Computer Science: Input/Output Management and Storage Devices

Input Output Management

• Input/Output (I/O) devices allow users to interact with the computer
• Types of I/O devices:
  • Input devices: keyboard, mouse, scanner, microphone
  • Output devices: monitor, printer, speaker, plotter
• I/O management involves:
  • Managing data transfer between devices and CPU
  • Handling I/O requests and interrupts
  • Managing I/O operations concurrently

Storage Devices

• Types of storage devices:
  • Primary storage (main memory):
    • RAM (Random Access Memory)
    • Cache memory
  • Secondary storage:
    • Hard Disk Drive (HDD)
    • Solid State Drive (SSD)
    • Optical storage (CD, DVD, Blu-ray)
    • Flash storage (USB drives, memory cards)
• Storage devices characteristics:
  • Capacity: amount of data that can be stored
  • Access time: time taken to access data
  • Data transfer rate: speed of data transfer

Operating Systems

• An Operating System (OS) manages computer hardware and software resources
• OS functions:
  • Process management: creating, running, and terminating processes
  • Memory management: allocating and deallocating memory
  • File management: creating, deleting, and managing files
  • I/O management: managing input/output operations
  • Security: controlling access to computer resources
• Types of OS:
  • Single-user, single-tasking OS
  • Multi-user, single-tasking OS
  • Multi-user, multi-tasking OS
  • Real-time OS

CPU Architecture

• CPU (Central Processing Unit) architecture:
  • Fetch-decode-execute cycle: retrieves, decodes, and executes instructions
  • Components:
    • Control Unit: manages instruction flow
    • Arithmetic Logic Unit (ALU): performs arithmetic and logical operations
    • Registers: small amount of on-chip memory
  • Instruction Set Architecture (ISA): defines instructions and their formats
• CPU types:
  • CISC (Complex Instruction Set Computing): executes complex instructions
  • RISC (Reduced Instruction Set Computing): executes simple instructions

Algorithm Design

• Algorithm: a step-by-step procedure to solve a problem
• Algorithm design principles:
  • Correctness: produces correct results
  • Efficiency: minimizes time and space complexity
  • Scalability: adapts to large input sizes
  • Simplicity: easy to understand and implement
• Algorithm design techniques:
  • Divide and Conquer: breaks down problems into smaller sub-problems
  • Dynamic Programming: stores solutions to sub-problems
  • Greedy Algorithm: makes optimal choices at each step
  • Backtracking: tries different solutions until one works

Input Output Management

• Input devices allow users to interact with the computer, including keyboard, mouse, scanner, and microphone
• Output devices display or produce the results of computer processing, including monitor, printer, speaker, and plotter
• I/O management involves managing data transfer between devices and CPU, handling I/O requests and interrupts, and managing I/O operations concurrently

Storage Devices

• Primary storage (main memory) includes RAM (Random Access Memory) and cache memory, which temporarily hold data and program instructions
• Secondary storage devices, such as Hard Disk Drive (HDD), Solid State Drive (SSD), Optical storage (CD, DVD, Blu-ray), and Flash storage (USB drives, memory cards), hold data when the computer is powered off
• Storage devices are characterized by capacity, access time, and data transfer rate

Operating Systems

• An Operating System (OS) manages computer hardware and software resources, including process management, memory management, file management, I/O management, and security
• Types of OS include single-user, single-tasking OS, multi-user, single-tasking OS, multi-user, multi-tasking OS, and real-time OS

CPU Architecture

• CPU (Central Processing Unit) architecture involves the fetch-decode-execute cycle, which retrieves, decodes, and executes instructions
• CPU components include the Control Unit, Arithmetic Logic Unit (ALU), and Registers
• The Instruction Set Architecture (ISA) defines instructions and their formats, and CPU types include CISC (Complex Instruction Set Computing) and RISC (Reduced Instruction Set Computing)

Algorithm Design

• An algorithm is a step-by-step procedure to solve a problem, and should be correct, efficient, scalable, and simple
• Algorithm design techniques include Divide and Conquer, Dynamic Programming, Greedy Algorithm, and Backtracking
• These techniques are used to develop algorithms that produce correct results, minimize time and space complexity, adapt to large input sizes, and are easy to understand and implement