Summary
notes
GRADE11:::::::::
2025
MR b. chibaya
Hardware
Software
Computer Management
Acknowledgment: These notes are compiled based on Mr. Muza’s teaching and content from IT is Gr8 and DBE Theory Textbooks.
Compiled: Bryne Chibaya
Email: brynechib@gmail.com
CAPS
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----------------------------------------------------------------------------------- Systems Technologies -----------------------------------------------------------------------------------------Hardware
Inside the Computer
Hardware refers to all the tangible parts of computer.
Motherboard
- Is a circuit board which is used to connect all other devices
on a computer.
Functions of the Motherboard: • It provides connectors for different devices. E.g. USB
port.
• Allows communication between/among devices.
• Distributes power to different parts of the computer.
Modular Design
Is a concept whereby a computer is made up of separate
parts.
Advantages
- Easy repair
- Easy upgrade
Components That Support Modular Design on The Motherboard
ZIF (ZERO Insertion Force)
- Is a socket used to insert the CPU.
DIMM (Dual Inline Memory Module)
- Is a socket used to insert the RAM(Memory)
SATA (Serial Attachment)
- Is a connector/socket for connecting storage devices e.g
HDD/SSD or optical drive.
External Connectors e.g USB, VGA (Monitor), Sound ports
- Used to connect all devices which support the plug & play.
-
Expansion Slots
- Upgrade e.g external VGA card
- PCI (Peripheral Component Interconnect)
- PCIe (Peripheral Component Interconnect express).
-
CPU
Responsible for all the processing
Factors to be considered when buying a computer: - Speed of the CPU which is measured in Ghz, the higher the
GHz the faster the computer.
- Number of cores, the more the cores the faster the
computer e.g core i7 is faster than core i3.
- Cache
NOTE a Core is a single processor.
Machine Cycle
1. Fetch – Fetches instruction from the RAM/Register.
2. Decode – Computer reads the instructions
3. Execute – Processing
4. Transfer – result is sent to the monitor or storage.
RAM (Random Access Memory)
- Is a temporary space used during processing.
- Is measured in GB or MB.
- Is also known as memory.
Characteristics of RAM/Memory
- It is volatile – it loses its contents in case of power cut.
- Is temporary.
- It is relatively expensive as compared to storage.
- Is limited.
- Faster than storage
•
•
•
•
RAM(Memory)
Volatile
Electronic
Relatively Fast
Relatively Expensive
Hard Disk Drive (Storage)
• Permanent
• Magnetic
• Relatively Slower
• Relative Cheaper
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----------------------------------------------------------------------------------- Systems Technologies -----------------------------------------------------------------------------------------ROM (Read Only Memory)
- None-volatile: holds its contents even after power cut.
- You can read on ROM but you cannot write on the ROM
- Found on chips on the motherboard
- ROM is used to keep software which is used by the
computer to start firmware.
- BIOS- Basic Input and Output System
o Is a chip which contains information used by a
computer during booting.
Functions of the BIOS: • Loads the operating system from the HDD
• Checks the functionality of hardware.
• It provides a menu to configure your computer.
• It controls hardware at low level.
CMOS – Complementary Metal Oxide Systems
- Gives power to the BIOS so it does not lose contents after
power cut.
Firmware – Software on the ROM
- Controls the basic working of a device.
EPPROM – Electronically Erasable and Programmable ROM
- ROM found mostly on mobile devices
- Flash drives
- smartphones
- GPS devices
Activity
1.
List 5 characteristics of RAM
5
2.
Explain the functions of the BIOS
4
4.
Give an example of a ROM chip on the motherboard
1
5.
Differentiate between memory and storage
6
-
Video Card VGA
A port used to connect the monitor
Is used to create images which are displayed on the
computer.
-
-
Some computers have a video card with a Graphics
Processing Unit.
Therefore, a computer without a GPU makes use of the CPU
to create images.
Data Transmission on the motherboard
Data is transmitted via some wires or lines on the
motherboard and these lines are called buses.
Bus is a set of wires used to transmit data on the
motherboard.
Types of Buses
i.
Point to point Bus (Dedicated Bus)
- Is a fast connection which is dedicated for two devices. E.g
CPU- RAM dedicated channel or CPU – VGA
- The point-to-point bus is also known as the FSB (Front Side
Bus
ii.
BSB – Back Side Bus (ordinary bus)
- Used to transmit data among slow devices
- E.g USB, networks, sound
Co-ordination of data transmission
System clock – a small device used to co-ordinate the way how
data is transmitted on the motherboard.
Driver – is a program that allows communication between two
devices.
Configuration – loading of drivers so that a computer can work with
a connected device
----- END OF HARDWARE ---CONGRATULATIONS FOR MAKING THIS FAR!!!
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----------------------------------------------------------------------------------- Systems Technologies -----------------------------------------------------------------------------------------Software
Processing Techniques
Operating System – is a set of programs designed to manage all
the operations of the computer.
Functions
a) Manages Memory
b) Manages Storage
c) Manages Input/Output
d) Manages processing
e) Manages interface
Examples of operating systems
a) Mobile devices operating system
b) Personal Computer operating system
Mobile Operating Systems
Personal Computer (Desktop)
1.
2.
3.
4.
5.
Android
iOs
Blackberry
Windows Mobile
Windows RT
-
Computers from Apple are known as MacBook.
Other computers are called PCs
A computer with an OSx Operating System is a called a
Macintosh
Jailbreaking is the installation of an operating system on a
device which was not designed for it.
-
1.
2.
3.
4.
Windows
OSx
Linux
Unix
i.
-
Multitasking
Is when a computer appears to be running many programs
at the same time whereas it splits time among the programs.
ii.
Multiprocessing
- Is when an operating system allows a computer to process
programs, instructions and threads at the same time using
different cores or processors.
iii.
Multithreading
- Is when the operating system split a program into different
threads and process the threads at the same time using
different cores or CPUs
Programming Languages
Programmers design software by instructing computers to do what
they want.
Examples of programming language.
i.
Delphi
ii.
Scratch
iii.
Python
iv.
C++
v.
Java
vi.
Java Script
vii.
COBOL
viii.
C
ix.
C#
x.
Pearl
xi.
PHP
Types of Programming Languages
i.
High Level
ii.
Low Level
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----------------------------------------------------------------------------------- Systems Technologies ------------------------------------------------------------------------------------------
High Level Programming Languages
- Are written in the programmer’s language and converted by
the computer into machine language.
- The conversion of code from human understandable
structure to machine language is done by an interpreter or a
compiler.
- Compiler works in such a way that it converts the whole
program into an object code.
- Interpreter works in such a way that it converts line by line
until the whole program is converted.
Examples of Compiled Languages
i.
Delphi
ii.
Objective C
iii.
C++
Examples of interpreted languages
i.
Java
ii.
Python
iii.
Scratch
Low Level Programming Languages
- Is when the programmer uses machine language to write
short programs.
- Used to write short programs found on devices such as
washing machine, microwave.
Reasons
i.
To test your programs
ii.
Reduce the cost of hardware by using one computer.
Advantages
i.
Reduces costs on hardware
ii.
Allows testing of software on the same machine.
iii.
It provides convenience as you work on one computer.
Software used for virtualization
i.
VM Ware
ii.
Perales
iii.
Virtual Box
Process
i.
ii.
iii.
iv.
Install the operating system on the main computer.
Install the virtualization software
Install the additional operating system.
Repeat step 3 until all operating systems are installed.
Networks
Network- is an interconnection of computers using a communication
media which can be wired or wireless for the purpose of sharing
resources.
Components on a network (LAN)
Switch – is a device used to connect computers on a network.
Virtualization
Virtual – not real an idea implemented using Software and
Hardware.
-Virtualization is the ability to put an operating system on top of
another operating system.
Communication Media
i.
UTP – Unshieded Twisted Pair
- It uses electrical signal to transmit data over copper wires.
ii.
Fiber Optic
- It uses light pulses to transmit data over a glass tube.
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----------------------------------------------------------------------------------- Systems Technologies -----------------------------------------------------------------------------------------Computer
- A computer which is connected to a network must have a
Network Interface Controller (NIC)
Purpose of NIC
1. Allows communication on a network.
2. It decodes and encodes data transmitted over a device.
Components on a network. (WAN).
WAP – Wireless Access Point.
Types of Cables
1. UTP
- It uses copper wires to transmit data in form of electronic
signals
- It is cheaper to buy
- It covers short distance of less than 100m (signal
attenuation).
- It is easy to install.
- It has a slow speed measured in mb/s , max 100mb/s
2. Optic Fiber
- It uses glass tube to transmit data in form of light pulses.
- It is expensive to buy.
- It covers long distance
- It is not easy to install
- It has a high speed measured in GB/s or 1GB/s
Wireless
1. Bluetooth
- Is wireless method which transmit data in form of radio
signals via the space.
- It covers short distance
- It is normally used for on PAN (Personal Area Network)
- It has weak security.
- A network of devices using Bluetooth is called a piconet.
2. Wi-Fi (Wireless Fidelity)
- Is a wireless method used to connect devices on a network
over a long distance that Bluetooth
- The standard for Wi-Fi is (801.g or 801.n) 802.11g; 802.11n
- It transmits data in form of radio signals
-
-
Router
A device used to connect to the internet
A router contains WAP, MODEM and Network technologies
in one
Modem
Converts signals from one form to the other.
Cellular Technologies
5G – fifth generation
4G – fourth generation (LTE)
3G – Third generation
Edge – Evolution for Digital Global Enhancement
GPRS – Global Packet Radio System
PAN (Personal Area Network)
-
Is established around an individual
HAN (Home Area Network)
-
Is a network established in a home
HAN (Home Area Network)
-
Is established over a short geographical area e.g School,
hospital, university
WAN (Wide Area Network)
- Is established over a wide geographical e.g town, country,
region, worldwide.
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----------------------------------------------------------------------------------- Systems Technologies ------------------------------------------------------------------------------------------
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GRADE 11-----------------------------------------TERM 1--------------------------------------------SUMMARY NOTES BOOKLET-----------------------------------------------------------2025