unit 2 : P1

Backing storage

• Pen drive also known as a memory stick are one of the main backup resources that can be used in computers. It enables you to store anything, although they do have a limit. It also allows you to easily move data from the hard drive onto the pen drive, by plugging into the computer via the USB port which is connected to the motherboard, allowing it to communicate easily with the rest of the components.

                                               

• Hard drive is the computers’ main storage media device that permanently stores all data on the computer. Most are situated on the front of the computer, which is connected to the motherboard, it is connected via cables such as SATA and power cables, this enables it to communicate with the rest of the components with ease. There are internal and external hard drives, External hard drives can be plugged into the computer via the USB port which can act as back up for the computer.

                                                
Peripherals

• Printers use USB connections so they plug into the computer and the printer, however many printers are now wireless. The cable plugs into the USB port, which is located on the motherboard. The computer can detect and communicate with the components that the printer is connected, once it is connected you will be able to control it from the computer, allowing you to print effortlessly.

                                                    

• Scanners, known as an input device can be also plugged into the computer in the same way as a printer. It allows you to transfer photographs and images etc. from paper onto the computer, these can then be sent via email or other forms of communication. This connects with the motherboard via USB communicating with the necessary components which then will store the images in the internal memory.

                                                     

• Twisting pair cabling are used to block out electromagnetic interference from external sources. The two wires carry signals in different directions. The cable carries signals to other components in the device, this allows them to communicate with one and other more quickly, thereby making a better performance.

                                              

Internal system unit components:

• Specialised cards:

- Graphics cards allow you to make things much easier when working with computers e.g. a multi-monitor. This allows you to see more than one screen when using a computer, this can also help to improve graphics on certain programmes.
                                                 
                                   
- Network cards allow you to connect to the internet via a LAN cable.
Both of these cards are not necessary for the other components to function or communicate with each other, however it makes using a computer easier for the user.
                                            

• Ports USB: the ports on the computer allow external devices to be plugged into the computer such as a computer mouse or a memory stick to transfer data. They can found on both the back and front of the computer.

- Parallel ports are the out-dated version, so cables had to be used for transferring data e.g. printer.

- Serial ports have a wider range of data transferring devices e.g. mobile phones or remote control devices.

The difference between the two is that parallel ports can only transfer data in one direction, whereas serial ports can transfer in two directions. Therefore serial ports can communicate with the other components allowing the computer to send data to other devices.
                                                    

• Internal memory (RAM, ROM and cache): the internal memory of a computer contains some of the most important information needed for all of the components to run. The ROM (read only memory) contains data that cannot be edited e.g. a CD. RAM ( random access memory) can be found on the mother board inside the computer. If RAM was not there the computer would not work properly. Cache memory is a type of RAM, but the computer can access it more quickly. Without these storage devices the internal system unit components would not be able to access important data.

                                                  

• Power supply maintains all the power entering and leaving the computer in order to keep the right voltage. It works with the fans and cooling system in order to keep the computer cool. When the power supply is connected up with the other components, power is provided to the computer, the other components rely on the power supply for the computer to work. The power supply exchanges alternating current to direct current which is used by the components.

                                                     

• Fan and heat sink or cooling: The fan pushes cool air into the computer to prevent it from overheating. Water coolers also help to cool computers down. The main fan is on the processor unit because this is prone to overheating. Without the fan and cooling system the computer would overheat, resulting in the other components being unable to function efficiently. 

                                                      

• Hard drive configuration and controllers (SATA or IDE or EIDE): The hard drive is connected to the computer by two wires called IDE (integrated drive electronics) and SATA (serial advanced technology attachment), these are two of the most important wires in the computer, without them the hard drive would not be attached. The EIDE is just an enhanced version of IDE, this has a bigger storage mass and is up to four times quicker.

                                                        

• Processor: Also known as a CPU( central processing unit), this is a unit inside the computer which needs to be used and installed correctly in order for the computer to work. This helps carry out all of the main processes in the computer. It carries out the instructions of a programme and it processes the computers data while sharing this with other components and peripherals.

                                                        

• Motherboard is the component that connects all of the other components together in order to allow the computer to work. There are slots and ports on the mother board for cards e.g. graphic card cards and USB devices. The hard drive and CD-ROM are connected to other components via the motherboard.  

                                                        

• BIOS: this is the part that allows the computer user to diagnose problems quickly and efficiently, so without it there would be many things that you couldn't do. It is vital component needed to allow the computer with all of its components to work correctly.