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Monthly Archives: October 2016


The Computer Output Devices

Output devices of computer are types of peripheral hardware connected to the computer either using cables or over a wireless network. An output given by the computer can be in the form of a display on the screen or a printed document or a song that is played. Immaterial of whether you have desktop computers, laptop computers or supercomputers, you will require at least one output device.


A monitor is also called video display terminal (VDT). The users can view the visual display of the processed data on the monitor. Computer monitors come in a variety of screen sizes and not to forget, visual resolutions. All monitors have a video card, which processes the data into images, to be eventually displayed. Cathode Ray Tube (CRT) and flat panel displays are the two types of monitors. CRTs are cheaper, and have good viewing angle. They are also bulkier and consume more power. On the other hand, the flat panel displays have no magnetic interference and lighter. They are also costlier.


Printer is an external hardware device, which takes processed data from the computer to generate a hard copy of the same. After the monitors, printers are the most used peripherals of computers and they are commonly used to print text data, images, etc. There are three main types of computer printers, namely inkjet, laser and dot matrix printers. The dot matrix printer is an impact printer. It uses striking pins against a ribbon to produce the characters in order to print the data. The inkjet printer uses magnetized plates that spray ink on the paper to produce the data. On the other hand, laser printers use a laser beam to produce the data.


A speaker is a hardware device, that is connected to a computer’s sound card, which outputs the sound generated by the card. Audio data generated by the computer is sent to the audio card that is located in the expansion slot. The card translates the data into audio signals, which are then sent to either the speakers or the headphones. In the initial phase, computers had on-board speakers, which generated series of different tones and beeps. When the popularity of multimedia and computer games grew, better quality computer speakers known for higher quality sound effects and music came into the market.


It is a hardware device with which an image and text is projected onto a flat screen. Image data is sent to the video card by the computer which is then translated into a video image and sent to the projector. A projector is often used in meetings or to make presentations as it allows the display to be visible to a larger audience. Ceiling mount projector and table mount projector are the two types of projectors available in the market today.


Plotters, like printers, create a hard copy rendition of a digitally rendered design. The design is sent to a plotter through a graphics card and the image is created using a pen. In simple words, plotters basically draw an image using a series of straight lines. This device is used with engineering applications. Drum plotter uses a drum, on which the paper gets wrapped. The plotter pen moves across the drum to produce plots. The other type of plotter is the flatbed plotter. The paper is placed on the bed and graphics are drawn on it. This kind of plotter is used for larger drawings.

Braille Embosser

It is nothing but an impact printer that prints braille output by punching dots on the paper. A few embossers also emboss graphics. Before printing, the data should be first translated into braille by using braille translation software. There are two types of braille embossers namely, single-sided embosser and two-sided embosser. Interpoint printers or double-sided printers, print on both the sides of the paper by lining the dots in such a manner that the dots do not overlap.

Braille Reader/Display

Specially designed for visually impaired, it is an alternative for a monitor. It is connected to a computer via a USB connection. This device displays the output braille characters by raising nylon or metal pins on a flat surface. The data that is highlighted on the computer screen will be automatically displayed on the device by converting the text to braille.


Ways Motherboards Conduct a Symphony of Data

UNDER the big top of your computer—or the little top of your smartphone or tablet—the microprocessor (the central processing unit or CPU) is always the headliner. You don’t see ads or reviews raving that a new PC has “revolutionary 100-ohm resistors!” Flash drives and incredibly realistic displays have the top supporting roles, but when it comes to the components on the motherboard—the mother of all boards—the CPU steals the spotlight.

There are many good reasons for the CPU’s fame, but like all stars, it owes a lot to the little components—the circuit board supporting parts without which the central microprocessor would be only a cold slab of silicon. And conversely, without the CPU and other specialized processors to keep all the parts running in harmony, the motherboard would be an orchestra without a conductor. Its components wouldn’t be able to hear what other members are playing. Electronic messages meant for the CPU would crash into the chips and each other, moving so fast there would be no time to read their license plates. Other messages would arrive like dying murder victims at the ER, so weak they can only whisper their crucial clues in pulses so faint the microprocessor can’t understand them. Computing would become a cacophony.

The role of the motherboard was much smaller in the early days of PCs because it was basically a platform for the microprocessor. It was a transportation grid for conveying signals back and forth between the CPU and the parts the CPU controlled—disc controller cards, video cards, sound cards, input/output cards. Back then, nearly everything that made a PC a PC was handled by expansion cards, which was handy because you could easily update a single component as innovation and budget allowed. Today, almost any computer comes with sound, video, disk controllers, and an assortment of input/output options all on the motherboard. Increasingly, some of these functions are now built into the CPU as well, but even then your computer’s character is largely determined by the mother-board’s capability, and those capabilities are largely defined by the parts that populate it.

Once again, we’re in LEGO land. The components that support the motherboard are made up of similar smaller parts divided among themselves in various strengths and concentrations. So here, ladies and gentlemen, are the little parts that make it all possible.

  • Tiny canisters house the circuit board’s strong men—the resistors! Clad in metal and ceramics, wrapped with colored stripes, they clamp down on the wild, untamed electricity before it has the chance to burn up the rest of the components. They literally take the heat for the rest of the motherboard.
  • Wrapped in ceramic casing and coats of plastic are the voracious, singing capacitors! They hum as they consume great quantities of electrical charge, holding it in so other components can have a steady supply or a sudden surge of electricity when they need it.
  • Scattered everywhere on the motherboard are those mysterious, miniature monoliths, the microchips! What the millions of transistors do inside them is known to only a few.
  • And connecting them all are stripes of copper and aluminum, circuit traces, that tie it all together so the individual players are a coordinated whole.


USB Microphones for Your Recording Need

A lot of folks are doing podcasts and voiceover work and even recording music on their home PCs and mobile devices. Even if you’re not doing this type of recording, chances are you’re chatting on Skype or Google Hangouts.

However you’re talking to your PC, you want to be heard – and heard well. The number-one thing that most affects the quality of your recording is the microphone you use. The better the mic, the better you’ll sound.

For computer-based recording, you need a microphone that connects directly to your PC’s USB port. While you can use mics with traditional XLR or 1/4″ connectors, going direct to USB is the best way to get that audio signal into your computer.

So how do you choose the best USB mic for your needs? Well, the best mic isn’t always the most expensive one. Let’s look at the top 10 USB microphones on the market today, and see which are best for your own recording needs.

Choosing the Best USB Microphone for Your Needs

When you’re recording your voice or instrument on a computer, the easiest way to connect is via USB. Most computers simply don’t have the XLR or 1/4″ inputs used by traditional recording or stage microphones. (XLR is a round, three-pin connector; the 1/4″ connector looks like any regular plug.) So you can either use an XLR-to-USB converter (which we’ll discuss at the end of this article), install some sort of outboard pro sound box (or internal audio card), or just use a microphone equipped with a USB connector. Naturally, the USB microphone is the easiest (and lowest price) of these alternatives.

How does a USB mic differ from a traditional microphone? In addition to the USB connector at the end, a USB mic contains its own preamplifier (not relying on an outboard preamp) and an analog-to-digital (A/D) converter. Aside from these unique components, a USB microphone contains all the normal elements found in a traditional mic – capsule, diaphragm, and the like.

Using a USB microphone is easy. All you have to do is plug it into an open USB port on your computer and you’re ready to go. (You may have to install a device driver for the mic, but that’s easy peasy.) USB mics are ideal for podcasters, voice actors, recording musicians, and anyone wanting better sound than that provided by their notebooks’ built-in microphone.

When you’re shopping for a USB mic, you want the highest quality sound at the lowest possible price. Obviously, different needs require different quality levels, and everyone has his or her own specific budget. Still, it’s the sound quality that matters, whatever your price range may be.

Most USB microphones are condenser mics, like those used in professional recording studios. A condenser mic captures sound waves via a thin conductive diaphragm. Condenser mics create a detailed sound that’s good for vocals, acoustics guitars, and other low- to medium-volume sound sources.

(The alternative to a condenser mic is a dynamic mic – although there are few dynamic USB mics. A dynamic mic works via electromagnetic induction, and is ideal for use on stage or where higher sound levels are present.)

By the way, many traditional condenser mics require an outboard power source (dubbed “phantom power”) to operate. A USB condenser mic derives this phantom power from the computer it’s attached to, via the USB connection.

All that said, let’s look at the 10 best USB mics for your recording needs, presented in alphabetical order.

Audio-Technica AT2020 USB

Audio-Technica is a Japanese company that produces microphones, headphones, and similar audio equipment for both the professional and consumer market. A-T mics are found in professional recording studios worldwide, and they’ve recently moved into the USB microphone market.

The AT2020 USB is a cardioid condenser mic, which means it’s fairly unidirectional; sounds from the side and rear are mostly suppressed. It’s a low-noise microphone, which makes it ideal for podcasting and similar voiceover work.

The AT2020 USB has a suggested retail price of $229, but you can find it as low as $99 at some retailers. Given the relatively high performance and affordable price point, this is the go-to mic for home artists concerned with recording quality.

Audio-Technica ATR2100-USB

If you prefer a hand-held mic, check out Audio-Technica’s ATR2100-USB. Like the ATR2020, the ATR2100 is a condenser mic with a cardioid pattern. Unlike the ATR2020, it’s designed for hand-held use, as well as on a desktop.

There’s another unique feature about the ATR2100 – it offers both USB and XLR outputs. So you can use the USB connector when recording to your PC, or switch to the XLR connector for traditional studio or stage work.

Audio-Technica ATR2500-USB

If you want a desktop USB mic but have a tight budget, check out the ATR2500-USB. It’s a cardioid condenser mic with relatively low internal noise. While overall performance is slightly below that of the ATR2020, so is the price – just $99, although available online for $69 or less. This gives you Audio-Technica quality at a bargain price.

Blue Snowball

Blue Microphones produces both studio and consumer microphones. The company has been in the forefront of USB microphone development since the beginning.

Blue’s most familiar, and arguably its most popular, model is the Snowball. The Snowball was the world’s first professional USB microphone, and it remains a strong contender today. It’s long been a popular choice among podcasters and in-home voiceover folk.

The Snowball is a condenser mic that offers the choice of ominidirectional or cardioid pickup patterns. This makes it useful for a single speaker or picking up a room full of people. It’s a sturdy fellow with decent sound quality.

One of the most appealing aspects of the Snowball is its price. It retails for $99 and is available, in a variety of colors (not just blue) for under $50 at many merchants. That makes it an appealing first mic for many home recordists and podcasters.

Blue Snowflake

If you want a really affordable USB mic and pro-level quality isn’t necessary, check out the Blue Snowflake. This is a good basic mic, certainly with better quality than your PC’s built-in microphone. It’s also small and portable, and easily clips onto your monitor or notebook PC screen.

Know, however, that you’re going to hear more noise with the Snowflake than you will with the higher-priced Snowball. But that’s probably acceptable for a mic that retails for $59 and sells for around $40. This makes it a good choice for Skype and Google Hangouts video chats, although it’s less than ideal for more professional voice work.

Blue Yeti/Yeti Pro

If you like Blue Microphones and want higher quality audio, then go with the Yeti. The Yeti is a condenser mic with its own built-in volume control and multiple pickup patterns – unidirectional cardioid, stereo, bidirectional, and omnidirectional. That makes the Yeti a flexible option for use in a variety of applications.

The Yeti produces a rich and rounded sound with tons of sensitivity. It’s as good or better as any other mic in its price range, and compares favorably with mics priced another hundred dollars or so higher. And that’s why the Yeti is a number-one pick of many discerning home recordists and podcasters.

Blue also offers the Yeti Pro that features a 24-bit interface for even higher-quality recording. It also comes with an optional XLR connector if you want to use it on stage or in traditional recording studio.


CAD produces both professional and consumer-grade microphones. The CAD U1 is a low-priced condenser mic, ideal for first-time podcasters and home recordists, as well as for anyone chatting on Skype or Google Hangouts. It can be used with a desktop stand or as a hand-held mic.

As with most sub-$100 mics, there’s no built-in volume control; you have to control the input volume from your computer. It features a cardioid pickup pattern.

The CAD U1 isn’t studio quality, but it’s pretty good for the price.


CAD also produces better performing mics, like the U37. This mic utilizes a larger, higher-end condenser element for a warmer, richer sound. It has a cardioid pickup pattern, and offers a bass-reduction feature and computer-adjustable sensitivity.

The result is very good sound quality for the price. Yes, higher-end mics (like the Blue Yeti) will capture better sound, but they also cost a lot more.

Samson Go Mic

If you want a lot of bang for your buck, go with the Samson Go Mic. Samson Technologies produces a variety of pro audio equipment, with some consumer models thrown into the mix. The Go Mic is definitely a consumer model, compact and portable, which makes it ideal for recording on the go. It’s great for Skype or Google Hangouts, or for situations where you don’t need the highest quality.

In terms of specs, the Go Mic offers a choice of either cardioid or omnidirectional recording. It’s also usable in non-USB mode, with a 3.5mm headphone connection. It can sit on its own desktop stand or mount on the top of your notebook PC screen or desktop monitor.

Samson Meteor Mic

Finally, we come to the Samson Meteor Mic. This is a unique looking, extremely small condenser mic with a cardioid pickup pattern. It offers solid performance that’s more than good enough for most podcasting and voiceover work – and for audio and video chatting, of course.

Because of its small size, the Meteor Mic doesn’t take up a lot of space on your desktop. It looks a little chrome bullet, and it’s three built-in legs fold up when you need to move it, which is kind of cool.

Using an XLR-to-USB Adapter

What do you do if you already have a microphone with an XLR connector that you use either onstage or in the studio? There’s no need to throw out your old mic just because you want to go the computer route. Instead, purchase an XLR-to-USB adapter that lets you connect your XLR microphone directly to your computer, no fancy sound boards or audio boxes required.

Probably the most popular of these adapters is Shure’s X2u. This adapter works with all of Shure’s iconic mics as well as models for other manufacturers. It includes built-in headphone monitoring and controls for both mic gain and playback volume. (It also provides switchable phantom power to those mics that need it.)

The X2u isn’t cheap, but chances are you’re using it with an expensive microphone, anyway, so it’s probably worth the bucks.



Ways to Clean Your Computer Keyboard

One of the best ways to keep a keyboard in top condition is periodic cleaning. As preventive maintenance, you should vacuum the keyboard weekly, or at least monthly. When vacuuming, you should use a soft brush attachment to dislodge the dust. Also note that some keyboards have keycaps that come off easily, so be careful when vacuuming; otherwise you may have to dig the keys out of the vacuum cleaner. I recommend using a small, handheld vacuum cleaner made for cleaning computers and sewing machines; these have enough suction to get the job done with little risk of removing your key tops.

You also can use compressed air to blow the dust and dirt out instead of using a vacuum. Before you dust a keyboard with the compressed air, however, power off the computer, unplug the keyboard, and turn it upside down so the particles of dirt and dust collected inside can fall out.

On most keyboards, each keycap is independently removable, which can be handy if a key sticks or acts erratically. For example, a common problem is a key that does not work every time you press it. This problem usually results from dirt collecting under the key. An excellent tool for removing keycaps on almost any keyboard is the U-shaped chip puller included in many computer tool kits. Simply slip the hooked ends of the tool under the keycap, squeeze the ends together to grip the underside of the keycap, and lift up. IBM sells a tool designed specifically for removing keycaps from its keyboards, but the chip puller works even better. After removing the cap, spray some compressed air into the space under the cap to dislodge the dirt. Then replace the cap and check the action of the key.

When you remove the keycap on some keyboards, you are actually detaching the entire key from the keyswitch. Be careful during the removal and reassembly of the keyboard; otherwise, you’ll break the switch. The classic IBM/Lexmark-type Model M keyboards (now made by Unicomp) use a removable keycap that leaves the actual key in place, enabling you to clean under the keycap without the risk of breaking the switches. If you don’t want to go through the effort of removing the keycaps, consider using cleaning wands with soft foam tips to clean beneath the keytops.

Spills can be a problem, too. If you spill a soft drink or cup of coffee into a keyboard, you do not necessarily have a disaster. Many keyboards that use membrane switches are spill resistant. However, you should immediately (or as soon as possible) disconnect the keyboard and flush it out with distilled water. Partially or fully disassemble the keyboard and use the water to wash the components. If the spilled liquid has dried, soak the keyboard in some of the water for a while. When you are sure the keyboard is clean, pour another gallon or so of distilled water over it and through the keyswitches to wash away any residual dirt. After the unit dries completely it should be perfectly functional. You might be surprised to know that drenching your keyboard with water does not harm the components. Just make sure you use distilled water, which is free from residue or mineral content. (Bottled water is not distilled; the distinct taste of many bottled waters comes from the trace minerals they contain!) Also, make sure the keyboard is fully dry before you try to use it; otherwise, some of the components might short out.

Fully drying a keyboard that has been soaked in water can take several days or more, so be prepared to wait. You can use compressed air to greatly speed up the drying process. Even then, if the contaminants were not fully flushed out, the keyboard may still not work correctly. In that case the best results will be obtained by completely disassembling the keyboard, washing and then drying each component individually, and then reassembling. Depending on the value and construction of the keyboard, a replacement may be the best option.