ICT
systems consist of two main parts:
Hardware
: Part of the computer that you can
touch
Example : keyboard, mouse, monitor,
ROM, RAM, speaker, printer, etc.
Software
: The programs that supply the instructions
to the hardware to tell it
what to do.
Example : Operating system
(Linux, Windows, IOS, etc), database,
web browser, web design package, word-processing package,
photo editing package, etc.
web browser, web design package, word-processing package,
photo editing package, etc.
The
main components of a general- purpose computer:
Example:
* Input
device: mouse, keyboard, webcam, microphone
* Output
device: monitor, printer, speaker
* Secondary
storage device: DVD-R/W, portable disk drive, usb flashdisk.
Central Processing Unit
often called processor is:
* The brain of the computer
* It consists of millions tiny circuits on a
silicon chip
* It controls the step-by-step running of the
computer system
* It do all the calculation, performs all the
logical operations and deals with the storage
of data and programs in memory
INTERNAL MEMORY OR
PRIMARY STORAGE:
1.
ROM ( Read Only Memory) is :
* Held
on a computer chip
* Called
non-volatile memory because it does not lose it contents when the power is
turned off
* Used
to hold instructions to start the computer (boot program)
* Used
to store data that cannot be altered by the user
2.
RAM (Random Access Memory) is :
* It
held on a computer chip
* It’s
called volatile memory because the contents disappear when the power is turned
off
* Can
be written to and read from
* Can
be altered by the user
* Holds
the software currently in use by the user
Note:
Having a large amount of ROM and
RAM in a computer is important, because having more memory means:
* Applications running faster
* More applications are able to run at the same
time
* Users are able to move quickly between
applications
Operating System are programs that control the hardware directly by
giving step-by-step instruction that tell the computer hardware what to do.
Operating system jobs:
* Handles
inputs and outputs
* Recognize
hardware
* Supervises
the running of other programs
* Handles
the storage of data
* Maximizes
the use of computer memory
* Handles
the interrupts and decided action to take
The Type of Interface used by OS
* Graphical
User Interface (GUI)
The main
features of GUI: Windows, Icons, Menus, Pointers (WIMP)
* Command
Line Interface (CLI)
Here you have to type in series
commands
Note:
Post-WIMP interaction for phones,
PDAs or tablet computers allows actions such as:
* Pinching
: pinch your fingers together to zoom in or spread the further apart to zoom
out
* Rotating
: one finger moves up and the other fingers move down to rotate the object
* Swiping : swipe your finger over the touchscreen to
turn over a page of a document
Types of Computer
* Mainframe:
very sophisticated and powerful computer that used in very large companies.
* PC
(Personal Computer) Desktop : designed to be use in one place
* Laptops:
designed to be portable and used while on the move.
* Netbook
: smaller and lighter than laptop
* Palmtop
: can be held the palm of the hand, usually have virtual keyboard which appears
on the screen
* Personal
Digital Assistant (PDA) : hand-held computer, used a real keyboard rather than
touch screen.
Cloud Computing: Internet-based
computing where the programs and data are stored on the internet
Application of
cloud computing:
* Streaming music over the internet
* Google docs
* E-books and newspaper, etc
