All computer systems consist of components. These components can either be internal, such as RAM, or external, such as keyboards. Components can also be categorised as INPUT or OUTPUT components. Components such as a keyboard, a mouse and a microphone are all examples of input components and are generally used to put data into the computer system i.e. using a keyboard to type a document. Output components deal with getting data out of the computer system like printing a document, examples of output components include: Graphics card, sound cards, printers and speakers.

Due to advancement in technologies some components can be both input as well as output devices. A common example of this is modern monitors which allow the user to interact by touching the screen (Touch Screen Monitors).

Here is a brief description of components that can be found on a system, both internal and external.

Common INPUT Devices

• Keyboard
• Mouse
• CD/DVD Optical Drives
• Microphone

Common OUTPUT Devices

• Graphics Card
• Sound Card
• Monitor
• Speakers

Storage

• RAM
• Hard Disk Drive (HDD)

Cooling System

• Fan and Heat sink

Processing

• Central Processing Unit

Motherboard

• North Bridge
• South Bridge

P1 Explain the function of computer hardware components.

Keyboard

A keyboard is a device used to input data and perform functions. A keyboard consists of keys which represent a number, a letter or a special character. The keyboard can also be used to open and close programmes as well as perform specific functions within software’s (e.g. pressing F5 in Microsoft word opens the ‘Find and Replace’ feature) which help save time and be more efficient. However the primary function of the keyboard is for the input of data. 

Mouse

The Mouse is another input device. The main function of the mouse is to allow the user to interact with the software. Using the mouse the user can point at, select text and navigate.  The mouse consist of two buttons, the left button is used generally to select and the right button opens a context menu allowing the user to perform other actions such as copying, pasting, creating new folders etc. There are two types of mouse’s. The older type is the Mechanical which has a little rubber ball inside the mouse and the sensors inside detect and then display all the movement on the display unit (Monitor). The newer types of mouse’s are optical and work by tracking the movements of the light or laser and this is displayed on the display unit (monitor). Using a mouse is very efficient and time saving; imagine how long it will take to click the third link at the bottom of the internet page you are viewing, without a mouse.

CD/DVD Optical Disk Drive (ODD) and Discs

These are drives which use a laser to read or right data from an optical disc (CD’s or DVD’s). Some drives can only read data but many are capable of writing data directly on to rewritable discs these can also be referred to as burners. Due to developments in technology there are now drives that support Blu-ray discs, allowing discs to be both read and written (burnt), offering more space. One of the main features of these drives is the capacity and ability to transfer very large quantity of data on a small disc. Data capacity of a CD is 700MB, DVD 4.7GB and Blu-ray can hold a staggering 25GB. Prior to using CD’s software’s were distributed on floppy disks, if a 32 Bit Windows 7 ultimate was distributed on floppy disks and the memory of the disks were 1.44MB it would require 1422 disks. The ability to install software’s using a single disk has allowed the installation process to become more efficient and time saving. The main function of the drive is to read the data from the discs and give the user access, drives which can write also allow the user to modify data on certain disks i.e. re-writable disks.

Microphone

An input device which allows the user to record audio data directly to the hard drive or use it to communicate over the network/ internet, can be used for socialising, business, gaming or to record a simple voice memo. The main feature of the microphone is the ability to input audio into a computer system.

Graphics Card

A Graphics Card is responsible for the data to be displayed through a monitor. Graphics cards can have several output interfaces, these include; Video Graphics Array (VGA), Digital Visual Interface (DVI), High Definition Multimedia Interface, S-Video, Composite Video and Component Video. Graphic Cards are also known as; Video Card, Display Card, Display Adapters and Graphics Adapters. The function of the better graphics card (with high end CPU’s) will allow the system to produce better picture quality and resolution and more quickly, this is further enhanced by VDU monitors offering HDMI support.

Sound Card

A sound card is responsible for the audio data that is played through speakers as well as received through the Mic-in or line-in ports. The sound card is also an input device, there are three main colour coded ports (newer sound cards have extra port allowing more functions) on sound cards of which two ports (pink/red and blue) are both Line-ins and allow audio to be recorder or played through the computer. The third port is green in colour and is used to output audio data, speakers are usually connected via this port. The sound card fits directly onto the motherboard in the available sound card slot. The primary function of the sound card is to act as an audio processor for a computer system.

Monitor (Visual Display Unit)

Using input devices such as keyboards or mouse’s require a device for the output data. A monitor can be used to display data input by keyboards and mouse e.g. typing text in a word document, highlighting text or selecting to print. There are several types of monitors available from the old Cathode Ray Tube (CRT) through to the more modern Organic Light Emitting Diode (OLED). The benefit of a more modern monitor is HD/4K picture quality along with low power consumption. The main function is to display the data which the graphics card has processed.

Speakers

Speakers are another output device which plays sound.  The speakers can be used by the user to playback data which is sound i.e. music. The speakers can also be used by applications to communicate with the user, i.e. warning sound by Operating Systems when critical changes are made (require rebooting), saving files before exiting applications etc. The main function of the speakers is to play the data processed by the sound card.

Random Access Memory (RAM)

A type of storage allowing data to be accessed randomly, the RAM is used to store temporary data. RAM memory is volatile, this means that once the power is switched off the memory stored in the RAM is lost. The main benefit of RAM is the ability to access data very quickly, with a hard drive data is accessed with a mechanical arm and the data can be located anywhere, this is very slow and time consuming. As it is volatile memory new data which is accessed more often will occupy the required space on the RAM, all other data is stored on the hard drive.

Referred to as memory modules, there are different types available and must be compatible with the motherboard. The most common type of memory module is Dual In-line Memory Module (DIMM).The capacity of RAM (or size) is measured in Gigabytes (GB). The more RAM a computer has, the quicker data can be loaded from the hard drive and accessed by the user.

Hard Disk Drive (HDD)

The Hard Disk Drive HDD or the Hard Drive is used to store and save data. This is the primary function, to store data. This is the part of the computer where the Operating System and all the software’s and applications are. This is the area of the computer where the end user ‘saves’ their work or ‘installs’ software. Unlike RAM the memory in a Hard Drive is non-volatile meaning data is not lost when power is switched off. The Hard Drive is mechanical using an arm to read data from the discs which is usually in a metal casing to protect all the components. The capacity is measured in gigabytes (GB) and terabytes (TB).

Hard drives are IDE devices (Integrated Device Electronics). IDE devices are controlled by IDE controllers. There are two types of IDE controllers they are Primary and Secondary. Hard drives are usually connected to the primary IDE Controller with an IDE cable. Each IDE cable is capable of connecting two drives. The two drives are known as Master and Slave.

The master drive handles all data on the IDE cable retaining information for master drive and passing on information to the slave drive. The slave drive could be an internal peripheral such as a CD/DVD drive.

Fan and Heat Sink

Both the fan and the heat sink keep the processor cool and stop it from overheating. The main function of the fan is to keep the components cool and the heat sink keeps the CPU cool. The heat is drawn away from the CPU by absorbing it and moving it away allowing the CPU to cool down. Compound paste or Thermal paste is used to secure the CPU to the heat sink; the paste eases the absorption of the heat by the heat sink. The fan also helps keep other components cool as well.  Due to advancements heat sinks and fans can also be found on graphics processors. Liquid cooling systems is also another option and can also be effective.

Ports

In order to connect external devices such as printers, monitors, keyboards etc. ports are required. This is the primary function of ports. The ports are usually on the back of systems and allows several types of devices to be connected allowing the user to interact with applications i.e. keyboards, web cams, allows the user to share information e.g. connecting to a network or the Internet via the Ethernet port, Printers can be connected allowing the user to print documents, pictures etc. Most new external components are connected through the USB (Universal Serial Bus) ports the other types of ports i.e. serial, parallel etc. are becoming obsolete and being replaced with new ports such as HDMI. Ports are connected directly to the motherboard.

BIOS (Firmware)

The BIOS is an acronym for Basic Input/Output System and contains the instruction for a system to boot up and allows all the components to function with each other. When the user first switches the computer on the POST (Power-On Self Testing), which is built into the computer’s hardware checks to see that all the components such as disk drives and random access memory, are all working correctly. The primary function of the BIOS is to set up the system and launch the operating system.

Due to the advancement in technology BIOS is slowly being out dated and replaced by UEFI which is an acronym for Unified Extensible Firmware Interface. Both BIOS and UEFI contain information to boot up the computer. The difference is UEFI is much more user friendly, utilises a graphic user interface and allows the user to interact with the use of a mouse. The BIOS and UEFI are installed during manufacture and BIOS is on an EPROMCHIP (Erasable Programmable Read Only Memory) which is on the motherboard and is non-volatile.

BIOS EPROMCHIP

Motherboard

Consisting of many slots, connectors and sockets, all the major components fit directly onto the motherboard. Components such as the CPU, the graphics card, sound card, the hard drive, BIOS, CD/DVD Drive and many more all have appropriate slots allowing easy installation.

The core logic chipset is made up of two chips known as the North Bridge and the South Bridge. The North bridge of the motherboard deals with tasks requiring the highest performance and is therefore connected directly to the CPU through the Front-Side Bus (FSB). The south bridge is tasked with dealing with all the slower processes of the motherboard these include integrated hardware such as USB, BIOS and sound card. The main function of the motherboard is to connect all the components together, supply power and help them communicate through the physical connections and circuitry.

The North and South bridge manage communication between the CPU and all the other components.

Here is a more detailed picture illustrating the connection on the motherboard between the North bridge, the South bridge and all other components. As you can see data travels from a component such as the USB through the South bridge through to the north bridge and finally to the CPU the same route is used in reverse when the data is sent from the CPU back to the USB.

P2 Explain the purpose of operating systems.

Operating Systems

In order for the software’s to work they require an operating system. Operating systems also control all the hardware and all the software on a computer with the exception of the BIOS.

The operating system deals with communication between hardware and software it acts as a translator between the computer and all the different components, the operating system is also responsible for allocating memory i.e. graphic based software will require more RAM, as well as allocating enough memory for software to run smoothly it also keeps all other software’s running in the background. The user only has to select the software the rest of the process is done in the background.

There are two main types of operating systems.

• Client
• Server

Client operating systems are usually in personal computers owned by individuals. Typical usage could include Using the internet, producing a word document, listen to music, playback a DVD as well as much more.  Client operating systems request information. Here are examples of client operating systems.

• Windows 7
• macOS 10.12 Sierra
• Ubuntu 17.04

Servers on the other hand provide information. They serve the requests of client computers attached to the network. For this reason servers are usually found being used by businesses. Everything that can be done by client operating systems can also be done by server operating system as well as much more for example, multiple users can log in at the same time, it is more secure as better security is incorporated into the operating system and the performance is much better. Here is a list of some server operating systems.

• Windows Server
• Red Hat Enterprise
• macOS X Server

Most modern operating systems are GUI based, there is no command line interface or DOS, wild cards etc. Due to the use of the Graphic User Interface the user can seamlessly use a computer, software, hardware, allocate memory for all required tasks and run all tasks/apps. The Operating System minimises the need for the user to have all the technical knowledge required on older technology such as MS DOS. Other Operating systems also use GUI’s to make the users experience and interaction with the system better.

There are many different Operating Systems available. The most common are:

• Windows
• Ubuntu
• Linux
• Apple macOS

The main features of an operating system

Windows

Windows was introduced by Microsoft in 1985. Windows is commonly associated with the IBM PC Compatible Architecture. The operating system uses graphics to allow the user to interact with the operating system, software and hardware. As this eliminated the need to learn and/or understand how MS DOS or Command Line worked and become very successful very quick. Windows was one of the first Operating System that allowed users to use a computer with little or no IT experience or knowledge. Microsoft have modified their operating system so that it (or a variation of their operating system) can be used by individuals i.e. Windows 10 or by businesses i.e. Windows server 2012 R2 or Windows 2016. Windows also offers technologies for the mobile platform.

The newer versions of windows (Windows 10) prioritise security threats such as malwares and viruses. The operating system has built-in AV components, this replaced the older Windows Defender (free but required user to download and install) and Windows Live OneCare which was a subscription based AV Software. The new Microsoft Security Essentials offers real time protection and a firewall and the user can change the security settings to suit their needs. This is a new function whereas on previous versions AV components were not built in to the operating system. The operating system also offers better use of graphics as well.

As Windows is so popular compatibility is not an issue and getting drivers and updates for components is relatively easy. Hardware is also not an issue due to the popularity of Windows.  One of the features offered by Microsoft is the ‘compatibility mode’ which allows a software which is no longer supported to still operate and run. However due to the popularity of Windows there are several viruses and malwares (cyber attacks) targeting Windows Operating Systems.

Linux

Linux was originally created by AT & T’s Bell laboratories and released in 1991 under General Public License. Linux is free and an open-source software and therefore is commonly ported to other platforms i.e. mobile. Originally based on Intel x86 architecture and developed for personal computers. Originally developed to be command line however with the use of packages Linux can be configured to be similar to WINDOWS (GUI based Interface). The operating system allows the user to try it while it is still on CD/DVD prior to installing it. Linux is also Open-source allowing progress in technology to be implemented quickly and by anyone. Multi-user system allows system resources to be accessed by multiple users all at the same time. Linux CAN run windows programmes by using a ‘Windows compatibility layer’ package called Wine.

As Linux is not as popular as other Operating Systems such as Windows, product support is limited as well as finding software for specific needs can be difficult to get hold off. However Linux is capable of running Windows programmes. As Linux is an open-source operating system it allows users to port it to work on may platforms mobile phones being one of them.

macOS

Originally produced by Apple and pre-installed on all Apple Macintoshes as of 2002. Originally it was released in 1984. macOS also known as OS X, is a UNIX based operating system. It is more secure than Windows. Similar to Windows OS X is graphics based. Unlike Linux it is closed source however it does have open source components.

M1 Compare the features and functions of different operating systems.