Top 10 Tips for Passing the A+ Exams
EDITOR'S NOTE: This article offers tips for the A+ exams based on the 1998 objectives; which retired on March 30, 2001. For a review of the new exams, click here.
by Faithe Wempen
10/7/2000 -- Even if you're an experienced PC technician with many years of service under your belt, you might be in for some surprises when you take CompTIA A+ certification exam. There's a big difference between practice and theory, after all. You may know how to assemble a PC in less than 10 minutes, but do you know the proper name for each of the parts? You can probably install Windows 95 on a system in your sleep,but do you know the names of the files that Windows 95 uses to boot, and in what order they are executed?
The A+ Certification exam favors people who are not only good, hands-on techs, but also competent in computer theory and terminology. Toward that end, here's my top 10 list of study tips for A+ exam success.
1. Know About the Changes to the Exam
Most of the study guides in stores today don't have the latest information about how the A+ exam is administered. That's because, as of July 28, 2000, the test has become adaptive.
What does this mean for you? A+ was originally a standard multiple-choice exam in which you were free to skip questions and come back to them later. Your answers were not final until you turned in your completed test. The new version of the test forces you to choose an answer to every question and, based on your answer, you get a different subsequent question.
Adaptive testing can also make the overall test more difficult because it reduces the number of questions asked, and if you are really weak in certain areas, you may get more questions in that area. For example, suppose your first question is on laser-printer operation, and you answer it incorrectly. The adaptive test may ask you more questions about printers to test that area of knowledge; these are questions you otherwise might not have encountered if you gotten the initial question right.
There's another, bigger change coming up, but it won't happen until December at the earliest. A completely new version of the test is coming out, which will omit coverage of Windows 3.1 and and will add Windows 98, Windows NT 4.0 and Windows 2000.
Once you become A+ Certified, you are certified for life, so now is a great time to consider taking the test. You can hurry and take the test now and not have to study Windows 98/NT/2000, or you can wait and take the test after the change and not have to study Windows 3.1.
2. Learn How a Laser Printer Works
To consider yourself a knowledgeable support technician, you should understand the innards of a laser. I can't make you an expert on it in a few paragraphs, but here's a brief synopsis.
The most important (and expensive) piece of a laser printer is its photoreceptor drum. The drum has a smooth coating that can hold an electrostatic charge. At the beginning of the print cycle, a uniform -600v charge is applied over the entire drum by the primary corona, a.k.a. the charger corona. Then the laser hits certain spots on the drum to partially neutralize the charge (down to -100v), creating an image of the data to be printed.
Meanwhile, the developer (a roller coated with fine magnetic particles that make the toner stick to it) is picking up toner and charging it negatively. When the developer roller passes by the photoreceptor drum, the toner particles (a mixture of plastic and iron oxide) are attracted to the parts of the drum that have a lesser charge, and repelled by the parts with the greater charge, forming the page image in toner on the drum.
Next, the drum passes close to the surface of the paper. Beneath the paper is another wire, called the transfer corona, that charges the paper to +600, making it attract the toner particles from the drum. The page then passes over a static charge eliminator, which applies a negative charge to cancel out the positive one so the paper won't stick to anything on its way out. Finally, the paper passes through a fuser, which melts the plastic toner particles to about 400 degrees Fahrenheit and makes them stick to the paper.
You'll want to study this in more detail on your own. If you remember nothing else, make sure you know the difference between the various coronas, and which type of charge (positive or negative) they put out.
3. Brush Up on Electricity Basics
Make sure you understand basic electricity, including the proper settings for testing various electronics with a multimeter. If you have never used a multimeter before, it might be a worthwhile investment to pick one up, as well as browse through a study guide that covers electrical testing.
There are two kinds of multimeters: analog and digital. Digital is better for computer systems because it uses less voltage to check resistance and is therefore less likely to do any harm to sensitive components.
A multimeter has a pair of wires called test leads or probes, with which you take readings. Depending on the meter's setting, you can check electrical resistance, DC voltage or AC voltage. You'll need to know the settings to use for various types of components, including cables, power supplies and circuitry. Each setting also has several ranges of operations. DC voltage, for example, can be read in several scales: 200 mv, 2v, 20v, 200v and 1,000v (these numbers refer to the maximum). Because computers use both +5v and +12v for various operations, you should use the 20v scale. If you are unsure of the voltage of something, start at the highest scale and work your way down until you get a meaningful reading.
You also need to know where to place the probes in order to get a reading. To test a power supply for proper output, for example, unplug the power connector(s) from the motherboard (with the power OFF, of course) and check the voltage at the Power Good pin (P8-1 on an AT, pin 8 on the ATX) for +3v to +6v of power. If the measurement is not within this range, the power supply must be replaced.
Besides electrical testing, you should also know about electrical safety. For example, one important fact to know is that a CRT can retain a high-voltage electrical charge for a long time after it's been unplugged from an electrical outlet--months, even. You should also be familiar with the various electrical hazards to equipment, such as electrostatic discharge (ESD, a.k.a. static electricity) and how to prevent it from harming electronics.
4. Study System Bus Architectures
There are a lot of acronyms surrounding PC bus architectures, and you need to know all of them. Study what they stand for, in what types of systems they are used, and their major unique features.
For example, make sure you understand the IDE interface backward and forward. You should know how to configure two IDE devices sharing a cable, for example, such that one is the master and the other the slave. Make sure you also know how to set those drives up on the BIOS setup program if they don't autodetect. You should also be able to distinguish the various flavors of IDE (such as EIDE and ATA-2) and explain how IDE differs from SCSI. Speaking of SCSI, know how to terminate both internal and external SCSI devices, and how to set SCSI ID numbers.
But the bus doesn't stop at drive interfaces: There are more buses (with more cryptic acronyms) on the motherboard. Make sure you are familiar with the various card slots: PCI, ISA (8-bit and 16-bit), AGP and so on, as well as the older VL-Bus (or VLB). You should also be familiar with the SCSI bus, and know how to terminate both internal and external devices.
5. Know Your Way Around Device Manager in Windows
Device Manager is part of Windows 95 and Windows 98. NT and 2000 have their own versions of it, too. To get to Device Manager, go through System in the Control Panel or right-click My Computer and choose Properties.
You need to know how to view a device's properties through Device Manager, as well as how to see what resources it uses. The three main types of resources a device uses are IRQs, memory addresses and DMA channels. (And speaking of DMA channels, do you know what types of devices typically employ them?)
As a PC technician, you should be able to manually set the resources for a device (turning off Plug and Play, etc.) to work around conflicts. You should also know how to create multiple hardware profiles and disable a device in certain profiles. Also, make sure you know the IRQs that various devices commonly use.
6. Memorize the Acronyms for Various Connector Types
The A+ exam often refers to a connector by its technical name. Instead of saying "the serial port," for example, it might say "the RS-232 port." This can really throw you off if you don't know the acronyms and model numbers for the various ports. This is by no means a comprehensive list, but here are a few to get you started:
- DB-9: A nine-pin, D-shaped connector (not necessarily a serial port, but commonly so).
- DB-25: A 25-pin, D-shaped connector (can be either parallel or serial).
- DB-15: A 15-pin, D-shaped connector (most commonly VGA video, but can also be used for Thicknet network connection).
- RS-232C: The standard for serial data transmission on a PC; can be either a DB-9 or DB-25 connector.
- RJ-11: A standard telephone plug.
- RJ-45: A plug for 10Base-T networking; looks like a wide telephone plug.
When dealing with connectors that have pins or holes (e.g., male or female), make sure you know which is for what purpose. For example, on the back of a PC, there is probably a 25-pin connector with holes and another one with pins. Quick--without looking!--do you know which is the parallel port and which is the serial?
7. Be Able to Explain the Boot Process for DOS and Windows
You'll need to know the steps a PC goes through when booting and how MS-DOS and Windows 9x systems differ. In addition, after December of this year, you will need to know the boot processes for Windows NT and Win2k.
The differences between MS-DOS and Windows 9x is where most people get tripped up. For example, do you know what Msdos.sys does in each system? In MS-DOS systems, Msdos.sys is one of two critical startup files (the other one being Io.sys). It initializes the base device drivers, determines equipment status, and resets and initializes attached devices. In Windows 9x, the functions that were formerly the domain of Msdos.sys are combined with and included in Io.sys. Msdos.sys is merely a text file that contains configuration settings for booting.
Do you know what files Io.sys loads? In MS-DOS, it loads Command.com and then processes Autoexec.bat and displays the command prompt. On a Windows 9x machine, Io.sys does not load Command.com unless it finds an Autoexec.bat file to process. Then it loads Himem.sys, Ifshlp.sys and Setver.exe, followed by Win.com (which starts Windows itself).
8. Understand the Windows Registry
You don't have to be able to edit Registry code with your teeth or anything, but you should at least know that the two files that make up the Registry in Windows 95/98 are System.dat and User.dat. System.dat contains machine-specific settings, while User.dat contains settings specific to the person logged in at the moment. Both are accessible as a single unit through the Registry Editor (C:\Windows\Regedit.exe).
9. Distinguish Between Memory Types
Do you know the difference between XMS and EMS memory? What about between high memory and upper memory? Here's a quick run-through:
The first megabyte (1024K) of a system's memory is divided into two chunks: conventional memory (the first 640K) and upper memory (the remaining 384K). Conventional memory is where MS-DOS runs programs; upper memory is where it stashes code needed to take care of system tasks such as the video system and the BIOS functions. On an MS-DOS system, you can load certain drivers "high" in Config.sys and Autoexec.bat so that they're placed in upper memory blocks (UMBs) instead of taking up space in conventional memory. Even old XTs have upper memory, but you can't stash drivers in it unless you've got a 386 or above.
The high memory area, or HMA, is the first approximate 64K of memory after the first megabyte. It can be used to stash a driver too, but it can accept only one at a time. The Himem.sys line in Config.sys controls this area; on DOS 5.0 and higher systems, the line DOS=HIGH in Config.sys can place the DOS kernel into high memory, freeing up about 40K of conventional memory.
The rest of the memory? On 386 systems and above, it's extended memory, which can be used by protected-mode programs such as Windows 9x. Most programs can't use extended memory directly; they want it in XMS format. XMS is a memory specification developed by Microsoft, Intel and Lotus back in 1987. Himem.sys grabs up all the extended memory and provides it in XMS format to the programs.
Expanded memory specification (EMS) memory is not extended memory, but rather an older kind of memory called expanded, used in the original 286 systems. Another acronym for it is LIM (which stands for Lotus/Intel/Microsoft). You will seldom run across a program that wants expanded memory, but if you do on an MS-DOS system, you can use Emm386.exe in the Autoexec.bat file to make some of your extended memory emulate it.
10. Choose the Right Study Guides
Even if you read this entire article and thought to yourself, "Yeah, yeah, I know all that," you owe it to yourself to study, at least a little. The best way to study is to take practice exams, because they can help you gauge your readiness in a practical way. Many study guides come with CDs full of practice questions and use test engines that throw randomly chosen questions at you as well as time your performance. Some of the better ones also allow you to take the test in study mode, where you can look up the answer to a question using an online version of the study book.
Don't get overly ambitious when choosing study guides. That six-volume set that costs $300 at your local bookstore might look like an awesome reference, but you'll probably never make it past Volume I. Instead, try a single-book reference such as Upgrading and Repairing PCs by Scott Mueller (Que Corp.), at only $59.99. Then, if you feel that you need more information about a specific subject, you can seek out a reference book specific to that topic.
And don't overlook the Internet as a source of free study materials. The CompTIA Web site provides a complete skill-by-skill listing of the objectives covered by the A+ exam. Find it at http://www.comptia.org/index.asp?ContentPage=certification/certification.htm. For more information on the A+ certification, please click HERE.
What do you think of the A+ exams? Post your comments below or enter our Forums.
Faithe Wempen, M.A.,is a Microsoft Office Specialist Master Instructor and an instructor in the Computer Technology Department of Indiana University/Purdue University at Indianapolis. She is the author of over 50 books on computer hardware and software, including A+ Jumpstart: PC Hardware and Operating System Basics. She also co-owns the Sycamore Knoll Bed and Breakfast.
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