"Shop windows display a tantalizing range of PCs. But do not give in to the sales pitch and choose one that looks or sounds good. Instead, remember these few valuable tips so that you buy the most appropriate PC and peripherals that will best suit you needs."


            Now that youíre serious about buying a computer you may consider the options available. If youíve ever visited a computer store, it is very likely the salesman tried to push you a computer by mouthing a whole lot of technical jargon. However, knowing what goes into the making of a complete personal computer (PC) will help you make an informed decision in buying the right one. Thus, in this section Dr.KSM will lead you step by step to what makes a computer tick, and what you should be aware of when you actually go out there move and buy your own PC. 

            Basically, PCs are of two types-the great looking iMac form Apple and the wide range of standard IBC compatible PCs. How does one decide which one to go for?  The iMac is pretty good for games, multimedia and Internet connectivity and its user-friendly interface. However, the software titles available for an iMac are pretty limited. Also, Upgrading an iMac isnít generally possible. 

            On the other hand, IBM PCs allow extensive upgrading and have a lot of software and hardware options. Whatever your choice, PCs are ideal for office as well as home usage. Even if we put all IBC compatible computers under one roof, each machine can be very different from the other in terms of the component they house inside.  

            Keeping your budget in mind, make a careful choice over which PC would best suit your needs.


Central Processing Unit (CPU) 

The CPU is the core unit of the computer. Akin to the brain, this is one critical component that decides how fast your computer will be. An indicator of speed is generally the clock speed of the CPU, given in Mega Hertz (MHz). Generally, higher the clock speed, faster the CPU. The CPU also houses a small amount of memory called  cache (pronounced: cash) the helps speed up memory accesses. Thus the amount of cache a CPU possesses serves as an indicted indicator of its speed. There are quite a few choices in CPUs, each having a balance between performance and cost. 

            At one end of the CPU spectrum are the Pentium ĖII, Pentium Ė III and Pentium - IV class CPUs, with fast execution  and high clock speeds. The Pentium ĖIII isnít much different from its predecessor (the Pentium- II), but it promises significant speedups, especially in 3D games, mathematical software and spreadsheets. The Pentium-IV has added a few new instructions that help software do match faster. The catch is the application runs faster only if the new features are explicitly used. Designed specially for repetitive  complex calculations, these instructions will definitely help upcoming 3D games to  become more realistic. What it means it that all the existing applications will run at about the same speed, but those taking advantages of the new features in Pentium-IV get a significant boost. And as more and more software being written  are supporting these features, the Pentium ĖIV  is becoming a successor to the Pentium-III. 

            On the other end is Celeron series. Introduced after the Pentium-II the Celeron CPUs, have slower performance, at a budget price. The slower speed comes partly due to reduction in the CPUs cache memory. Earlier Celeron chips had no on-chip cache. However in its recent incarnation, the Celeron is a stripped down Pentium-II with an affordable price tag. 

            A new contender on this side is the Advanced Micro Devices (AMD). Although not as well-known, AMDís K6 and recently introduced K7 processors churn out good performance at rock bottom prices. Though the AMD has not made a mark in India, the K7 processor beats Pentium-IIIís  performance, but at equal prices.


A motherboard is basically a printed circuit board housing all the slots for connecting the CPU, sound card, video card, hard disk, memory and everything else that goes in a computer. It also hosts basic hardware such as a floppy disk and hard disk controller, communication ports and sometimes the newer USB (Universal Serial Bus ) interface, Like glue, the motherboard connects the computer parts together and makes it all work as one.

            Since the motherboard hosts a connector for the CPU, only the CPUs compatible with that specific connector  will work on the given motherboard and vice versa. For example, the Pentium and AMD K6 can be connected to a Socket 7 motherboard. But the Pentium -II can only be used with a Slot I Motherboard that is designed to accommodate CPUs featuring Slot I type connectors which are motherboard supports defines which cards can be connected on your computer and overall how fast it will work. 

A PCI based motherboard with support for ISA and AGP slots is preferred, as it will give high performance in addition to compatibility with older ISA based cards. The chipset on which the motherboard is based is what decides its features and capabilities. Avoid older 440 LX motherboards for the Pentium-II/Celeron range, as they are pretty slow and have been replaced by faster ones such as the 440 BX Motherboards. For PIIIs, the 820 chipset is generally adequate. Support for the USB interface should also give future compatibility to upgrade to newer peripherals (such as scanners, mouse, keyboard, etc) designed for this connector type.


The computer bus

All the components inside the computer (video card, sound card, CPU, RAM, etc) are connected to each other by a complex interconnected network of wires known as the bus. The main types of buses are ISA and PCI. The industry standard Architecture (ISA) bus standard is the older and slower of the two. Brought out in the early 1980s, support for ISA is being eroded by the PCI standard. PCI, or Peripheral component interconnect, supports plug and play and is faster than ISA. AGP (Accelerated Graphics Port0 is another bus system. But  unlike PCI or ISA, AGP was exclusively designed for faster connections between the video card and the computer memory. Most new computers have an AGP slot inside where a video card supporting the AGP standard can be connected. In most cases, an AGP  card outperforms its PCI equivalent due to faster memory access.



Unlike a human brain, the computer houses its memory separate from the CPU. Computer memory, known as Random Access Memory or RAM, is measured in the number of byes it can store. A byte is a basic block of memory, composed  of eight bits, each bit having either a one or zero as its  value. Most computer memory nowadays is measured in Mega Bytes (MB), which are approximately 1,000,000 (million ) bytes.           

            The amount of memory needed is generally based on your usage; the more power hungry applications you use, the more memory you will, need. Although having more memory than needed wonít hurt, having less certainly will make its impact felt on performance. Hence the amount of memory in a system also ends up determining its speed. In fact, after the CPU, memory is the next component that affects a computerís speed. 

            Memory is generally available on small printed circuit boards housing a bunch of small chips on its surface in the form of modules. You however, wonít even be coming in visual contact with these as they lie inside your computer. Today, around 32MB is considered as the shoestring value that should just about make the computer start with windows 95. If you plan on using windows 98 and other software like excel or word, which you most certainly will, then 64MB is the baseline that you would probably need to comfortably. And if 3D games and complex data hogging applications is what you want, 128 MB of memory should be your target.



The computer operates on data in binary form. The binary number system has only two numbers (0 and 1) as opposed to 10 numbers (0 to 9) in the decimal system that we use. Computers use binary mainly for its inherent simplicity. Also, since Boolean logic also has two values: true or false, the binary system lends itself easily to logical operations that the computer performs. In computerdom, single digit in binary is called a bit. A collection of four bits is called a nibble, although the term is rarely being used today. Eight bits make a byte. Bytes are like basic chunks of binary data that the computer uses to perform all its operations.


 Hard Disk

If RAM is the computerís short-term memory, the hard disk its long-term counterpart. A hard disk does what the RAM canít ; it stores information even after the computer is switched off, while RAM loses it the moment power goes down. Although both memory and hard disk store data, hard disk is simply a huge storage device that the computer uses to store all the files and directories. 

            Essential to the computer, without them we would be stuck with floppies and clunky DOS like interfaces. Hard disks are available in two varieties: IDE and SCSI. IDE hard disks are the most popular, since they donít require any extra components and are relatively cheaper. These are ones that normally come with a computer. SCSI hard disks on the other hand, require a SCSI controller and are generally more expensive. But what they take, they make upon in their faster speeds. Also, a SCSI controller and are generally used except in critical process and where speed is of prime importance. 

            Hard disks now come with capacities measured in Gigabytes (GB); one GB being equivalent to more than 1,000,000,000 bytes! A 4.3 GB hard disk is the current baseline for housing all the software you need on your PC and having space left for your documents. Generally a maximum of four IDE hard disks can be connected on a computer, providing for an easy way to upgrade. Still more can be connected, but that requires you to opt for the SCSI option.


            Your monitor though among the most expensive, is generally also among the ignored components of your computer, You may insist on a cool new CPU have oodles of RAM installed and then probably won't care too much about the monitor. But consider this all the time you sit in front of the computer, your are staring at the computerís monitor. And a monitor is expensive, and it doesnít allow upgrading. So, carefully choose and buy the best monitor you can afford. Having a good monitor definitely goes a long way in deciding how your computing experience will be. Get a blurry, small monitor and all you've got is headaches and aspirin. And not to forget eyestrain! 

            A monitorís size is described in much the same way as your TV in inches. Most computers today come with a 15 inch monitor. Avoid 14 inch monitors they look like small cabin windows. Check up on the difference between a computer having a 15 inch monitor and its 17 inch counterpart. Recently prices of 17 inch monitors have gradually become lower, making an upgrade to the 17 inch ones more economical. So if you can afford a 17 inch one, go for it. 

            A few things you should know besides the size of a monitor are its dot pitch and maximum resolution. The dot pitch determines how crisp and clear your monitor can show. Lower the dot pitch, better is the clarity of the monitor. A dot pitch of .28 is standard. But there are monitors offering a .26 dot pitch. 

            If you can actually get to test the computer, check if the screen appears crisp and there are no noticeable deformations in color of shape. Also check if you can spot any obvious flickering of the monitor. If the monitor appears to be flickering too much, using it for an extended period of time will make your eyes strain.


Video card 

            All the stuff you see on the Monitor, the windows buttons, fancy icons and cute pointers are there courtesy of a video card residing inside the computer. And even though a video card is important in a computer's drawing speed, a few dealers tend to cut corners when it comes to choosing the right one for a given computer. Every video card has its own special memory that it uses for rending the display, known as Video RAM(VRAM). The amount of VRAM present in a video card determines how detailed your display can be. How much VRAM you need is determined not only by what you run on the computer, but also by which monitor you have. In  general, a 4 MB video card is fine for basic use with a 15 inch monitor. For a 17 inch one, around 8 MB should suffice. 

            Another thing to watch out for is which bus the video card connects to. There are there are three types of slots inside your computer where the video card can be plugged in ISA, PCI and AGP. ISA video cards are pretty old, and just avoid them, unless you want an authentic 80ís experience with windows 95. It is more likely that your video card will be PCI or AGP, AGP being the faster one among the two. The one you choose depends on whether your computer supports AGP or not. If your computer supports AGP, go for an AGP card. 

            The exact card you need basically boils down to what you will be doing with your computer. If you plan to play new 3D games on the computer, then a 3D accelerated AGP card from a popular company is recommended. These cards although a tad bit expensive, are worth the price for their impressive 3D rendering speed that new games demand. However, if basic office work is what you have in mind, then a simple PCI / AGP card with around 2 to 4 MB of VRAM  should suffice.


Compact Disc-Read Only Memory (CD-ROM)  and Digital Versatile Disk (DVD) drive 

            A CD-ROM with its high capacity (650 MB) can be likened to a removable hard disk. However the resemblance ends there, for CD-ROMs cannot be rewritten. Once  a CD-ROM is created, its contents cannot be deleted or changed. However, this hasn't stopped CD-ROMs from proliferating in the computer market. Due to its huge storage capacity, everything from games to business software to office suites, literally everything under the computing sun is distributed on CD-ROMs. And although not vital for the computer to work, the CD-ROM is indispensable nowadays due to its widespread popularity. To read data from any CD-ROM you need a CD Ė ROM drive, which fits into your computer in much the same way as a floppy drive does. Ordinary CD-ROM drives are limited to playing audio CDs and reading data off CD ROMs. But there are other available, which allow you to create one yourself. Known as CD-R drives, meaning CD Recordable, you can use these to create CD- ROMs yourself. However as a doctor, you will rarely need to create one. 

            A CD-ROM driveís sped is given in a speed factor followed by an 'x' like a 16x CD-ROM drive, for example. Choosing a good CD-ROM drive amounts to getting the one with the fastest speed  factor. In simple words, go for the highest speed number and you have got yourself nice drive. 

            The big brother of CD-ROM is the DVD which boasts of a huge capacity and superior performance. A single DVD can hold data of about two CD-ROMs and is faster. However, the evolution of DVD hasnít taken off well and although of late a lot of movies are available in DVD format, we have yet to see major software being etched onto DVD disks. However, most DVD drives can also read standard CDs and CD-ROMs. So if you have an inclination to watch high quality movies on your computer and donít mind the slightly higher cost, then a DVD drive is for you.


Sound card  

            A sound card is what makes your computer do a lot more than just beep at you it lets it play music and sound. If you plan to use programs that use audio capabilities of your computers such as multimedia titles, moves or speech recognition, then a sound card is a must. When buying a sound card, you should be aware of the maximum sampling rate (measured in Kilohertz) that a sound card supports. Most sound cards can sample at a rate of 44KHz, which is fine for almost all audio processing. Avoid buying older cards with lower sampling rates, as they may not come with drivers needed for their proper functioning. 

            The size of audio data that the sound card can process in a given instant is also important to the output sound quality. The higher the number of bits it can sample at a time, higher is the quality. A 16 bit sound card should be adequate, but if you are thinking of using your computer as home theatre system or the likes, go for a 32 bit/64 bit sound card. Also try getting one that is SoundBlaster compatible, as these are the ones most supported on the PC platform.


Standard Components 

Along with the above given parts, a PC generally is also equipped with stuff which hasnít changed much since the 1980s. Take the Keyboard for example. It has been shipped with every PC ever assembled and hasnít changed much since its inception. Tailored after the typewriter, the QWERTY keyboard (named after the six top left keys on the keyboard) has always ruled computers. And unless speech recognition comes of age, the keyboard is bound to adorn every computer userís desk for another decade or so. 

            Another peripheral that is found on almost every PC since Windows became the popular operating system is the Mouse. Mice come in lot of types and shapes but the basic design remains the same: a handheld device with two or more buttons. 

            They Floppy drive is the third device that comes along as a standard in all PCs. Floppies and their drives come in two sizes: 3 Ĺ inches and 5 ľ inches. Both are common, although the 3 Ĺ inch floppies are more popular.



Along with the standard computer configuration, need for more peripherals connecting to your PC is more than ever before. Peripherals allow the computer to input or output information in more than one way, making a computer more useful. For example, instead of typing printout your received, wouldnít it be great if you could somehow get your computer to read the print itself? Its possible using a scanner coupled with an OCR (Optical character Recognition) software. In the following passage, we will show you some peripherals that should help your make the most of your computer.



            If  using your computer to create invoices, health records, prescriptions and the like is what you have in mind, you age going to need a printer. There are quite a few types of printers for the PC dot matrix, bubble jet, inkjet and laser printer. Each of them is outlined below to help you decide the one for you. 

            Dot matrix printers have an array of small print heads and their impressions on an ink ribbon are transferred onto a paper, thereby printing characters on the paper. Among the oldest technologies, the dot matrix printers now have limited use in that of printing pure text. Anything other than text and printer will show poor quality. In short, if you are looking at fast printing of text only dot matrix is your choice. 

            The inkjet and the bubble jet printers although different, work similarly by placing ink directly onto the paper. The inkjet printer squirts ink, while the bubble jet prints by heating ink to the same effect. In fact, the bubble jet printers can be likened to an offspring of the inkjet family. Inkjet printers are very economical at the performance they give and they are getting better at it.

The king among printers is the laser printer which represents the ultimate in printing technology. Dishing out fantastic print quality (photo realistic), the cost of their color versions however are sky-high. But being a doctor who doesnít want to dabble in 3D modeling and graphics, it makes sense to buy an inkjet/bubble jet printer. However, if all you need is text, then go for dot matrix ones. When choosing an inkjet, bubble jet or laser printer cheek on its maximum printing resolution. The printing resolution determines how much detail can be crammed into an inch. Measured in Dots Per Inch (dpi), ones with resolution of around 720 dpi should be adequate for quality letters and documents.


Much like the way we talk over the phone, computers can be connected to each other through modems, thereby allowing files and data to be shared. So you could get that program your friend has without using a floppy disk. If both of you have modems, then all you have to do is connect and use the right software to transfer the file to your PC. Having a modem also allows you to connect to the Internet and that is perhaps the sole reason why modems are popular accessories. 

            An increasing number of computers nowadays come with a modem bundled along with it. Modem speed is measured in the number of bits per second (bps) that can be sent over the phone line, Though a 33.6 Kbps (33,6000bps) modem is decent enough to connect to the Net, todayís standard is 56Kbps. However, note that  a modem can achieve maximum given speed only when modems on both sides support it and the phone line is reasonably clear. Some modems have extended features which may suit your needs such as built-in voice mail, support for sending and receiving faxes, built-in answering machine beckons you, go forward with a modem.



            As the printer takes a hard copy from the soft one, the scanner works in reverse. Grabbing a soft copy from a given hard one. Although used mainly by graphics professionals for getting photos in computers, scanners are nowadays being widely employed in a number of other fields. Coupled with a text recognizer (OCR software), It can function to read printed matter. It can also be used for keeping records of documents, by scanning them into a computer and keeping the soft copy instead.

            But in what way could it help a doctor? One possible use could be scanning the patientís photo or x-ray plates into the computer and incorporating them into a database of all your patients. Currently in experimental phase, a project similar to this is being developed by MIT, where, a special dedicated X- ray plate scanner has been developed. Coupled with specially developed software it allows doctors to scan a single x-ray plate and then use the software to simulate how x-rays of the same place taken with different intensity  and exposure times would look like, thereby decreasing the need for taking multiple x-rays. Another use is to unclutter your desktop by scanning and categorizing all documents so they can now be retrieved efficiently just by a click of a button.

            Scanners have a limit to the maximum details that they can scan in an image, and this is measured in dots per inch. A maximum scanning resolution of around 600x 1200 dpi should be fine for scanning just about anything  photos and x-ray plates.


Uninterrupted Power Supply (UPS) 

            What is the worst nightmare that can befall a computer user? Indisputably, itís working for  hours on end without a break and then having your masterpiece wiped out by a power outage just before saving it. It is not surprising when you hear that a number of people have faced this disaster. However, what can avert such an eventuality is a device known as the UPS.

            As a highly glorified battery, the UPS is what brings a computer back to life when its oxygen supply is cut. Just when the power outage occurs, UPS kicks in and allows you to save your work and gracefully shutdown, thereby avoiding all the shouting and swearing that would normally follow otherwise. If your PC is set up in a place where power supply is unpredictable and blackouts often occur, then what is needed is a UPS. A UPS provides limited power supply which is measured in KVA (Kilo Volt Ampere) and  decides just how much load it can take, And since all that is needed is that your work is saved and later shut down when the power outage occurs, a UPS of around 0.6 KVA that will last around five minutes should suit your needs.


            If you intend to travel a lot and would like to carry your PC with you, a desktop computer may not be a good idea. A laptop computer would best suit your needs. Laptops may look deceptively small, however these bonsai PCs give you what desktops cannot Ė computing freedom. Great for presentations and working during air travel, laptops allow you to use idle time to the maximum. Choosing a laptopís configuration amounts to about the same as that of a desktop, but there are also some extra things to watch out for. Laptop screens are of two types Ė active matrix and passive matrix. Passive matrix screens cost less but have a lower clarity and limited field of view. In comparison, though active matrix panels cost much more, it can be viewed nearly edge-on without losing any of its sharpness. 

            Different laptops have different pointing devices like track points, track balls and track pads. A track point is a small stub in the middle of the keyboard that can be used as a joystick to maneuver the pointer. A track ball does the same by allowing you to move a small ball attached to the notebook while a track pad uses a flat surface that you touch to move the pointer. 

            Most laptops come with a modular design allowing your to attach and remove CD-ROM drives, hard disks or extra batteries. Built Ė in PCMCIA slots allow laptops to connect to devices like hard disks, network cards, modems and external CD-ROM drives. Having a modem either built-in or in a PCMCIA slot should keep you connected to Internet. However, to make a presentation right off your laptop would mean that you use an active matrix screen, as it would be clearer. On the whole, a full-fledged laptop computer should set your off by around Rs. 70,000 to Rs. 1,00,000 and more. Other budget laptops with basic functionality can be had for around Rs. 50,000. But for the freedom it offers, it would well be worth it. Dr.KSM uses Compaq Presario 1200XL Model Laptop for all his work.


Putting it all together 

By now you now almost all the parts that go into creating a complete computer system. But like a jigsaw puzzle, all this information is of use only when the pieces are brought together and create a whole picture. So to bring all the parts together, we will present you with three basic configurations, which you can customize depending upon your needs to create the perfect PC configuration for yourself. Keep in mind that these configurations and their prices are bound to change in the near future.


Budget user

CPU                : Celeron or AMD K6-II (350 to 500 MHZ)

RAM               : 32 to 64 MB

Monitor            : 14/15Ē SVGA color

Hard disk         :  6.3 GB

Video card       : 4 MB Video RAM

CD-ROM         : 48x speed

Optional            : Sound card, modem , etc.

Estimated price  : Rs. 25,000 to Rs. 40,000


Average user

CPU                : Celeron  (466 to 600 MHZ)

RAM               : 64 MB

Monitor            : 15/17Ē color

Hard disk          :  6.3  to 10 GB

Video card        : 4 to 8  MB Video Ram

CD-ROM         : 48x speed

Sound card        : 32 bit PCI

Optional            : Printer, scanner and modem

Estimated price : Rs. 35,000 to Rs. 60,000


Power user

CPU                : Pentium ĖIII (500 to 800 MHz) or Pentium IV (1 to 1.5 GHz)

RAM               : 128 MB or more

Monitor            : 17Ē

Hard disk         :  8.3  GB  or more

Video card       : 3D accelerator, 8-16 MB

Video RAM

CD-ROM        : 48x or more / DVD ROM Drive

Sound card       : 32 bit PCI with wave table

Printer             : Inkjet printer

Modem            : 56.6 Kbps

Optional           : scanner

Estimated price : Rs. 60,000 to Rs. 80,000

Copyright © 2002 Dr. Subrahmanyam Karuturi