What is a computer hardware organization?

A computer has several modules, with possibly more than one instance of each.

The system hardware consists of the following −

  • Keyboard

  • Display

  • Printer

  • CPU Board

  • Memory Board

  • I/O Board

The keyboard, display and printing devices need an interface so that it interacts with the system and the I/O board provides that interface for communication, that interacts is a system bus.

The figure given below is of the computer hardware−


It is the heart of the computer that controls the operations of the computer and also performs the data processing functions.

CPU performs the operations like exchanging data with memory with the help of memory address register and memory buffer register.

CPU also performs the operations like exchanging data with I/O devices with help of I/O address register and I/O buffer register.

Main memory/Primary memory

The main memory or primary memory is used to Store’s data and programs. The RAM (Random Access Memory) is called a Main or primary memory.

It is a volatile memory, meaning whenever the power or window is closed the data in the RAM will be lost, which means it is not permanent.

It is abstracted as a set of locations, which is defined by sequentially numbered addresses.

Each location in main memory contains a bit pattern to be interpreted as either an instruction or data.

I/O modules/architecture

I/O modules help in moving data between a computer and external environment.

It communicates with a variety of devices that include secondary memory (disks), communications equipment, and other terminals.

The data flows between CPUs, RAM and I/O devices can take place with the help of buses.

System bus is as follows −

  • It provides communications between processors, main memory, and I/O modules

  • It connects the internal hardware devices.

  • PCI bus, ISA bus, EISA bus, SCSI, USB

  • A typical computer consists of several buses of different types that are linked by bridges.