UNIT 1: TYPES AND COMPONENTS OF COMPUTER SYSTEMS
1.1 HARDWARE AND SOFTWARE:
Hardware is a general term for the machinery and electronic parts of the computer system such as keyboard, mouse, monitor, processor, circuit board and so on.
Software is a general term for the programs used to operate a computer
There are two types of software:
+ systems software: System software is computer software designed for the operation and control of computer hardware and provides an architecture for running application software. System software can be divided into two types, operating systems and software utilities.
+ applications software: Application software is a program capable of making a computer to direct a certain job the user wants to perform.
This is some pictures:
Hardware is a general term for the machinery and electronic parts of the computer system such as keyboard, mouse, monitor, processor, circuit board and so on.
Software is a general term for the programs used to operate a computer
There are two types of software:
+ systems software: System software is computer software designed for the operation and control of computer hardware and provides an architecture for running application software. System software can be divided into two types, operating systems and software utilities.
+ applications software: Application software is a program capable of making a computer to direct a certain job the user wants to perform.
This is some pictures:
1.2 MAIN COMPONENTS OF COMPUTER SYSTEMS:
Input devices: keyboard, mouse, scanner, digital camera, joystick.
Output devices: monitor, printer, plotter, projector, speaker, headphones, light/led.
Secondary storage devices: DVD R/W drive, removable hard drive, flash memory drive, external hard drive.
* There are four key components:
_ central processing unit (CPU)
_ internal hard disk
_ random access memory (RAM)
_ read only memory (ROM)
* The central processing unit (CPU) - interprets and executes the commands from the computer hardware and software.
The internal hard drive - is the computer's main memory. This is where the applications software, disk operating system and data files are stored.
Random access memory (RAM) - is an internal chip where data is temporarily stored when running applications.
Read only memory (ROM) - is a memory used to store information that needs to be permanent.
HERE ARE SOME PHOTOS:
Input devices: keyboard, mouse, scanner, digital camera, joystick.
Output devices: monitor, printer, plotter, projector, speaker, headphones, light/led.
Secondary storage devices: DVD R/W drive, removable hard drive, flash memory drive, external hard drive.
* There are four key components:
_ central processing unit (CPU)
_ internal hard disk
_ random access memory (RAM)
_ read only memory (ROM)
* The central processing unit (CPU) - interprets and executes the commands from the computer hardware and software.
The internal hard drive - is the computer's main memory. This is where the applications software, disk operating system and data files are stored.
Random access memory (RAM) - is an internal chip where data is temporarily stored when running applications.
Read only memory (ROM) - is a memory used to store information that needs to be permanent.
HERE ARE SOME PHOTOS:
1.3 OPERATING SYSTEMS
The general tasks for a typical operating system include:
+ controlling the operation of input, output and backing storage devices
+ supervising the loading, running and storage of applications programs
+ dealing with errors that occur in application programs
+ maintaining security of the whole computer system
+ maintaining a computer log (which contains details of computer usage)
+ allowing communication between user and the computer system (user interface)
The general tasks for a typical operating system include:
+ controlling the operation of input, output and backing storage devices
+ supervising the loading, running and storage of applications programs
+ dealing with errors that occur in application programs
+ maintaining security of the whole computer system
+ maintaining a computer log (which contains details of computer usage)
+ allowing communication between user and the computer system (user interface)
*Command line interfaces
Is a means of interacting with a computer program where the user issues commands to the program in the form of successive lines of text (command lines).
Is a means of interacting with a computer program where the user issues commands to the program in the form of successive lines of text (command lines).
* Graphical user interfaces
One of the most common is windows icons menu and pointing device (WIMP) which was developed for use on personal computer (PCs)
In recent years, devices such as touch screen phones use post - WIMP interaction, where fingers are in contact with the screen.
One of the most common is windows icons menu and pointing device (WIMP) which was developed for use on personal computer (PCs)
In recent years, devices such as touch screen phones use post - WIMP interaction, where fingers are in contact with the screen.
1.4 TYPES OF COMPUTERS
* PC/desktop computers
Advantages
+ Spare parts and connections tend to be standardized, which usually results in low costs.
+ Desktops tend to have a better specification for a given price (often due to size and construction constrains in laptops)
+ The large casing allows good dissipation of any heat build-up.
Disadvantages
+ Desktops are not particularly portable since they are made up of separate components.
+ All the components need to be hooked up by wiring, which can be quite complex and clutters up the desk space.
+Because they are not particularly portable, it is necessary to copy files, etc. When you want to do some work elsewhere
Advantages
+ Spare parts and connections tend to be standardized, which usually results in low costs.
+ Desktops tend to have a better specification for a given price (often due to size and construction constrains in laptops)
+ The large casing allows good dissipation of any heat build-up.
Disadvantages
+ Desktops are not particularly portable since they are made up of separate components.
+ All the components need to be hooked up by wiring, which can be quite complex and clutters up the desk space.
+Because they are not particularly portable, it is necessary to copy files, etc. When you want to do some work elsewhere
* Laptop computers
Laptop (or notebook) refers to a type of computer where the monitor, keyboard, pointing device and processor are all together in one single unit
The key features are: + low weight (to aid portability)
+ low power consumption (and also long battery life)
+ a processer that does not generate too much heat (cooling is very important).
Advantages
+ They are very portable, since the monitor, pointing device, keyboard, processor and backing store units are all together in one single box.
+ There are no trailing wires
+ They can take full advantage of WIFI
+ Since they are portable, they can link into any multimedia system
Disadvantages
+ Since they are portable, they are easy to steal!
+ They have been limited battery life so the user may need to carry a heavy adaptor
+ The keyboards and pointing devices can sometimes be awkward to use
+ Heat dissipation is more difficult due to the structure of the laptop computers
Laptop (or notebook) refers to a type of computer where the monitor, keyboard, pointing device and processor are all together in one single unit
The key features are: + low weight (to aid portability)
+ low power consumption (and also long battery life)
+ a processer that does not generate too much heat (cooling is very important).
Advantages
+ They are very portable, since the monitor, pointing device, keyboard, processor and backing store units are all together in one single box.
+ There are no trailing wires
+ They can take full advantage of WIFI
+ Since they are portable, they can link into any multimedia system
Disadvantages
+ Since they are portable, they are easy to steal!
+ They have been limited battery life so the user may need to carry a heavy adaptor
+ The keyboards and pointing devices can sometimes be awkward to use
+ Heat dissipation is more difficult due to the structure of the laptop computers
* Netbooks
Disadvantages
+ Netbooks don't have optical drives
+ The keyboards are only about 80 per cent the size of laptop keyboards
+ They lack some of the features found in larger machines, principally due to the size constraints and to the fact that they are cheaper to purchase
Disadvantages
+ Netbooks don't have optical drives
+ The keyboards are only about 80 per cent the size of laptop keyboards
+ They lack some of the features found in larger machines, principally due to the size constraints and to the fact that they are cheaper to purchase
* Personal digital assistants
Advantages
+ They can be used anywhere because of their size
+ They are very lightweight and are more portable than laptop computers
Disadvantages
+ It is difficult to enter text quickly
+ They have very limited capabilities due to the software and the operating system used
Advantages
+ They can be used anywhere because of their size
+ They are very lightweight and are more portable than laptop computers
Disadvantages
+ It is difficult to enter text quickly
+ They have very limited capabilities due to the software and the operating system used
* Mainframe computers
Uses
The main features of main frame computers are as follows
+ They can have several CPUs
+ They have very fast processor speeds
+ They can support multiple operating systems
+ They have huge amounts of storage capacity
+ They have huge internal memories
+ They often operate using time sharing or batch processing
Advantages
+ They can be used to do large jobs
+ The very powerful facilities afforded
+ They are capable of very large number crunching
Disadvantages
+ Mainframe computers need to be permanently housed in a large room, so cannot be moved around
+ They are very expensive to operate and maintain
Uses
The main features of main frame computers are as follows
+ They can have several CPUs
+ They have very fast processor speeds
+ They can support multiple operating systems
+ They have huge amounts of storage capacity
+ They have huge internal memories
+ They often operate using time sharing or batch processing
Advantages
+ They can be used to do large jobs
+ The very powerful facilities afforded
+ They are capable of very large number crunching
Disadvantages
+ Mainframe computers need to be permanently housed in a large room, so cannot be moved around
+ They are very expensive to operate and maintain
1.5 TABLETS
Tablets are a relatively new interest-enabled portable computer
Some of the typical features of tablets include;
+ high-definition, anti-glare displays
+ front-and back-facing cameras
+ lower weight and longer battery life than laptops
+ Bluetooth connection to printers and other devices
+ flash (solid state) memory and cloud storage facilities to back up and synchronize (often just referred to as 'sync') data sources
+ sensors to carry out the following functions
Tablets are a relatively new interest-enabled portable computer
Some of the typical features of tablets include;
+ high-definition, anti-glare displays
+ front-and back-facing cameras
+ lower weight and longer battery life than laptops
+ Bluetooth connection to printers and other devices
+ flash (solid state) memory and cloud storage facilities to back up and synchronize (often just referred to as 'sync') data sources
+ sensors to carry out the following functions
Advantages
+ very fast to switch on (no time delay waiting for the 'windows' system to load up)
+ fully portable-they are so lightweight that they can be carried anywhere
+touch screen technology means they are simple to use and don't need any other input devices
+ can use several Apps as standard (such as built-in camera, MP3/4 players and so on)
+ don't generate any hear - they use solid state technology
+ battery life of a tablet is a lot longer
+ when the power button is pressed it goes into standby but remains connected to the internet, so the user still hears alerts when emails or other 'events' are received
+ very fast to switch on (no time delay waiting for the 'windows' system to load up)
+ fully portable-they are so lightweight that they can be carried anywhere
+touch screen technology means they are simple to use and don't need any other input devices
+ can use several Apps as standard (such as built-in camera, MP3/4 players and so on)
+ don't generate any hear - they use solid state technology
+ battery life of a tablet is a lot longer
+ when the power button is pressed it goes into standby but remains connected to the internet, so the user still hears alerts when emails or other 'events' are received
Disadvantages
+ they often have limited memory or storage compared to a laptop
+ they can be expensive to run if the internet is being accessed frequently via 3G/4G/5G mobile phone networks
+ typing on a touch screen can be slow and error-prone compared to a standard keyboard
+ transferring of files often has to be done through an 'Apps store'; the lack of an App 'drag and drop' facility can prove irritating for users
+ laptops tend to support more types of file format than tablets, and are also better equipped to run different types of software
+ they often have limited memory or storage compared to a laptop
+ they can be expensive to run if the internet is being accessed frequently via 3G/4G/5G mobile phone networks
+ typing on a touch screen can be slow and error-prone compared to a standard keyboard
+ transferring of files often has to be done through an 'Apps store'; the lack of an App 'drag and drop' facility can prove irritating for users
+ laptops tend to support more types of file format than tablets, and are also better equipped to run different types of software
1.6 SMARTPHONES
Smartphones allow normal phone calls to be made but also have an operating system (such as Android or Windows), allowing them to run a number of computer applications
Advantage
+ Smartphones today have integrated many features of other simple tools, from watches to contacts, compass ... all in one tiny device.
+ It is compact and convenient
Disadvantage
+ Low battery capacity
+ Application error and restart frequently
+ expensive
+ very easy for other people may gain unauthorized access to information remotely personal data and use it for purposes that are sure you do not want and it is difficult to trace the fellows to return fairness to you.
Smartphones allow normal phone calls to be made but also have an operating system (such as Android or Windows), allowing them to run a number of computer applications
Advantage
+ Smartphones today have integrated many features of other simple tools, from watches to contacts, compass ... all in one tiny device.
+ It is compact and convenient
Disadvantage
+ Low battery capacity
+ Application error and restart frequently
+ expensive
+ very easy for other people may gain unauthorized access to information remotely personal data and use it for purposes that are sure you do not want and it is difficult to trace the fellows to return fairness to you.
TEST OF ICT'S SECTION 1