Hardware

• Hardware is referred to as the physical or mechanical device that constitutes the computer.
• Central Processing Unit (CPU) - the brain of the computer
• CPU consists of Arithmetic Unit and Control Unit
• Peripheral Unit is a hardware input or output device that expands the functionality of your PC.
• Storage unit is a part of the computer system which is employed to store the information and instructions to be processed.
• Integrated Circuits are sometimes called a chip or microchip, is a semiconductor wafer on which thousands or millions of tiny resistors, capacitors, and transistors are fabricated.
• Random Access Memory (RAM) is the main storage of the computer. A semiconductor memory where all read and write functions are performed. It is a volatile memory which needs constant supply of power to store data. All data will be lost when power is turned off.
• Volatile memory stores data when a computer is on but erases it as soon as the computer is switched off, whereas non-volatile memory remains in a computer even after the system shuts off.
• Read Only Memory (ROM) is also known as Firmware. Instructions written in ROM by the firm or manufacturer of the chip. Data stored in such a chip is non-volatile. Data stored in these chips is either unchangeable or requires a special operation to change.
• • RAM - volatile memory
• • ROM - non-volatile memory
• The CPU is the backbone of the computer, often compared to the human brain.
• Control Unit

  • Controls all operations of the computer.

  1. Retrieves instructions stored in the main storage unit.
  2. Decodes retrieved instruction using the instruction decoder.
  3. Executes and transmits instructions to each unit.
• Arithmetic Unit

  • Or officially called the Arithmetic Logic Unit (ALU)

  1. Performs calculations, comparison, brand and other processors.
  2. ALU has functions performing fixed point operation, floating point operation, and decimal. Even conversion!
• Executing Program

  • Processor’s four operating stages: Fetch, Decode, Execute, Retire
• Fetch - a program’s instruction and any needed data into the processor.
• Decode - determines the purpose of the instruction and passes it to the hardware element.
• Execute - carries out the instruction.
• Retire - takes the result of the execution stage and places them into other processors registers or the computer's main memory.