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Computer Operating System

IBM compatible and most other kinds of computers have three different type of components. First you have the hardware that has to be manufactured, you buy it and it cannot be changed. Whenever you want better hardware you have to replace them physically. The main components include the main board, central processing unit (CPU), random access memory (RAM), graphics card, controllers and so on.

The second category includes some basic software, called BIOS (basic input/output system) for the motherboard, firmware for other computer parts. For example the motherboard’s BIOS crates the connection between hardware components and more sophisticated software (like the operating system and applications). It sits in a flash memory chip on the motherboard, so it can be changed any time, assuming that the motherboard’s manufacturer released a new version with some fixes or added support for new computer hardware.

Firmware is basically same thing as BIOS, but the main difference is that it’s not a system, because it can only handle the hardware in which it’s installed (in hard disks, optical drives, video cards …etc.). This circuit board is from a simple DVD-player. Chips that are covered with stickers hold its firmware:

Please note that upgrading the BIOS or Firmware is risky, because if anything goes wrong during the upgrade then the motherboard (or any other components that has firmware) won’t function anymore. In such cases you also may lose the warranty and it may cost you a lot to have it repaired.

The computer operating system is much more complicated software. It’s usually hundreds of times bigger than the BIOS or firmware and its main role is to create a framework for programs. This framework also has to deal with firmware in different hardware devices using drivers. The final result of hardware, BIOS, firmware, drivers and operating system is a very programmer friendly environment. Programmers can manipulate any part of the assembled computer with a few simple commands in a programming language. For example in Visual Basic the Console.WriteLine(“Hello world!”) command displays “Hello World!” on the screen, thanks to hardware, BIOS, firmware and computer operating system working together.

At first computer operating systems were very basic, in fact one of them was actually called Basic. It was the first step toward friendly command-based programming. Since then Microsoft has pretty much dominated the operating system market (and development). There have always been challengers, but unfortunately Microsoft’s products still dominate the computer software market and it will take some time for the situation to change. For example MAC OS X is a far superior operating system, Apple laptops run up to 10 times more with MAC OS X than with any of Microsoft’s operating systems, while desktops run very similar with both operating systems.

Another very important thing to know about operating systems is that alongside firmware and/or BIOS they are needed in all programmable devices (mobile phones, Internet routers, DVD players, gaming consoles, and so on) that have any kind of processors. Sometimes it’s hard to tell them apart because if the device is simple enough then its BIOS and operating system are stored in the same flash memory and basically form one unified piece of software.