Computer Generation 3

Third Generation Computers (1964-1971)

• Used remote processing, time-sharing, and multi-programming operating systems
• Featured high-level programming languages such as FORTRAN-II TO IV, COBOL, PASCAL PL/1, and ALGOL-68
• Characteristics:
  • Integrated circuits (IC) used
  • More reliable compared to previous generations
  • Smaller in size
  • Generated less heat
  • Faster
  • Required lesser maintenance
  • Costly
  • Required AC
  • Consumed lesser electricity
  • Supported high-level languages
• Examples of third generation computers: IBM-360 series, Honeywell-6000 series, PDP (Personal Data Processor), IBM-370/168, and TDC-316

Fourth Generation Computers (1971-1980)

• Used Very Large Scale Integrated (VLSI) circuits
• Featured real-time, time-sharing, and distributed operating systems
• Characterized by:
  • VLSI technology used
  • Very cheap
  • Portable and reliable
  • Use of personal computers
  • Very small size
  • Pipeline processing
  • No AC required
  • Concept of internet was introduced
  • Great developments in networks
  • Computers became easily available
• Examples of fourth generation computers: DEC 10, STAR 1000, PDP 11, CRAY-1 (Super Computer)

Output Devices

Projector

• Projects output onto a screen using light and lenses
• Ideal for presentations or teaching large groups

Printer

• Produces hard copies of processed data
• Enables users to print images, text, or other information onto paper
• Types of printers:
  • Daisy Wheel Printer
  • Dot Matrix Printer

Daisy Wheel Printer

• Invented by David S. Lee at Diablo Data Systems
• Features a wheel or disk with spokes or extensions resembling a daisy
• Has molded metal characters at the end of extensions
• Prints characters by rotating the wheel and striking the ink ribbon against the paper
• Cannot print graphics, slow, and noisy, hence obsolete

Dot Matrix Printer

• An impact printer that prints characters and images using patterns of dots
• Uses a print head with pins to produce dots on paper
• Widely used for storing and viewing movies and distributing software programs
• Also known for its ability to store large files and programs

Ports

PS/2 Port

• Used for old computer keyboards and mice
• Also known as the mouse port
• Typically found on older computers, with two PS/2 ports each for the mouse and keyboard

Universal Serial Bus (USB) Port

• Can connect various external USB devices such as hard drives, printers, scanners, mice, and keyboards
• Introduced in 1997
• Minimum of two USB ports found on most computers
• Data travels at 12 megabits per second
• USB compliant devices can draw power from the USB port

VGA Port

• Connects a monitor to a computer's video card
• Has 15 holes, similar to a serial port connector but with holes instead of pins

Power Connector

• A three-pronged plug that connects to the computer's power cable and a power bar or wall socket

Firewire Port

• Transfers large amounts of data at high speeds
• Connects camcorders and video equipment to computers
• Data travels at 400 to 800 megabits per second
• Invented by Apple
• Has three variants: 4-Pin FireWire 400 connector, 6-Pin FireWire 400 connector, and 9-Pin FireWire 800 connector

Modem Port

• Connects a PC's modem to the telephone network

Data Measurement Units

Megabyte

• A unit of measurement for data storage
• Frequently used to calculate the size of documents, software packages, and media files
• Still an important and commonly used unit of measurement

Gigabyte

• Contains 1024 megabytes
• Has a considerable data storage capacity
• Often used to measure the storage capacity of hard drives, solid-state drives, and other data storage devices
• Commonly used to describe the size of multimedia files and the demand for large amounts of storage

Terabyte

• Contains 1024 gigabytes
• Represents a huge data storage capacity
• Often used in large databases, video collections, and enterprise-level storage systems
• Becoming increasingly significant due to the growing need for large-scale data processing and storage

BIOS

• Stands for Basic Input Output System
• A type of system software stored in Read-Only Memory (ROM) on the motherboard or flash memory in advanced systems
• The first software to activate when a computer is turned on

Operating System

Introduction

• Acts as an interface between software and computer hardware
• An integrated set of specialized programs used to manage overall resources and operations of a computer
• Controls and monitors the execution of all other programs that reside in the computer

Objectives of Operating System

• Make the computer system convenient to use in an efficient manner
• Hide hardware resource details from users
• Provide users with a convenient interface to use the computer system
• Act as an intermediary between the hardware and its users
• Manage resources of a computer system
• Keep track of who is using which resource, granting resource requests, and mediating conflicting requests from different programs and users
• Provide efficient and fair sharing of resources among users and programs

Functions of Operating System

• Memory Management: keeps track of primary memory usage and allocates memory to programs
• Processor Management: allocates the processor (CPU) to a process and deallocates when no longer required