Computer Basics

Table of Contents

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Welcome to computer basics, this course should not only help you understand computers a little more but some of the electronics you’ve already been using every day.  It could be an alarm clock, a converter, the TV or something a bit more powerful like your smart phone!  Although they aren’t traditional computers they all operate on similar principals. As we learn more about computers and the hardware inside of them you’ll have a better understanding.

Before we start talking about hardware I’d like to bring to light how computers understand what we want them too.  The first thing you need to know is that a computer only understands a 1 or 0 which can also be looked at as true/false or yes/no or on/off. How this translates to picture, sounds or even text is a bit complicated but here’s the easy explanation.  A single 1 or 0 is referred to as a bit, in order for computers to understand more than just a 1 or 0 these bits needed to be grouped together.  At first this was done in bytes which are 8 bits put together. Using a byte we can now tell the computer instructions using text as every character on a standard English keyboard is covered within these 8 1 and 0’s.

By specifying for example the letter “A” a value of 65 we can use 01000001 to represent this character in what’s known as ASCII. The way we convert all those 1’s and 0’s to a value of 65 is simple once you understand it. Here you can think of a 0 as off and 1 as on, each space from the right to the left is equivalent to a certain value, if it’s on with a 1 we then add that value to the next one etc. until we have a total.  The right most space is a value of 1, next to the left is 2 and then 4,8,16,32,64,128. So in our example of “A” we see the right most value is turned on with the 1 and then moving to the left the second last space is on as well. Adding up the values associated with the on positions are 1 and 64 totaling 65.

Just to give you a bit more history on how the 1 and 0’s evolved to what’s being used today.  With our example above the 1 byte could represent any English character on the keyboard but we live in a huge world so how do we represent other characters, the solution was simple just add more bytes this gives us enough room for every character in every language with some room to spare (Unicode). Now don’t confuse Unicode and ASCII with the unit of measurement for computer storage.

To understand the different units of measurements computers use for data, just follow the list below.  Currently most computers come with hard drives that are a number of gigabytes or some low number terabyte.

• 1 bit = 1 bit
• 8 bits = 1 byte
• 1024 bytes = 1 kilobyte
• 1024 kilobytes = 1 megabyte
• 1024 megabytes = 1 gigabyte
• 1024 gigabytes = 1 terabyte
• 1024 terabytes = 1 petabyte
• 1024 petabytes = 1 exabyte
• 1024 exabytes = 1 zettabyte
• 1024 zettabytes = 1 yottabyte
• 1024 yotabytes = 1 brontobyte
• 1024 brontobytes = 1 geobyte

File Extensions

It’s these 1’s and 0’s that we combine together inside of different types of files, the computer knows how to deal with these individual files based on their extensions. In the Microsoft world these are typically the last 3 or 4 characters that you see in the filename. There are many of them but some of the most common ones are in the diagram to the right.

What’s inside a computer?

Your basic components that make up a computer are a power supply, motherboard, processor, RAM, video/sound/network cards and storage devices.  We’ll talk about these individually and elaborate on storage devices and the internet some more as well.

Power Supply

The power supply is pretty much self-explanatory it’s the piece of hardware that draws power from the wall and distributes it to the hardware inside your computer.  The only real thing you need to know about them is there are specific types for specific motherboards and that they come with different power ratings. Depending on what you have inside your computer you might be ok with a lower power supply something like 400W for example where if you are like me with multiple hard-drives and video cards you might need something like 800W or more. If you are not supplying enough power for the hardware you are running in your machine you eventually can fry a component, which could take a while because the computer doesn’t always use every single piece of hardware at the same time but once it does that’s when it could happen.

Motherboard

The motherboard is basically a circuit board where all the parts are connected.  In order for the computer to see things it has to know where they are and how to operate them.  The basic details of what’s installed in your computer and where to find them is located in the motherboards BIOS (Basic Input Output System). Today’s BIOS’s are a little more advanced than the ones of yesterday, now you more or less just attach devices and they’ll atomically be detected.  In some older BIOS’s you had to manually specify all the details about the piece of hardware including the address it was using, today a lot of this is controlled by the Operating System.  Although the BIOS is not really all that complicated once you know what’s going on, I wouldn’t recommend touching it for beginners until you’re more familiar. If you need to access your BIOS though, the option is typically given to you when you fire up your computer.  In the beginning when your computer is being started up you might see press “del” for setup.  This can also be F1, F10 or another key depending on the manufacturer.  Typically they have a menu driven system where you can browse through categories for settings like your processor, fan controls, hard drives and more. The motherboard also dictates what type of processor, RAM and other hardware can/will be used, for example Intel and AMD will not work on the same motherboard, nor will an Intel P4 work in one that’s designed to work with an I3 type chip for example.

Microchips

Before we get into RAM and the processor we’ll talk a bit about microchips.  I’ll use the term loosely here as RAM and the processor technically are microchips as well as the BIOS we just talked about.  A chip (short for microchip) typically falls into two categories ROM and RAM.  ROM stands for Read Only Memory and is basically a set of instructions that will permanently stay on the chip, whereas RAM stands for Random Access Memory and will be erased once power is lost to the component. The BIOS is a ROM type chip and holds instructions on it to recognize components along with a graphical menu system to adjust them.  You can change these instructions, which with ROM is called flashing.  The main thing to remember when flashing a BIOS or chip is that the process needs to complete properly without interruption or corrupt instructions, if this is not done you might just lose your BIOS altogether and have to look for a new motherboard because of it. ROM type chips also power a lot of stuff you might use, like a converter, TV, toaster and pretty much any electronic device you can think of, some of these could also require updates or to be flashed as well.  Since RAM was designed for temporary memory storage this doesn’t matter with it because once the powers off it becomes a clean slate for the next use.

Processor

Now let’s move onto the processor which is your computers brain, it’s been programmed to understand instructions in a particular format almost like teaching a human to speak English.  Through these instructions programmers utilize the processor to crunch numbers by using equations and formulas etc. they tell it what to do. Two of the most popular brands of processors are Intel and AMD with Intel being the more popular of the two. Depending on the manufacturer as well they will be named different and have different catch phrases flashing around but what it boils down to is the speed it calculates information at along with the amount of cores it has these days.  The speed is measured in hertz and will be talked about separately in a minute. A core is basically an extra processor for each core it has, this is not exactly what it is as you can have multiple processors in a computer which can be more powerful than a core. A benefit of having multi-cores is that the CPU (Central Processing Unit, the processor) can use one core to work on a specific task while others are available for other tasks, this is known as multi-tasking. One thing to keep in mind here is that although two processor from different companies like AMD and Intel might have the same speed the way they process the data is different so for the time being Intel’s chips are faster at the same speed rating. There are also 32 and 64 bit processors which is the amount of information that is processed at a time.  This also requires programs to utilize this difference as well, 32 bit programs will not utilize the 64 bit processor the way a 64 bit program would, keep in mind that the operating system behaves in the same way and 32 bit processors can’t handle 64 bit programs.

RAM

RAM is the temporary memory which your computer uses a lot, especially with the programs being created these days. Everything that you see/hear on your computer is being stored in memory (RAM) and unless you physically save it, it can be lost.  Once it’s saved though you’ll have a copy of it unless there’s a malfunction or virus etc.  To give you a rough idea of what goes into RAM, say you’re on your computer running windows, where you open up a video file which starts up in your default video player.  All these events are being stored in RAM including the operating system, you might be thinking but I have my video file saved on a hard drive not in RAM, although the file is on your hard drive the computer needs to run that file and puts it in RAM for you to make use of it.  To simplify it picture a book novel/textbook doesn’t really matter this is you’re saved data because the words will never change as they are printed on paper.  Now as a teacher you want your students to see this as well, so you start writing it on your whiteboard where they can see it now and afterwards erase it just like RAM when the power is cut off. The type of RAM you can use depends on your motherboard and the capacity along with the speed of your RAM is what you want to consider when purchasing it. The capacity today is measured in gigabytes and the speed in hertz which will be talked about soon.

Video & Sound Cards

The video card or sound card do exactly what it sounds like they do, your motherboard might come with built in ones which typically are not that powerful but still do a good enough job for most. They can also be attached to your motherboard through card slots which come in a variety of types but typically today it’s the PCI-E slot.  Also the motherboard typically only has a certain number of them which vary based on board design and the size of the tower you’ll be putting them in. The way they are rated is slightly different, since video cards have their own memory this is typically the first thing we’ll look at, the size and type are important as is the speed it works at along with the resolution. Of course this means nothing without finding the right type of card to fit into your motherboard so you’ll need to know the connection type. The same will apply with a sound card you’ll need to know what type of slot you have, then from there you’ll want to know how many channels you’d like it to be this all depends on the speakers you’d like to get as well, do you want 7.1 surround sound with 6 speakers around you and a woofer in the middle or maybe 5.1 with 4 speakers around you and one center. The next part is the bits it uses for example 16 bit or 24 bit, the higher the number the better the quality.  After that basically each manufacturer has propriety stuff that will be listed with the card and could be beneficial or not depending on your use and needs.

Storage

One of the main components inside your computer is the hard drive which is one type of storage device but there are many more.  Some of these include flash drives, floppy disks, solid state drives, SD cards, CD/DVD’s and Bluray.  All these items hold information permanently, this doesn’t mean that it’s there forever though, damage or time can affect the data on these different components. The three main things to look at storage devices is how they connect to the computer and if your computer can support it.  For example a SATA hard drive won’t fit in a motherboard with only IDE slots nor will a Blu-Ray or DVD work in a basic CD player. The other is the capacity or size of the device which jumps across the board depending on what

we’re talking about a hard drive for example could be several Terabytes. The last thing is the transfer speed, this will typically depend on the connection that’s being used, SATA, USB or whatever else and then there’s versions of this as well for example SATA I, SATA II and SATA III.

Now that you’re familiar with the main parts inside of a computer let’s put them together and bring you the bigger picture.  The first thing that happens when you power up your computer is the BIOS is ran, this will now look to make sure it has everything it needs to run, if everything is up to par the next step will be to locate the operating system. This typically is on your main hard drive and usually the BIOS will know where to find it, occasionally if you switch hardware you might be asked for its location.  Now that the BIOS located the hard drive with the

operating system (OS) it’ll start running the program and pushing data into the RAM which is where most of the data while running a computer will be, this is done by the CPU that receives the data from the hard drive and figures out what needs to be done with it.  This will be the point where you’ll start seeing graphics and the login screen appear depending on the OS and settings you have set.  As you continue to use programs through your OS you’ll continually cause the CPU to process data and push it to RAM, which is temporary memory and will be erased when the computer is turned off.  In order to keep your work you’ll need to send your file to a storage device for safe keeping, probably a hard drive but could be any of the ones mentioned.

Input Output

Now that you have somewhat of a better idea of what goes on inside a computer let’s talk about how you can communicate with it.  This is known as input/output in the computer world.  Some examples of input devices are a mouse, keyboard, microphone etc.  Some examples of output devices are the usual monitor, speakers, printer etc.  Now we also have devices capable of both in things like tablets or touch screen monitors.  There have also been a number of different connection types throughout the years, like parallel ports, serial ports but the most popular now a day’s seems to be USB.  Although all USB connections are backwards compatible it might be worth noting that they have type I, II and III the main difference is the speed at which data can travel through.  Another great thing about USB is that you can connect up to 255 devices on a single connection, provided all the devices don’t all require power through the USB to operate and that you have enough ports.

Hertz

When we measure the speed of computer components they are typically measure in Hertz which when visualized is a wave, the information we pass through this wave is done during the low and high peaks of the wave. The higher the hertz the more peaks we have and therefore the faster the information can be passed. Hertz have a scale just like the metric system and as you go up the scale from millimetres to centimeters to meters and kilometers the numbers increase. In hertz we start with hertz and move upwards to kilohertz, megahertz and gigahertz. You can see this terminology used in a number of gadgets today like your cordless phone at home for example.

Resolution

When we work with anything that involves an image we deal with what’s called resolution. This all bowls down to the dots (pixels) that create the image and depending on what type of device we’re talking about, these dots could be referred to as Dots Per Inch (DPI), MegaPixels, Pixels Per Inch (PPI) etc. In any of these the higher the number the more pixels/dots are available and the sharper the picture will be. This is where pixilation comes into play, with not enough dots the images lose their quality and could be unrecognizable. Not only do our devices have pixels but the image files they create have them as well, so an image that was taken with a high resolution camera that was reduced in size to do something like send an email will lose quality. This might not be as noticeable if the image is viewed at a small size but will be when the image size is increased. Also we can reduce image quality but we can’t increase it while maintaining resolution, some software will interpret missing information when we do and increase the size but it’s basically taking its best guess as to what the missing pixels should look like and therefore might not work out that well. Through the images we can see that a triangle is much more recognizable with the image that has more pixels in it. Another thing to note is that a high quality image won’t look as great on a low resolution monitor this is due to a bottleneck.

Bottleneck

A bottleneck can happen with anything inside of a computer, it’s the weakest or slowest item in the chain of parts that are used. A perfect example of this is the internet compared to the home network, typically anything we use today in home networking is much faster than the internet speed you have, so if you see slow speeds happening chances are that it’s your internet connection rather than your network.

What’s this OS?

Now that we know some of the components inside the computer let’s talk about how we as people use them and a bit about how we used to use them. I’m going to use the most familiar Operating System (OS) that most people have heard and that’s Windows. Unless you’re a MAC person then chances are this is what you are using.  Approximately 82{463c70c279fb908728b910a090d44fbe4ae7aabcd875de9c1a518a8c8e2be8bd} of the personal computers are running some type of Windows. This number is different when taking into account tablets or mobile devices, which run on other OS’s as can computers. Some other operating systems that are available are Unix the grandfather pretty much, Mac OS, IOS, Android and Linux which I’ll talk a bit about after, there’s also more OS’s then just this.

Now that you know Windows is an Operating System what does it do exactly. Today’s OS is a graphical way for us to communicate with the computer.  It allows us to open up programs to search or surf the internet. It allows us to play music, watch videos, calculate spreadsheets, play games and more. It also allows us to manage the way things look inside these windows or screens and more importantly allows us to manage our data and secure it as much as possible so others won’t have access to it.  The list is actually a long, long one as there are tons of programs out there for manipulating information.  This is the fundamental use of the computer, to use and manipulate information from text, video, to sound it’s all information. Before GUI (Graphical User Interface) came along interacting with the computers was much more difficult, if you’ve ever used DOS you’ll know what I mean.  DOS was what Microsoft sold as an operating system before you could use a mouse to click here and there.  It was basically a black screen with white text, using commands like dir or cd you could do things like read the contents of directories and changing the location for the current active directory.  This meant you had to remember some strange names like fdisk, bootcfg, defrag, emm386, echo, scanreg and the list goes on.

Linux

Now that you know what an Operating System is I want to quickly introduce a name for another Operating System that’s worth talking about.  I mentioned it earlier, it’s Linux.  Before I say one more thing about this Operating System, please sit down.  One of the biggest pluses for this OS is that it’s absolutely free, as are a number of programs that you can use on it.

Yes you heard correct 100{463c70c279fb908728b910a090d44fbe4ae7aabcd875de9c1a518a8c8e2be8bd} Free, this is thanks to one gentleman’s dream and a huge community of programmers that are living it. What Linus Torvalds did was this, he created a core operating system that was Unix based and licensed it under an Open Source agreement.  What this means is, it’s free for anyone to see the code he used to create it, they can change it do whatever they want with it as long as they do the same and continue to offer it for free.  So now with the community of programmers I spoke of there are over a 100 different versions of Linux, some of the more popular ones are Ubuntu, Debian, Fedora, Mageia and Mint.

After deciding which version you want simply go to the appropriate site and download it, burn it to a DVD and you’re ready to install it. One’s like Ubuntu even allow you to try it out before installing it by running it from a CD/DVD.  It pretty much installs just like Windows or any other program, answer a few simple questions and in no time you should be up and running. For some complicated tasks if you’re a windows user there will be a bit of a learning curve but for new computer users most will adapt to it as fast as someone would to windows.

The last thing I’d like to mention about it is that it doesn’t use as much resources as Windows does.  Therefore that computer you thought was worthless sitting somewhere in a closet, basement or

garage might just run beautifully with it on it. Big bonus if you have kids and don’t want them using your expensive one that use for work or just Facebooking.  Even better for the children there are countless amounts of learning programs available for free or for purchase, depending on whom the supplier is.  Yes darn there’s the catch you might actually have to pay for some programs but chances are you’ll never get there unless you really want something or need something specific.

The Internet

What fun would all these devices and computers be without what we call the internet? It allows us to communicate across the globe, research anything, has endless types of entertainment and can do so much more. Obviously we need our devices to connect to the internet but what do they use to do that and how do they actually connect?

Modems/Routers/Switches/Bridges/Hubs

Typically in our homes we have an internet connection through an Internet Service Provider (ISP) like that provided by a cable company for example, this requires a modem to be installed for us to connect to. If we had just one computer connected this would be all we need but typically we have multiple devices we’d like to connect so we utilize other devices like routers/switches/bridges/hubs to establish a home network so that all our devices can share that one single address on the internet. Newer modems tend to be both modem and router allowing us to just use the one device if we needed to.

TCP/IP

TCP/IP is the communication language of the internet, it basically gives an address (called an IP address) to each computer/device that connects to it. For regular users this means this address comes from an Internet Service Provider (ISP) who we pay for our connection to the internet. This can be our cell phone provider, cable/phone provider or some other type of man-in-the-middle. We use these addresses to look for and find other computers that contain similar types of addresses but are known as web-servers, these computers are the ones that hand out the information found on the internet for us to see.

Through TCP/IP there are a number of ports (65,535) and other protocols or languages that are used through them. For example most of the internet is found on port 80 and uses the HTTP protocol. Other parts that require security, use port 443 and the HTTPS protocol which utilizes encryption to communicate. This means the information sent is being scrambled up so if somebody is eavesdropping they won’t be able to make sense of it where normally everything that we do can be eavesdropped on.

There are also many other languages used inside of TCP/IP for stuff like emails, file transfers, skype or specific programs/games etc. Also since the internet was created to maintain communication it’s important to make sure we block any method we’re not using through something called a firewall.

IP Addresses

Currently we are still using IPv4, which means our addresses consist of 4 octets. An octet is basically a number from 0-255 which basically is the same as one byte. So our address might look something like this 192.168.0.1, as the internet has grown drastically we are starting to loose available addresses and eventually will shift to IPv6 which we won’t get into. IPv4 address also rely on something which is called a subnet mask, without getting to complicated this basically lets the computers know what address are on the same network. This allows us to use things like routers to communicate with other networks and a perfect example of this is the internet and our home network. In our home network we use the IP address we get from our ISP and share it to other computers on our network that can have different internal IP address. It’s up to the router to distinguish which address we actually want to talk to and this same process happens repeatedly up the ladder to the top part of the internet. In order to do something like host a website we need a computer called a webserver to have a permanent (static) address available on the internet, typically our home internet address changes from time through what’s called a dynamic address that’s specified by our ISP.

Domain Name Server (DNS)

In order to find websites etc. on the internet we ultimately need to know the address of the computer that is hosting that website. Since it’s easier for us as humans to remember words over numbers like mr.tutor-tech.com rather than 192.168.0.1 we need something to be able to resolve that name to an address and this is exactly what a DNS server does. You can kind of look at it this way, I work at 9109 Derry Rd, Unit #2 inside of Milton, ON L9T 7Y9 vs using something like my business name which is Mr.Tutor-Tech, using something like the yellow pages (DNS in this example) to find Mr.Tutor-Tech we would be able to find out the more specific address information.

Firewalls & VPN’s

Unlike a webserver which allows connections in order to display web pages, our home computers don’t need to allow those connections, unless we have a reason too. Like being able to access your computer when on the road for example or wanting to view your home security camera. This is where we open ourselves up to security threats. Typically we use what’s called a firewall to block all the ports available in TCP/IP on our home computers/networks along with any incoming requests. This blocks anyone from connecting to us or does the best job it can, security/programming flaws may exist. Sometimes we need to put holes in the firewall to access some of the things we mentioned, although our intentions are pure, others like hackers for example can utilize this hole to their advantage and see everything that you’re doing, potentially steal your identity or more. You may have read articles recently how people’s security cameras/baby monitors have started to follow them around the home or even heard breathing through the speaker. This is because they have to allow an outside connection to their network and have a hole in the firewall to do so, they missed an important device to help protect them from that happening.

VPN’s or Virtual Private Networks are router type looking devices typically that should be connected to your modem. They allow you to connect to that device from the outside world through secure protocols that form a tunnel between you on the outside internet and your home/office scrambling (encryption) all the information so nobody can read it, along with making it much, much harder for someone to simply connect to your network if done correctly, remember to use really long and complicated passwords as well. Simple passwords can be hacked in minutes because there are programs out there that will try every combination until success is reached. VPN’s also make it appear as if you are connected to the internal network even when you are on the outside of it.

Network Card

Although this belongs to the devices we have on our computers I thought I’d mention it here with the internet. A network card is the component on our computers which can be added-on or is more than likely built right into it. It is used to establish a connection through TCP/IP to an Internet Service Provider (ISP) which connects us to the internet and the webservers that are connected to it.

Wireless (WiFi) vs Wired

There are two types of network cards, wired and wireless. Besides the obvious difference of one of them not having wires there are other differences as well. Security probably being the most important of them! Through a wireless connection we use one of a few ways for our devices to connect to special modems/routers that support a wireless connection. Because there are no wires a wireless connection uses airwaves to establish these connections which means anyone that is close enough to detect them can try to do it. Some of these methods are more secure than others which can be hacked into rather quickly like WEP that can be cracked in minutes. One of the other biggest mistakes here is the password you set and provide to establish a connection, short and weak ones can crack fairly quickly and easily. Connecting a wired computer to a wireless router doesn’t make it any more secure, since the router uses airwaves anyone connecting to it also has access to the wired computers attached, a fully wired network without wireless connection is a bit securer though as far as local attempts go. You’d still be at risk from someone hacking you through the internet itself or internally.

WiFi vs Cellular

Many people also confuse WiFi vs a cellular connection. WiFi is something that can be used at home or have hot spots outside of the home that we can connect to using a wireless network card or device that has one built in. Cellular connections are provided by the cellular company you’re using with your device, they are both wireless connections but behave slightly different. Your cellular provider usually has limits on the data you can use, so if you’re around a WiFi it could be beneficial to connect to it instead, this way you use less of your cap from the cellular provider. I say this with hesitation though because depending on what WiFi you’re connecting yourself to you could potentially be opening up a world of trouble.

The problem here is that the person supplying the WiFi connection contains all the power over that connection, so unless it’s your own or someone/place that you fully trust I wouldn’t recommend connecting to it. They could be baiting you into using their connection so that they can listen to everything you do, install software on your computer to continue eavesdropping and more. Even WiFi’s that might be trusted, like say the one being offered at your favourite coffee shop could be utilized against you. As anyone on that same network connection can utilize that connection to gain access to your weakly secured device or if the WiFi itself wasn’t secure enough utilize that security flaw.

 
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Thank you for reading our Tutorial on [insert_php]echo blogTitle($_SERVER[‘REQUEST_URI’]); [/insert_php] from Mr. Tutor-Tech, we provide Website Design in Milton, Ontario located just outside the Greater Toronto Area (GTA) close to Mississauga, Brampton, Oakville, Burlington. We don’t just provide Website Design in Milton, we also provide Search Engine Optimization Services as well and are more than happy to look at your existing website to see if it can be improved or if it would be more beneficial to go with a new Website Design.

Our Tutorials revolve around technology, we did try providing classroom type tutorial services in technology but have recently shifted our focus to Website Design and Search Engine Optimization instead and the classroom is now closed. Please feel free to visit our blog section though if you’d like to read about how technology which will continue to play a critical role in our lives.

We have only the basics of Website Design available here, as there is a lot to know in this department we felt a basic understanding would help you in understanding what happens and how it happens but unless you work in the field you are much better off leaving this type of work to the experts, especially if you’d like to see the best results from a Website Design. Please feel free to Contact Mr.Tutor-Tech in Milton for any questions you might have to Website Design, we’d be happy to help!