Transcript Chapter 1 PowerPoint

Chapter 1 – Computing
Fundamentals
History of Electronic Computers
 First
computer
– ABC (Atanasoff Berry Computer) at Iowa State U.
– 1930’s
– Solved large numbers of simultaneous equations
 First
“all-purpose” computer
– ENIAC (Electronic Numeric Integrator And
Calculator)
– Main idea developed from ABC notes
 Both
had set wiring –data was input to memory
Lesson 1.1
John von Neumann
 Mathematician
 Proposed
alternative to “hard wiring”
 Introduced concept of stored program
instructions
– Both data and instructions were stored
– Led to development of multipurpose
computers
Lesson 1.1
Computer Categories
Supercomputers
Mainframe computers
Workstations
Personal computers (microcomputers)
Laptops
More powerful than ENIAC
Palmtops
Speed and size!
Lesson 1.1
Architecture
 Four
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main parts
CPU (central processing unit)
Main memory
Controllers
Peripheral devices
 Hardware
– Electronic and mechanical devices integrated or
connected to computer
Lesson 1.2
Schematic
Motherboard
CPU
Arithmetic
Logic Unit
Register
Register
Register
Control
Unit
Peripheral Devices
Lesson 1.2
Main
Memory
Controllers
Main Memory
 Stores
information to be process or
instructions to be executed
 Information stored in bits (binary digits)
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Two states: on or off
Byte is 8 bits (character of information like ‘b’)
Grouped into packets called cells or words
Bit pattern is code
Lesson 1.2
Memory Sizes
 Represented
by 2 raised to a power
Trillion
1,099,511,627,776
Billion
1,073,741,824
Million
1,048,576
Thousand
1,024
240 = terabyte
230 = gigabyte
220 = megabyte
210 = kilobyte
23 = 8 bits (byte)
Lesson 1.2
Memory Access
 RAM
– Random access memory
– Allows access to cells in no particular order
– Volatile
 ROM
– Read only memory
– Cannot be modified by user
– Information is permanent (non-volatile)
 Serial
access
– Sequence of cell followed to extract information
Lesson 1.2
Central Processing Unit (CPU)
 Control
Unit
– Controls activities of CPU
– Directs flow of instructions
– Communicates with ALU
 Registers
– Rapid access memory cells
 Arithmetic-Logic
Unit (ALU)
– Arithmetic operations
– Logic operations (compares, etc)
Lesson 1.2
Peripheral Devices
 Two
categories
– Mass storage
Disk drives
 Tape drives
 CD drives, etc.

– Input-output (I/O)
Monitors
 Keyboards
 Printers
 Speakers, etc.

Lesson 1.2
Mass Storage Devices
 Store
information
 Devices that rotate, write to or read from
called drives
 On/Off (binary)
– Magnetic spots on disks or tape
– Pits or “lands” on CDs (optical disks)
Lesson 1.2
Major Differences between Main
and Mass Storage
 Slower
access in mass storage than main
 Mass storage portable
 Mass storage usually have greater capacity
and can hold large amounts of information
 Main memory is volatile and disappears
when power is off, but mass storage
permanent (unless deliberately erased)
Lesson 1.2
Input-Output Devices
 Input
– Convert information coming in to computer
compatible form
– Examples: keyboards, scanners, microphones
 Output
– Convert computer codes into user
understandable format
– Examples: monitors, printers, speakers
Lesson 1.2
Controllers
 Coordinate
actions of peripheral devices
with actions of computer
 Constant
flow between peripheral
equipment and controller
– Need to know what peripheral equipment is
doing
Lesson 1.2
Networks
 Groups
of individual computers and
peripheral devices linked together to share
information and resources
 Two
categories
– Wide area network (WAN)
– Local area network (LAN)
 Topology
Lesson 1.3
is “shape” of connection
Network Topologies
Bus
Ring
Tree
Irregular
Lesson 1.3
Data Representation
 Each
bit is either on or off, 1 or 0
 ASCII code – 8 bits make a byte
 Integers represented by base 2, binary system
– Each place position is power of 2 (23+22+21+20)
 Two
other number systems used
– Octal (powers of 8)
– Hexadecimal (powers of 16)
Lesson 1.4
Memory Addresses
 Every
memory cell needs to be addressed
 Binary
 One
code represent address of cell
cell can contain address of another
memory cell
Lesson 1.4
Programming Languages
 Assembly
language
– One level above machine language
 High-level
language
– Designed to simplify writing programs
– Four types
 Procedural (imperative)
 Functional
 Declarative
 Object oriented
Lesson 1.5
Software
 Set
of instructions read into computer’s
memory and later executed on demand
 Two types
– System
 Operating systems
 Utility programs
 Language translators
– Application
Lesson 1.6
Operating System Software
 Software
written into memory upon startup
 Interface
between user, computer and
peripherals
 Two
categories
– Multiple-user computers
– Single-user computers
Lesson 1.6
Utility Programs
 Perform
basic operations necessary for
performance of computer system
– File operations
 creating, copying, saving
 deleting, merging, sorting
 Encapsulated
Lesson 1.6
with operating systems
Language Translators
 Convert
programmer-made instructions
(source code) into machine-language
instructions (object code)
 Three types
– Assemblers: Convert assembly language programs
to object code
– Interpreters: Converts an instruction to object code
then executes it
– Compilers: Converts entire program to object code
Lesson 1.6
Integrated Development
Environment (IDE)
 Full
package
– Compiler
– Text editor
– Debugging tools
 Allows
creation, repeated execution and
modification of a program
– Helps find violations of language rules
Lesson 1.6
Application Software
 Many
types exist
 Examples of common types
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Games
Word processing
Database management
Graphics
 Program
solves practical problem or does
specific tasks
Lesson 1.6
Software Engineering
 Describes
process of software development
 Process involves many steps (Figure 1.10)
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Definition of problem
Design scheme (breaking into modules)
Coding modules
Testing
Program never “done”
Assemble modules
Test until working correctly
Lesson 1.7
Structured Programming
 Top-down
design
– Defines all tasks program is to perform
 Tasks
separated and functions developed
– Can be designed separately
– Two types
 Library
– Included in C++ development environment
 Programmer-defined
– Custom made by user
Lesson 1.7
Development of C++ Language
 Middle
1980s at Bell Laboratories
 Bjarne Stroustrup
 Improvement upon C language
 Standardized in 1997
– American National Standards Institute (ANSI)
– International Standards Organization (ISO)
 Object-oriented
Lesson 1.7
C++ Development Environment
 Primary
goal to produce executable file
– Machine language instructions
 Allows
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user to
Create source code
Test it
Modify it
Convert it to executable format
Lesson 1.7
C++ IDE Operations
 Editing
text to create source code
 Preprocessing source code
 Compiling source code and code attached
by preprocessor
 Linking object code generated in step 3
with other object code
Lesson 1.7
Summary
Learned about:
 Computer
history
 Basic computer architecture
 How bits are stored
 Differences between programming languages
 Software engineering
 C++ language background
 Using IDE to create executable programs
Chapter 1