Evolution Of System Software

In the last 60 years, the computer has gone through different phases, we will discuss the evolution of the operating system as follows.

  1. Serial Processing
  2. Batch processing
  3. Multiprogramming
  4. Time-sharing
  5. Real-time OS
  6. Distributed System

1. Serial Processing:-

Execution of process is Done serially (one after another).

Example:- Dos(Disk Operating-system)

2. Batch Programming:-

Batch means Group of Programs

Example:- Group of java programs, another group of c programs.

Advantages:-  1. Less time for Processing.

2. Switching(one program to another) time for less.

Disadvantage:- Cpu is idle.

3. Multiprogramming:-

More than one programs are loaded in memory at a time.

Here:- Context switch takes place(Context switch means Switching from one too another).

Example:- “C” Program and listening to music at the same time.

=> Switching takes place during I/O operation(Because During I/O operation CPU is Idle).

Advantage:-  1. The CPU utilization is more.

2. Overall time is less hence the system is faster.

4. Time Sharing:-

It is the special case of multiprogramming.

–> Program is given with a fixed time. this time is called “Time Quantum”

5. Real-time OS:-

Real-time refers to the exact time. It guarantees that the program must complete in time.

=> It is of two types.

  1. Hard RIOTS

Short time constraints. No Delay in the time allowed

Example:- ex-works (missile firing system, satellite launching system)

2. Soft RIOTS

Delay In time is allowed. Example:- Linux, window

6. Distributed System:-

It is a multiprocessor system. A group of computers is connected to share data. Each computer has its own memory.

Example:- Internet

LAN = college

MAN = city

WAN = World


->Resource(Data sharing)