Lecture Notes on Computer Interfacing and BIOS

Key Concepts

• Device Communication:

  • Programs execute from hard drive to CPU.
  • Input devices (e.g., mouse, keyboard) don't have instructions for CPU.
  • Devices use programs called services or drivers to communicate with CPU.

• Drivers:

  • Contain instructions for CPU to understand devices like keyboards, webcams, printers.

• BIOS (Basic Input Output Services):

  • Software that initializes hardware and boots operating systems.
  • Stored in ROM chip (non-volatile memory) on the motherboard.
  • Provides essential instructions before the operating system loads.

• ROM vs RAM:

  • ROM is non-volatile; data is not erased when computer turns off.
  • RAM is volatile; data is erased when power is off.

UEFI (Unified Extensible Firmware Interface)

• Modern replacement for traditional BIOS.
• Better compatibility and support for newer hardware.
• Expected to become the standard BIOS.

Power On Self Test (POST)

• Test run by BIOS during boot-up to check hardware functionality.
• Issues with hardware produce beep codes (Morse code-like series) instead of screen errors.
• Beep codes vary by manufacturer.
• Not all computers have built-in speakers for beep codes.

BIOS Settings and CMOS Chip

• CMOS chip stores basic booting data (date, time, boot preferences).
• Access BIOS settings via a specific key during boot-up.
• Important for IT support roles to modify BIOS settings.

Re-imaging and IT Tasks

• Re-imaging refers to wiping and reinstalling an operating system.
• Performed using programs on external devices (USB, CD-ROM, network server).
• BIOS settings must be modified to boot from an external device for re-imaging.