Operating Systems – Introduction

Operating System Brains

A computer’s heart is the operating system. The core processing is done at the CPU, and it’s only possible if there is an operating system. So what is an Operating System? Operating system is a set of software, written using a low-level programming language (either C/C++ or Assembly).

Operating system is responsible to manage the requests made by any software applications, and direct them to be executed via the hardware that it’s installed upon. In essence, it acts as an interface between the software and the hardware. You might be wondering “Why do i even need an Operating System? I might as well code to use the hardware directly!!”. Valid concerns, but your application will not be the only application running. If you need your application to run at the Operating System level, that can be achieved via kernel mode access (which will be covered at a later stage).

So, you need an operating system. But what exactly does an Operating System do?

  • Process Management – makes sure that your applications runs smoothly without any interruption, and to ensure that it executes successfully
  • Memory Management – the CPU can only execute a limited number of processes/applications at one time. And as these applications are run, they need storage space to manipulate data. This storage (RAM) needs to be managed so that both applications and operating systems have their own space.
  • Input/Output – Your applications will leverage on the existing hardware. As such, the Operating Systems provide a structured means of accessing these devices (by providing a generic access layer called the device drivers) to access myriads of hardware without having to worry about the specifics.

Though this is a limited list, most other functionality are some form of variation of these basic functions. The exact functions will be covered in the later blog entries.