The four main structural components are the Central Processing Unit (CPU), main memory, input/output devices, and system interconnection.
Central Processing Unit (CPU):
Controls the operation of the computer and performs its data processing functions; often simply referred to as a processor. It is the brain and the heart of the computer. The operations of a CPU can be reduced to the following:
- Fetch the next instruction from memory.
- Decode the instruction.
- Execute the instruction.
- Store the result of the instruction in the main memory.
Main memory:
Main memory is used to store information for immediate access by the CPU. Main memory is also referred to as primary storage or main store.
- They are closely connected to the processor.
- The contents are quickly and easily changed.
- Stores the programs that the processor is actively working with.
Main memory includes Random Access Memory (RAM) for temporary storage and Read Only Memory (ROM) for permanent storage.
Input/output devices:
Input/output devices move data between the computer and its external environment. These devices provide an interface between the computer and the user. Input/output devices like keyboards and printers, together with external storage devices are referred to as peripherals.
System interconnection:
Some mechanism provides for communication among the CPU, main memory, and I/O. A typical example of system interconnection is means of the system bus, consisting of a number of conducting wires to which all the other components attach.
