How data and program flow from secondary storage device to ram to cpu?

  1. (CPU) sends a request to the memory controller, which manages the communication between the CPU and memory.
  2. The memory controller then sends a request to the storage controller, which manages the communication between the memory and the secondary storage device.
  3. The storage controller retrieves the requested data or program from the secondary storage device and sends it to the memory controller.
  4. The memory controller then stores the data or program in the computer's random access memory (RAM). This is a type of volatile memory, which means it is wiped when the computer is powered off.
  5. The CPU then retrieves the data or program from the RAM and processes it.
  6. Once the CPU is done processing the data or program, it is stored back in the RAM and/or the secondary storage device.

The controllers are typically integrated into the motherboard as chipsets, which are small integrated circuits that control the communication between different components. These chipsets are designed and manufactured by different companies and are integrated into the motherboard during the manufacturing process.

  1. Some controllers are:
  2. Memory controller
  3. Storage controller
  4. Network controller
  5. USB controller
  6. Power controller
  7. Graphics controller
  8. Input/output (I/O) controller
  9. Temperature controller

And many more

What happen when computer is turn on ?


When a computer is turned on, several things happen in a specific sequence, known as the boot process or boot sequence. Here is a general overview of what happens:

  1. The power-on self-test (POST) runs.
  2. The BIOS (basic input/output system) or UEFI (Unified Extensible Firmware Interface) firmware is loaded.
  3. This is a program that controls the communication between the computer's hardware and its operating system.
  4. The BIOS or UEFI is stored on a chip on the motherboard and is responsible for initializing and identifying the hardware components, such as the memory, storage, and keyboard.
  5. The bootloader is loaded. The bootloader is a program that loads the operating system. It is stored on the primary storage device, typically the hard drive or SSD.
  6. The operating system is loaded into the memory (RAM) from the storage device. Once the operating system is loaded, it takes control of the computer and starts initializing the rest of the system.
  7. The operating system runs through its startup process, which includes loading drivers, initializing services, and starting up any programs that are set to run automatically when the computer starts.
  8. Once the startup process is complete, the operating system is fully loaded and ready for use. The user can then interact with the operating system and launch programs as needed.

Note that depending on the computer, the boot process can have variations, for example newer computers use UEFI instead of BIOS, and some use a combination of both.