ملخص لمادة COMP-A بجامعة نزوى
من إعداد إسلام أحمد علي عبدالعزيز أحمد
A summary of COMP-A
BY:Islam Ahmed Ali
:Types of computers
- personal computers
- handheld computers
hardware: is Collection of electronic devices
software: devices cooperate with each other, by means of specified instructions that software
Types of personal computers
Types of handheld or mobile (pocket computers):
- celluler phones
- music or media players (MP3)
- personal digital assistants (PDAs) or smart phones
Specifications for Desktop:
1-Sit on, beside, or under desk
2-Process data quickly
3-used in small company, schools, and homes.
4-two types of them (pc and apple)
Advantages for notebooks or laptop:
2-Power consumption considered “greener” alternative
3-Can purchase accessories to enhance enjoyment
4-bigger hard drive for storages
5-a larger screen
6-wireless external mouse or keyboard or more memory
1-Similar to notebook but smaller and less expensive
2-Designed to handle wireless communications or access to
1-Similar to notebook for portability and connection to data
2-Screen can swivel or fold over
3-Uses touch screen capability for data entry With finger, pen device, or built-in keyboard
1-playing and listening to music
2-taking pictures or video
6-accessing the Internet
7-global navigation systems (GPS)
PDAs Or smart phones:
1-Specific software helps make appointments, keep contact lists, or write notes
2-Very popular for portability and software
3-Can be main computing device
4-Incorporates touch screen technology
MP3 or media players:
1-MP3 refers to file type for music to be recognized on audio player.
2-Media player enables viewing of movies, videos, or books
3-Provide audio and visual capabilities or access to Internet
the System Unit:
1-Often most important and expensive part
2-Many separate devices inside the box (motherboard, CPU, RAM etc….) that perform specialized functions for the computer.
3-Notebook has same components as desktop
1-Often called “brain” of computer as instructions from software programs and input received are executed here
2-Referred to as Central Processing Unit (CPU) and processes information and instructions at different speeds
3-Hertz (Hz) measures speed of internal computer clock in terms of frequency or number of cycles per second
4-Dual and quad core processors contain two or four processor chips
Looking at memory:
1-Computers developed using numbering system of 1s and 0s or binary system
2-For computer to store information, must have memory chips installed
3-Memory measured in bits and bytes
4-Bit is smallest unit of data used by computers
5-Group of eight bits make one byte (8 bits= 1 byte).
6-Read the table Page 8
Read Only Memory (ROM) Bios:
1- Group of integrated circuits responsible for:
-Loading operating system
2- Occurs only when computer first turned on or each time you restart (reboot) computer ,is also used to control input and output devices such as disk drives, keyboard, and monitor while the computer is running.
3- This memory is found in calculators and printers, as it reads information entered and processes it during time it resides in memory
4- When process complete, clears itself and waits for next entry
5-Does not perform any tasks other than reads information and
Random access memory (RAM):
1-Located in system unit as electronic memory pool where computer holds copies of programs and data
2-Temporarily stores software program currently using and data created in program; may be referred to as system RAM (RAM is volatile)
Measured in nano seconds ns
|Ram volatile||ROM non volatile|
|Read and write||Reading only|
|Used in printers||Used in calculators and printers|
|Short time-temporary||Long time-permanently|
What is a storage system?
1-it is the ability to store data and information on a computer for future use.
2- RAM is temporary so you must save work to storage device
3-Storage device you use depends on amount of storage you need and speed of data retrieval or data transfer rate
4-Data transfer rate: The amount of digital data that is moved from one place to another in a given time.
5-Hard disk drives used most often to store and retrieve software programs and data
6-Can use other media such as flash drive or optical disc for backup or portability purposes
Working with hard disk drives:
1-hard disk drive is a primary storage area for both data and programs
2-it has 3 functions:
– Rotates disk at constant speed to access sectors on entire disk surface
-Moves read/write head across tracks on entire disk surface
-Reads data from disk and writes data to disk using read/write head
3-data and information located on the disk must be divided into tracks sectors.
4-types off hard disk internal and external
5- Data transfer rate (throughput) of hard drive is function of hard drive rotation speed and number of heads per surface
6-The higher the rotation speed and/or number of heads,
the less time it takes to find data
7-Range in capacity from 100 MB to 100+ GB
8-Data from RAM written on disk arranged in tracks divided in sectors
9-Places special information on each track that marks location of each sector
10-Process of preparing disk for use is called formatting
Formatting: is process of preparing disk for use
|Optical writers||Optical drives|
|Reading and write||reading|
Read the table Page 14
*Removable media systems: include flash memory cards, USB flash key/thumb drives, or external hard drives
*Benefits include portability, large storage size, and data-sharing capability.
1-Hard drives in network server similar to hard disk drives in computer
2-Traditionally much larger than available with desktop computer
3-May be set as disk array, as drives usually organized to work together.
What are input/output devices?
Enables communication between user and computer
Three classifications of Input/Output devices:
1-Send information to computer
2-Display or transmit information from computer
3-Communicate between computers
Anything used to enter data into computer
Anything used to display data on or from computer
1-Mini-program tells operating system what kind of device it is, what make or brand it is, and its purpose
2-Main purpose is to enable communication between operating system and device
1-Automatically identifies new device connected so it looks for and installs device automatically
2-If cannot find right driver, will need to use software that came with device or search for driver on Internet
Remember printers properties page 23
Factors that affects computer performance:
1-Size of RAM if is smaller that will effects:
-System resources are too low to process work if many programs and files open at same time.
-Take a long time to display the contents of document on screen.
2-Size of hard disk(HD) if is smaller that will effects:
-No enough space to install many programs and save files.
-No enough space for operating system to processing many programs at the same time.
3-Speed of CPU if slower that will effects :
-Take a long time on open and close large file.
4-Add new hardware, and software for computer that will cause:
-Slowdowns the computer.
-Conflicts with other system components.
To protect your computer system from theft you should to do:
1-Use security cable to lock down your computer.
2-Store it in locked room and can’t any person to enter into it.
3-Avoid store any sensitive data or information in your computer.
To protect your computer system from overheating you should to do:
1-Do not store near heat source or cold environment.
To protect your computer system from magnetic fields you should to do:
1-Ensure there are no magnetic items near computer.
To protect your computer system from electrical damage you should to do:
1-Use surge suppressor or UPS to protect from power surges, brownouts, or general fluctuations.
2-Use converter that adapts electrical system and voltage.
3-Avoid connecting too many electrical devices on same power
*make backups of data
*ensure antivirus program is up to date and scan computer regularly
Performing Basic Troubleshooting:
Analyzing the Information
Attempting Basic Solutions
Communicating the Problem Accurately
Analyzing and Selecting the Proper Action
Implementing the Solution
Confirming the Problem is Fixed
Documenting and Communicating the Incident
Avoiding Similar Problems in the Future
Determining the Purpose:
How will this computer be used and by whom?
Size and type of hard drive
Desktop or notebook or netbook?
Microprocessor speed, amount of RAM, quality of video card, size of monitor, and size of hard drive
Selecting the Operating Platform:
Which is best for this environment and what is currently in use?
What application programs run and any compatibility issues
Looking at Support Options:
Warranty(usually one year and covers any replacement costs associated with manufacturing defects)
Support agreements( Retailers often offer support agreement which can help extend the life of your computer for a cost that may be less than paying for each repair as need arises)
Extended warranties( cover two years beyond the manufacturer’s one year warranty)
Useful life of new computer (minimum of two to three years)
What is a Software Program?
1-Refers to everything that makes computer run
2-Only functions when loaded into computer’s RAM
1-Created using programming languages to create software code
2-Algorithms are set of rules designed to complete specific tasks in specific sequences
3-Specifies how software program identifies input type, and then proper format for output
Update: Renew for a program. Adding or renew some features in that program
Upgrade: replace of a program with newer version of the same program.
Look at these pictures is important the definitions
You must look at page 48, 49, 50 and 51