Computer programming

Lecture 1
Introduction to Computers and C++ Programming

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What is Computer?
Computer Organization
Computer Languages
C++
Your First Program in C++
Variables and Operators

Computer Programming
(HKU SPACE HDIT 10/11)

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Computer Programming
(HKU SPACE HDIT 10/11)

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Computer

◦ Device capable of performing two major functions
1.
2.

Computations
Making logical decisions

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Computer programs

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Hardware

◦ Sets of instructions used by computers to process data
◦ Various devices comprising computer

 Keyboard, monitor, mouse, disks, DVD-ROM, processing units, etc. 

Software

◦ Programs that run on computer, i.e., sets of instructions to command computer to perform actions and make decisions ◦ Computer programs are subset of software

Computer Programming
(HKU SPACE HDIT 10/11)

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Six logical units of computer
1. Input unit

 “Receiving” section
 Obtains information from input devices
 Keyboard, mouse, microphone, scanner, networks, etc.

2. Output unit

 “Shipping” section
 Takes information processed by computer
 Places information on output devices
 Screen, printer, networks, etc.
 Information may be used to control other devices
(becomes input of other devices)

Computer Programming
(HKU SPACE HDIT 10/11)

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3. Memory unit
 “Warehouse” section
 Rapid access, relatively low capacity
 Retains information from input unit
 Immediately available for processing

 Retains processed information
 Until placed on output devices

 E.g., Random Access Memory (RAM)

4. Arithmetic and logic unit (ALU)
 “Manufacturing” section
 Performs arithmetic calculations and logic decisions

Computer Programming
(HKU SPACE HDIT 10/11)

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5. Central processing unit (CPU)

 “Administrative” section
 Supervises and coordinates other sections of computer 6. Secondary storage unit

 Long-term, high-capacity “warehouse”