Input and Output Notes

Input & Output Overview

  • Definition of I/O:

    • Anything connected to a computer for input or output purposes.

    • Examples include keyboard, mouse, touch screen, printer, hard disk, USB.

  • Von Neumann Architecture Recap:

    • Fundamental computer architecture where the CPU, memory, and I/O operations are interconnected.

Early Input/Output Methods

  • Limited I/O in Early Computers:

    • Early computers utilized very basic input/output methods:

    • Punched paper tape or cards

    • Teleprinters

  • Key Historical Devices:

    • Discussed examples:

    • Teleprinters were essential for early communication and data input.

Modern Input/Output Devices

  • Examples of Input Devices:

    • Keyboard, mouse, touch pad, touch screen

    • Microphones, cameras

    • Gestures, accelerometers, barometers

    • GPS, LIDAR

  • Examples of Output Devices:

    • Screens, printers, audio systems

    • Vibration motors, smart home appliances

    • Robots, network devices (WiFi, 4G/5G, Ethernet, Bluetooth)

  • Storage Devices:

    • Hard disks, SSDs, SD cards.

Modern I/O Interfaces

  • Connection Types:

    • Modern I/O devices are often connected via interfaces.

    • Standardised connectors and protocols

    • These can be either internal or external.

    • Examples of Interfaces:

    • USB, PCIe, HDMI.

  • Importance of Standardization:

    • Ensures compatibility and robustness across various devices.

Characteristics of I/O Interfaces

  • Reasons for Different Standards:

    • I/O interfaces need to balance multiple factors such as:

    • Convenience: Simple and durable connectors (e.g., USB plug).

    • Speed:

      • Different devices have varying speed requirements (e.g.,

      • graphics cards require high data rates while keyboards need low).

    • Cost:

      • Cheaper interfaces for low-cost devices (e.g., $5 USB drive)

      • Can invest more in higher-cost devices (e.g., $1,000 graphics card).

    • Compatibility:

      • Ensures external devices can work with multiple computers over time.

Summary of I/O

  • Importance of I/O Devices:

    • Computers cannot function without input/output devices.

    • Most modern devices connect via standard interfaces, facilitating communication between I/O devices and the CPU.

Conclusion

  • Key Takeaways:

    • Understanding how I/O interfaces evolved from basic methods to the sophisticated systems in today’s computers is essential for grasping computer functionality.