fundamentals and a brief history of computer systems
TRANSCRIPT
Fundamentals and a Brief History of Computer Systems
The first computer was called the ENIAC, which was built during World War II (1943-1946).
Charles Babbage is considered to be the father of computing after his invention and concept of the Analytical
Engine in 1837.
The IBM 5100 is the first portable computer, which was released on September 1975.
Q: What is a computer?
A: A machine that manages information
Definition: General purpose machine, commonly consisting of digital circuitry, that accepts (inputs), stores, manipulates, and generates (outputs) data as numbers, text, graphics, voice, video files, or electrical signals, in accordance with instructions
called a program.
Representing Information
• Computers store and manipulates numbers– Information needs to be encoded or
represented– The numbers need to be interpreted
• The memory of any computer just looks like:
010011010010011101001001001011010100100100100100100101111110000001
Adding meaning to bits
• As programmers we add meaning to the bits by defining an interpretation
• Handled by the programming language– Types and variables
• Examples
42 -> 000000000000000000000000001010103.14159 -> 01000000010010010000111111010000“unix” -> 01111000011010010110111001110101
• Four components of a computer system:– CPU - central processing unit
• Makes decisions, performs computations, and delegates input/output requests
– Memory: Disk Drives, CD drives, Tape drives, USB flash drives.
• Stores information– Input devices: Keyboard, Mouse,
• Gets information from the user to the computer– Output devices: monitor
• Sends information from computer to the user
Hardware
Hardware
Memory
CPU
InputDevices
OutputDevices
SystemSoftware
ApplicationSoftware
Software
• Application software– Easy-to-use programs designed to perform
specific tasks• System software
– Programs that support the execution and development of other programs
– Two major types• Operating systems• Translation systems (compilers & linkers)
Software
Copyright © 2000 by Brooks/Cole Publishing Company
A division of International Thomson Publishing Inc.
Computer Software Relationships
UserInterface
Basic Input and Output Services (BIOS)• needed for a computer to boot up
User Interface Operating System
User Interface Application Programs
Computer Hardware
Application Software
• Application software makes computer popular and easy to use
• Common application software: Microsoft Word, WordPerfect PowerPoint Netscape, Internet Explorer PhotoShop, Photo-Paint Quick Time Dreamweaver
• Controls and manages the computing resources• Examples
– Windows, Unix, MSDOS,
• Important services that an operating system provides:– Security: prevent unauthorized users from accessing
the system– Commands to manipulate the file system– Input and output on a variety of devices– Window management
Operating System
What is a (programming) language?
• A program needs to be written in a language• There are many programming languages
– Low-level, understandable by a computer– High-level, needs a translator!
• C++ is a high level programming language
A sequence of instructions
A program(in computer language)
An algorthm (in human language)
• Machine binary language: unintelligible
• Low-level assembly language – Mnemonic names for machine operations– Explicit manipulation of memory addresses– Machine-dependent
• High-level language– Readable– Machine-independent
Levels of programming language
Machine binary language Low-level assembly High-level
An example:
How to translate?
Examples of compilers:– Microsoft Visual C++, Eclipse, g++
A program written in high-level programming language (for example, C++ program)
A low-level (machine language) program that is understandable by a computer (for example, a PC)
COMPILER (for example, Visual C++)
Integrated Development Environments
• Combine all of the capabilities that a programmer would want while developing software (VC++ 2008, Eclipse) Editor Compiler Linker Loader Debugger Viewer