Computer Systems Overview

Computer System Functions

• A computer takes data as input.
• Stores data and instructions in memory for later retrieval and use.
• Processes data into useful information.
• Outputs information.
• Controls all the above steps.

Computer System Definition

• An electronic data processing device.
• Accepts and stores input data.
• Processes data, and outputs results in the required format.

Advantages of Computers

• High Speed: Process data quickly.
• Accuracy: Minimize errors in calculations.
• Storage Capability: Store large amounts of data efficiently.
• Diligence: Perform tasks repeatedly without fatigue.
• Versatility: Handle different applications.
• Reliability: Provide consistent results and minimize downtime.
• Automation: Perform tasks automatically, reducing human intervention.
• Reduction in Paperwork: Digitalize information reducing storage requirements.
• Reduction in Cost: Increase efficiency and lower costs in the long run.

Disadvantages of Computers

• No I.Q: Cannot think or reason independently.
• Dependency: Reliance on computers can be risky if they malfunction.
• Environment: Computers need specific environmental conditions for optimal performance.
• No Feeling: Lacks emotions and cannot understand human feelings.

Computer Applications

• Computers are used in every field.
• Business Organizations:
  • Payroll Calculations.
  • Budgeting.
  • Sales Analysis.
  • Financial Forecasting.
  • Managing Employee Database.
  • Stock Management.

Computer Generations

First Generation (1946-1959)

• Used vacuum tube technology.
• Unreliable due to frequent breakdowns.
• Supported only machine language.
• Expensive to operate.
• Generated significant heat and consumed a lot of electricity.
• Slow input/output devices.
• Large in size and not portable.
• Some examples: ENIAC, EDVAC, UNIVAC, IBM-701, IBM-650

Second Generation (1959-1965)

• Transistors replaced vacuum tubes.
• More reliable and smaller size.
• Consumed less electricity and generated less heat.
• Faster performance and supported assembly languages.
• Still costly, required A.C., and not as portable.
• Some examples: IBM 1620, IBM 7094, CDC 1604, CDC 3600, UNIVAC 1108

Third Generation (1965-1971)

• Used integrated circuits (ICs).
• Further improvements in reliability, size, speed, and efficiency.
• Reduced maintenance needs.
• Supported high-level programming languages.
• Some examples: IBM-360 series, Honeywell-6000 series, PDP (Personal Data Processor), IBM-370/168, TDC-316.

Fourth Generation (1971-Present)

• Employed very-large-scale integration (VLSI) technology.
• Cheaper and more portable.
• Introduction of personal computers (PCs).
• Smaller size with improved performance.
• Pipeline processing for speed optimization.
• No A.C. required.
• Internet and network advancements.
• Examples: DEC 10, STAR 1000, PDP 11, CRAY-1 (Supercomputer), CRAY-X-MP (Supercomputer)

Fifth Generation (Present-Future)

• Utilize ultra-large-scale integration (ULSI) technology.
• Focus on Artificial Intelligence (AI) development.
• Natural language processing advancements.
• Parallel Processing for further performance improvements.
• Superconductor technology development.
• User-friendly interfaces with multimedia features.
• Powerful and compact computers at affordable prices.
• Examples: Desktop, Laptop, Notebook, Ultrabook, Chromebook

Types of Computers

PC (Personal Computer)

• A small, inexpensive computer for individual users.
• Based on microprocessor technology.
• Used for word processing, accounting, desktop publishing, spreadsheets, and database management.

Workstation

• Computer designed for engineering applications (CAD/CAM), desktop publishing, software development, and graphics-intensive tasks.
• Features high-resolution graphics, large RAM, networking support, and a graphical user interface.

Minicomputer

• Midsize computer capable of supporting up to 250 users simultaneously.
• A multi-processing system with moderate computing power.

Mainframe

• Large and expensive computer supporting hundreds or thousands of users concurrently.
• Execute many programs simultaneously and offer high processing power.

Supercomputer

• Fastest computers currently available.
• Extremely expensive and used for complex tasks involving massive calculations.
• Applications include:
  • Weather forecasting.
  • Scientific simulations.
  • Animated graphics.
  • Fluid dynamics calculations.
  • Nuclear energy research.
  • Electronic design.
  • Geological data analysis.