Computer Architecture: Memory, I/O, Buses, and Motherboard

Memory Components

For a device to function, it requires:

• Storage Medium/Support: The physical element containing the memory, capable of supporting two different energy states. The medium can be:
  • Discrete: A single item stores each bit.
  • Continuous: Bits are stored sequentially, differentiated by a clock signal.
• Memory can be classified based on data retention:
  • Durable/Non-Volatile: Information is stored permanently unless intentionally erased.
  • Volatile: Information is lost when power is removed.
  • Refresh-based: Information fades over time and requires periodic rewriting.
  • Destructive Read: Reading erases the data, requiring a re-write after each read operation.
  • Read-Only: Information can only be recorded once.
• Drivers: Manage reading and writing operations.
• Controllers: Select the desired memory location.

Input/Output Subsystem (I/O)

This subsystem consists of two main parts:

1. Peripherals: Devices enabling direct communication with the external world (e.g., mouse, keyboard, monitor).
2. Interface: A hardware and software system facilitating communication between peripherals, the CPU, and main memory. It resolves differences between the processor and devices.

Buses

Connections are established through a shared bus, a set of lines allowing multiple devices to transmit signals. Each line transmits binary signals (0s and 1s). Bus lines are categorized into:

• Data Lines: Transmit data between system modules.
• Address Lines: Designate the source or destination of data on the data bus. The set of address lines is called the address bus.
• Control Lines: Control access to data and address lines, shared by all components. The set of control lines is called the control bus.

Motherboard

The motherboard connects all other elements.

Key Components:

• Socket: Connects the processor to the motherboard.
• Chipset: Connects and synchronizes all computer parts, adjusting speeds.
• Memory Sockets: Hold the RAM modules.
• BIOS (Basic Input/Output System): Programs stored in EPROM that initialize devices during startup.
• Power Connector: Connects the power supply cables to the motherboard.
• I/O Connectors: Connect input and output devices.
• Expansion Slots: Elongated connectors for expansion cards.
• Battery: Powers the memory storing PC startup configuration.