Information Systems Notes - Week 2 Overview

Introduction to Information Systems Engineering

  • Overview of information systems in the context of computer engineering.
  • Focus on Week 2 content related to System Unit.

Key Concepts in Information Systems

  • Information Systems: Interrelated components that process data and convert it into information, integrating hardware and software.
  • Data vs Information: Data represents raw facts, while information is processed data that has meaning.

Computer System Characteristics

  • Computer systems consist of hardware (physical components) and software (programs and data).

Computer Hardware Components

  • Input Devices: Hardware that allows data entry (e.g., keyboard, mouse).
  • Central Processing Unit (CPU): Brain of the computer that executes programs and manages operations.
  • Memory: Temporary storage for data and instructions (e.g., RAM).
  • Storage Devices: Permanent storage for data (e.g., hard drives, SSDs).
  • Output Devices: Translate processed data into human-readable form (e.g., monitors, printers).

Detailed Overview of CPU

  • The CPU consists of:
    • Arithmetic and Logic Unit (ALU): Performs mathematical and logical operations.
    • Control Unit: Directs operations; interprets instructions.
    • Memory Unit: Temporary data storage for ongoing processes.
  • Processor speeds and architectures have evolved, leading to multi-core CPUs (e.g., dual-core, quad-core).

Clock Speed and Performance

  • Clock speed limits processing speed and is measured in Hertz (Hz).
  • Multi-core processors allow simultaneous instruction execution.

Cache Memory

  • Cache Memory: Fast-access memory that reduces the need to fetch data from slower main memory. Types include:
    • L1 Cache: Small and fast.
    • L2 Cache: Larger but slightly slower.

Input Devices Overview

  • Various input devices include:
    • Keyboard: Standard data entry tool.
    • Mouse: Most common pointing device.
    • Touchscreens: Allow for direct interaction with display.
    • Optical Scanner: For digitizing printed documents.
  • Selection Criteria: Volume, speed, accuracy, cost, data complexity.

Output Devices Overview

  • Types of output devices include:
    • Visual Display Unit (VDU): Monitors; quality measured in resolution and refresh rates.
    • Printers: (Laser, Inkjet, Dot-matrix) used for hard copies of documents.
  • Selection Criteria: Appropriateness, permanence, speed, cost.

Storage Devices Overview

  • Primary Storage: Temporary storage like RAM.
  • Secondary Storage: Permanent storage solutions like HDDs and SSDs.
    • HDDs: Use magnetic disks for storage.
    • SSDs: Faster, using flash memory.
    • Optical Discs: (CDs, DVDs, Blu-rays) offer portability and various capacities.

Measuring Storage Capacity

  • Bit: Basic unit of data (0 or 1).
  • Byte: 8 bits.
  • Kilobyte (KB): ~1000 bytes.
  • Megabyte (MB): ~1000 KB.
  • Gigabyte (GB): ~1000 MB.

Types of Memory

  • Volatile vs Non-volatile memory:
    • Volatile (e.g., RAM) loses data when powered off.
    • Non-volatile (e.g., ROM) retains data.
  • Cache Memory enhances performance by storing frequently used data close to the CPU.

Final Notes on Selection Criteria**

  • Each component (input, output, storage) has specific selection criteria that include speed, cost, and capacity.