اول محاضرة فى مادة الحاسب الالى لكلية التجارة عندنا فى هيبس جروب بالشرح
chapter 1:an introduction to computers
*** what is a computer?
A computer is an electronic device operating under the control of instructions stored in its own memory unit that can:
1. accept data
2. process data arithmetically and logically
3 .produce output from the processing
4. store the results for future use
data{input}--------------> computer{processsing}------------------> information{output}
(this figure shows ablock diagram of the computer)
*** the difference between data and information?
Data:
• raw material from which information is derived.
• If considered on its own an item of data has very little value. .
• Example: The name of person.
The score of student. .
The date of event.
.
Information:
*The data that have been collectd and Processed into ameaningful form.
*we use data to produce information that will help us making decisions.
*The processing of data can be carried out by human or by computer.
*** The computer system:
A computer system is a combination of six elements:
1. hardware
2. software
3. data – information
4. procedures
5. people
6. communications
*** computers hardware:
*The computer hardware is the physical equipment you can see and touch when using a computer system
*The computer system consists basically of the units list below:
1. input hardware.
2. processing hardware.
3. storage hardware.
4. output hardware.
5. communication hardware.
*** input hardware (input device):
*input: is the data put into the computer for processing.
*the function of input hard ware is to collect data and convert it into aform suitable for computer processing.
*the most common input device are the keyboard and the
***processing hard ware(processor)(cpu):
*processing hard ware is the brain of the computer where all computations, decisions control is carried out.
*cpu it consists all the electronic circuits necessary to execute aprogram stored in memory.
*actually, the cpu transform data into informations.
***storage hard ware:
*storage hard ware is used to hold the program that controls the function of the computer , along with the required data to be processed.
*there are two main types of storage(memory):
Main memory or internal memory
Closely associated with the cpu
auxiliary memory or external memory
are: magnetic disk, magnetic tape and optical disk
*** output hardware(output device):
• output: is the results produced by the cpu.
• output hardware is a device connected to the computer to deliver information for human use.
• The most common output devices are the printer and the monitor.
*** communications hardware (network):
*the function of communications hardware is to facilitate the connections between computers and between groups of connected computers (networks)
*an example of communications hardware is the modem which allows computers to be communicate with each other over telephone lines.
*** computer software:
• software is instructions that tell the hardware what to do.
• Software is ageneral term for all of the computer programs that are involved in the operation of the computer system.
• Actually, without soft ware the computer system is of on use.
• You cannot touch software but it can be stored in and retrieved from memory.
*** generally speaking software can be categorizd as: system software or applications software.
System software:
*consists of programs supplid by the computer system manufacturer to help the user of the system and to control the operation of the computer system.
* at the core of the system software are the operating system.
Applications software:
• consists of the programs to do the various jobs the computer was purchased to do in the first place
• example: programs that make up pay rolls, play games , solve mathematical equations.
• The most popular activities carried out on smaller type or microcomputers are: graphics, word processing, and office work sheet
موضوع: اول محاضرة فى مادة الحاسب الالى لكلية التجارة عندنا فى هيبس جروب بالشرح 
الأحد أغسطس 10, 2014 7:15 pm