has received larger Shuffle and Repeat buttons.

Camera settings do not reset any longer once you restart the app, and you'll expect to examine further video widgets and single sign-on support for cable subscribers within the United States. Live Photos are improved, whereas the News app gets a Saved section wherever you'll return to the stories you have set to stay around for later. you'll additionally swipe left or faucet Next Story whereas reading to urge to a different item.

One Plus Three 3T Review

2016-12-10T23:32:00.001-08:00

The OnePlus 3T is to the OnePlus 3 what the iPhone 6S was to the iPhone 6. it's significantly identical, however there are some seriously welcome upgrades beneath the body.

Key changes embody a quicker Qualcomm flower 821 processor, thirteen larger battery capability and improved front-facing camera. But, with the rating currently beginning at £399, do the changes justify 3T's multiplied direct cost? as luck would have it for OnePlus, the solution is basically affirmative, that is doubly excellent news because the OnePlus three is being interrupted.

One Plus 3T Design

Not a good deal has modified here. There ar currently 2 color choices, a replacement bronze end or Soft Gold, though if you wish the new larger 128GB capability possibility you’re restricted to solely bronze. The bronze possibility replaces the previous black lead end accessible with the OnePlus three and could be a very little darker in shade.

Outside of this, the OnePlus 3T remains seven.4mm thick and is formed from one block of aluminum alloy that feels beautiful in hand. OnePlus created an enormous deal regarding however the highest of the frame curves otherwise from the remainder of the perimeters. It’s not one thing you’re planning to notice unless you search for it, however it’s still a pleasant bit.

Look to the lowest of the phone and you’ll notice a showing neatness trained speaker grille, a USB-C port and a electro-acoustic transducer jack. The latter is value drawing attention to as, despite Apple's efforts to kill the three.5mm jack, nobody looks to be during a nice rush to form USB-C headphones over Lightning headphones.

I’m truly all for moving off from the three.5mm jack and use Bluetooth headphones additional typically than not, however there square measure still times once I wish to use a wired affiliation on the far side headphones. Too typically I visited plug the jack-less Moto Z into my automobile radio solely to recollect I’d left the adapter connected to my wired headphones back home. It’s a frustration I will do while not.

Along the left edge could be a three-level Alert Slider to toggle between notification profiles. you'll either have all, priority or none, similar to the OnePlus three. It’s a helpful addition you don’t see typically. Below this is often the amount rocker, and on the other aspect the facility button.

There’s a front fingerprint device, that I’ve forever declared is my most well-liked position over a rear placement. The fingerprint device additionally doubles because the Home button, flanked by electrical phenomenon Back and up to date keys that square measure solely marked by a backlit dot, instead of their customary icons. this is often as a result of you'll swap their positions within the OnePlus 3T’s settings.

The button setup is comparable to the Samsung Galaxy S7's, and means that you'll do away with Android’s on-screen navigation buttons, liberating up additional of the show. you'll still activate the on-screen navigation within the settings if you wish.

Having a alternative is nice and also the customisation choices don’t finish there, on the 3T you'll additionally opt for completely different cutoff actions for double-press and hold inputs for any of the electrical phenomenon buttons.

The fingerprint device feels responsive and on a par with alternative nice fingerprint sensors, like the Huawei P9's, once it involves fastness. It will fall tangled of constant pitfalls as all alternative fingerprint sensors I’ve used tho', thus wet hands can still see you resorting to additional ancient unlock strategies.

Have no text to check? don't have any text to check? Click "Select Samples".Turn the OnePlus 3T over and you’ll see a moderate camera bump from the projecting rear camera. It’s not as pronounced as on sure different phones tho' and OnePlus has additionally created enhancements here by coating the detector in sapphire glass, for an additional level of resilience.

The OnePlus 3T supports twin SIMs, helpful if you've got a private and work variety and don’t wish to hold multiple devices. The second SIM slot doesn't double as a microSD card slot, as is that the case with sure different phones, thus there’s no expandable storage, similar to the OnePlus three.

But as mentioned, there's currently 64GB (£399) and 128GB (£439) capability choices. further|the additional} for 128GB isn’t a whole heist compared to what others have charged for extra storage, either. Otherwise, NFC makes a welcome come thus you'll be able to use golem Pay.

ONEPLUS 3T – Display

The 3T's 5.5-inch screen is on paper a twin of the OnePlus 3's. it's an equivalent one,920 x 1,080 resolution and uses an equivalent Optic AMOLED technology. That’s not progressing to quantity to the best pixels-per-inch density within the world, however with general use it’s not one thing you’re progressing to notice.

The Optic AMOLED technical school suggests that black levels ar very good and therefore the show still appearance super sharp, notwithstanding its comparably low pixels-per-inch count. Viewing angles also are glorious, with restricted brightness drop-off once viewed off-centre.

I was additionally affected with the reserved car brightness adjustment. Too several of the phones I’ve tested have had terribly aggressive automatic adjustment settings that kick in even once close light-weight levels haven’t modified. Brightness on the OnePlus 3T is additionally quite adequate for outside use.

One of the chief complaints once the OnePlus three launched was its uncomplimentary and unnatural color activity. This was one thing that eventually got mounted through software system updates, that is a minimum of a testament to OnePlus paying attention to its customers.

Luckily, a number of these learnings are applied to the OnePlus 3T. Out of the box colors ar somewhat oversaturated however the show appearance nice and if truth be told, this is often however I left the show throughout most of my testing.

If you wish additional natural, representative colors, associate sRGB activity profile is additionally associate possibility, that makes the colors look significantly additional muted. Another custom possibility helps you to manually modify the color temperature to your feeling.

From the short Toggle menu you'll be able to additionally activate an evening mode, that knocks down the blue light-weight a part of the color spectrum. This makes the show somewhat less harsh on your eyes within the dark moreover as purportedly reducing the impact on your biological time.

Like the Moto Z, there’s additionally associate close show that turns the show on in an exceedingly low-power mode once notifications are available, moreover as Proximity Wake that activates the show once you wave your turn over the camera. The latter doesn’t work moreover because the Moto Z’s dedicated proximity sensors, however.

One Plus Three Review

2016-12-10T22:24:00.000-08:00

It looks the OnePlus three hasn't been out long enough to get replaced, however that is exactly what is going on, and solely mere 5 months once it absolutely was 1st proclaimed. The OnePlus 3T is here, it's attending to be OnePlus' new flagship smartphone and once existing stocks of the OnePlus three run out the corporate will not be creating from now on.

The OnePlus threeT is that the OnePlus 3, however a trifle bit higher. It offers a processor upgrade, from the 2.15GHz Qualcomm flower 820 utilized in the OnePlus three to the two.35GHz flower 821 — a similar processor utilized in the Google element phone and element XL. The battery is slightly larger at three,400mAh compared with the first version's three,000mAh and its Dash Charge technology will deliver nearly five hundredth charge in half-hour..

There's additionally AN upgrade to the front-facing camera, with the OnePlus 3T moving from AN 8-megapixel snapper to a honestly silly 16-megapixel one, however one issue that hasn't modified a lot of is that the chassis. Physically, the OnePlus threeT is near-indistiguishable from the OnePlus 3.

Alas, there is some unhealthy news here likewise. The OnePlus threeT can price far more than the OnePlus 3 — at £399, in fact, it's twenty first costlier — and, as long as it'll replace instead of complement the OnePlus three, it is a blow for smartphone discount hunters.

Our full OnePlus three review follows, however fulfil to mention if you are looking for a mid-range smartphone discount, it's like you are going to wish to act quickly and snaffle a OnePlus three. OnePlus itself has already sold out, thus you'll have to seem elsewhere from currently on.

ONE plus Three Full Review

The OnePlus three is one in all the foremost extremely anticipated smartphones of 2016 thus far, and it's lots to measure up to. Its forerunner, the OnePlus a pair of, has been my decide of the sub-£300 smartphones ever since it launched last year, and remains on sale at £249. The new model is £60 dearer, thus is that the OnePlus three definitely worth the worth hike?

Immediate impressions square measure positive. though the phone has an equivalent five.5in-sized screen because the OnePlus a pair of, elsewhere, it’s all amendment. The headline specifications see the new phone move to the quicker, additional economical flower 820 processor, with double the quantity of RAM. The OnePlus three has NFC additionally to a front-mounted fingerprint reader, permitting it to be used for contactless payments via humanoid Pay. though the screen is that the same size, OnePlus currently employs AMOLED school wherever its forerunner had associate degree IPS show. and therefore the camera sees associate degree upgrade in resolution and options.

I wasn’t quite as taken aback with the planning after I initial clapped eyes on that. it's bland from a distance; a style that’s blurred, that appears spookily just like the long-lost by-blow of the HTC One M9 and Honor 5X, that merely doesn’t build a press release.

Get it in your hand, however, and it’s a special story. The OnePlus feels strong and refined all told the proper ways in which. In fact, you recognize what? It’s nice. extremely nice. chuck the tasteless appearance – the OnePlus three is fabulous price.

In fact, if you gave this to American state and blanked out the brand, I’d guess it absolutely was a way more pricy phone, nearer to £600 than £329. It’s lighter and slimmer than the OnePlus a pair of, shaving one7g off that phone’s weight and 1.5mm off its thickness, despite having the same-sized screen, and it’s full of beautiful very little details. the sides of the screen area unit slightly rounded, the buttons have a solid, positive click, and therefore the do-not-disturb slider on the left edge includes a beautiful mechanical snick thereto.

security for your computer

2011-11-23T19:20:00.001-08:00

We use computer to perform several task in our daily life. They are used to process and store valuable information. Some information may be very important to organization. The loss of these important data can cause serious damage to the organization. It takes lots of money and effort to recover them. As the computer system is delicate electronic and electro mechanical system. It should be used and kept safely. If we do not use it properly, its hardware as well as software, may damage any time. Hence, computer security plays a vital role to the growth and survival of any organization. So, proper management of computer is essential for every organization.

Computer security includes the policies, procedures, tools and techniques designed to protect a company’s computer assets from accidental, international or natural disasters, including accidental input our output errors, theft, breaking or physical damage and illegal access or manipulation of data.

The protection of computer system from accidental or intentional harm, including destruction of computer hardware and software, physical loss of data, deception of computer users and the deliberate invasion of database by unauthorized individuals is called computer security. In other words, the protection of computer, its accessories, data and programs for a long life of computer system is known as computer security.Computer security is concerned with the hardware security as well as software security.

HARDWARE SECURITY

Hardware is the essential part of computer system. Computer can not perform any task without hardware. All the physical parts of the computer such as CPU, Mouse, Monitor, Keyboard, Printer etc are known as hardware. Without existence of hardware software is useless. Hardware plays very important role for proper functioning of our computer system. So, we must check and maintain hardware components frequently. We should replace defective parts of hardware immediately. Now-a-days, hardware diagnostic facilities are

available to find defective hardware comments of the computer system.The protection of al l hardware components used in computer system is known as hardware security.

Some common hardware security measures are as follows:

I. Regular Maintenance

II. Insurance

III. Dust free environment

IV. Protection from fire

V. Protection from theft

VI. Air Condition System

VII. Power Protection Devices (UPS, Volt Gu

ard and Spike Guard)

VIII. Avoiding unrelated persons in the computer rooms.

REGULAR MAINTENANCE

Regular maintenance is necessary for proper functioning of our computer system. We should clean our computer and its peripherals regularly by using dust cleaner. We should scan hard disk using latest and updated Anti-virus software to make it virus free. We should format hard disk time to time in order to make our computer system fast. It is better to delete unnecessary files from hard disk. Upgrade some hardware components as well as software to make computer system fast.

INSURANCE

The term Insurance is not new for us. Generally people insurer their health, life, company, building, vehicle, etc. But nowadays many people also insure their computer. If our computer is damaged or lost we can claim for the insurance amount and replace the computer system easily. So, it is being one of the hardware security measures of our computer.

DUST FREE

Dust is one of the major factors which cause infection of our computer system. Dust effect external as well as internal parts of our computer system. So we should keep our computer in the dust free place. We should use dust cover to prevent our computer from dust.

PROTECTION FROM FIRE

Fire is another factor, which cause infection of our computer system. Fire can damage whole computer system. It is very dangerous factor so we must be very careful about fire. It may cause by smoking, so it is better to avoid smoking inside computer room. Another chance is by electricity so proper wining is necessary inside the computer room. Keeping fire extinguishers can be a good idea.

PROTECTION FROM THEFT

As we all know that computer is an expensive machine as compared to other common machines. So we must keep our computer system in the secure place to protect from theft. If we are not careful, someone can easily state important parts of computer system from computer room. We must lock doors of computer room properly. The entry and exit of computer room must be well controlled and monitored. Unknown or unauthorized persons should not be allowed inside the computer room. Construct the computer room with emergency doors and windows. We can hire security guards to guard computer room.

AIR CONDITION SYSTEM

We should maintain suitable temperature and circulation of air in the computer room. Low or high temperature in the computer system may cause unexpected crashes during the operation of computer. Heat can break down contracts or junctions in the chip or other devices. So, there should be proper air condition to maintain suitable temperature in the computer system. Similarly there should be enough light in the computer room. We can use cooler or fan to prevent heat built-up.

POWER PROTECTION DEVICES

The computer system is made of delicate electronic and electro-mechanical components. We all know that it needs electric power to operate. It needs 220-240 Volts (AC) and the frequency of AC should be 49.5 Hz to 50Hz. High voltage or fluctuating voltage may cause several hardware damage. Our important data and programs can be lost due to sudden power failure. To avoid such unpredictable behavior of the power supply, we have to use some kind of power protecting devices. Some power protection devices are:

I. Uninterruptible Power Supply (UPS)

II. Volt Guard

III. Spike Guard

UPS

A computer needs a well regulated power supply for the proper functioning of its various parts. UPS is a device that stores electricity and automatically provides backup power to the computer in case of electricity failure is the source. It is activated when it detects a loss of power from the source and prevents loss of data and damage of computer parts that might be caused due sudden power failure. It also prevents our computer system against sudden power surge. It acts like a buffer between the incoming power supply and the computer system. It constantly monitors the quality and characteristics of the power supply. Nowadays a several different types of UPS having different capacities are available in the market. We should buy UPS from a well-known and reputable company.

VOLT GUARD

Volt Guard is another important power protection device. It provides constant output voltage to the computer system in case of high input voltage coming from the source. As we have known that our computer system needs voltage between 220 to 240volts and high or low voltage affects our computer system. Volt Guard plays important role to save our computer system from damage due to high voltage. If the input voltage comes from the source, it provides constant output voltage between the ranges 220 to 240 volts. So, we must use Volt Guard in our computer system.

SPIKE GUARD

The lightening in the rainy season can cause sudden increase in the voltage level of the AC-line supplied to our house. The voltage can increase more than 2000V in our normal 220V supply. The over voltage can severely damage the electric device running at the time. This sudden over voltage is known as spikes. Spikes are very brief over voltage up to 2000V or more caused due to lightening, power- line faults etc. To save the electronic device from these spikes, we need the special, equipment called spike guard. Spike guards are the electronic device, which remove the spike and prevent it from entering into the main system.

SOFTWARE AND DATA SECURITY

Data and programs or software is very important things. Computer can not perform any task without software. We cannot operate our computer without operating system software. Some information of organization may be very important and the loss of these data can cause serious damage to the organization. It is very costly to recover these important data and some cases that is impossible to recover them. So, data and software security is essential for any organizations as well as every computer users. Software security is the most convenient way of safeguarding our computer system.

The protection of data and programs used in computer system is known as software security.

For protection of data and programs in our computer systems, we should apply some security measures. Some common software security measures are as follows:

Ø Password Protection

Ø Backup System

Ø Defragmentation

Ø Scan Disc

Ø Virus Scanning

PASSWORD PROTECTION

The password scheme is one of the easiest and easiest and reliable method of protecting important data and information in our computer system. It is the common type of authorization control. If we protect our document by using password, only authorized users can open the document. Password is the primary source of data protection; it is a set of characters that acts like a key to unlock the system. Separate password can be used to access a system, an application, or even a file in a given application. The user in an organization who is permitted to access the company database is issued with a user ID and password and only certain level of access rights are provided to them by database administrator.

The success of this type of security depends on the ability of the user to create a password that is difficult to guess and to keep the password confidential. In order to ensure tight system security, many companies have policies that mandate the use of hard to guess passwords or randomly generated password and require employees to change their passwords frequently.

Some common rules while creating password:

· Password must be at least 6 characters.

· The word used in password should be difficult to guess for others.

· We should keep our password confidential.

· We have to change our password frequently.

· Files, which store password, must be encrypted.

BACKUP SYSTEM

Creating backup consists of making extra copies of programs or data. It provides safeguard against the loss of data or programs in computer memory, on hard disk or on diskettes. While creating backup data to a file, we have to give file name and location for the file to be saved. We can create a extra copy of data in our hand disk by using backup utility. Sometime our original data in the hard disk may erase, in that case we can restore our data from backup copy. It is always a good idea to create backup copies of our important data and programs.

DEFRAGMENTATION

Defragmentation is the process of rewriting parts of a file to contiguous sectors on a hard disk to increase the speed of access and retrieval. When files are updated, the computer tends to save these updates on the largest continuous space on the hard disk, which is often on a different sector than the other parts of a file. When the files are fragmented the computer must search the hard disk each time the file is opened to find all of the file parts, which slows down response time.

Thus hard disk needs to be defragmented using disk defragmenter. The defragmenter is available in most of the latest operating system such as windows 98, windows XP, windows vista in its system tool.

SCANDISK

Scandisk feature is used to detect and repair errors on disk. This feature is available in windows 95/98/Me and Dos.6.2 operating systems. The scandisk feature included in windows 95/98 can search corrupted files also.

VIRUS SCANNING

Computer viruses are the most defective factor of data and software. Viruses may damage our data and software. Viruses produce several unusual symptoms in our computer and used to give trouble to the user while working with computer. So, we should keep our computer free from viruses. For that we should scan our computer regularly using latest and updated Anti-Virus software. We can also install an ‘On access’ scanner and configure it to start automatically each time we boot our computer.

USING ORIGINAL SOFTWARE

We should not use pirated software but should go for the original software. The pirated software can contain several viruses. No one can guarantee the stability and performance of the pirated software.

What is Multimedia Technology?

2011-09-01T07:43:00.000-07:00

As we know multimedia system can create, store, compress, decompress and show the multimedia contents. Several techniques can be used by multimedia systems to do so. These techniques are collectively called the multimedia technology. Multimedia technology comprises of different techniques that are used by multimedia systems.

By the use of multimedia technology different multimedia applications have been built and implemented in real life to make different jobs easier. Educational multimedia applications enable students to study at home. Different animation packages help to visualize the different phenomenon, which would otherwise be impossible in classrooms. We can visualize several complicated processes like how human heart works, how is the structure of human heart, how brain transmits signals, how volcanoes erupts and lots of other things with the help of multimedia technology. Thus, multimedia technology has enabled us to visualize and realize virtually, many things that would not be possible otherwise. Even if it was possible, it would be very costly for general people to afford it. We can even do the lab exercise without science laboratory by the use of laboratory multimedia made by simulating the laboratories.

Multimedia technology has also improved the communication systems. We can use videoconferencing tools these days by which we can held the huge world wide conference without every body meeting in a same place. In video conferencing every body taking part in the conference sit aside of their computers and put their news, views and ideas in front of other participants. The participants also can comment, accept or reject ones ideas or put any questions ahead for discussions. Through video technology every participants of the conference can also see each other in their multimedia computers. Video conferencing is in fact a tool and a technology that virtually brings many people spread all over the world together to discuss on some matters. People could interact witheach other as if the single conference hall.

MULTIMEDIA AND ITS APPLICATION

2011-09-01T07:37:00.000-07:00

MULTIMEDIA

We often see different pictures, songs and movies in our computer. Sometimes we also hear that some actions in films are not performed real but are made by computer animations. We see TV advertisements, different attractive advertisements in newspapers, and many other designs in walls, pamphlets and other places. How these have been possible after all? All of these things are made by using multimedia tools. These days, multimedia computers are used as the most prominent multimedia tool to develop such graphics designs, animations, videos, image editing, etc. multimedia computers are nothing but simply the computers like we use in our home which are enhanced with many other multimedia hardware and software. Multimedia computers are capable of generating, storing and displaying multimedia contents. Now a question arises”What is Multimedia?” lets try to answer it.

As the name implies, multimedia is the integration of multiple forms of media. Multimedia is the technology that uses any combination of different media; it may or may not involve computers. It may include several media like text, spoken audio, music, images, animation, and video. For example, a presentation involving audio and video clips would be considered a “multimedia presentation”. Educational software that involves animations, sound and test is called “multimedia software”. Multimedia programs are often interactive and include games, sales presentations, encyclopedias, and many more. Any systems can be said interactive if users could act or command the system and the system works accordingly. For example: in media player a playing video pauses if the user clicks on the pause button and starts again when user clicks on the play button and starts when user clicks on any button. The user’s clicks here are considered as the user’s interaction and the response made by the system is called interactive response. Users can interact in many other ways instead of mouse. If any multimedia supports or response specifically on one or more of the user’s interaction, then such multimedia is called the interactive multimedia. Such interactive multimedia has gained lots of popularity these days.

Multimedia requires the large amount of data to be stored. Hence, CD-ROMs and pen drives are the good option for storage of computer multimedia files. We could store multimedia in other high capacity storage devices which are also faster and easy to use. But mostly we choose CD-ROM and pen drive as multimedia storage devices as it is very cheap, it can store lots of data and it is very easy to store and handle. Such CD-ROMs which contain multimedia files are called “Multimedia CD-ROMs”. Nowadays we can get different multimedia CDs in the market which contain the entertaining and educational materials.

MULTIMEDIA SYSTEM

System means the combination of different components which work in coordination with each other in a certain manner so as to serve some specific purpose. Multimedia is the technology which can disseminate two or more different media like text, audio, video, etc in a single time frame. Thus multimedia system means the proper combination of different multimedia components which work together to create, edit, store and disseminate the multimedia components. Almost all of today’s multimedia systems take advantage of power and ease of computer systems. Without computers, today’s sophisticated multimedia cannot be thought of. So, multimedia system could be more accurately defined as the combination of computer hardware and software designed so as to create, store and disseminate the multimedia content.

The multimedia computer generally contains the following components.

1) Computer

2) Multimedia Software

3) Sound card

4) CD-Drive

5) Micro-Phone

6) CD-ROM Disk

7) Multimedia speakers/Head-Phones

8) Digital Camera and many other components.

All of some of the above mentioned components work together to make up the multimedia system which can capture, digitize, compress, decompress, retrieve the multimedia component (multimedia data) and show it into the output devices like Computer Monitor, Multimedia Projectors, etc. Literally speaking, all the components that could be used in the multimedia system are impossible to list out. The above mentioned are only some of the important components of multimedia computer system.

ADVANTAGES OF MULTIMEDIA

We have already mentioned various advantages of using multimedia. We can still specifically list out following points that explains the advantages of the multimedia.

1. It can be used to help students and teacher to teach as well as learn the given topics easily.

2. It can be used to spread the knowledge easily all over the world wide in the cheap cost.

3. It is easy to take the multimedia files from one to other places as it can be stored in the cheap and light storage devices like CD-ROM.

4. It can be used for any subject and for anyone.

5. It can be used in Television, Films Industries and for personal entertainments.

6. It is highly used to realize the concept of Open University, Distance Education System, and Video Conferencing.

7. It is also used in Internet to make up the interactive web-page contents.

8. We can give the everlasting impression to the intended audiences on a specific topic by the use of multimedia.

9. Colored pictures, Motion pictures and other graphics could be shown in monitors and other big screens so that many people could view it and make out the impression about it.

10. Multimedia systems are generally very interactive so it is interesting to use.

DISADVANTAGES OF MULTIMEDIA

In comparison to the enormous advantages we have very little disadvantages of multimedia. These disadvantages could be listed out as:

1. It is expensive to produce multimedia contents.

2. It is expensive to set up the multimedia systems.

3. It needs well trained manpower to create and use it.

4. Multimedia files are too large so, it is time consuming to transfer across the Internet and Intranet.

MULTIMEDIA TECHNOLOGY

Detailed System Design

2011-08-24T21:51:00.000-07:00

Detailed System Design

As we already know the concept is a sketch of the structure and/or skeleton of the Information System, it guides the detailed design hence adding flesh to make it move towards becoming the system. As the scope and general configuration of the Information System have been established, the detailed design of the system may be started.

Sometimes it is impractical to explain each and every steps of doing procedure for detailed design for the following reasons.

1. There is a wide variety of approaches to system design in terms of organizing, conducting and defining it.
2. Systems design is a complex of concurrent activities where as the nature of description can proceed along only one line.

The first step in systems design is not a technical one. It is concerned with gaining support for the work that follows. Systems designers must have the support of most members of the organization to obtain information for the design of the system and to obtain acceptance of the final system.

Therefore, at least members of the organization should be informed of the objectives and nature of the study. It is preferable to draw many members into the study.

Aim of the detailed design

The detailed design of an Information System is closely related to the design of operating systems.

The aim of the detailed design is to furnish a description of a system that achieves the goal of the conceptual system design requirements.

This description consists of drawings, flowcharts, equipment and personnel specifications, procedures, support tasks, specification of information files, and organization and operating manuals required to run the system.

Conceptual design gives the overall performance specifications for the Information System; the detailed design yields the construction and operating specifications.

Document the detailed design

The end of the detailed design project is production of the documents that specify the system, its operation, and its design justification.

Documentation Consists of
1. A summary
2. Detailed flowchart
3. Operations activity sheets showing inputs, outputs and transfer functions.
4. Specification of the data base or master file.
5. Computer hardware requirements.
6. Software (programs)
7. Personnel requirements by type of skill or discipline.
8. Final (updated) performance specifications.
9. Cost of installation and implementation of the system.
10. Cost of operating the system per unit of time.
11. Program for modification or termination of the system.

Implementation, Evaluation and Maintenance of Information System

2011-08-24T21:50:00.000-07:00

Implementation, Evaluation and Maintenance of Information System

Implementation

The design of a management information system may seem to management to be an expensive project, the cost of getting the MIS on line satisfactorily may often be comparable to that of its design, and the implementation has been accomplished when the outputs of the MIS are continuously utilized by decision makers.

Once the design has been completed, there are four basic methods for implementing the MIS.
These ares-
1. Install the system in a new operation or organization.
2. Cut off the old system and install the new
This produces a time gap during which no system is in operation. Practically, installation requires one or two days for small companies or small systems.
3. Cut over by segments
This method is also referred as” phasing in” the new system. Small parts or subsystems are substituted for the old. In the case of upgrading old systems, this may be a very desirable method.
4. Operate in parallel and cut over.
The new system is installed and operated in parallel with the current system until it has been checked out, then only the current system is cut out. This method is expensive because of personal and related costs. Its big advantages are that the system is fairly well debugged when it becomes the essential information system.

Plan the implementation

The three main phases in implementation take place in series.
These are

1. The initial installation
2. The test of the system as a whole
3. The evaluation, maintenance and control of the system.

Many implementation activities should be undertaken in parallel to reduce implementation time. Training of personnel and preparation of software may be in parallel with each other and with other implementation activities.

The first step in the implementation procedure is to plan the implementation. Some analyst includes the planning of the implementation with the design of the system, the planning and the action to implement the plan should be bound closely together. Planning is the first step of management, not the last. The MIS design and the urgent need for the system at the time the design is completed will weigh heavily on the plan for implementation.

Implementation Tasks

The major implementation tasks consists of-

1. Planning the implementation activities
2. Acquiring and laying out facilities and offices
3. Organizing the personnel for implementation
4. Developing procedures for installation and testing
5. Developing the training program for operating personnel.
6. Completing the system’s software
7. Acquiring required hardware
8. Generating files
9. Designing forms
10. Testing the entire system
11. Completing cutover to the new system
12. Documenting the system
13. Evaluating the MIS
14. Providing system maintenance(debugging and improving)

1. Planning the implementation activities

Establish Relationships among tasks

For small projects, the order of performance may simply be described in text form. A Gantt chart or network diagram makes visualization of the plan and schedule much clearer.

For large projects, many concurrent and sequential activities are interrelated so that a network diagram must be employed in any good plan.
Establish a Schedule

Schedule is prepared by having the system designers estimate the times between the events in the program network. The critical path (longest time through the network) can be calculated. After specifying the starting date, the end date is established.

Cost Schedule to Tasks and Time

The cost for completing each task required to complete is established as part of the plan; then the rate of expenditures should be budgeted.

Reporting and control of the work in progress may be obtained by weekly meetings. The financial personnel must make certain that report formats allow them to show cost and technical progress relationship as well as cost and time.

2. Acquiring and laying out facilities and offices

For the installation of a new system to replace a current one may require a major revision of facilities as well as completely new office, computer room etc.

The MIS project manager must prepare rough layouts and estimates of particular floor areas that feel to be needed. The manager then prepares cost estimates.

Space planning must be done by the space to be occupied by people, the space occupied by equipment and the movement of people and equipment in the work progress. A large investment in good working conditions will repay its cost many times.

3. Organizing the personnel for implementation

As the implementation tasks have been defined, management usually assigns a project manager to guide the implementation.

The purpose of the MIS is to increase the amount and quality of their contributions, the system is their system.

Top management must make the middle managers for their involvement in implementation, besides these, systems specialists, computer programmer; top management should make sure that each people who will operate the system should have active parts in the implementation.

4. Developing procedures for installation and testing
After organizing the personnel for implementation the next task is to develop or prepare the procedures for implementation. As the project leader has the network plan for proceeding with the implementation, this leader calls the key people in the project to prepare more detailed procedures for system installation.

Procedures for evaluating and selecting hardware must be spelled out. Procedures for phasing in parts of the MIS or operating the MIS in parallel must be developed.

The major part of implementing the MIS is the testing of each segment of total system as it is installed.

5. Developing the training program for operating personnel

A program is developed keeping in mind to impress management and support. After developing the program, it is necessary to train operating personnel in their new duties. They must have a thorough understanding of what the new MIS is like and what it is supposed to do. They must learn how it will operate. They are faced with many changes in their work and have to obtain acceptance of changes.

As there are various levels of personnel and these people will be working with only a small part of the MIS, the seminars should be designed to provide them with an understanding of the complete system.

6. Completing the system’s software

As the software is developed internally or under contract, in both cases, the software development must take in mind the nature of the hardware required.
As the system designers and programmers provide the flow diagrams and the block diagrams during the detailed design state. Some modification may be required, as the implementation stage progresses.

7. Acquiring required hardware

This acquisition is usually the limiting factor in getting am MIS implementation. These tasks should be started during the design stage.

The decision is to be needed, whether to buy or lease the hardware. Capital expenditure analysis is only one of many factors involved in this decision. Others are prestige, usage etc.

8. Generating files

In the implementation stage, the actual data must be obtained and recorded for the initial testing and operation of the system. This requires format of the data, storage form and format and remarks to indicate when the data have been stored.

The collection of data used in routine operations is often called the master file.

Responsibility for file maintenance for each file item should also be assigned. The development of files or databases belongs to information system designers and storage and retrieval experts.

The translation of specifications for files into computer programs is a function of computer specialists.

9. Designing forms

For controlling the marketing, a salesperson has to fill out the forms summarizing the day’s activities. The form ensures the right information to be supplied for computer storage.

Forms are required not just for input and output but also for transmitting data at intermediate stages.

10. Testing the entire system

As the total system is installed, tests should be performed with the test specifications and procedure. A test during installation stage consists of component tests, subsystem tests and total system acceptance tests.

Components may be equipment (that can be new or old), new software programs, new data collection methods, work procedures, reporting formats. Difficulties that occur during component tests may lead t design changes.

As more components are installed, subsystems may be tested. There is a difference between the testing of component and the testing of a system.

System tests require verification of multiple inputs, complex logic systems, and timing aspects of many parts.

11. completing cutover to the new system

Cutover is a point at which the new component replaces the old component to the new system replaces the old system. This involves old forms, old files and old equipment being retried.
The debugging proves associated with the cutover to the new system may extend for several months.

12. Documenting the system

Documentation of the MIS means preparation of written descriptions of the scope, purpose, information flow components, and operating procedures of the system.

Documentation is a necessity for troubleshooting, for replacement of subsystems, for interfacing with other systems, for training new operating personnel and also for evaluating and upgrading the system.

13. Evaluating the system

After the MIS has been operating smoothly for a short period of time, an evaluation of each step in the design and of the final system performance should be made.

Evaluation should not be delayed beyond the time when the system’s analysts have completed most of the debugging. The longer the delay, the more difficult it will be for designer to remember important details.

The evaluation should be made by the customer as well as by the designers.

14. Providing system maintenance

Control and maintenance of the system are the responsibilities of the line managers.

Control of the systems means the operation of the system as it was designed to operate. Sometimes, well-intentioned people or operators may make unauthorized changes to improve the system, changes that are not approved or documented.

Maintenance is closely related to control. Maintenance is that ongoing activity that keeps the MIS at the highest levels of effectiveness and efficiency within cost constraints.

Maintenance is directed towards reducing errors due to design, reducing errors due to environmental changes and improving the system’s scope and services.

Conceptual System Design

2011-08-24T21:20:00.000-07:00

Conceptual System Design

During the system analysis, the analysis of system data is very important. Analysis of data is made up of more than one level at the beginning (first level) and different ideas are used at each level. At first level, analyst develops a conceptual system design.

Since the conceptual design sets the direction for the management information system (MIS). It is vital that managers participate seriously and heavily at this stage. Conceptual design is sometimes called feasibility design, gross design or high level design.

The conceptual design phase takes as input.
1. A crisp statement of a management information requirement and
2. a set of management objectives for the MIS

In the conceptual design stage that the alternative overall MIS designs are conceived and the best one is selected by the system analyst in consultation with the top management. The feasibility of meeting the management objectives for the MIS is assessed showing how the system will work at the high level is drawn. Therefore, conceptual design is also known as gross design; high level becomes the basis for the detailed MIS design.

Hence, conceptual design is a pre-design for the detailed design. In fact, conceptual design is the “centerpiece” of the process. Only after conceptual design is completed, it can be sure that the MIS can successfully be constructed.

The conceptual design involves the following tasks.

1. Defining problems in more details.
2. Refining the management objectives to set system objectives.
3. Establishing system constraints.
4. Determining information needs and their sources.
5. Developing alternative designs and selection one from these various designs.
6. Document the conceptual design and preparing the report.

1. Define the problem-

There is no doubt that problems exists in any dynamic business. The most important is that what are usually lacking are clear definitions of the problems and the priority system on the basis of problem is the main solution. Therefore, management must take the first step in MIS design by formulating problems to be solved. The problem can be solved by the iterative process.

The goal for the business leads to the objectives of the general business. From the objectives, plans are derived. Each business objectives and business plans are derived. Each business objectives and business plans are associated with information needs. These Information needs are the problems to be solved by the MIS function. The statements of needs are enough for designing process.
1. Stating the information need.
2. Asking questions about that need.
3. Suggesting interpretation of that need.
4. Detailing the original statement.
5. Reviewing the more detailed statement of need with management.
These steps are repeated until the information needs and the problem to be solved are really understood. The process of problem refinement flows naturally into the system objectives.

2. Set System Objectives

Most of the time it is quite difficult to state objectives for systems that covers all the functional areas.
The manager must define the system objectives in terms of the importance of information demands and not in terms of the satisfaction of demands that are not related to an objective. System analyst tends to stress processing efficiency and staff and functional supervisors commonly believe that their objective is “to complete the required report in time for management use”. This view disregards the real objectives of the system design, management’s effectiveness.

The value of system lies in the benefits of the users. When we ask for the objectives, a college principal may reply,” provide quality education” and a government bureaucrat may say” provide more jobs for the unemployed”. Despite its difficulty being specific is necessary. System objectives should be expressed in terms of what managers can do after their information requirements have been met.
In summary, the first steps in systems design attempts to answer the question” what is the purpose of the system?” why it is needed? What is it expected to do? Who are the users what are their objectives?

3. Establish System Constraints

The iterative nature of the systems design process is easily understood when we consider the third step in the process-establishing constraints. It can also be called as problem boundaries or restrictions, constraints enable the designer to stipulate the conditions under which objectives may be attained and to consider the limitations that restricts the design. The two steps of setting objectives and establishing constraints may be considered together as one.
Constraints may be viewed as a negative limitation on systems design, there is a positive benefit also. Establishing constraints will help to ensure that the design is realistic.
Constraints may be classified as external or internal to the organization.

External Constraints
The external environment of the organization is concerned by the customer. Order entry, billing and other systems that interface with the customer’s needs in mind. If some outputs from the system are not acceptable to the customer, a definite limitation must be faced up.
The government imposes certain restrictions on the processing of data. That may be the need to maintain the security of certain classes of information to comply with law and regulation in the conduct of business (e.g. taxes, reporting).
Unions can also affect the operations of systems involving members in working conditions.
Suppliers are also an important group to be considered when designing information systems because these systems frequently interface with that group.

Internal Constraints
If top management support is not obtained for the systems concept and for the notion that computer based information systems are vital for management planning and control, the type of design effort cannot be implemented. A good environment for information systems must be set, and one essential requirement is the approval and support of the top management.

Organizational and policy considerations frequently set limit on objectives and modify an intended approach to design of the system. Company policies frequently define or limit the approach to systems designs.

Personnel needs and personnel availability are a major limiting factor in both the design and utilization of information systems. Computer and systems skills are among the most critical in the nation. The most significant constraint of all is the one concerning the people.

Cost is a major resource limitation. The cost to archive the objectives should be compared with the benefits to be derived.

Self-imposed restrictions are these placed on the design by the manager or the designer. The manager will also restrict the amount of time and effort devoted to investigation. To achieve the objective, the manager may have to scale down several requirements to make the system fit with other outputs, equipments or constraints.

4. Determining Information needs and sources

For a good system design, a clear statement of information needs is very important and necessary. Many organizations spend huge amounts on hardware and software to maintain existing systems or build sophisticated data banks, without first determining the real information needs of management: the information that can increase the ability of managers in critical areas such as problems, alternatives, opportunities and plans.
The optimum results cannot be achieved unless managers can provide the specifications for what they want out of an information system. The manager needs information for variety of reasons concerned with the management process. The type of needs at various times and various purposes depends largely upon two factors.
a) The personal managerial attributes of the individual manager and
b) The organizational environment in which decisions are made.
The information sources are important for determining information needs. The system may require external information or the internal.

5. Alternative conceptual designs and selecting one

The development of a concept of a system is a creative process that involves synthesizing knowledge into some particular pattern. The concept of an MIS would consist of the major decision points, patterns of information flow, channels of information and roles of managers and competitors. The concept is the sketch of the structures or skeleton of the Information System, which guides and restricts the form of the detailed design. If conceptual design is the skeleton, then detailed design is the flesh.

E.g. two teams of students are trying to do project on the tourist guide and contact information system. One concept produced is a sketch showing a detail about the particular places describing its culture, heritages along with the colleges. Hotels and trade. Where as another team produces a sketch of description of colleges along with the description of faculty and the fee structures on various needs.

It is obvious that each alternative concept of a system has advantages and disadvantages. Sometimes one concept will dominate all others by major criteria.

6. Document the best design

Sufficient information has been accumulated to begin a more detailed description of the system concept. This description includes essentially a flowchart or other documentation of the flow of information through the system, the inputs and the outputs.

The manager should be involved to the extent that the system provides the information required, the designer is concerned with the nature of the materials and equipment as well as with technical processing considerations.

Details to be worked out later by the designer will include exact instructions as what data are to be captured and when, the files are to be used, the details of how processing is to be done, what outputs will be generated by the system etc.

Definition, Bus, Ring, Star Topology

2011-08-24T21:14:00.000-07:00

The computers on LAN can be physically connected with the wires in different manner as the requirement of an organization or office. The manner in which the computers on the LAN are connected is known as LAN Topology. So, network topology is the physical layout of cabling for connecting computers on the network. It can be defined as the arrangement or connection pattern of computers on a LAN. A LAN topology describes how the computers are physically connected and how do they communicate on the network. It determines the data paths that may be used between any pair of nodes of the network. There are three basic network topologies. They are Bus topology, Ring topology and Star topology.

BUS TOPOLOGY

In a bus topology computers are arranged in the linear format. So, it is called Linear Topology. In this topology, all nodes are connected directly to the common cable with the help of T-connectors. The common cable is also known as also known as a network bus or trunk. The network bus acts as a backbone to the network.Many different lengths of co-axial cables are used in this type of topology. On the both side of the network bus (i.e. coaxial cable), BNC (Bayonet Naur Connector) jacks are connected. A T-connector is used to join segments of cables and computers. The BNC jack on each side of network bus is connected to the T-connector i.e. top the T-connector is connected to the NIC card of a Computer. The T-connectors connected to the last computers on both sides are attached with terminators.

In this network topology, the position of the server is not fixed i.e. can be any where on the network. When any node sends the data, the data passes on both directions in the form of packets through the bus and reaches to all the nodes. Since each data packet contains the data bits and the destination address, only the destination node accepts the data packets. The terminators at both end sides absorb the packets or signals travelling on the bus to prevent the bouncing of the signals which causes interference.

ADVANTAGES

a. Since each small segments of cables are joined to form a trunk or network bus it is easy to setup computers on the bus.

b. Since nodes are arranged in the linear form, it requires the less amounts of cables.

c. The coaxial cables used for networking are inexpensive and joining connectors on the cables is also easy.

d. Failure of any node does not affect other nodes on the topology.

e. Well suited for temporary networks (quick set

up).

DISADVANTAGES

a. If the backbone cable i.e. network bus has problem then the entire network fails.

b. Finding fault on this topology is not easy.

c. It provides limited flexibility for change, so adding or removing nodes in between is not easy.

d. The performance degrades when the

number of computers is more on the. so, it is not suitable for big size network.

RING TOPOLOGY

In a ring topology, all nodes are arranged in the shape of a circle (ring). Both ends of a cable are connected to the nodes so there is no any point like a bus topology. Since the both ends are connected to the nodes there is no any terminator in this topology. In this topology, many different lengths of co-axial cables are used according to distance of computers. In this topology each computer acts like a repeater that boosts an incoming signal before passing it on to the next computer.

In this topology, data or messages are transmitted in one direction either clockwise or anticlockwise. When any node sends a message or data, the message or data reaches to the first node on the circle. If the first node in the circle is the destination node then it absorbs the data or message otherwise it regenerates the signal and passes to another node on the loop and so on. If the message or data is not absorbed by any node then it is absorbed by the sender node.

ADVANTAGES

a. Since each node on the ring acts as a repeater, no any external repeater is required to boost up the signals.

b. It supports high data transmission. Rate.

c. It is easy to setup.

DISADVANTAGES

a. If any node or connecting cable fails the entire network does not work.

b. The diagnosis of the fault is difficult.

c. Since data or message reaches on the node in sequence, so addition of few nodes increases the communication delays.

d. It provides limited flexibility for change,

so adding or removing nodes in between is not easy.

STAR TOPOLOGY

Star Topology is the most popular topology used to connect computers and other network devices on the network. In a star topology all nodes are connected through a centrally located device in the form of star. But the shape of arrangement of computers is not necessarily to be star. The device whic

h connects computers on the network is either a hub or a switch. A hub or a switch has connecting ports or slots where the wires running from each node are connected. A twisted pair cable (specially unshielded twisted pair cable) is used for connecting a computer and a hub or switch. Each segment of UTP cable is attached with RJ-45 jacks. And one side of the UTP cable is connected to the node and another side is connected to the hub or switch. When any node sends data or message, the data or message reaches to the hub or switch and then to the targeted computer on the network.

ADVANTAGES

a. Computers can be added or removed easily without affecting the network.

b. If any of the workstation or the connecting cable fails, it does not affect the remaining portion of the network.

c. Fault detection in the star topology is easy.

d. It is easy to extend so it is suitable for a large network.

e. It is one of the reliable network topology.

DISADVANTAGES

a. Since each node is required to connect with the centralized hub or switch more cables are needed which increases the cost of installation.

b. The entire network fails if there is any problem on the hub or switch.

c. In comparison to Linear and Ring topologies, it is little expensive as it requires more length of cables and other controlling devices.

Definition of Computer Virus, Protection

2011-08-24T20:31:00.000-07:00

Computer viruses are the software programs that have the ability to clone itself and can operate without the knowledge or desire of the computer user. In other words, a computer virus is a program designed to spread itself by first infecting executable files or the system areas of hard and floppy disks and then making copies of itself. Computer virus can transfer from different

means to a computer without the knowledge and permission of the user and they can hide themselves in other files. Whenever a host file or program is used, the virus become active and performs destructive tasks such as dislocating, deleting and changing contents of files. It infects data or program every time the user runs the infected program and it takes advantages and replicates itself. It is the intellectual destructive creation of computer programmer.

In 1949, Dr. John Von Neumann introduced the concept of replicate computer program. The first replicating program named “Creeper” was reported during 1970 in the network system of American department of Defense. In 1983, an American electronic engineer ‘Fred Cohen’ had used the word “Computer Virus” in his research paper for the program that replicates andprevents other programs to be executed. In 1987, two Pakistani brothers , Amjad and Basti released the first IBM virus “C-Brain” to stop illegal reproduction of software developed from Alvi’s Brain Computer Shop. An Indonesian programmer released the first antivirus software in 1988 to detect the C-Brain virus. This antivirus software could remove C-Brain from a computer and immunized the system against fur

ther Brain attacks. After this event, people started to have much interest in viruses and various viruses have started to be produced.

The number of computer viruses is increasing day by day. The nature of virus varies from each other. Virus spread from computer to computer through electronic bulletin boards, telecommunication systems, and shared floppy disks, pen drives, compact disks and the Internet. Viruses are created by computer programmers for fun, but once they began to spread they take on a life of their own. Antivirus software are developed to protect from computer virus.

PURPOSE OF CREATING COMPUTER VIRUS

1. To stop the software privacy. Software

can be easily copied from one computer to another computer. In order to stop software piracy, the programmers of the software themselves create computer viruses.

2. To entertain the users by displaying interesting messages or pictures.

3. To steal data and information.

4. To remind the incidents that happened at different time.

5. To destroy data, information and files.

6. To expose their programming ability.

7. Computer viruses are made in order to earn the money.

Computer viruses activate when the infected files or programs are used. Once a virus is active it may replicate by various means and tries to infect other files or the operating system. When you copy files or programs from a infected computer, the viruses also transfer along with files or programs to the portable disk which in turn transfers viruses to another computer whenever it is used. So, mostly the computers get infected through the external sources. The most common ways through which viruses spread are:

· Sharing of infected external portable disk like floppy disk, pen drive or compact disk.

· Using pirated software.

· Opening of virus infected e-mail messages and attached files.

· Downloading files or programs from the web

site, which are not secured.

· Exchanging of data, information or files over a network.

The number of viruses is increasing daily and each virus possesses different characteristics. It is very difficult to know whether a computer is infected with viruses or not. You may see the following symptoms, if a computer is infected with computer viruses.

· Programs take more time to load, fail to load or hang frequently.

· Unexpected messages or images appear su

ddenly on the screen.

· Displays unusual error messages or encounters errors frequently.

· Missing of files or appearing of unexpected files.

· Displaying low memory message frequently.

· Programs open automatically without giving instruction.

PROTECTION FROM VIRUS

We have already known that, viruses are harmful to our computers. They affect our computer systems. Virus can damage our important files and programs. They make our computer slow. Similarly, viruses create several effects to our computers and they irritate the users frequently. So, protection and prevention of our computer from viruses is necessary. If we follow some tips, we can prevent computer from viruses.

Some general tips on prevention and protection from virus infections are as follows:

1. Install anti-virus software from a well known, reputable company and use it regularly.

2. Update the Anti-virus software frequently in order to get the latest virus definition and scan the hard disk using latest virus definition because new viruses come out every single day.

3. Install an ‘on access’ scanner and configure it to start automatically each time you boot your computer system. This will protect your system by checking for viruses each time your computer accesses an executable file.

4. Virus scans any programs or other files that may contain executable code before you run or open them, no matter where they come from. There have been the cases of commercially distributed floppy disks, pen drives and CD-ROMs spreading virus infections.

5. If your E-mail or news software has ability to automatically execute Java Script, word macros or other executable, code contained in or attached to a message, it strongly recommended that you should disable this feature.

6. Be extremely careful about accepting programs or other files during on-line chat session. This seems to be one of the more common means that people wind up with virus or Trojan horse problem.

7. Do backup your entire system on a regular basis. Because some viruses may erase or corrupt files on your hard disk and recent backup data can be recovered.

8. Before using the pen drives of others, check it whether it is virus infected or not. First scan and then only open it.

9. Do not use pirated software.

10. Lock the computer system using password to prevent your computer from being used by others.

11. Do not download any programs from Internet unless you are confirmed they are virus free.

12. Be careful! While checking mail having attached documents.

HISTORY OF CPU

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EARLY COMPUTERS

In the first computers, CPUs were made of vacuum tubes and electric relays rather than microscopic transistors on computer chips. These early computers were immense and needed a great deal of power compared to today’s microprocessor-driven computers. The first general purpose electronic computer, the ENIAC (Electronic Numerical Integrator And Computer), was introduced in 1946 and filled a large room. About 18,000 vacuum tubes were used to build ENIAC’s CPU and input/output circuits. Between 1946 and 1956 all computers had bulky CPUs that consumed massive amounts of energy and needed continual maintenance, because the vacuum tubes burned out frequently and had to be replaced.

TRANSISTOR

A solution to the problems posed by vacuum tubes came in 1948, when American physicists John Bardeen, Walter Brattain, and William Shockley first demonstrated a revolutionary new electronic switching and amplifying device called the transistor. The transistor had the potential to work faster and more reliably and to consume much less power than a vacuum tube. Despite the overwhelming advantages transistors offered over vacuum tubes, it took nine years before they were used in a commercial computer. The first commercially available computer to use transistors in its circuitry was the UNIVAC (UNIVersal Automatic Computer), delivered to the United States Air Force in 1956.

THE INTEGRATED CIRCUIT (IC)

Development of the computer chip started in 1958 when Jack Kilby of Texas Instruments demonstrated that it was possible to integrate the various components of a CPU onto a single piece of silicon. These computer chips were called integrated circuits (ICs) because they combined multiple electronic circuits on the same chip. Subsequent design and manufacturing advances allowed transistor densities on integrated circuits to increase tremendously. The first ICs had only tens of transistors per chip compared to the millions or even billions of transistors per chip available on today’s CPUs.

In 1967 Fairchild Semiconductor introduced a single integrated circuit that contained all the arithmetic logic functions for an eight-bit processor. (A bit is the smallest unit of information used in computers. Multiples of a bit are used to describe the largest-size piece of data that a CPU can manipulate at one time.) However, a fully working integrated circuit computer required additional circuits to provide register storage, data flow control, and memory and input/output paths. Intel Corporation accomplished this in 1971 when it introduced the Intel 4004 microprocessor. Although the 4004 could only manage four-bit arithmetic, it was powerful enough to become the core of many useful hand calculators at the time. In 1975 Micro Instrumentation Telemetry Systems introduced the Altair 8800, the first personal computer kit to feature an eight-bit microprocessor. Because microprocessors were so inexpensive and reliable, computing technology rapidly advanced to the point where individuals could afford to buy a small computer. The concept of the personal computer was made possible by the advent of the microprocessor CPU. In 1978 Intel introduced the first of its x86 CPUs, the 8086 16-bit microprocessor. Although 32-bit microprocessors are most common today, microprocessors are becoming increasingly sophisticated, with many 64-bit CPUs available. High-performance processors can run with internal clock rates that exceed 3 GHz, or 3 billion clock pulses per second.

CURRENT DEVELOPMENTS

The competitive nature of the computer industry and the use of faster, more cost-effective computing continue the drive toward faster CPUs. The minimum transistor size that can be manufactured using current technology is fast approaching the theoretical limit. In the standard technique for microprocessor design, ultraviolet (short wavelength) light is used to expose a light-sensitive covering on the silicon chip. Various methods are then used to etch the base material along the pattern created by the light. These etchings form the paths that electricity follows in the chip. The theoretical limit for transistor size using this type of manufacturing process is approximately equal to the wavelength of the light used to expose the light-sensitive covering. By using light of shorter wavelength, greater detail can be achieved and smaller transistors can be manufactured, resulting in faster, more powerful CPUs. Printing integrated circuits with X-rays, which have a much shorter wavelength than ultraviolet light, may provide further reductions in transistor size that will translate to improvements in CPU speed.

Many other avenues of research are being pursued in an attempt to make faster CPUs. New base materials for integrated circuits, such as composite layers of gallium arsenide and gallium aluminum arsenide, may contribute to faster chips. Alternatives to the standard transistor-based model of the CPU are also being considered. Experimental ideas in computing may radically change the design of computers and the concept of the CPU in the future. These ideas include quantum computing, in which single atoms hold bits of information; molecular computing, where certain types of problems may be solved using recombinant DNA techniques; and neural networks, which are computer systems with the ability to learn.

HOW A CPU WORKS

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CPU FUNCTION

A CPU is similar to a calculator, only much more powerful. The main function of the CPU is to perform arithmetic and logical operations on data taken from memory or on information entered through some device, such as a keyboard, scanner, or joystick. The CPU is controlled by a list of software instructions, called a computer program. Software instructions entering the CPU originate in some form of memory storage device such as a hard disk, floppy disk, CD-ROM, or magnetic tape. These instructions then pass into the computer’s main random access memory (RAM), where each instruction is given a unique address, or memory location. The CPU can access specific pieces of data in RAM by specifying the address of the data that it wants.

As a program is executed, data flow from RAM through an interface unit of wires called the bus, which connects the CPU to RAM. The data are then decoded by a processing unit called the instruction decoder that interprets and implements software instructions. From the instruction decoder the data pass to the arithmetic/logic unit (ALU), which performs calculations and comparisons. Data may be stored by the ALU in temporary memory locations called registers where it may be retrieved quickly. The ALU performs specific operations such as addition, multiplication, and conditional tests on the data in its registers, sending the resulting data back to RAM or storing it in another register for further use. During this process, a unit called the program counter keeps track of each successive instruction to make sure that the program instructions are followed by the CPU in the correct order.

BRANCHING INSTRUCTIONS

The program counter in the CPU usually advances sequentially through the instructions. However, special instructions called branch or jump instructions allow the CPU to abruptly shift to an instruction location out of sequence. These branches are either unconditional or conditional. An unconditional branch always jumps to a new, out of order instruction stream. A conditional branch tests the result of a previous operation to see if the branch should be taken. For example, a branch might be taken only if the result of a previous subtraction produced a negative result. Data that are tested for conditional branching are stored in special locations in the CPU called flags.

CLOCK PULSES

The CPU is driven by one or more repetitive clock circuits that send a constant stream of pulses throughout the CPU’s circuitry. The CPU uses these clock pulses to synchronize its operations. The smallest increments of CPU work are completed between sequential clock pulses. More complex tasks take several clock periods to complete. Clock pulses are measured in Hertz, or number of pulses per second. For instance, a 2-gigahertz (2-GHz) processor has 2 billion clock pulses passing through it per second. Clock pulses are a measure of the speed of a processor.

FIXED-POINT AND FLOATING-POINT NUMBERS

Most CPUs handle two different kinds of numbers: fixed-point and floating-point numbers. Fixed-point numbers have a specific number of digits on either side of the decimal point. This restriction limits the range of values that are possible for these numbers, but it also allows for the fastest arithmetic. Floating-point numbers are numbers that are expressed in scientific notation, in which a number is represented as a decimal number multiplied by a power of ten. Scientific notation is a compact way of expressing very large or very small numbers and allows a wide range of digits before and after the decimal point. This is important for representing graphics and for scientific work, but floating-point arithmetic is more complex and can take longer to complete. Performing an operation on a floating-point number may require many CPU clock periods. A CPU’s floating-point computation rate is therefore less than its clock rate. Some computers use a special floating-point processor, called a coprocessor, that works in parallel to the CPU to speed up calculations using floating-point numbers. This coprocessor has become standard on many personal computer CPUs, such as Intel's Pentium chip.

CENTRAL PROCESSING UNIT (CPU)

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INTRODUCTION

Central Processing Unit (CPU), in computer science, microscopic circuitry that serves as the main information processor in a computer. A CPU is generally a single microprocessor made from a wafer of semiconducting material, usually silicon, with millions of electrical components on its surface. On a higher level, the CPU is actually a number of interconnected processing units that are each responsible for one aspect of the CPU’s function. Standard CPUs contain processing units that interpret and implement software instructions, perform calculations and comparisons, make logical decisions (determining if a statement is true or false based on the rules of Boolean algebra), temporarily store information for use by another of the CPU’s processing units, keep track of the current step in the execution of the program, and allow the CPU to communicate with the rest of the computer.

How A CPU Works
History Of CPU

BUS NETWORK

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Bus Network, in computer science, a topology (configuration) for a local area network in which all nodes are connected to a main communications line (bus). On a bus network, each node monitors activity on the line. Messages are detected by all nodes but are accepted only by the node(s) to which they are addressed. Because a bus network relies on a common data “highway,” a malfunctioning node simply ceases to communicate; it doesn't disrupt operation as it might on a ring network, in which messages are passed from one node to the next. To avoid collisions that occur when two or more nodes try to use the line at the same time, bus networks commonly rely on collision detection or Token Passing to regulate traffic.

COMPUTER

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Computer is an electronic device that receives input, stores and manipulates data, and provides output in a useful format at high speed. Computer performs tasks, such as calculations or electronic communication, under the control of a set of instructions called a program. Computers perform a wide variety of activities reliably, accurately, and quickly. The most versatile machine that man has ever created is computer. In the sectors of education, industries, government, medicine, scientific research, law and even in music and art computer has played a vital role. So without computers, life would certainly be difficult and different.

CHARACTERISTICS OF COMPUTER
Today, computers are found everywhere in offices, homes, schools and many other places. Much of the world runs on computers, and computers have changed our lives. Some of the characteristics of computers, which make them the most essential part of every emerging technology, are listed below:

Speed
Computers work at tremendous speed which process data at an extremely fast rate. At present a powerful computer can perform billions of operations in just a second.
Milli second = A thousandth of a second (1/1,000)
Micro second = A millionth of a second (1/1,000,000)
Nano second = A billionth of a second (1/1,000,000,000)
Pico second = A trillionth of a second (1/1,000,000,000,000)

Accuracy
The computers are very accurate. The level of accuracy depends upon the instructions and the type of machine being used. Computer is capable of doing only what it is instructed to do. Inaccurate instructions for processing lead to inaccurate results. This is known as GIGO (Garbage In Garbage Out). Errors may occur in the results due to human factors rather than the technological weaknesses.

Automatic
Computers are automatic machines. Once a program is in the memory of a computer, no human intervention is needed; it allows the instructions step by step, executes them and terminates the execution when it receives the command to do so.

Storage capacity
Computers have got a main memory and the secondary storage systems. The main memory of the computer is relatively small and it can hold only a certain amount of information. Therefore, the larger amount of data and information is stored in the secondary storage media such as magnetic disk and optical disk. Computers can also retrieve the information instantly when desired.

Diligence
Computer, being a machine, does not suffer from the human problems of tiredness and lack of concentration. It can continuously work for hours without making mistakes. Even if millions of calculations are to be performed, it will perform the last calculation with the same accuracy and speed as it has done in the first one.

LIMITATIONS OF COMPUTER
Computers have certain limitations too. As a machine, a computer can only perform what it is programmed to do. Computers lack decision-making power, computers cannot decide on their own. If an unanticipated situation arises, computers will either produce erroneous results or abandon the task altogether. They do not have the potential to work out an alternative solution

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BEST INPUT DEVICE AVAILABLE IN MARKET

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INPUT DEVICE
An input device can be defined as an electromechanical device that allows the user to feed data and instructions into the computer for analysis, storage, and to give the commands to the computer. Data and instructions are entered into the computer’s main memory through an input device. Input device captures data and translates it into a form that can be broadly classified into the following categories:

Key board
A keyboard is the most common input device. Using a keyboard, the user can type the text and execute commands. Keyboard is designed to resemble a regular typewriter with a few additional keys. Data is entered into the computer by simply pressing various keys.
The layout of a keyboard comes in various styles but QWERTY is the most common layout. The layout of the keyboard has changed very little ever since it was introduced. In fact, the most common change in its technology has simply been the natural evolution of adding more keys that provide additional functionality. The number of keys on a keyboard varies from 82 keys to 108 keys. Portable computers such as laptops quite often have custom keyboards that have slightly different key arrangements from a standard keyboard.

Pointing Devices
Pointing devices are the input devices by which we can point out and select the items rapidly from the multiple options displayed on the screen. These devices can also be used to create graphic elements on the screen such as lines, curves and freehand shapes. The most common types of pointing devices available are;
a) Mouse b) Trackball c) Joystick
d) Touch Screen e) Light Pen d) Touch Pad

a) Mouse
A mouse is a small hand-held pointing device, which is used to create graphic elements on the screen such as lines, curves, and freehand shapes. It is also used to run a program and pull down a menu in GUI (Graphic User Interface) base computer system. It is rectangular shaped with a rubber ball embedded at its lower side and buttons on the top. Usually a mouse contains two or three buttons, whish can be used to input commands or instructions. The mouse may be classified into two categories:
I) Mechanical mouse II) Optical mouse

I) Mechanical mouse
A mechanical mouse uses a rubber ball at the bottom surface, which rotates as the mouse along a flat surface to move the cursor. It is the most common and expensive pointing device. Microsoft, IBM and Logitech are some well-known makers of the mechanical mouse.

II) Optical mouse
An optical mouse uses the light beam instead of rotating ball to detect the movement across a specially patterned mouse pad. As the mouse rolls the mouse on a flat surface, the cursor on the screen also moves in the direction of the mouse’s movement. It is more expensive in comparison with the mechanical mouse. Modern optical mouse are accurate and often do not need a mouse pad.

b) Track Ball
A track ball is another pointing device that uses a ball which is settled in a square cardle. In general, a track ball is just like a turned upside down a mouse. The ball is rolled by fingers to move the cursor around the screen. A track ball requires less space than a mouse for operation because the whole device is not moved for moving the curser. It is often attached to or inbuilt into the keyboard. The trackball built into the keyboard are commonly used in laptop computers, because the mouse is not practical for laptop users in a small space. This pointing device comes in various shapes but with the same functionality. It works like a mouse.

c) Joystick
Joystick is a device that moves in all directions and controls the movement of the cursor on the screen. The joystick offers three types of controls.
• Digital control
• Glide control
• Direct control
Digital control allows in a limited movement in a number of directions such as up,
down, left and right. Glid and direct controls allow movements in all directions (360 degree). The basic design of a joystick consists of a stick that is attached to plastic base with a flexible rubber sheath. It has some pushing buttons and a circuit board which is placed under the stick. Joysticks are mainly used for computer games, controlling industrial robots and for other applications such as flight simulators, training simulators, etc.

d) Light Pen
A light pen is a hand-held electro-optical pointing device which is connected to the computer by a cable. When it touches to a connected computer monitor, it will allow the computer to determine where on that screen the pen is pointed. It facilitates drawing images and selects objects on the display screen by directly pointing to the objects with the pen. Light pens give the user the full range of mouse capabilities, without using the pad and any horizontal surface. Using light pens, the user can interact more easily with applications in such modes as dragging and dropping or highlighting. It is very popular for graphic work in engineering like CAD (Computer Aided Design)

e) Touch Screen
A touch screen is a special kind of screen device, which is placed on the computer monitor in order to allow the direct selection or activation of the computer’s information, when somebody touches the screen. Essentially, it registers the input when a finger or other object to touch the screen. Touch screen is normally used to touch the screen. Touch screen is normally used to access the information with minimum effort. However, it is not suitable for input of large amount of data. Typically, they are used in information-providing systems like the hospital, airlines, railway reservation counters, amusement parks, etc.

f) Touch Pad
A touch pad is one of the latest pointing devices. It looks like a small gray window, about two inches wide. It is use din potable computer such as laptop and notebook to substitute the mouse. It has two buttons below or above the pads which work like the mouse buttons. You can move the cursor on the screen by making a finger or other object along the pad .And one can also click by tapping a finger on the touch pad, and drag with a tap in the continuous pointing scale.

Digital Camera
A digital camera is also an input device which stores pictures digitally rather than recording them on a film. Once a picture has been taken that stores on its chip memory. The picture can be downloaded to computer system and then manipulated with an image editing software. Then it can be printed. The major advantage of digital cameras is that making photos is both inexpensive and fast because there is no film processing.

Scanner
A scanner scans an image and transforms the image to ASCII codes and graphics. This can be edited, manipulated, combined and then printed. Scanners use a light beam to scan the input data. If the data to be scanned is an image, it can be changed by using the special image editing software. If the image is a page of a text, then the special optical character recognition software must be used to convert the image of letters in the text and this can be edited by using a word processor. Most of the scanners come with a utility program that allows it to communicate with the computer and save the scanned image as a graphic file on the computer. Commonly scanners are classified in two types:
• Hand-Held scanner
• Flat-Bed scanner

Microphone
A microphone is a speech recognition device. Speech recognition is one of the most interactive system to communicate with the computer. The user can simply instruct the computer about the task to be performed with the help of a microphone. It is the technology by which sounds, words or phrases spoken by humans are converted into digital signals, and these signals are transformed into the computer generated texts or commands. Most speech recognition systems are speaker-dependent so they must be separately trained for each individual user. The speech recognition systems system learns to voice of the user, who speaks isolated words repeatedly. Then, these voiced words are recognizable in the future. It is more popular in the corporate world among non-typists, people with disabilities, and business travelers who tap-record information for later transcription.

Graphic Digitizer
Graphic digitizer is an input device, which is used for converting pictures, maps and drawings into digital form for storage in computers. This enables re-creation of the drawing whenever required. It also facilitates any changes in the drawing whenever required.
A digitizer consists of a digital tablet (also known as graphics tablet) associated with a stylus. The digitizing tablet is a flat surface, which contains hundreds of fine copper wires forming a grid. Each copper wire receives electric pulses. The digitizing tablet can be spread over a working table, and is connected to computer.

Optical Scanners
New technologies have developed alternative methods to input data instead of entering data through keystrokes. Devices such as bar code reader can interpret machine printed marks or codes. Accordingly there are four types of optical recognition.
a) OCR (Optical Character Recognition)
b) OMR (Optical Mark Recognition)
c) MICR ( Magnetic-Ink Character Recognition)
d) BCR(Bar Code Reader)

Optical Character Recognition (OCR)
Optical Character Recognition is a process of scanning printed pages as image on a flatbed scanner using OCR software which recognizes the letters as ASCII text. The device used for this technology is called optical reader. In the OCR system book or a magazine article is fed directly into an electronic computer file, and then this file is edited by using a word processor. Advanced OCR systems can read the text large variety of fonts.

Optical Mark Recognition (OMR)
Optical Mark Recognition is the process of recognizing a pre-specified type of marks made by pencils or pen on the paper. This type of technology is used to evaluate the papers of competitive examination. Optical mark reading is done by special device called optical mark reader.

Magnetic-Ink Character Recognition (MICR)
Magnetic-Ink Character Recognition technology is used by the banking industry for faster processing of the large volume of cheques. This technology also ensures accuracy of data entry, because most of the information is pre-printed on the cheque and is directly fed to the computer. Magnetic ink character reader is a device used in the technology.

Bar Code Reader (BCR)
A bar code is a machine-readable code in the form of a pattern of parallel vertical lines. They are commonly used for labeling goods that are available in supermarkets, numbering books in libraries, etc. These codes/strips are sensed and read by a photoelectric device called bar code reader that reads the code by means of reflective light. The information recorded in a bar code reader is fed into the computer, which recognizes the information from the thickness and spacing of bars.

FIRST GENERATION COMPUTERS

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FIRST GENERATION OF COMPUTERS

During the period of 1940 to 1956 first generation of computers were developed. The first generation computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. The vacuum tube was developed by Lee DeForest. A vacuum tube is a device generally used to amplify a signal by controlling the movement of electrons in an evacuated space. First generation computers were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions.

CHARACTERISTICS
1) First generation computers were based on vacuum tubes.
2) The operating systems of the first generation computers were very slow.
3) They were very large in size.
4) Production of the heat was in large amount in first generation computers.
5) Machine language was used for programming.
6) First generation computers were unreliable.
7) They were difficult to program and use.

UNIVAC, EDVAC, EDSAC and ENIAC computers are examples of first generation computing devices.

Read About Second Generation of Computer

SECOND GENERATION COMPUTERS

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SECOND GENERATION COMPUTERS

During the period of 1956 to 1963 second generation of computers were developed. The second generation computers emerged with development of Transistors. The transistor was invented in 1947 by three scientists J. Bardeen, H.W. Brattain and W. Shockley. A transistor is a small device made up of semiconductor material like germanium and silicon. Even though the Transistor were developed in 1947 but was not widely used until the end of 50s. The transistor made the second generation computers faster, smaller, cheaper, more energy-efficient and more reliable than their first-generation computers. Even though the transistor used in the computer generated enormous amount of heat which ultimately would lead to the damage of the computers but was far better than vacuum tubes.
Second generation computers used the low level language i.e. machine level language and assembly language which made the programmers easier to specify the instructions. Later on High level language programming were introduced such as COBOL and FORTRAN. Magnetic core was used as primary storage. Second generation computer has faster input /output devices which thus brought improvement in the computer.
CHARACTERISTICS
1) Transistors were used in place of vacuum tubes.
2) Second generation computers were smaller in comparison with the first generation computers.
3) They were faster in comparison with the first generation computers.
4) They generated less heat and were less prone to failure.
5) They took comparatively less computational time.
6) Assembly language was used for programming.
7) Second generation computers has faster input/output devices.

IBM 7000, NCR 304, IBM 650, IBM 1401, ATLAS and Mark III are the examples of second generation computers.

Read About Third Generation Computer

THIRD GENERATION COMPUTERS

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THIRD GENERATION COMPUTERS

During the period of 1964 to 1971 Third generation computers were developed. The third generation computers emerged with the development of IC (Integrated Circuits). The invention of the IC was the greatest achievement done in the period of third generation of computers. IC was invented by Robert Noyce and Jack Kilby in 1958-59. IC is a single component containing a number of transistors. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.
Keyboards and monitors developed during the period of third generation of computers. The third generation computers interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory.

CHARACTERISTICS
1) IC was used instead of transistors in the third generation computers.
2) Third generation computers were smaller in size and cheaper as compare to the second generation computers.
3) They were fast and more reliable.
4) High level language was developed.
5) Magnetic core and solid states as main storage.
6) They were able to reduce computational time and had low maintenance cost.
7) Input/Output devices became more sophisticated.

PDP-8, PDP-11, ICL 2900, IBM 360 and IBM 370 are the examples of third generation computers.

Read About Fourth Generation Computer

FOURTH GENERATION COMPUTERS

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FOURTH GENERATION COMPUTERS

After 1971 the fourth generation computers were built. The fourth generation computers were the extension of third generation technology. The fourth generation computers emerged with development of the VLSI (Very Large Scale Integration).With the help of VLSI technology microprocessor came into existence. The computers were designed by using microprocessor, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The fourth generation computers became more powerful, compact, reliable and affordable. As a result, they give rise to personal computer (PC) revolution.
For the first time in 1981 IBM introduced its computer for the home user and in 1984 Apple introduced the Macintosh Microprocessor.

CHARACTERISTICS
1) The fourth generation computers have microprocessor-based systems.
2) They are the cheapest among all the computer generation.
3) The speed, accuracy and reliability of the computers were improved in fourth generation computers.
4) Many high-level languages were developed in the fourth generation such as COBOL, FORTRAN, BASIC, PASCAL and C language.
5) A Further refinement of input/output devices was developed.
6) Networking between the systems was developed.

IBM 4341, DEC 10, STAR 1000, PUP 11 and APPLE II are the examples of fourth generation computers.

Read About Fifth Generation Computer

FIFTH GENERATION COMPUTERS

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FIFTH GENERATION COMPUTERS
Fifth generation computers are in developmental stage which is based on the artificial intelligence. The goal of the fifth generation is to develop the device which could respond to natural language input and are capable of learning and self-organization. Quantum computation and molecular and nanotechnology will be used in this technology. So we can say that the fifth generation computers will have the power of human intelligence.

CHARACTERISTICS
1) The fifth generation computers will use super large scale integrated chips.
2) They will have artificial intelligence.
3) They will be able to recognize image and graphs.
4) Fifth generation computer aims to be able to solve highly complex problem including decision making, logical reasoning.
5) They will be able to use more than one CPU for faster processing speed.
6) Fifth generation computers are intended to work with natural language.

UNIVAC

2010-06-23T23:30:00.000-07:00

Universal Automatic Computer (UNIVAC)

UNIVAC (Universal Automatic Computer) was the first commercially general purpose electronic computer. John Eckert and John Mauchly at the Moore School of Engineering, Pennsylvania developed it in 1951. It was used for the analysis of 1952 Presidential Election in the United States. It was 8 feet high, 15 feet long and weighed 5 tons. It contained 5600 tubes, 18000 crystal diodes, and 300 relays. A magnetic tape was used for data input and output.