Software Utilities - CS2 - P3

In this blog i will be explaining the uses of two software utilities.

These Utilities will be:

• Firewalls
• Virus Protection

Firewalls

If you use the internet a lot, you nay have heard of the term "firewall". But what is it? How is it Used? And how does it work?  Firewalls for years have been a great help with protecting computers in large companies. It is now become a critical part of a home networks safety too. It turns out that even a small home network can have many of the same security issues that a large company can have. A firewall is used to protect your computer from offensive websites (websites that pass on viruses) and potential hackers.

A firewall is a barrier to keep dangerous forces away from your property. This is where its name comes from. Its job is very similar to a physical firewall which keeps flames from speading from one area to the next. A firewall is simply a program which filters the information that pass through your computer system. If a packet of information is flagged by these filters its is not allowed through.

Some operating systems come with a firewall already built in. if this isn’t true for you a firewall software can easily be installed with a network that has an internet connection.

Why use firewalls?

There are a large amount of creative ways people can use to access or abuse unprotected PCs:

• Remote Login – this when someone can connect to your computer and control it in some form. A program which can do this is known as a RAT (remote access Trojan or remote access tool). This can range from accessing files on your PC to running programs on your computer.
• Application back doors – some programs have special features which can allow remote acess. Others contain bugs which provide a backdoor, or a hidden access point which provides someone to enter your system and provides some level of control of that program.
• Viruses – this is probably the most know threat to your computer. A virus is a small program which copies itself to other computers. This is how a virus can quickly spread from one PC to hundreds. It can travel through a network and infect others. Viruses can range form a simple harmless message, to a complete wipe of all your data.
• Spam – this is typlically harmless, but very annoying, spam is the electronic junk mail. However it can be dangerous. Some spam may contain links to offensive websites. Therefore you should always be carful when clicking these links.

There are many more ways someone can cause damage to your PC. These are just the most common.

This can be all it takes to realise how important a firewall is. There are so many of these dangers that it is near impossible to safely browse the internet without a firewall.

In  a quick summary, a fire wall is a piece of software which prevents harmful programs from entering your PC.

Virus Protection

Although a firewall can protect your computer from viruses. Some still are able to get through. This is usually encrypted in other downloads, which you will then download and infect your PC. If you have found a free open access program and wish to download it, if you have a firewall, a warning message may coming up, requesting permission to download this piece of software. Sometimes without realising, clicking yes to this can give your PC a virus. This is why we also need Virus protection.

There are many programs that are committed to keeping your PC safe. Some can even be free, examples like AVG are good quality but free virus protection programs. These can detect harmful viruses and quickly remove them.

CS1 Health and Saftey

This is very important, not just for you but for your PC as well.
First of all the obvious, make sure nothing dangerous to the PC like liquids is around where your working. Also make sure there is space available for your working. The next thing you will need is antistatic protection. For any product you buy for the computer, the part is stored in an antistatic bag. These can be bought in any specialist computer store.

These bags ensure nothing can damage the part to your computer. However when you go into the computer you also needed to be protected from static electricity, as with the components you could get quite a shock.

Antistatic protects comes with an antistatic mat and wristband. What the matt does is absorb and static electricity and then removes it. this is done by the mains. The matt is connected to the mains and the any static electricity enters the current and moves with the mains. the way of assembling this is fairly obvious. An Electrostatic Wristband is used to protect the computer from you. Electrostatic Discharge Damage occurs when a source of stored static electricity leaves something such as another person, into a conductor with a different potential, like a computer.

CS1 - Computer Systems - Graphics Cards

Graphics cards

Think of a graphics card as a translator, its main job is to translate binary data from the CPU as an image seen on the screen. Your computer screen is made up of millions of pixels, tiny dots that eventually build up an image. Although a graphics cards job is complex, its componants are very easy to understand. To understand the card, we can use a bit of metaphorical examples, think of the PC as an ordinary company, with an art department, when another department needs some artwork done, the art deparment gets a request, and the art department decides how to create the image and puts it on paper. A graphics card is this art department and the CPU sends information about the image or “requests” the graphics card then chooses how to use the pixels to display this image needed. It will then send this information the monitor to display it. The graphics card is placed on a slot in the motherboard, these slots can be:

• PCI-X
• PCI-Express 1.6X
• PCI
• AGP
• PCI-Express 1X

As you can see the AGP is the only brown port.

The main way of knowing which is which is by the indents, make sure the indents are the same in the slot on the graphics card. without looking at this, you will most likely break the card or the port.

It is simple, on the slot, there are two clips, if there is already a graphics card, pull these clips on the end apart and remove the graphics card. Make sure you have an Anti-static band handy, when an electronical piece of equipment is placed in here and sealed, you can be certain it will not be damaged by static electricity. When placing your new card in, all you have to do is carefully place the card in the slot and push down, this will automatically lock the card into place.


Health and Saftey must be thought about when any changes or repairs are made to a PC, Read my post on Health and Saftey

ports

Here Is a diagram of the ports found at the back of the computer.These Ports are from the cards which are connected to the motherboard.  I will go through all the ports in this post.

Power Supply: This is fairly obvious. It is where you plug the machine to the, dare i say it, power supply.

Mouse And Keyboard (PS/2): These ports were introduced, by IBM. it supports a plug with just 6 pins. Most PCs will have this port. The plugs and ports are colour coded for the piece of equipment that is going to be connected. Green is for mouse and Purple is for the keyboard.

Parallel Port: this port is mainly used to connect external devices like printers. Most PCs have this port, however recently more and more external devices have been increasing in it's USB 2.0 Connection. However if you cannot find a device that will connect to this port, you can still get Adapters to plug a USB printer to the  port.

VGA Port: this is the port which is part of the graphics cards. Obviously there is no way you can view the graphics without a monitor. This is what this port does, it connects the monitor. this is how the graphics card sends its information. Afterall all it does is change the data in the PC to a graphical format for us to use.

USB Slots: USB is frequently becoming the most commonly used port in the PC. Due to the new adaptations like USB 2.0, the port is constantly increasing in speed. now a USB port is now capable  to connect anything other ports do. It can connect external devices like Parallel Ports. it also is increasingly being used for Mouses and Keyboards too. This is the one slot you will need the most off. this is due to almost everything connecting to them, like Music Players or Memory Sticks. 

Ethernet Port: This is the connection for an ethernet cable, usually linked to the telephone line. This is your source of your local area network. It is what connects you to the internet. Increasingly Broadband Modems have been used to increase the speed of your internet, not just that but on a dial-up connection, the phone cannot be used and visa versa. A broadband modem lets both be used.

Microphone and Speaker: These are used to connect audio devices to the computer. obviously the Microphone (pink) connects a microphone and the Speaker (green) connects speakers

CS1 - Computer Systems - CD-ROM drive

CD-ROM drive

This is a device which reads information from a CD-ROM. These are fitted either externally which connect usually to a parallel port, or internally, this is fitted in a bay on the case. External drives are easier to install but have several disadvantages: they are more expensive than internal. They use up the port which may be needed for other devices like a printer, and the port itself may not be fast enough for the amount of data that pours through it. The most important factor that differs each CD-ROM drive is the speed.


A CD-ROM drive is again very easy to replace. it is usually linked with a connector and power supply cable. then make sure you remember which links into it, unscrew the old CD-ROM drive, remove it, replace it and screw the new one in. The plugs will be the same and so will any connectors.


Health and Saftey must be thought about when any changes or repairs are made to a PC, Read my post on Health and Saftey

CS1 - Computer Systems - Hard Drive

Hard Drive

The Hard Drive is one of the main features in the PC and is the main memory. The memory in a hard drive is not volatile and whenever a piece of work is saved on the PC it saves onto the hard drive.

The reason why this links into graphics is because without this the graphics is useless. Without a hard drive there would be no space for any software or even graphics itself. As RAM is volatile, you would need to start everything from scratch every time you turn the PC on.

Hard Drive Configuration and controllers.

On a PC, a hard drive can either be IDE or SATA. PC’s have many SATA ports, around 1-4, but generally there is only one IDE. You may put 2 IDE drives in one port, these will be either master or slave. Which drive that boots is defined in the BIOS which I will be getting mentioning soon.

It is generally the master that boots up or SATA1 if you are working with SATA.

The controllers which are normally places as a chipset or expansion card on the motherboard is just what its name says, a controller. It controls the transfer of data and holds any bits of information it needs to have some kind of intelligence. The controller will need to be able to communicate with the components in the computer and as time goes on it will be more critical. Most controllers are already built into the motherboard.


A Hard Drive is almost exactly the same as Installing a CD-ROM.


Replacing the master drive: Just the same as a CD-ROM. just unscrew the hard drive, remove any wires, replace the hardrive, screw it back into place and replace wires.


Adding Or Replacing a Slave drive: a second hard drive can be added to the PC.  A Slave hard drive performs in exactly the same way, whoever the master usually always has the operating system and the master always boots up first. 


Adding a slave is simple, in the case of your PC, in the right hand sight there will be a set of slots, they look more like a set of shelves. above there should be a drive already in. That is the master. 

here is an image showing you what there is, as you can see the hard drive "slots" have the CD-Rom drive slots above, which are mentioned in another post of mine, so are the power supplies, one of these hard drive "slots" should have a drive in it. when getting a hard drive you should get a hard drive in an antistatic bag and some screws. Please before you touch any components read Health And Saftey, this ensures you and the parts are safe. Hopefully once that is read you have decided to go to the measures I mentioned and are ready to tackle the task.
First you must take your new hard drive, if you are replacing the master, first remove the cables, then just remove the screws for the first drive, slide the drive out, place it in the antistatic bag and replace the slot with your new drive, screw it back in and you are done, remember to place all the cables back in. 

for a slave drive there is a few adjustments you must do to your hard drive, there is a switch on the hard drive known as a jumper. Here is an example 

Usually a key of which jumper is for which is written either on the board itself or on back of the drive.
Just switch this jumper CAREFULLY to the slave setting. then add it to the next slot like a normal master drive.

CS1 - Computer Systems - RAM

RAM

This is a type of computer memory that can be accessed randomly; to be precise; any byte of memory can be accessed without touching any other existing bytes. RAM is the most common type of memory found in computers and other devices, such as printers. There are two different types of RAM: DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory). The two types are different because of the technology they use to hold data, DRAM is the most common type. SRAM however is the fastest. DRAM also needs to be refreshed thousands of times per second while SRAM does not need to be refreshed, which is what makes it faster than DRAM. The reason why SRAM isn’t the most commonly used is due to it’s cost. DRAM is the cheap option.

DRAM and SRAM are both known as being volatile. This means that when the power is turned off all memory is lost. This is why you need to save work when shutting down the computer. When work is saved it is saved onto the hard drive.


RAM is simple to add and remove. First Look Over Health And Saftey then once you have gotten ready, you must open the case and look for the RAM slots, they should be fairly easy, they are usually away from the edges of the PC with two clips either side. Here is an example:

Then you must slot the bars of ram in, take notice of the notches in the slots, as you can see in this image there is a notch in the middle,  here is an image of the types of RAM, the only ones you should use is either DDR or SDR. as you can tell, these slots then only hold DDR. DO NOT try placing a bar of RAM in a slot with the wrong notches. Place your bar on the slot WITHOUT pushing it, double check the notches are correct and this is the right slot, then unlock the click by pulling them upwards or downwards, it is different for different PCs, carfully push the bar downwards, this locks the clips into place when you know it is in place. now you know it is safe. When removing, just unlock the clips and this will unlock the bar of RAM. remember to store it in an antistatic bag.