1
Researching
Computer
2 Computer Technologies
Computer technology refers to all types of technology that use microchips. Some technologies can be programmed to do different things, laptops, smartphones and tablet computers can all be programmed to do different things, and others carry out specific tasks, such as MP3 players and digital watches.
Personal computers are designed to be flexible and carry out a wide variety of tasks. This type of technology can be programmed to do many things so can smartphones or computer tablets, the programmes for smartphones and tablets are often referred to as Apps.
Technologies that carry out a specific task are often referred to as embedded computers.
Task 1 Find out:
Below is a list of different technologies, create a table like the one below and put the technology into the correct column.
mp3 players, mobile phones, videogame consoles, laptops, digital cameras, touch screen computers, DVD players, GPS receivers, smartphones, printers, microwave ovens, washing machines, network servers, and dishwashers,
3 How do computers work?
Any computer technology can be represented by a simple diagram.
Input Process Output
Data is input; the computer processes this data and outputs the result
Data is inputted often by the user (you), or you instruct the computer what to do, load a program, play music o connect to the WWW. The computer processes the data or instruction and then outputs the result of this processing.
Hardware devices
Some pieces of equipment (devices) are specifically designed to input data into computer
technology and some are specifically designed to output. Here is a typical desktop computer with its input and output devices labelled.
Task 2
a) Look at the desktop computer above, name a piece of equipment that you could attach to it and state whether it would be an input or output device.
Find out:
b) What are the input and output devices on a laptop?
c) What are the input devices and output devices on a tablet computer and smartphone?
Monitor/screen – OUTPUT device
Keyboard – INPUT device
4 The Processor
The processor is the “brain” of the computer. It deals with of the movement of data around the computer and does all the calculations.
A processor is made of silicon crystal wafers which hold millions of tiny electronic components. There are processors in all sorts of computer technology smartphones, computer tablets desktop and laptop computers.
You will also find processors in watches, microwave ovens, radios, DVD players and recorders, televisions, in cars, on planes in fact in almost any electronic device.
You will find that modern computers have two or more processors working together to make the system work better.
Two processors dual core
Four processors quad core
The more processors that can work together the faster the process can be completed.
Task 3 Find out:
a) What are the most processors working together in a desktop computer system available for the public to buy? State how many processors it has and its cost.
5 Clock speed
Clock speeds are a measure of how powerful a processor is. The clock pulses, measured in GHz, regulate and co-ordinate the activities of the processor. Processor clock speeds are increasing all the time.
1 Megahertz (MHz) = 1 million pulses per second 1 Gigahertz (GHz) = 1000 million pulses per second
Task 4 Find out:
a) Which computer tablet has the highest clock speed? State what its clock speed is and how much it costs.
b) Which laptop computer costing £1000 or less has the highest clock speed?
c) Explain why a dual core computer tablet with a clock speed of 1.3 GHz will process data quicker than a single core computer tablet with a clock speed of 1.8GHz.
6 Other measures of how powerful a computer system
There are other measures of how powerful a computer system is, for example, the size of its memory, the speed of data transfer from backing storage to memory and the performance of its graphics card.
Backing storage is anything that can store applications and data which can be accessed by the processor and loaded into RAM.
Computer memory
The main memory can be either Random Access Memory (RAM) or Read Only Memory (ROM). It is RAM that that computer manufactures talk about when they state a computer system has 4GB of memory.
Desktop computer Tablet computer
Information provided by pcworld.com
RAM is the working space that the computer needs to run software. RAM holds all the programs and data files currently being used by the system and the user.
Smartphones have RAM as well. Operating System Android Jelly Bean Processor Quad Core 1.7 GHz
RAM 2GB
The more RAM you have the quicker your apps will run and/or the more apps you can have open at the one time.
Key points about RAM:
The processor can write to, or read from RAM at high speed, much quicker than reading from backing storage
Data held in RAM can be changed
All data in RAM is lost when the power is switched off
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Task 5 Find out:
a) The latest type of RAM is known as DDR3. What is the data transfer rate of DDR3 and how much faster is it than the previous version DDR2?
b) Different types of tablets have different amounts of RAM and different versions of tablets have varying amounts of RAM, find the amount of RAM available on the different versions of; i) the iPad, ii) Samsung tablet and iii) the Kindle
c) What are the two top selling smartphones? How much RAM do they have?
d) How much RAM is in a desktop PC priced between £400 and £450? Give two examples, name the computer manufacture, the RAM size and how much it costs.
The other type of computer memory is ROM.
ROM is stored on a microchip and contains all the vital start up instructions which are need when you first switch your computer on.
Data is stored permanently in ROM, it is not lost when the power goes off
Data held in ROM cannot be changed
ROM holds vital systems data and programs which are needed to get your smartphone, tablet laptop or desktop computer up and running when its first switched on
Task 6
a) Copy the table. Look at the feature in the table and indicate whether it applies to RAM or ROM
b) ROM chips are often in embedded computers, list three embedded computers that have ROM chips
Feature RAM ROM
Permanent storage for operating or control programs Temporary storage for programs and data
Data can be read from /written to memory Data can only be read from memory
8 Graphics cards
A Graphic card contains a processor and its own RAM and is the part of the computer that deals with graphics. This frees up the main processor to get on with other tasks. Graphics need a lot of processing and a lot of RAM if there are not to be slow and jerky.
Task 7 Find out:
a) Name three graphic cards that you could buy for £150 or under. List their processor speed, the type of RAM and amount of RAM each has.
Sound cards
Computer systems use sound cards to capture audio data. Sound cards operate by taking tens of thousands of samples of analogue sound waves each second. They then change each sample into a binary number and store each sample in memory. Sound sampled at 44KHz (the sampling rate for CD quality music) means that the processor has to convert 44000 analogue quantities to binary form every second and store each one. Using a sound card will free up the main processor to get on with other tasks.
Task 8 Find out:
a) Get the name of two sound cards, one costing less than £50 and one costing between £100
and £150. Compare them according to their processor speed and RAM capacity. What does the more expensive sound card provide that the cheaper card does not?
9 Input
Output Central Processing Unit
Arithmetic/Logic Unit Control Unit Registers RAM ROM Backing storage Main memory Buses A computer system
The processor is also known as the Central Processing Unit and it controls the running of a computer system.
Task 9
Copy the diagram (above).
Buses
The arrows in the diagram indicate data flow. Data in a computer system travels along wires known as buses. Buses are defined by how much data can be transmitted at once. The bus width refers to how many bits can be transmitted at the one time. Typical bus widths will 32 bit, 64 bit and 128 bit. A bus with a width of 32 bits means it has 32 wires in place connecting it.
Bus speed is number of packets of bits that can be sent or received per second. This is the frequency and is expressed in Hertz, 133 MHz means 133 million times per second.
To calculate how much data can be transferred per second we can do a calculation. A bus with a width of 16 bits and a frequency of 133 MHz has a transfer speed equal to: 16 * 133.106 = 2128*106 bit/s, 2128000000
2128*106/8 = 266*106 bytes/s, 266000000 266*106 /1024 = 259765.625 Kb/s
10 Types of Buses
Different buses are used in the computer to transmit different things. The data bus provides the transmission of data between
internal backing storage (Hard Disk Drive) and main memory (RAM) and the processor.
The more lines a data bus has the more data can be transferred.
The address bus holds the address of the memory location where the data is to be stored or from which the data is about to be read (taken from).
The more lines an address bus has the more memory locations a computer can have (it can store more)
A control bus is used by the CPU for communicating with other parts of the computer. While the address bus carries the address of the data and the data bus carries the actual data being processed, the control bus carries commands from the CPU of what is to happen to the data. The control bus sends out instructions like “read from memory” (load) or “write to memory” (save). The control bus states what is to happen to the data, where it is to go and what is to be done with it once it arrives.
Task 10
Open the file “What is a bus”, copy and paste the paragraphs and missing words in to your
11 The Central Processing Unit (the CPU/the processor) The CPU comprises the parts, the ALU, the CU and registers.
The arithmetic and logic unit (ALU) carries out all the calculations and performs all the logical operations, that is, it makes the decisions, for example, if one number is bigger than another. The control unit acts like a combination of traffic cop in a very busy junction and a parcel delivery service. The control unit organises the flow of data in and out of the CPU and to and from main memory and backing storage. Millions of pieces of data are moving every second, the control unit ensures that there are no collisions and the correct piece of data or instruction arrives at the right place at the right time.
Registers are the processor’s own internal memory. Registers are used to store data and instructions while they are being processed. They are used to:
Store data that is being transferred to and from main memory (RAM)
Hold the address of the location in memory which the processor is accessing to read or write
Hold the instruction that
are being carried
out
Task 11
a) Copy the diagram (above).
b) Name the three parts of a CPU.
12 User Interface
How we communicate with technology
We communicate with technology through the user interface provided by the operating system, this can be via a mouse or keyboard or touch screen to input data and we receive output via a screen or speakers or even a printer.
Task 12 Find out:
a) Copy and complete the table below, adding in two more input and two more output
devices.
Input devices Output devices
Mouse Screen
Keyboard Speakers
Touchscreen Printer
Interface
How different technologies communicate
Another use of the term interface is to describe a piece of hardware or software that allows different parts of the computer system to communicate with each other. A new device attached to a
computer may need a “driver” to allow it to communicate with the existing operating system. A “driver” would be downloaded or come on some form of backing storage. An example of a hardware interface is a Network Interface Card that allows technology to be hard wired to a
network. It is into the NIC that you attach the cable that comes from your phone or network socket.
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Task 13 Find out:
b) What other ways can you connect to the internet apart from using a NIC?
c) Pick one of the other ways identified in b) and list two advantages it has over using a
hardwire internet connection.
d) State two advantages that a hardwire connection has over other types of internet
connection.
Speed of data transfer
Different devices transfer data at different speeds that is why connecting hardware together often requires the need for an interface to compensate for the different speeds that the different hardware operate at.
Different types of hardware will also transfer the data in different ways. The computer may transmit the data in parallel along 32 wires but other devices may transmit the data in serial along just one wire. Obviously parallel data transmission is faster than serial.
Eight wires used in parallel data transmission
Task 14 Find out
1. What is maximum the data transfer speed of the following; a) USB 2
b) USB 3
c) Ethernet (latest version) d) Wifi (latest version) e) Firewire 800 f) Express card g) Thunderbolt
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2. Explain the idea of serial and parallel data transmission using a single track road and a four lane motorway as an example. (use a drawing if you want)
Backing storage
Backing storage is the term given to any device that allows you to store data permanently. It is backing storage that stores all the files you save on a desktop or laptop computer. It is backing storage that stores your game save on the Xbox or PlayStation or Wii, it is backing storage that stores you MP3 tracks on your smartphone, computer tablet or MP3 player.
Hard Disk Drive USB Drive
Task 15 Find out:
a) Copy and complete the table below for typical backing storage capacity available to the general public:
Backing Storage Device Storage Capacity (Gb) Data Transfer Rate
Internal Hard Disk Drive From 250 Gb to 1 Tb (or bigger)
1 Gb/s to 3 Gb/s External Hard Disk
Drive USB Drive SD cards DVD-R Blu-ray CD-R
Secure Digital Cards (SD cards)
15 The three main types of backing storage
Magnetic
These use magnetic fields to store the data. Examples of magnetic storage devices are Hard Disk Drives and Magnetic Tapes.
Hard Disk Drives can be internal, that is inside the computer technology or external (outside). External HDD mans they are portable and can be attached to other devices and the data on them transferred.
Optical
These store data by means of lasers ‘burning’ a disk. Examples of these are CD/DVD/Blu-ray Solid State Devices (SSD)
This uses no moving parts at all, SSD use memory chips. Examples of these are; USB Drives and SSD Hard Disk Drives. SSD can be found in some computers but mostly in smaller devices.
Task 16 Find out:
a) List three types of backing storage.
b) What do the letters HDD and SSD stand for?
c) Find out which of these HDD or SSD can transfer data to the processor quickest? d) Find out which type of backing storage is in i) Desktop computers? ii) Smartphones? e) Find out which type of backing storage HDD or SSD is the most robust?
f) Other than HDD and SSD, list two more types of backing storage.
g) If you wanted to store 100 GB of data which backing storage device would be the cheapest?
16 Networks
Networks allow people using technology to communicate with each other. Computers that are not connected to a network are called stand alone computers.
Local area networks (LAN)
LAN’s are networks that are in a localised area; that can be in a home, office or classroom. It may be across one floor of an office buildfing or the whole building.
Client/Server networks
Your school will be most likley be a client/server network. A client/server network has clients (the computers on the network) and a server which controls the network. Stations or clients on a network are connected by cables these could be copper wire in one room and fibre optic to link the rooms or floors to the server. A network cable attached to the network interface card in the computer and the network port on the wall will allow the workstation to access the network. The three types of wire used in LAN.
Task 17
Find out about the three types of wire of cabling used in wired networks. Use the table below. The three types of wire used in LAN.
Type Description Speed of transmission
(mbps)
Cost
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Stations or clients on LANs can also be connected wirelessly. Laptops and computer tablets will have the wireless technology built in but many desktop computers will require a USB wireless adaptor or a wireless interface card fitted. A wireless “router” will also be needed to to send data around the network.
Task 18 Find out:
a) List the three benefits of a LAN in comparison to a set of standalone computers? b) Find out what advantages a wireless network will have over a wired network?
c) List the disadvantages a wireless network will have in comparison with a wired network? A USB wireless adaptor A wireless interface card A wireless router
18 The internet
The internet is a network. The internet is a global system of many computer networks which are all linked.
The internet comprises of a number of different elements.
The World Wide Web
Search Engines
Forums and chatrooms
Task 19 Find out:
a) Write a short description of each of the three elements of the internet listed above. b) The internet has many uses, explain the following uses; email, social networking, online
19 Cloud computing
A LAN typically has its own server which runs the network and stores data and machines that have their own
processor to run applications, organisations have to pay the running costs of operating the network including maintenance and network connection costs. In Cloud computing the organisation will rent the equipment, the software and the storage facilities all of which will be provided online as well as access to the internet. This can be paid for on a pay-as-you-go-basis or on a monthly contract.
Task 20 Find out:
a) Three advantages of cloud computing over traditional a LAN.
b) Three disadvantages of cloud computing compared to a traditional LAN.
c) Open the file Cloud Computing V LAN. Copy the table into your document and complete the missing sections.
internet
servers database
20 Peer-to-peer networks
A peer-to-peer network is a network in which computers are independent. The main difference from client/server network is that PTP networks do not have a central server to store data, manage security and provide backup services. In a PTP network all workstations may need to back up their own data and as all workstations can access all data many different versions of the same file may abound. There is a need for careful thought in using the PTP system. PTP networks are often found in a trusting environment such as a home network where security and levels of access are not an issue.
A peer-to-peer network A client/server network
Task 21 Find out:
a) Describe a peer-to-peer network? b) Describe the security on a PTP network?
c) What is the purpose of the “hub” in a PTP network? d) How are files stored on a client/server network? e) How are files stored on a PTP network?
21 The most powerful computers
Servers
A server is a powerful computer with fast processors and a large memory used on a LAN. Most LAN network will have a range of servers such as:
Print server, controlling printing resources
File server, controlling access to files, saving files and loading files
Application server, controlling access to application packages
Mail server, storing and passing emails
Web server, controlling accesss to the internet
Task 22
a) What is a server?
b) What does the file server do?
c) Name one other type of server and explain what it does?
Re-read the notes on networks starting at page 17 and answer question d) d) What on a network is a “client”?
Find out using the WWW,
22 Network topology
How a network is physically arranged is known as its topology. Each “client” or “node” on the network is represented by a circle in the diagrams below. Each type of topology is given a name that describes something about that topology.
A Bus network uses a common backbone to connect all devices.
In a Ring network, every device has exactly two neighbours for communication purposes. All messages travel through a ring in the same direction.
A star network features a central connection point called a "hub node". Extended stars will combine many star topologies.
Tree topologies integrate bus and star topologies together.
A mesh network can take any of several possible paths from source to destination. A full mesh network is a network in which every device connects to every other
1. Bus 2. Ring 3. Star 4. Extended Star 5. Tree 6. Full Mesh Task 23
a) What does the term topology mean?
Find out using the WWW,
b) Give an example of an organisation that would use a bus network?
c) An advantage of a ring network?
d) A disadvantage of a star network?
23 Mainframe computers
A mainframe computer is a very large computer system that can process very large amounts of data at high speed. Hundreds of user terminals can be connected to it and using it at the one time. This is known as a multi-user or multi access system.
A mainframe computer is a multi-processor machine with lots of RAM and a lot of backing storage such as tape and disk drives.
Users access the mainframe through a dumb terminal. Mainframes are used for transaction
processing and are used by supermarkets stock control, online shopping and banking, including the control of automated teller machines (ATMs)
But big and powerful as mainframes are there are not the fastest and most powerful computers these are called supercomputers.
Task 23 Find out:
a) What is a mainframe computer? What makes it different from a server? b) Find out what the hardware of a “dumb terminal” is?
c) What does a desktop computer have that a dumb terminal doesn’t? Explain why a dumb terminal doesn’t need what the desktop has.
24 Supercomputers
Supercomputers are used for intensive mathematical calculations such as weather and climate forecasting, car design, aerospace engineering and the production of high resolution graphics such as digital animation in motion pictures. Supercomputers have many processors working together and lots of memory (RAM). Sometimes organisations connect lots of microcomputers (ordinary desktops and laptops) together, by linking lots of microcomputers together (1000’s) they can create their own super computer.
Task 24 Find out:
a) List another two uses of supercomputers other than the ones listed above
b) Go to the website www.top500.org, write down some of the details of the top
supercomputer
Site, Manufacturer, Core, Theoretical Peak, Power, Memory
c) What do think it means by “cores”?
d) The typical memory of a desktop computer is 4 GB, how many times bigger is the memory of the top supercomputer?
e) Write a short note on Big Red II Indiana University’s latest supercomputer; include the date of first use and how many instructions it can process per second.
25 Distributed/Grid computing
Distributed computing, is a type of grid computing, it brings together of lots (1000s) of desktop computers to solve a problem as a network. In distributed computing the processing power and memory of each individual computer is harnessed to tackle a small part of the task. Working
together means thousands of processors and terabytes of RAM can be used to solve the problem. In a distributed system computers of different types work on the one task you only need to download a small program, which will allow your computer to talk to the organising computer. Distributed computing is often used in academic research and public-interest projects.
Distributed computing uses the processing and memory of many 1000’s of desktop computers unlike a supercomputer which has its own processors and memory. But it can replicate the power of a supercomputer without the costs involved.
Task 25 Find out:
a) Terabyte is a term of measurement used in computing, how many bytes are there in a terabyte?
b) Listed below are some projects that are being undertaken using distributed computing, pick any three and write a short paragraph on each, stating what the purpose of the project is, how many computers are involved and any other details such as estimated RAM used and the amount of Teraflops (instructions per seconds that can be processed).
Climateprediction.net DistrRTgen Einstein@home FreeHAL Milkyway@home Renderfarm.fi
26 Quantum computers
The future may produce an even faster type of computer by doing things differently. It is claimed that the quantum computer will be 3600 times faster than today’s technology.
The BBC recently reported that:
“A $15m computer that uses "quantum physics" effects to boost its speed is to be installed at a Nasa facility. It will be shared by Google, Nasa, and other scientists, providing access to a machine said to be up to 3,600 times faster than conventional computers.”
“ … according to a paper presented this week (the result of benchmarking tests required by Nasa and Google), it is very fast indeed at finding the optimal solution to a problem that potentially has many different combinations of answers. In one case it took less than half a second to do something that took conventional software 30 minutes.”
27 Screen resolution
This determines the quality of images that can be distinguished, for example, a 1680 *1050 high resolution screen or a 1280 * 1024 medium resolution.
1024 × 768 means the width is 1024 pixels and the height is 768 pixels.
The term "pixel" is actually short for "Picture Element." These small little dots are what make up the images on the screen.
Pixels
Task 26 Find out:
Get the names, prices and screen resolution of two 17 inch TFT screens. Pick the one you think is best and give the reasons (not just price) for your decision.
28 Simulation
Simulations can be used to train people and to help them develop skills, such as driving a car or flying a plane, by using a computer based model.
Simulators can be very realistic and accurate ways of training people to handle complex machinery in an environment where a
learner’s mistakes are not dangerous or costly.
Simulations can also be used for leisure purposes
Task 27 Find out:
In flight simulation a trainee pilot can experience many different types of emergency without any risk to themselves, passengers or expensive equipment. Produce a short presentation on the use of a simulation to train people. Your presentation should contain key points, relevant graphics and hyperlinks to useful websites.
29 Virtual reality
A virtual reality (VR) system is an advanced form of simulation that can create the illusion that the user is part of the computer’s world and can move about and manipulate that world. VR is the digital representation of the real world.
VR systems can be used for:
Training people who work in dangerous places, for example, a nuclear power station
Training people such as surgeons, as real training on patients would not be acceptable
Creating a 3-d plan of a new construction which can be looked at from all angles, even from inside. A plan of a single building can be modelled or even a whole town
For leisure activities
A range of specialised sensors that detect movement are fitted to goloves, suits and headsets worn by the user. The user can point to, lift and touch objects in the virtual world. The headset can have a pair of small screens that create a 3-D visual effect. The feeling of reality is improved by sound from headphones to immerse the user in the world of virtual reality.
Task 28 Find out:
a) What do you think is meant by the word “immerse”?
b) Have a look at this website http://www.amusitronix.com/ and give three examples of how
30 Software
Software is the name given to all the programs that run
technology and run on
technology, these programs can be applications like browser software or the operating system which mangaes the hardware of computers, smartphones and tablets and gives a platform for the “apps” to run.
Task 29 Find out:
a) What are the NO1 apps from Google and Apple today? b) What are the words top 3 business software applications? c) What is the bestselling software at Amazon.com?
31 Operating Systems
The operating system is the most important program that runs on a computer. Operating systems
perform basic tasks, such as recognizing input,
sending output to the display screen, keeping
track of files on backing storage, on desktops and
laptops the OS will control peripheral devices
such as hard disk drives and printers. The OS
provide a software platform on top of which
other programs, called application programs, can
run. The application programs must be written to run on top of a particular operating system. Apps designed for smartphones running on the Andriod OS cannot (without alteration) work on Apple products, and vice versa.
Task 30 Find out:
a) What is the latest version of the Android operating system that is used on smartphones and tablets? State the version number and its name and when it was released.
b) What operating system is on the latest smartphones from i) Windows, ii) Blackberry, iii) Apple and iv) Nokia?
c) What is the latest version of OS issued by Microsoft for laptops? d) What is the latest version of the OS used by Apple desktop computers?
32 Browser software
A browser is a program that helps you navigate the World Wide Web, move between and look at web pages by entering the address of the page you want or by clicking on a hyperlink or using the back and forward arrrows.
Examples of browser software are:, Chrome, Opera, Firefox, Safari and Internet Explorer.
Task 31 Find out:
a) Identify the browser software from the icons shown below.
33 Search engines
You access a search engine using your browser software. Search engines are used to look for web pages that are related to you search term. The most popular search engine in recent years has been Google. So popular has this search engine beome that the word “google” has become a verb, when people need to find out about something on the WWW they use the phrase “I’ll google it”. Other search engines are provided by Yahoo and Alta Vista and many others.
Don’t get mixed up between a browser and a search engine.
Task 32 Find out:
a) What is the purpose behind the Blackle search engine? b) What company is behind the Bing search engine?
c) Rank these search engines in order of popularity, with the most popular first: Bing, Yandex, Baidu, Google and Yahoo.
d) Which countries are the Baidu and Yandex search engines popular in?
e) Which company rose to prominence using the innovation “PageRank”? Describe what pagerank is.
34 Systems analyst
A systems analyst designs new systems or improves existing ones. System analysis involves finding out which task the system has to carry out and then deciding on the hardware and software needed. The systems analyst will look at all the jobs the company does currently and decide which jobs can be improved by introducing new technology and new software. This process is called systems analysis.
Task 33 Find out:
a) Systems Analyst is a job that comes about because of the introduction of technology, listed below are other jobs that linked to computer technology, write a brief paragraph about each: Programmer, Computer Engineer and Network Manager.
35 Projects
Project 1 The Cloud
In two recent surveys both IT specialists and consumers both cast doubt over their use of Cloud computing. The biggest concern for IT specialists was concern about the security of data stored in the cloud with 92% expressing concerns1. Just over 75% of all consumsers surveyed stated that they would rather purchase software than rent it as they did not want to commit to an on-going
payment2.
Find out:
a) Examine the surveys produced by PEER 1 Hosting and Corel Corporation and state what the main concerns are for both IT specialists and consumers about using the Cloud.
b) Put forward an arguments that would allay the concerns of the IT specialists. c) Present reasons to the consumers why using the Cloud could be to their benefit.
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PEER 1 Hosting 2 Corel Corporation
