hardware interview

8/11/2019 Hardware Interview

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Question:What is the difference between Firewire 1394a and 1394b?

Answer:Firewire is a high-speed digital interface that comes in two varieties - 1394a (or just 1394) and 1394b. The 1394a standard (Firewire 400) supports data transfer rates up to 400 Mbps and uses a 6-pin connection. The 1394b standard (Firewire 800) can transfer data up to 800 Mbps and uses a 9-pin connection.

Question:What is the difference between SDRAM and VRAM?

Answer:Computer memory is commonly referred to as RAM, or Random Access Memory. Both SDRAM and VRAM are types of RAM, but they are used for different purposes.

SDRAM is the primary memory used by computers and is located in memory slots onthe motherboard. It is used to load the operating system and running programs. Therefore, the more SDRAM your computer has, the more programs it can run at onetime. Having an abundant amount of SDRAM may also allow your computer to run faster that a similar machine with less RAM. This is because more data can be loaded from the hard drive and stored in memory, which enables it to be accessed more quickly.

VRAM is short for "Video RAM" and is used to store graphics data. VRAM is typically located on the computer's video card, though on computers with an integrated video chip (such as entry-level laptops), it may be located next to the video processor. Regardless of where the VRAM is located, its purpose is to load and store video data. The more VRAM a computer has, the more 2D and 3D images it can display at one time. Therefore, computers with lots of VRAM have large buffers for 3D graphics and can produce faster frame rates than machines with limited VRAM. This is helpful when playing 3D games and using 3D rendering applications.

Question:What do the terms Mk2 and Mk3 mean?

Answer:

Mk is short for "mark." Therefore Mk2 is pronounced "Mark Two," and Mk3 is pronounced "Mark Three." Mark 2, also written Mark II, refers to the second version of a product. Mark 3, also written Mark III, is the third version of a product. Likewise, Mark 4, Mark 5, etc. can be used to identify additional versions.

The "Mark" naming scheme is typically used by hardware products and is similar to the version numbers used by software programs. By adding "Mk2" or "Mk3" aftera product name, manufacturers can keep the same name when a product is upgraded. This is useful for brand recognition and helps companies continue successful product lines through incremental upgrades.

The "Mark" labels were traditionally used to identify different versions of military equipment. However, they have become more commonly used for consumer produc

ts as well. Examples of products that use "Mk" or "Mark" in their names includedigital cameras (such as the professional line of Canon cameras) and audio equipment (such as MOTU digital audio hardware).

So if you ever see a product name followed by "mk2," you'll know it's the second version of the product. Then you can compare it to the first version and see all the amazing improvements that have been made.

Question:Why won't my computer boot up after I installed new memory?


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Answer:Installing memory, or RAM, is a great way to improve the performance of your computer. However, there are many types of RAM, and it is important to install thecorrect RAM when updating your computer's memory.

For example, not all 1GB RAM memory modules are the same. Some may run at 400MHz, while others may run at 667MHz. A 1GB SDRAM chip may have 168 pins, while a SO-DIMM may only have 144. These and other differences can cause RAM to not work with your machine.

If you install the incorrect RAM in your machine, one of two things will happen. 1) The computer will boot up but will not recognize the new memory, or 2) The computer will not boot up at all. If you remove the new RAM and the computer boots up fine, it is pretty clear that the RAM is causing the problem.

While RAM chips can be defective, memory problems are usually caused by installing the wrong type of RAM. You can verify the RAM type using your computer's user guide or by searching for your computer model on websites that sell memory.

When buying RAM, it is also a good idea to make sure it has a lifetime warranty. That way, if the RAM is bad or ever has problems, you can get it replaced freeof charge.

Question:What does it mean to "power cycle" a device?

Answer:Power cycling an electronic device is a technical way of saying "resetting" it.When you power cycle a device, you turn it off and then turn it back on again. Pretty high-tech, huh? Usually, you should let the device sit for a couple seconds after turning it off to make sure the memory in the device is fully cleared before turning it back on.

Any electronic device can be power cycled, but the term is frequently used withcable modems, DSL modems, and routers. This is because small internal errors inthese devices can prevent them from functioning correctly. Resetting them typica

lly fixes the errors and allows them to work correctly again.Question:How can I tell if my CD/DVD drive burns CDs or DVDs?

Answer:If the drive only says "CD-ROM" or "DVD-ROM" then it probably does not burn CDsor DVDs. If it says CD-R, then it can burn recordable CDs and if it says CD-RW,it can write and rewrite to rewritable CDs.

If the drive says DVD-R or DVD+R, it can burn DVD-R or DVD+R discs. If it says DVD-RW or DVD+RW, then it can burn rewritable DVDs.

Drives that can burn CDs and read DVDs are often referred to as "Combo Drives" by many PC manufacturers. Apple Computer uses the term "SuperDrive" to refer to drives that can read and write to both CDs and DVDs.

Question:What is the difference between the DVD-R and DVD+R formats?

Answer:DVD-R (pronounced "DVD dash R") and DVD+R (pronounced "DVD plus R") are nearly identical formats. The discs look the same and are both supported by most DVD-ROM


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If you are using Windows, you can find out how much RAM you have by right-clicking the My Computer icon and selecting "Properties..." This will open the SystemProperties window and you can view the amount of physical memory installed under the General tab. You can find out how much memory your computer is currently using by right-clicking anywhere in the open space of the Taskbar and selecting "Task Manager." Then click the Performance tab of the window that opens and you will be able to view your memory usage.

If you are using Mac OS X, you can see you much RAM is installed in your computer by choosing "About This Mac" from the Apple menu. This is located in the far upper left-hand corner of the screen. To find out how much memory is being used,open the Activity Monitor program, located in the Utilities folder (within the Applications folder). Then click the System Memory button near the bottom of thewindow to see how much memory your system is currently using.

Question:Can I use a generic v.92 modem from Wal-Mart in my Dell computer?

Answer:It may surprise you to learn that most companies don't make the modems that go into their computers. Instead, companies such as Dell use modems from other manufacturers who specialize in making modems. Therefore, a modem you buy from Wal-Mart should work just as well as one you buy from Dell.

However, you should check the system requirements of the modem you are interested in to make sure your computer supports it. It is most important to check the required operating system since the drivers need to be compatible with the OS. If the software drivers don't work with your operating system, your computer may not be able to recognize the modem.

Question:What is the difference between physical memory and available memory?

Answer:Physical memory is how much RAM you have installed in your computer. For example, if you have two 512 MB memory chips in your machine, you have a total of 1 GB

of physical memory. This memory is what your computer uses to load the operating system as well as individual programs and files.

Available memory refers to how much RAM is not already being used by the computer. Because loading the operating system takes up memory, your available memory drops right after your computer boots up. You can reduce how much memory the operating system uses by uninstalling system files or extensions that are often installed by utility programs.

Each time you open a program, it is loaded into your computer's memory, and therefore reduces your available memory. Large programs such as Adobe Photoshop and3D action games take up more memory than simple programs like text editors or spreadsheet programs. If you need more available memory to open a large program, y

ou should first quit other programs that are running.

The best way to increase available memory is to add more RAM, or physical memory, to your computer. Before doing this, make sure your computer has open memory slots. Some utility programs claim to "double your RAM," but they often slow down your computer signficantly in the process. Adding more physical memory to yourcomputer gives your applications more breathing room and therefore should help your computer run faster.

Question:


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What is the difference between memory and hard disk space?

Answer:Memory and disk space are perhaps the most widely-confused terms in the computing world. To truly comprehend how your computer works, you must first understandwhat memory and disk space are.

The hard disk, sometimes called the "hard drive," which is actually the mechanism that holds the hard disk, is a spindle of magnetic discs that can hold several gigabytes of data. Therefore, disk space refers to how much space you have available on your hard disk for storing files. When you save a document or install a new program, it gets stored on your hard disk. The more files you download, install, or save on your hard disk, the more full it becomes.

Memory, on the other hand is not the same as disk space! Memory refers to the random access memory (RAM) inside your computer. These are small chips that hold several memory modules side by side. Your computer uses memory (RAM) to store actively running programs on the computer, including the operating system. For example, the operating system's interface and other processes get loaded into memory when the computer boots up. When you open a program like Microsoft Word, it gets loaded into the computer's memory as well. When you quit the program, the memory space is freed up for other programs.

RAM can be accessed several hundred times faster than a hard drive, which is why

active programs must be loaded into the RAM from the hard drive. Because most data on the hard disk does not need to get loaded into the system memory at one time, computers typically have much more hard disk space than memory. For example, a computer may come with a 200 GB hard drive, and only 1 GB of RAM.

So if your computer tells you that you don't have enough space to install a program, you will need delete files from your hard disk that you don't need or buy an additional hard drive. If your computer says there is not enough memory to run a certain program, you will need to upgrade your memory by buying more RAM. Knowing the difference between these two types of hardware can save you precious time and money.

Question:

What is the difference between an AGP and a PCI graphics card?Answer:The biggest difference between AGP and PCI graphics cards is that AGP cards canaccess the system memory to help with complex operations such as texture mapping. PCI cards can only access the memory available on the actual card. AGP doesn't share bandwidth with other devices, whereas PCI cards do. AGP also makes pipelined requests, which means it can execute multiple instructions at one time. PCIcards are not pipelined, which means each instruction has to finish before the next one is run.

So, with all these great advantages of AGP, you'd think it would be the clear winner in performance, right? Well, not quite. Tests of similar AGP and PCI graphi

cs cards show they perform almost the same (typically measured in frames per second). The area where AGP really shines is in high-resolution tests, where the direct access to the system memory is most beneficial.

If you're installing an AGP or PCI card in your computer, the AGP slot is usually the shortest and should be brown. The PCI slots are slightly longer and are colored white. The actual size of the cards can vary as much as a few inches, though the pins on the bottom of the card should match the correct slot.

Question:


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What are the Alt (Option) and Control (Ctrl) keys for?

Answer:These keys on the keyboard are called "modifier keys." They are typically used in conjunction with another key on the keyboard to perform a specific function. For example, in Windows, Alt-F4 (press and hold Alt, then press F4) is often a shortcut to close the active window. Control-C is usually a shortcut to copy selected text or a selected object. Control-V is the shortcut for pasting the copieddata.

On the Macintosh, the Command (or Apple) key typically has the same function asthe Control key in Windows. The Control key on the Mac can be pressed while clicking the mouse button to perform a right-click. Many programs on both Macs and PCs use mutliple modifier keys for shortcuts for certain operations. For example, to save an image for the Web in Photoshop, you can press Ctrl-Alt-Shift-S in Windows or Command-Option-Shift-S on the Mac.

Question:Can I fax a document without a fax machine?

Answer:There are a number of fax programs available for faxing documents electronically using your computer's modem, or simply through the Internet. Some popular fax programs include FaxSTF (Mac) and Fax Wizard (Windows). These programs allow you

to fax electronic documents such as Word documents or documents you scan into your computer. I would suggest visiting Download.com for a shareware fax program if you don't have one or visiting eFax.com for more information.

Question:What is the difference between burning and ripping?

Answer:"Ripping" refers to extracting audio files off a CD and copying them to your hard drive. After ripping the audio, you can then convert the files to the more compressed MP3 format if you want.

"Burning" refers to the process of writing data onto a CD. You can burn both aud

io and data CDs, as well as DVDs, provided your computer has a CD/DVD burner.Question:Can I put my computer (tower) on its side, or does it need to stand up?

Answer:It is likely that your computer will operate normally while laying on its side.However, unless the computer's manual specifically states that it is OK to place the tower on its side, I would keep it an upright position. This is because there are a few components inside the computer that may malfunction if the computer is placed on its side.

While most of the hardware inside the computer -- the motherboard, CPU, graphics

card, and memory -- are solid state parts, there are a few components that have moving parts. The hard drive, for example, is spinning at thousands of rotations every second. If the hard drive is not designed to be used at various angles,it may wear down sooner than expected. While most hard drives can be used horizontally or vertically, it is best keep them in the position they came in.

The most common problem with tilting a computer on its side is related to the optical drive. When you put a CD or DVD in your computer, it spins very fast, just like the hard disk. If the drive is not meant to be used vertically, the disc may wobble and the computer will not be able to read it correctly. You may even h


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ave problems getting the disc into the computer when it is sideways. Optical drives that can be used vertically often have small levers around the edges of theCD tray that can be pushed over the CD to hold it in place. Some slot-loading optical drives can also be used vertically (i.e. the iMac G5), but many should only be used horizontally.

Whether or not you think your CD/DVD drive supports vertical positioning, it isbest to check your computer manual to see if the computer can be placed on its side. The convenience of positioning the tower horizontally certainly isn't worth the hassle of replacing a broken optical drive or hard disk.

Question:Why is my mouse jumpy?

Answer:If the cursor on your screen isn't following the movement of your hand, there'sa good chance you've got a dirty mouse. No matter how hard you try, it is basically impossible to keep your mouse pad dust and dirt free. And after hours and hours of rolling on a dirty surface, your mouse ball is bound to pick up some gunk. This grime gets twisted around the rollers inside your mouse and prevents them from rolling smoothly against the mouse ball. Since these rollers are what tell your computer what the mouse is doing, it's not good when they don't roll.

So if your cursor isn't moving how you want it to, before you decide to throw yo

ur mouse against the wall, check to see how dirty it is. To check the mouse, twist off the cover on the bottom that holds the ball in. Then take out the ball and examine the rollers. If you can see stuff on them, it's time to clean 'em. Toclean the inside of your mouse, you can use a Q-tip or even your fingernails toget the dirt off the rollers. Make sure you clean all the way around them. Thenblow inside the mouse to make sure everything gets out. Finally, wash off the mouse ball with soap and water and dry it. It is also a good idea to clean off your mouse pad. Once you've done all this, you can put the clean ball back in yourclean mouse and experience smooth rolling freedom once again.

Of course, if you have an optical mouse, this should never be a problem. =)

Question:

Is it possible to increase the number of available PCI slots on my computer?Answer:Unfortunately, you can't increase the number of PCI slots inside your computer.The only option you have, other than buying another computer, is to get a PCI tower, which has multiple PCI slots. The tower connects to any PCI slot on your computer's motherboard. (For example, it could turn one slot into six.) However, these are typically only used by people that do high-end video editing, and theyare pretty expensive.

Question:What is the difference between the AMD Athlon and Intel Pentium processors?

Answer:Intel and AMD (Advanced Micro Devices) are the two major manufacturers of processors for PCs. Intel makes the Pentium and Celeron processors; AMD makes the K6 and Athlon processors.

So what's the difference? Well, historically, Pentium processors have had the best overall performance. However, the new AMD processors are faster than their Pentium counterparts in some tests. In general, you'll pay the most for an Intel processor, which means the AMD processors typically have a better price-performance ratio.


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Question:What does scalable mean, in reference to a computer?

Answer:Scalable is synonymous with expandable. A computer with a scalable architectureis able to be upgraded easily and for a long time. When buying network equipment, it is especially important that it is scalable so that it can work with the newer systems that may be added on later. The less scalable your equipment is, the sooner you'll be forced to upgrade.

Question:How long does it take to complete a 7-pass erase on a hard disk?

Answer:A 7-pass erase is a secure way of erasing the data on a hard disk. It overwrites the data seven times, making it impossible to recover any usable data from thedrive. Apple's Disk Utility programs, as well as other hard disk utilities offer this option. Some offer 3 or 5-pass erase options, while some, including Apple's Disk Utility allow you to perform up to a 35-pass erase.

The amount of time a 7-pass erase will take depends mostly on the size of your hard drive. Because the software erases every bit on the drive, the amount of time each erase will take is directly proportional to the hard drive's size. The ov

erall time may also be affected by the speed of the hard drive, the software program you use, and possibly the computer's processor speed.

What is the difference between "recover" and "restore?"

Answer:The terms "recover" and "restore" both refer to retrieving files from a backup device, such as a hard disk, external hard drive or other storage media. However, recovering files typically refers to salvaging one or more files, while a restore usually refers replacing a complete system or hard drive from a full system backup.

For example, if you accidentally erase a document, you may be able recover the f

ile from a recently backup (assuming you have a recent backup). If for some reason, several files in a folder are corrupted and cannot be opened, you may be able to recover the entire folder from a backup. Individual files and folders can be recovered using a backup utility program or by simply dragging files from thebackup disk to the original hard disk.

Then there are times when an entire hard drive crashes and stops functioning orthe system directory becomes corrupt and the computer cannot boot up. In these desperate times, a full hard disk restore or system restore may be necessary. A hard disk restore can be done using a backup program, which copies every file from the backup to the original disk exactly, essentially duplicating the hard disk. Some backup programs copy a "disk image," or exact binary copy of a hard diskfrom one the backup drive to the original hard drive.

A system restore can typically be done using the original operating system installation disc(s). A fresh operating system can be installed from the CD/DVD thatcame with the computer, ensuring there are no problems with the system. While this gives your computer a fresh start, it does not replace the personal data youhad previously saved on your hard drive. These files will have to manually be copied back to the new hard drive from a backup device.

So "recover" and "restore" are related, but have different meanings. It might help to think of restoring a hard disk as recovering all files at once. In other w


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ords, restoring a hard disk is a much bigger process than recovering individualfiles. Regardless of how you memorize the difference between the two terms, theimportant thing to remember is to back up your hard drive!

Question:How can I make sure everything is deleted off my hard drive before I sell my computer?

Answer:The quickest way to "erase" a hard disk is to initialize it. This process clears the current file system and creates a new directory structure. However, the files on disk are not actually removed -- only their references are gone. This means it is possible to retrieve many of the files on a newly initialized drive.

In order to make sure all your data is truly deleted, you need to "wipe" your hard disk. If you use a Macintosh, the Disk Utility program allows you to choose "Zero All Data" or perform an "8 Way Random Write" when erasing a disk. Either of these options will effectively make your data unrecoverable. Windows does not have a built-in option for wiping the hard drive, but there are several utility programs that will do the job for you. An example is Darik's Boot and Nuke. Several others can be found at CNET's Download.com. If you want to keep any of your data before wiping the drive, be sure to back it up on another drive since you will not be able to recover it.

Question:Is it possible to recover files off a disk that has been reformatted or initialized?

Answer:When a disk is formatted, the directory structure of the disk is rewritten, butthe actual files are not deleted. Therefore it may be possible to recover some of the files from a disk that has been reformatted or initialized. As long as the reformatting did not write over the files you want to recover, it is sometimespossible to recover the files using a program like Norton Utilities Unerase, File Rescue Plus, Handy Recovery, or FinalRecovery.

These programs will search the disk, whether it be a hard drive, floppy disk, or

other media, for valid files. Even though the files are "invisible" to the system, the program should be be able to find them and list the ones that are recoverable. You have the best chance of recovering files if you run the recovery utility immediately after the disk has been formatted. Most disk recovery utilitiescan also recover files that have been accidentally deleted.

Question:What does it mean to defragment a hard disk?

Answer:Over time, new files get written to your hard disk and old ones get deleted. When files are removed, gaps are created in the hard drive where new data can be written. Sometimes the new data doesn't quite fit in the gaps and some files get w

ritten in multiple areas on the hard disk. These files become "fragmented," meaning they consist of fragments of data. Because the hard drive has to scan multiple parts of the the disk to read a fragmented file, it can slow down the operation of the computer.

Defragmenting the hard disk cures this problem. A hard disk utility, such as Norton Utilities, can put file fragments together to create contiguous files. Contiguous files are read more efficiently by the hard drive and therefore lead to faster data access. Some defragmentation programs can also optimize the hard disk, which places similar files in similar locations. For example, program files are


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stored in one area, system files in another, and documents in another area of the disk. It is a good idea to defragment you hard drive about once a month during typical use.

Question:Why does my hard drive make a lot of noise?

Answer:If your hard drive seems to be making more noise than usual, there is a good chance it has become fragmented. Hard drive fragmentation occurs when files and folders are moved around, added, copied, and deleted.

Your computer's hard drive stores information in blocks of data. When information becomes scattered on your hard drive, some files are written onto blocks thatare not next to each other. This is known as file fragmentation. Your hard drive can still run when there are fragmented files on it, but it will run slower. This is because it has to scan more of the disk to access certain files. The extra scanning is what causes the hard drive to make more noise. When you start hearing an excessive amount of grinding from your hard drive, it is time to defragment it. A program like Norton Utilities will do this well.

You can also take the defragmentation process one step further and optimize your hard drive. This process moves similar types of files next to each other, so the hard drive head doesn't need to jump around as much. Optimizing your hard driv

e is a great way to increase performance. If you like your computer running as fast as possible, it is a good idea to defragment it at least once a month and optimize it every three months.

Question:Why does my hard drive spit and shutter so much even after I defragmented it?

Answer:There is a good chance you have some bad or corrupted blocks on your hard drive. The best thing to do is to run a disk utility program (like Norton Disk Doctor, part of Norton Utilities). This usually fixes problems such as bad blocks or corrupted disk directories. If the utility program can't fix it, you may have to reformat the hard drive, which means erasing all your data. If you have important

files on the drive, make sure you back it up before you do anything.Question:What is the difference between a double density (DD) diskette, and a high density (HD) diskette?

Answer:The terms high density and double density are pretty confusing. A high density diskette can store 1.44 MB after being formatted. (It can hold about 2.0 MB before being formatted.) A double density diskette can only hold 720K of data, or half that of a high density diskette. Sometimes, high density diskettes are referred to as HD/DD, which makes the difference a little more obvious. Double densitydiskettes are pretty much obsolete now, and it looks like HD diskettes are soon

to follow.

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