Backing storage

Types

Disks are plates where data is encoded. There are two types of disks which are magnetic disks and the other is optical disks. Magnetic disks are data that is encoded by microscopic magnetized needles of the surface, they come as floppy disks, hard disks and removable cartridges. Optical disks are basically the same as magnetic disks but the data is encoded by laser, they come as CD-ROM, WORMS.

Universal Serial Bus Drives- flash memory storage device. USB supports data transfer rates of 12 Mbps. A USB port can be used to 127 devices, such as mice and keyboards.

Optical media

Portable devices

Portable devices means that it is light weight such as a laptop

 

 

 

Peripherals

Output devices

Monitors are an output device and there are two types. One is Cathode Ray Tube (CRT). It works by moving electrons back and forth, when the pass across the screen it lights up and produces an image. The second on is liquid-crystal display. It works having two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causing the crystals to align so that light cannot pass through them.

Printers are also output devices and there are two main types. One is the ink printer. It works by spraying ionised ink onto a sheet of paper and Magnetized plates draw the ink into the desired shape on the paper. The second one is the laser printer and it works by. Another form of output devices is a plotter which is pens that are plotted on to a page and that draw a picture, they are mainly used for technical drawing such as blue prints.

Input devices

An input device is something that feeds data into the computer. One input device is a camera such as a web cam which inputs the image into the computer. The second input is a keyboard is a set of keys which allows the user to enter data into a computer. Another input device is a mouse which is a device which allows the user to control the movement of the pointer on the display screen. The last input device is a scanner which transfers hard copies into electronic data.

Cabling

Coaxial cabling is a wire surrounded by insulation and then a grounded shield of braided wire. They are mostly used for computers.

Optical cabling is a glass wire which reflects the light through the wire which send the signal. Mainly used for television networks.

Twisted pair are two independently insulated wires twisted around one another, it is used to reduce crosstalk and mainly for old telephone networks.

Internal systems

Central processing unit

Better known as the processor.

The processor is the brain of the computer because it handles all the calculations. The processor also keeps the memory of the computer called a program. There are 4 steps in the use of their operation: fetch, decode, execute, and writeback. You can have more then one processor in a computer, then it is called a duel processor, etc. The modern processor is small and square and had metallic connectors or pins. The processor is connected to the motherboard by the CPU socket.

 

Motherboard

 

The motherboard is where everything is puts into, such as the processor, BIOS, memory, mass storage interfaces, parallel ports and contorllers (keyboard, display screen etc). You can also plug in more memory chips into the motherboard directly.

 

BIOS

 

The BIOS carries out all the input and output systems. It does a power on post check, meaning that it checks everything is working before the computer turns on. It also sends the instructions to the processor to boot up. On the computer, the BIOS contains all the codes required to control the keyboard, display screen, and disk drives. BIOS is placed in ROM chips in order for it not to get damaged in disk failures. Modern BIOS are now made in Flash memory chips so they can be updates if necessary.

 

Power supply

Most computers can me plugged into a standard electrical outlet which will supply the computer with power. Standard computers require 240 V from the mains which is alternating current and that is changed into 5V of direct current.

Fan and heat sink or cooling

Draws heat away from the processor and other components

 

Hard drive

The hard disk drive reads data. Computers generally have seek times (Refers to the time a program or device takes to locate a particular piece of data) of about 12 milliseconds or less. There are several interface standards for passing data between a hard disk and a computer, these are intelligent drive electronics (IDE) and small computer systems interface (SCSI).

 

Ports

Ports are an interface which you can plug in different devices such as, keyboards, display screen, mice, USB etc. Is it non volatile.

 

Internal memory

Internal memory refers to a chip that hold memory on the computer such as a Random Access Memory (RAM) or Read Only Memory (ROM). It only have temporary memory and it is volatile.

 

specialised cards

Specialised cards are slots on the motherboard where you can add cards which better the computer such as graphic cards ect.

How software utilities can improve the preformance of computer systems D1

Software Utillities P3

One software utility is security which is protection against viruses which is called Anti- Virus Software. Anti- Virus Software protect again Malware which is Viruses, worms, Trojans, adware etc, I will be explaining about them. A virus is a programme that is unwanted on someone’s computer, they can range from something minor such as a virus that is just annoying such as loads of pop ups, then to could go to something more terrible such as the virus might cause applications to stop working. The best way to protect your computer you have to update you Anti-Virus Software every day because there might be a new virus made every day. There are also something called a worm which is something that once opened by the user of the computer replicate themselves and damages all the files, they can be opened because they look like attachments on emails. A Trojan is a programme that have an unwanted hidden function, one example is one can actually delete files from the computer. Another virus which isn’t the serious just annoying is Adware which is when a load of adverts pop up on the screen and the user of the computer has to close them all down because they can do anything on the computer. Because of Anti-Virus Software the people that design the virus have to make ones that will not be detected by the Anti- Virus Software, this is called Polymorphic Virus which is constantly changing to make it go unnoticed. All these things are an offence of the Computer Misuse Act of 1990.

Another software utility which protects the computer is a Firework, they are not used to protect against viruses but against hackers and worms. The Firewall does this by closing certain ports to protect the files on the computer. There are two types of hackers’ one, White hat hacker which is the legal hacker and hacks to fix problems and the second one is called the Black hat hacker which hacks to cause damage to the computer.

One other software utility is Clean up tools. Whenever you do something on a web browser there are temporary files made in order for the user so they don’t have to keep going over what they have done, they can go straight to where they left off. Also some websites have Cookies which also creates files about the website and sometimes help for easy use of the website. This is all sorts as web history and the user can use it. But if there are too many files it can slow down the performance of the computer, so the Clean-up tools get rid of the files that don’t need to be there, also the files only last a certain amount of time before they are cleaned away. This also happens with the operating system when it does things temporary files are made and they have to be cleaned up in order to make the performance of the computer better. All these files are stored on the hard disk drive.

Defragmentation is when you save this the get saved into sections on the hard disk drive. Fragmentation is when the files are stored in different sections of the disk and it tasks a long time to load the file because the pin has to physically move. So defragmentation is when the files are reorganised so they are all together and they can be opened quicker.

Drive formatting is preparing a drive to receive data. There is a low one which physically deletes the files from the disk. Then there is a high one which makes the disk look like it is blank.

The features and functions of different operating systems M1

Feature	Windows	MAC OS	Linux	Dos	Comparison+ conclusion
Ability to customize	Windows is hard to customize because it is a programme which has a code which the user cannot get to meaning they cannot change the codes within the programme. But the user can personalize their display screen with a picture and colours which makes the computer more personal.	MAC OS is similar is windows in the way that the user cannot change the code that the programmers have designed for the computer to work.	Linux is the one operating system that can be customized the most. It is an open source operating system meaning the user if they have the knowledge to change the codes, can do so. Meaning they can change things about the codes to make the operating system work to their advantage.	Dos is very difficult to customize because it is limited and it doesn’t have GUI which you have personalise.	Looking at these it looks like not having to change the code works better for most users before then everyone can use this computer and doesn’t have to know anything special to operate the system.
Support for connectivity of portable media	Windows lets the user add portable media through USB ports.	MAC OS is again similar to windows in that is lets the user add portable media through USB ports.	Modern Linux lets the user plug in devices and once the system is running the computer opens the right applications to running the plugged in device.	Dos is an old operating system so people don’t make portable media devices for Dos anymore.	Looking at these operating systems it doesn’t look like in the modern ones there is much difference in them.
Security	Windows is the operating system that will be mostly attacked because it is really vulnerable because it has the largest ‘surface area’ of files accessible on the internet.	Mac is medium secure because it is a more operating system and it is expensive so not many people would make virus to destroy the operating system because there isn’t many users.	Linux is more secure because the system the most popular and more technique person would be using this operating system so there will be less ways to send the virus to their computer because they know how to get rid of it.	Another that was a problem of Dos’s operating system won’t have been because it is so old now.	Looking at this is seem like Linux would be the best option to get in the security part of it because it is less likely to get attacked by viruses.
Stability and reliability	Windows is reliable because
Ease of management	The ease of management with Windows is good because everything is in one place such as the control panel, the user can change things about the computer such as the keyboard and the mouse and how they work, faster slower. Also there are easy management opinions in the system which makes using the system so much easier for the user.	Mac OS has something called to At Ease which helps the user operate the system. So this will be a lot like Windows in the way that everything that will help the user is in one place.	The ease of management with Linux is very much like Windows in that the user can go and change things such as the keyboard but it is different because	The ease of management would have been difficult because everything had to be loaded by a command and the user would have to know these commands in order to work the whole operating system.	Looking at this is seem that the modern systems are mostly the same in the ease of management but there are some differences between the different operating systems.
Associated utilities,	Windows have utilities such as clean up tools and
Cost	Windows is the second most expensive because you have to buy the operating system but it isn’t as expensive as the MAC OS operating system. Windows operating system costs £73.40 roughly.	MAC OS is the most expensive operating system because in order to have this operating system you have to buy a MAC computer and they are the most expensive brand of computer for every day use and also specialist work such as music creation etc.	Linux is the cheapest operating system because it is free.	Dos is no longer made because the operating system is so old, but the price of what it was back when it was still made wouldn’t be that much now.	Looking at this it looks like getting the Linux would be the better opinion price wise, but is it the best operating system for most users, users who don’t have the knowledge to work the Linux system. Windows would be the best opinion because it isn’t the most expensive operating system but it is the easiest operating system to use.
Support for the user	Windows is good for supporting the user because they are websites that they can go on and get help and also there are books and help opinions that the user can get hold of.	MAC OS will be very similar to Windows in the way that they have ways to help and support the user but there isn’t as much because it has been around for as long as windows and also it isn’t used in the same way as windows is, it is used for programming and design.	Linux will have less support for the user because it is for the more technique people and they wouldn’t need the help.	Dos is no longer being made so there will not be any support for the operating system.	Looking at this it shows that window offers a lot more support for the user of their computer which is good because then they will have a wider audience for their product because they feel like they can use the operating system and if they get stuck there are many ways they can be helped.