lesson 1 0x001 001
DESCRIPTION
Lesson 1 0x001 001. Mohamed Zaki Principal Lecturer. The Computer System. Main Topics. What is a Computer? General-purpose & Dedicated Computers. Computer as a system. Computer hardware system. Peripherals Input Peripherals. Output Peripherals. Storage. Course Assessment. - PowerPoint PPT PresentationTRANSCRIPT
Lesson 1 0x001
001
The Computer System
Computer Systems / Ch. 1 1
Mohamed ZakiPrincipal Lecturer
Main Topics
• What is a Computer?• General-purpose & Dedicated Computers.• Computer as a system.• Computer hardware system.• Peripherals
– Input Peripherals.– Output Peripherals.– Storage.
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Course Assessment
Computer Systems / Ch. 1 3
Attendance & Contribution
10
Assignments (2) 20Presentation 10Midterm 20Final 40
What is a Computer?
Computer: is a programmable machine that receives input, stores and manipulates data/information, and provides output in a useful format.
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General Purpose and Dedicated Computers
1. General-Purpose computer solves many types of problems, such as (document typing, Drawing, games,..etc)
2. Dedicated Computers is used for only one task.(Control process in the manufacturing industry)
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Remark: In general a dedicated computer is the same as a general-purpose computer in its fundamental construction
General Purpose and Dedicated Computers (cont.)
System: is a set of interrelated components working together to achieve a certain goal.
So, to consider a computer as a system, the computer must contain related components working
together to perform the main functions.
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Computer as a system
Computer Components As a System
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Computer System
Hardware Software
Peripherals Central Processing
System Programs
ApplicationPrograms
Control Unit ALU Main Memory
Input Unit Output Unit SecondaryStorage
1-Computer Hardware Hardware devices can be organized according
to the following system functions:
• Input: Devices that convert data into electronic form in the computer system.
• Output: The output devices are used to convert the electronic information into a human understandable form.
• Processing: The CPU is the main processing component. ALU (Arithmetic Logic Unit) will perform all the processing.
• Storage: Takes place in the primary storage unit of the CPU and in secondary storage units. these devices store data and program instructions are needed for processing.
• Control: control unit of the CPU is the control component of the computer system. It interprets computer program instructions and transmits directions to other components of the computer system.
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Peripherals
Parts of computer that transfer data in and out.
• Input Peripherals.• Output Peripherals.• Secondary Storage.
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Input Peripherals:Devices used for transferring data from the outside
world representation into the internal character code of the computer.
• Keyboard.• Barcode reader: Barcode data can be described as a
sequence of vertical lines vary in thickness, light focuses on and scanned across these lines using a small laser beam, then data can be read and input to computer.
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Other input peripherals:
• Light pens. }• Mice } Pointing devices• Touch screens. }• Digitizers.• Scanners.• Microphones.• Cameras.
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Output Peripherals
• Printers 1- Impact Printer: this method of printing
is based on the impact of a hard object against an ink-coated ribbon, which is then forced on the paper to make it mark the shape of the character.
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Line printersDot matrix printers
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Output peripherals (Impact Printers) (Cont.)
Output peripherals (cont.)2- Non-Impact Printers
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Ink-jet printers.
Thermal printers.
Laser printers.
Comparison between printersDisadvantages Advantages Mechanism Impact/Non-impact Type
Low quality. • Used ordinary papers.
• Not expensive.
It prints a whole line of text at one go.
Impact Line printer
Low speed. noisy
• Used ordinary papers.
• cheap
Use a pattern of dots in the shape of a character.
Impact Dot Matrix
Ink is expensive compared with printer cost.
High speed. Silent. Colored Not expensive.
Sprays a stream of ink on an ordinary paper.
Non-impact Ink-Jet
Slow. Paper is costly.
Silent. Use heat to produce an image on special paper.
Non-impact Thermal
Expensive Large compared with others.
High speed.High quality.Silent.
A laser beam is used to dry up a powdered ink on the paper.
Non-impact Laser
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• Plotters.
• Visual Display Unit(VDU).
• Projectors (Data Show)
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Output peripherals (Cont.)
Secondary Storage
• Optical Storage - CD (Compact Disc) - DVD (Digital Versatile Disc)
• Flash Memory
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Storage Units
1. Bit (Binary Digit): it is the smallest unit to store data,(0 or 1).
2. Byte (B) :it is the basic storage unit of memory. It consists basically of 8 bits. It can hold one symbol only at a time.
3. Kilo Byte (KB)=1024 B =210 B
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Storage Units of Memory
4. Mega Byte (MB)=1024 KB =(1024 x 1024) B =104,8576 B = More than a Million of bytes. =210 x 210=220 B.5. Giga Byte (GB)=1024 MB =(1024 x 1024) KB =(1024 x 1024 x1024) B =104,8576 KB = 1,073,741,824 B = More than a Billion of bytes. =210 x 210 x 210 = 230 B.
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Storage Units
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*
Bit Byte KByte MByte GByte 8 1024 1024 1024
%
Bit Byte KByte GByte TByte 8 1024 1024 1024
TByte 1024
MByte 1024
Refreshing Questions
• The ……………………. Can be described as an input device.
1.Light pen 2.HP laser jet printer 3. Plotter 4.None
• A device used for transferring a paper based image into a computer image is……………….
1. Ink jet printer 2. Scanner 3. Digitizer 4. None
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Refreshing Questions (cont.)
• RPM stands for _________.• DVD stands for _________.• VDU stands for _________.• 10 MB =_____ KB.• Arrange the following in ascending order:
0.6GB, 840MB, 15000KB
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