Monday, August 18, 2008

Computers and You: Part 1: Demystifying the Box

"Computers and You". Sounds kinda like a PBS series that would have aired on any random Saturday afternoon back in the '80s, right before the weekly installments of "Doctor Who", "Blake's 7", and "Red Dwarf", doesn't it? (Actually, there was such a show, called "The Computer Chronicles", but we won't go there, at least not today.) Anyway, this is not that show, mainly because I have no budget for video production, and I've already tried my hand at being on television talking about this stuff on a show that hopefully no one will ever remember. No, this is, instead, a series that I plan to use to tackle some of the issues that new computer users face every day.

This first installment will be devoted to getting you up to speed on that complex little machine that makes your Internet addiction possible. First, I'd like to give you an introduction to the hardware that makes up your computer. In the next installment, I'll tell you about the software that makes it do what it does.

First, what I'm about to tell you mainly refers to desktop computers. Laptops are similar but a bit different, so I'll try to point out those differences as we go along. Mac users, I'm afraid, will get little attention here, since Macs aren't my thing...yet. Remember, this is not meant to be a highly-technical explanation, merely an introduction to your computer's hardware so you won't be baffled by the terms you often see.

What's in the box?

The best place to begin, I think, is with that whirring metal and plastic box that is taking up your desk's or floor's real estate. First, let's get a term out of the way. Over the years, many times I've heard people struggle to give that thing a name when they're trying to describe it. They'd call it the CPU, processor, hard drive, and even the modem. Relax, folks, it isn't that hard. That box is the computer. Sometimes, if the case stands upright, as most do these days, you'll also hear it called the tower. Either term is fine, unless it doesn't stand upright or is a laptop.

Now, let's delve into what's inside this thing.
  • CPU: Also called the Central Processing Unit, the microprocessor, the processor, or, informally, the chip, this is the brains of your system. All the calculations the computer must do to get work done happen here. The primary CPU manufacturers are Intel and AMD, and each company has multiple product lines aimed at everyone from casual users to those running resource-hungry applications. Processors used to be rated by their speed in megahertz (MHz) or gigahertz (GHz), and you can still find such ratings if you look hard enough, but they mean little these days. Now, CPU's are often differentiated by the size of their caches and how many cores they have.
  • RAM: Random Access Memory, often simply called memory, is what your computer uses to store the information the CPU is using in its calculations. RAM is classified by the type of package it comes in (SIMM, DIMM, and SODIMM, to name a few), how much memory is in each package, and how quickly the RAM can store the data sent to it by the CPU and retrieve the data the CPU needs. The package type and speed of the RAM you buy is determined by your CPU and motherboard model (more on motherboards in a sec). About the only thing you have control over is how much RAM you install in your computer. The manufacturer has already installed a certain amount before selling the computer to you, but you can (and sometimes must) add more later. The maximum amount you can add is determined by the maximum capacity of your motherboard. As of mid-2008, you should have, at the absolute bare minimum, 512 MB (megabytes) of RAM, with a more comfortable lower limit of 1 GB (gigabyte). Many computers these days are shipping with 2, 3, or even 4 GB of RAM.
  • Graphics Card: This is the hardware that allows your computer to put all those pretty images on your monitor. It's also often referred to as a Graphics Processing Unit (GPU) or simply a video card, and, in truth, on many computers, it isn't even a card anymore but instead a chip soldered directly onto the motherboard. Like a CPU, graphics cards are also rated by speed, and they need their own memory to function, although it comes preinstalled on the card and is not usually upgradeable. One thing that you should note is that, on some cheaper computers, where graphics are handled by a chip soldered onto the motherboard, manufacturers cut corners by allowing that chip to use some of the computer's main memory for graphics processing. The downside is that this steals often-valuable RAM away from being used by the CPU. It can also make shopping for a computer a little more confusing, since you need to subtract the amount of RAM the graphics card uses from total system memory. So, if you see a system advertised with 512 MB RAM, but then you see that the video card uses something like "up to 64 MB shared memory", then you only really have 448 MB RAM available to the CPU. If you have such a system, there are two ways to remedy this situation: add more RAM or install a standalone video card with dedicated memory. The last solution is best, provided your computer has an available slot for a graphics card, but this is getting a little too technical for this article.
  • Sound Card: The sound card, also called the audio card, has, like the graphics card, often been reduced to a chip soldered onto the motherboard. It's the device that creates the sounds that you hear from your computer's speakers. Like a built-in graphics chip, a built-in audio chip can be replaced with a more advanced unit by adding a dedicated sound card, but this is usually done by gamers, audiophiles, and audio professionals. Most people don't bother, and with the quality of on-board audio chips having improved over the years, most folks don't have to mess with it.
  • Modem: A modem is the device that lets you connect your computer to a phone line and experience slow-as-Christmas Internet surfing. Once, most modems were external devices that connected to your computer using a cable, but then someone decided that they could build them cheaply and either include them as internal cards or simply solder them right onto the motherboard. I guess this is a good idea to reduce desktop clutter, but, with fewer and fewer people using dial-up Internet access, I have to wonder how long it'll be before cost-conscious manufacturers will strip it out and relegate it once again to the status of external device.
  • Network Interface Card: Also called a NIC, Ethernet card, or network card, this is the device that lets you connect your computer to a Local Area Network or broadband Internet modem. NIC's used to be something you bought and installed into your computer, but, like the modem, they've been added to almost every computer sold these days.
  • Wireless Local Area Network Card: Most people call them WLAN cards or simply wireless cards. Yes, they're available as cards that you can install in a computer, but most of them are chips soldered onto motherboards. Just about every laptop sold these days has one preinstalled, and I've even seen a desktop or two that had them. As you might guess, a wireless card lets you connect to a wireless network.
  • Hard Disk: Often also called a hard drive, this is your computer's main storage system. When you install software or save documents or other files, this is most likely where they are stored. A hard disk is a small enclosure that contains several rapidly-spinning metal platters, which are read from and written to by a group of heads, which write to and read from microscopic magnetic areas on the platters. Hard drives are mainly rated by storage capacity, which is measured in gigabytes (GB) or, in the case of the largest ones, in terabytes (TB). You'll also sometimes see them rated by speed in RPM, such as 5400 RPM, 7800 RPM, and 10,000 RPM. The faster the platters spin, the faster data can be written and read, and the faster the computer will perform. Many laptops have slower hard drives, mainly because faster ones consume more power and shorten battery life.
  • Optical Drive: Your computer almost certainly has one or possibly two of these. They come in several variants, including CD-ROM drives, CD-D/W drives, DVD-ROM drives, and DVD-R/W drives, to name the most common varieties. Drives ending in -ROM can only read, while drives ending in -R/W can bth read and write. Creating CD's and DVD's isn't quite as simple as that, but knowing what kind of drive(s) you have can tell you what you can do with them. By the way, a drive that can read or write DVD's can also handle CD's, so if you have a DVD-R/W, you can also use it to create CD's. And, in case you didn't know, drives that can write to CD's and DVD's are often simply called CD burners or DVD burners.
  • Card Reader: This one is fairly new, but it's showing up on more and more computers, both desktops and laptops. It's a little device that can read one or more memory card formats, such as SD Cards, CompactFlash, Memory Stick, etc. This makes it easy to transfer pictures from a digital camera or add audio or video files to a personal media player.
  • PCMCIA: Also called a PC Card, most likely because no one can remember PCMCIA, this type of card slot is common on laptops, which used to contain two of them but now often seem to have only one. They're supposed to be able to accept many kinds of devices, such as modems, network cards, tiny external hard drives, etc., but, with modems and network cards being built into most laptops, and with most external hard drives using USB to connect, they mainly seem to be used for specialized wireless networking cards, such as those that connect to cellular networks.
  • Floppy Drive: Ah, the floppy drive. For years, we carried countless files around on floppy disks. There were two major sizes: 3.5" and 5.25", with the 3.5" version storing either 720 KB or 1.44 MB, and the 5.25" variety storing 360 KB or 1.2 MB, depending on the disk used. Nowadays, few computers come equipped with floppy drives, since recordable CD's and DVD's are very cheap, can hold much more data, and are more durable. If you still need a floppy drive, you can buy an external model that connects to your computer via a USB port.
  • Power Supply: The power supply, sometimes called the PSU, is a power transformer that takes your household electrical current and converts it to the voltages used by your computer's internal components. It also contains a fan that helps keep the computer cool. If you switch on your computer, hear a loud pop, and smell an acrid odor, it likely means your power supply blew. This isn't usually as bad as it sounds, since it's designed to blow out if it is fed a voltage it can't handle. In most (but, unfortunately not all) cases, no other components have been damaged, and replacing a blown power supply is relatively inexpensive (at least as far as parts are concerned). But remember that fan I mentioned? If you notice that it isn't operating as it should, such as not turning very fast or at all, or it sounds as if its bearings are wearing out, then you need to shut your computer down immediately and get a new power supply installed before using it again. If your fan dies, there's nothing there to cool the inside of your computer, and the built-up heat will fry its innards in very short order.
  • Motherboard: Last but not least is the motherboard. If the CPU is the computer's brain, the motherboard is its spinal cord. Every component inside a computer connects to the motherboard. The CPU and RAM fit into sockets and slots on it, expansion cards fit into slots, storage devices plug into connectors, and the power supply feeds power to it via a cable. All the computer's data passes through the motherboard at some point.
That covers most of the common devices inside a computer. Now let's see what connectors are on the outside.

Ports, connectors, and jacks, oh my!
  • Power Connector: Your computer has got to get its juice some way. Fortunately, computer manufacturers have settled on a standard power connector for desktops, so cords are plentiful and cheap. In fact, most monitors and quite a few printers use the same connector, making your life much easier if you're looking for a power cord. Laptop users aren't so lucky, since there seems to be absolutely no standard for which power cords work with which computers. I firmly believe this is a way for the manufacturers to squeeze more money out of you when your charger goes bad. On a completely unrelated note, someone in the power wheelchair business must have a brother-in-law in the computer business because desktop computers and power wheelchairs (at least the wheelchairs I've seen) use the very same power cords and connectors. I'm not sure how that bit of info might help you, but tuck it away in some dark corner of your brain, and you might use it on "Jeopardy" some day.
  • USB: USB stands for Universal Serial Bus, and it's turning into the workhorse of ports. Name a device, and there's a good chance it will connect to your computer via USB. Most printers and scanners now use USB, and just about all webcams do. Even keyboards and mice, which have had their own ports for years, are moving to USB. Many external storage devices, like external hard drives, optical drives, and floppy drives, connect using USB, and it goes without saying that USB flash drives do. The most recent USB standard is USB 2.0, which replaced USB 1.1 several years ago. Naturally, USB 3.0 is on the way as soon as the manufacturers can sort out their differences and settle on a standard. Don't let these standards worry you too much, since USB 1.1 and 2.0 will happily coexist. If you have a choice between a USB 1.1 and 2.0 device, buy the one with 2.0, but don't get too worked up over which you choose. A USB port is rectangular and about the size of a large bug. Your computer can have from two to sometimes as many as six on the back and several on the front. If that isn't enough for you, connect a USB hub to one of them, and you'll get more. You can connect up to 127 USB devices to your computer.
  • Ethernet Port: Technically, it's called an RJ-45 jack, but don't worry about that. It's where you plug your network cable in. It looks like an oversized and slightly mutated phone jack.
  • Phone Jack: Called an RJ-11 jack, this is where you plug in your phone line so you can surf the Internet at a snail's pace. If your computer has two, one is for the cord that connects to your wall jack, and the other can be used if you want to connect an extension telephone. In case you're wondering if this will let you use your phone while you're online, sorry, you're SOL on this one.
  • PS/2 Connector: There are likely two of these on the back of your computer. They're round and sitting side-by-side. These are where you connect your keyboard and mouse. Although they look identical, they aren't, so it does matter what gets plugged into each one. Some laptops will have one of these for folks who want to use an external mouse, but PS/2 connectors are being phased out in favor of USB. And by the way, if you thought PS/2 referred to a short-lived line of computers released by IBM in the mid-'80s, it did, but, if you know that, why are you reading this, you nerd!?
  • VGA/DVI: These are two connectors that do the same thing: get video from your computer to your monitor. The older VGA port is slightly under an inch long, not quite rectangular, and has 15 tiny holes for the video cable's pins to fit into. There are also threaded holes at each end for the cable's thumbscrews to fit into. The DVI connector is slightly smaller, rectangular, and has anywhere from 17 to 29 pins, one of which is flat. VGA connectors are used to output analog video to older analog monitors, while DVI outputs digital video to newer digital flat panel monitors.
  • Audio Jacks: You need these to get sound to your speakers. You'll always find one set on the back of your computer and possibly a second set on the front. Usually, one will connect to your speakers or headphones, one will allow you to plug in a microphone, and one will allow you to connect a line-in device. I guess someone was thinking ahead because these jacks are often color-coded: green=audio out, red=mic in, and blue=line in.
  • FireWire: This interface, officially called IEEE 1394 but called i.LINK by Sony and FireWire by Apple and about everyone else, can be used for high-speed data transfer. What it's mainly used for is to connect digital camcorders to computers and other electronics so video can be transferred. Some more-expensive external hard drives include it along with a USB connector. If your computer has a FireWire connector, great. If it doesn't, and you really need it, you can install an expansion card to add it.
  • Parallel Port: Back in the day, parallel ports were mainly used to connect printers to computers, and your computer might still have one hanging around. They look roughly rectangular and have 25 little holes and thumbscrew holes on each end. If you don't have one, don't sweat it, since I doubt you'll need it unless you own an old printer or scanner you're particularly attached to.
  • Serial Port: It looks like a shorter version of a parallel port but with only 9 pins. Serial ports were once used to connect things like mice and modems, but they've fallen into disuse lately. Your computer may or may not have one. If not, don't shed any tears over it.
  • Bluetooth: Technically, this isn't a port, since you don't connect to it with a cable, but some laptops include it. Bluetooth is a short-range (from 10-100 meters, depending on the type) wireless communications technology. Right now, its most common use is to allow computers, cell phones, and Personal Digital Assistants (PDA's) to share data. If this means nothing to you, then you probably don't need it right now.
That's it for ports and connectors. Now I want to briefly discuss what can be plugged into your computer.

Yo! I got the hookup!
  • Keyboard: Um, what can I say? It lets you type. Other than that, I can tell you that keyboards can be connected via a PS/2 connector, USB, or even wirelessly using either a little receiver plugged into your computer's USB port, or, if you really want to get nerdy, Bluetooth.
  • Mouse: Mice are connected in the same ways as keyboards. Originally, mice used a little ball that rolled as you moved the mouse, causing your cursor to move. In the last few years, optical mice, which use a light source to track your movements, have become extremely popular. If you happen to still have a mouse with a mechanical ball, you'll be much happier with an optical mouse. They operate much more smoothly, and they don't collect dirt the way the old ones do. And don't worry, they're cheap. Laptops don't come with mice but usually use a touchpad, and, in some cases, a tiny pointing device that looks like a small eraser tucked between keys in the middle of your keyboard. But never fear; if you'd like to use a mouse instead, feel free to plug one into an open USB port.
  • Monitor: This is where video is displayed. The old CRT (tube) monitors are quickly being replaced by flat-panel LCD models, since they take up less space. Still, some people, especially gamers, prefer CRT's, since they can refresh faster than LCD's. If you want to see this in action, quickly scroll a Web page or document on an LCD monitor. See how it blurs a little as stuff whizzes by? A CRT doesn't do that because it can refresh much faster. And remember the VGA and DVI ports I mentioned a while ago? The analog VGA was used to connect to CRT and older analog flat-panel monitors, while DVI is used to connect to new, digital flat panels.
  • Speakers: These can range from small two-speaker setups that sound like a fast food drive-up speaker to surround-sound setups that can set off seismographs 500 miles away.
  • Printer: The name is pretty self-explanatory. Most current models connect via USB, but some can plug directly into a network using Ethernet cable. Inkjet printers are usually the cheapest and produce excellent color, but the ink can get expensive if you do lots of printing. Laser printers cost more, but they produce the best quality text, often print faster than inkjets, and are cheaper in the long run because their toner is cheaper than inkjet ink. It's true that a new laser toner cartridge can cost more than a set of inkjet refills, but it will last much longer. Most cheaper laser printers print in black and white, but there are also color models. A popular type of printer is the all-in-one device, which can print, scan, copy, and fax, provided you have a phone line connected to it.
  • Scanner: As you can guess, these are used to scan things, usually photographs and documents. Once you scan something, you can save it as an image file, make a copy using your printer, or even perform what's called Optical Character Regognition on it, which is where the computer "reads" the document and saves its content as text. If that sounds too nerdy to you, don't worry about it.
  • External Hard Disk: If You need to store lots of files in a little box that you can easily transport, this is what you need. They usually connect via USB, but some also have FireWire, and a few even have Ethernet ports.
  • Flash Drive: If you need to take your data with you, but you don't have enough to fill an external hard drive, flash drives are for you. They're small (about the size of a pack of gum), connect to a USB port, and are light enough that you can easily forget them in your pocket when you do laundry. And with sizes going up to 16 GB right now, you can lose a whole lot of data when you do.
  • Webcam: These little cameras connect to your computer using USB and are great for videoconferencing, especially since most Instant Messaging software can send and receive video. Don't try this over a dial-up Internet connection, though. You won't like the results.
That's about it. Well, not really, since I didn't even touch on connecting your computer to a network, but I figure I have to stop somewhere, at least for now.

At this point, you may be completely overwhelmed, thouroughly confused, or hungry for more, so I'm going to recommend a few books. The first is PCs for Dummies, which covers many of the things I did here but in greater detail.

Order PCs for Dummies from Amazon.com

If you have a laptop and want something specifically written for your type of computer, then consider Laptops for Dummies.

Order Laptops for Dummies from Amazon.com

If you're a senior or want to get a book for a senior, then you might want to consider Computers for Seniors for Dummies. It approaches the subject from the perspective of an older person who may be less comfortable with technology.

Order Computers for Seniors for Dummies from Amazon.com

And if you happen to have a Mac, although I didn't tell you much in this post, I can at least show you a book: Macs for Dummies.

Order Macs for Dummies from Amazon.com

That's all for now. As always, if you have any questions or comments, feel free to post them.

In the next installment of Computers and You, we'll talk about software. See ya soon!

2 comments:

Johnny_UPC said...

Would have called the "hookup" section something like "Peripheral Vision", but that's a nitpicky stylistic choice.

Oh yeah, you gonna wear that blazer to the Bloggies when you win?

Marion Stevens said...

Peripheral Vision. I like it. See, that's why I keep you around. :)

I don't know about the jacket, though. I'm thinking maybe a tux t-shirt would be more tasteful.