Introduction to Computer Components

Introduction to Computing Sciences Course Outline

• The course covers the definition, historical background, characteristics, and generations of computers
• It details the basic functional components of computing systems, including classification of computer hardware and software
• Topics include computer hardware (functional components, modern input/output units), software (system software, introduction to computer networks and internet), operating systems, utilities, application software, and data storage/internal data representation
• The course also delves into bits and character representation, data compression, records, and files, along with basic file processing models
• Content also includes diverse and growing computer/digital applications and information processing within society
• Discussion of the Internet's application and impact on the world
• Content includes various areas and programs of the computing discipline, job specializations for computing professionals, and future trends in computing

What is a Computer?

• A computer is a device or set of devices that operate under the control of a stored program
• It automatically accepts and processes data to produce information
• The essential elements of any processing include input, processing, storage, and output

Computing Defined

• Computing is the process of using computer technology to complete a task
• It may involve hardware and/or software, but it must involve a computer system
• Most people use some form of computing on a daily basis, such as email, telemedicine, or business transactions

Computing Includes

• Designing, developing, and building hardware and software systems
• Designing a mathematical sequence of steps, known as an algorithm
• Processing, structuring, and managing various types of information

Computing Field

• Computer engineering
• Software engineering
• Information systems
• Information technology
• Computer science

Computer Science

• The study of theory, experimentation, and engineering behind the design and use of computers

History of Computer Science and Generations

• Computer development is often discussed through generations, each with key technological advancements that change how computers function
• These advancements lead to smaller, cheaper, more powerful, efficient, and reliable devices

First Generation (1940-1956)

• Used vacuum tubes for circuitry and magnetic drums for memory
• Extremely large, expensive, and consumed significant electricity and generated substantial heat
• Relied on machine language for performance
• Used punched cards and paper tape for input
• Solve one problem at a time

First Generation (1940-1956) - Key Examples

• Universal Automatic Computer (UNIVAC) - 1951: First fully electronic digital computer built in the U.S.; built at the University of Pennsylvania
• ENIAC (Electronic Numerical Integrator And Calculator): First general-purpose computer; weighed 30 tons and contained 18,000 vacuum tubes

Second Generation (1956-1963)

• Replaced vacuum tubes with transistors
• Smaller, faster, cheaper, and more energy-efficient computers
• Still used punched cards for input/output
• Transition from binary machine language to symbolic or assembly language
• Developed high-level programming languages such as BASIC, COBOL, and FORTRAN

Third Generation (1964-1971)

• Introduced integrated circuits (transistors, resistors, and capacitors on a single chip)
• Interaction via keyboards and mouse
• Computers were smaller and cheaper
• Development of the operating system (OS)

Fourth Generation (1971-Present)

• Availability of microprocessors (thousands of integrated circuits on a single silicon chip)
• Introduction of the Intel 4004 chip and IBM computers
• Computers linked to form networks, leading to the Internet
• Development of a graphical user interface (GUI)

Very Large Scale Integrated Circuit (VLSI)

• Transistors, resistors, and capacitors on a single chip
• Intel 4004 had 2,250 transistors
• Pentium IV has 42 million transistors

Birth of Personal Computers (MITS Altair) - 1975

• 256-byte memory
• 2 MHz Intel 8080 chips
• Cost $395 (kit) / $495 (assembled)

Fifth Generation (Present and Beyond)

• Based on artificial intelligence
• Includes voice recognition and superconductors
• Parallel processing and superconductors are helping make artificial intelligence a reality
• Quantum computing and molecular technology will profoundly shape computers in the years to come
• Goal is to create devices responding to natural language and capable of learning.

Types, Classification, and Characteristics of Computer Systems

• Computers are classified by:

  • Representation of numbers (digital, analog, and hybrid)
  • Size (supercomputer, mainframe, minicomputer, microcomputer)
  • Purpose (special-purpose, general-purpose)

• Computer characteristics include speed, capacity, versatility, diligence, accuracy, and automation

Benefits of Computer Systems

• Used in engineering, science, health, marketing, security, education, management, and production

Computer Systems: Hardware and Software

• A computer comprises both hardware (physical components) and software (programs)

Hardware

• Hardware is the physical part of the computer, including the input unit, central processing unit (CPU), storage unit, and output unit

Software

• Software directs the computer system operations.
  • System software (interface, hardware controls, utilities, translators, and database management systems)
  • Application software (programs for specific tasks, from word processing to database management, and spreadsheets)

Input Unit

• The primary source of information input into the computer
• Includes keyboard, mouse, joystick, trackball, light pen, stylus, graphic tablet, touch screen, scanners, magnetic tapes, audio input, computer disks, and DVDs

Central Processing Unit (CPU)

• Acts as the "heart" of the computer
• Manages input, output, and processing from other devices
• Consists of arithmetic and logic unit (ALU), control unit, and memory unit
• Speed measured in GHz

Storage Unit

• Manages data storage (temporary or permanent)
• Main Storage (RAM) is where active programs and data are stored
• Backing Storage (secondary storage, e.g., hard drive) is used for mass storage, often for permanent storage

Output Unit

• Translates data into a form that the user can understand
• Commonly includes monitors, printers, plotters, computer output microfilm, and voice outputs

Main Memory (RAM)

• Also called internal storage or primary storage
• Integral part of the processing unit
• Acts as the computer's working memory and stores operating systems, application programs, and utility routines
• Volatile; data lost when computer is turned off

The Control Unit

• Coordinates all computer activities inside and outside the CPU
• Receives instructions, decodes them, fetches data, and generates signals for processing
• Doesn't directly perform calculations; it directs the operations.

Arithmetic and Logic Unit (ALU)

• Carries out arithmetic and logical operations like addition, subtraction, multiplication, division, logical operations, and comparisons
• These data processing calculations are performed by the ALU.

Random Access Memory (RAM)

• The main working memory used by the computer
• Modern computers contain as much RAM as user can afford
• Volatile; data is lost when the computer is turned off or restarted

Secondary Storage (Auxiliary Storage)

• External to the main processor area, providing permanent storage
• Includes magnetic tapes, magnetic disks, and compact disks
• Used for mass storage, where data is not immediately needed by the computer

File Organizing Models

• Random: Data accessed without a specific sequence (used for enquiry purposes)
• Sequential: Data organised consecutively (for master files, updated with transaction files)
• Index-Sequential: Combination of sequential and random; data is organised sequentially but with an index for more rapid search

Basic Models of File Processing

• Data is stored and retrieved using file processing systems (FPS)
• Files are organized into categories using a hierarchical structure, making retrieval and management efficient

Advantages of File Organization Systems

• Cost-effective
• Easy to use
• Scalable, allowing for adjustments in data size based on needs

Types of Files

• Master: Contains regularly updated and dynamic data, including details about people, places, things, etc.
• Update: Contains information that updates the master file
• Reference: Contains less-frequently changing, reference-type data (like price lists)
• Historical: Contains archived data.

Key Considerations for Software Acquisition

• The software should improve the operating function of the business.
• The software should be high-performance and easy-to-learn.
• Provide good documentation including installation, use, and maintenance instruction
• Have readily available backup and support resources
• The software should be of dependable quality and should be acquired from reputable sources/providers.

Computer System Maintenance

• Regular care and maintenance, to prevent problems later, save downtime, stress levels, and expense

System Maintenance Procedures

• Deleting temporary files
• Running scandisk (to check for and fix disk errors)
• Emptying the Recycle Bin

Defragmenter

• Organises a hard drive for more efficient storage
• Breaks large files into pieces and stores them in different locations on the hard drive (due to hard drive construction)

Scandisk

• Can be run to check for and correct errors on the hard drive
• Important in cases of computer freezes or power outages

Data Communications

• Communication between devices involves sharing information, which can be local (face-to-face) or remote (over a distance)
• Telecommunication is communication over distance
• Data is information in a form agreed upon by communication parties, including pictures, letters, numbers, and sounds
• Data communication is how data is exchanged between two devices using a communication medium (e.g., wires for networks)

Data Flow

• Communication between two devices can be simplex, half-duplex, or full-duplex
• Simplex: One-directional (e.g., keyboard/monitor)
• Half-duplex: Two-directional but only one can transmit at a time
• Full duplex: Two-directional and simultaneous transmission

Effectiveness of Data Communication

• Delivery: Correct delivery to the intended destination
• Accuracy: Delivering data without errors
• Timeliness: Timely delivery in real-time scenarios
• Jitter: Uneven delays in data delivery

Five Components of Data Communication

• Message: The information being sent
• Sender: The device transmitting the message
• Receiver: The device receiving information
• Transmission Medium: The physical means of transmission (e.g., cables, radio waves)
• Protocol: Rules governing communication between devices.

Public Switched Telephone Network (PSTN)

• Used for both voice and data communication