TYPES OF OPERATING SYSTEMS

TYPES OF OPERATING SYSTEMS

The operating system has evolved a long way . of the the simplest to the most modern of today. Each has advantages and disadvantages especially with respect to the functions it has. The following sections will discuss some of the operating system are widely used and familiar to computer users .

1 . DOS

DOS stands for Disk Operating System . DOS refers to the operating system used on many computers provide abstraction and management of secondary storage devices and information. For example, the use of the file system that manages the existing files on the storage device . DOS usually run from one or two discs . This is because the DOS is used in the media is very limited capacity (at most maybe only 1.4 Megabytes ) . There are many types of DOS including Apple DOS , Commodore DOS , Atari DOS and others. This depends on the type of device computer . The most famous type of DOS is a DOS type running the machines are compatible with the IBM Personal Computer . To execute operating system commands , use the DOS text -based commands or CLI . Each time you finish typing a command , we must press ENTER to execute the command.

2 . UNIX

UNIX is an operating system originally developed by a group at AT & T Bell laboatorium . Unix is widely used both for servers and workstations . Unix environments and client-server programming model showed that the more developed as a Unix operating system strong The computer network of the operating system for personal computers . UNIX is designed to be portable , multi - tasking , and multi - user . concept Unix main among many others using plain text files to store data, using a tiered file system , treating the device as a file , and use a lot of small programs that execution in the CLI can be combined with a pipeline ( | ) . In Figure 5.2 above , it appears some UNIX commands combined with the pipeline . The concept is very solid and stable makes Unix a lot form the basis of modern operating systems .

UNIX system consists of several components that are normally packaged together . Most packages are as follows :

* Kernel with sub- components such as :
- Conf = config file .
- Dev = hardware drivers

- Sys = kernel operating system , memory management , scheduling processes , system calls, and others .

- H = header files , defining key structures within the system .

* Development Environment :
o cc - compiler for the C language
o as - machine - language assembler
o ld - linker , to merge the object files
o lib - object - code libraries ( installed in the folder / lib or / usr / lib ) libc ,
collection of libraries for C language
o make - a program to compile source code
o include - header files for software development and
specify standard interfaces
o Other languages ​​- programming languages ​​such as
Fortran - 77 , Free Pascal , and others .

* Commands :
o sh - " Shell " to do a CLI based programming or
execute certain commands .
o Utilities - A set of useful CLI commands for the functions
diverse , including :
1 . System utilities - programs for management
systems such as mkfs , fsck , and others .
2 . User utilities - programs for the management of
work environment , such as passwd , kill , and others .
o Document formatting - The program for the preparation of documents such as
nroff , troff , tbl , eqn , refer , and pic . Some modern Unix systems
also includes applications such as TeX and Ghostscript .
o Graphics - Modern Unix systems provide the X11 system
standard windowing and GUI .

3 . Microsoft Windows

Micosoft Windows or the more frequently mentioned Windows only initially only add -on from MS - DOS because of the high demands on the system GUI -based operations . Early versions of Windows running on top of MS - ​​DOS . although Thus the Windows version has shown some functions common operating system , among others : executable file types of its own , has its own hardware drivers , and others . In concept actually more intended for Windows personal computer . At first Windows also does not support the concept multi - tasking and multi - user . Accommodation on the network or functions client - server is also not as strong as in UNIX and its derivatives . so the problem which often appears in the Windows operating system is a safety issue associated with the network . However, Windows has the advantage of the ease of use . In the latest version ( Windows Vista ) multiuser concept and multi - tasking has become more mature . Additionally GUI has revamped with many using the three-dimensional effect .

4 . Apple Mac OS

As shown in Figure 5.10 , Apple Mac OS is a derivative of UNIX BSD through ( Berkeley Software Distribution ) . Therefore strength in multi - tasking , multi - user , networking also exist on UNIX owned by the Mac OS . Mac OS is a GUI -based operating system . Apple is a pioneer in the use of the GUI on the operating system . use icon , mouse and some GUI components are outside contributions uncommon for the development of GUI -based operating system . The initial version of the Mac OS is almost fully rely on its GUI capabilities and greatly limit the use of the CLI ( Figure 5.15 ) . Although very easy but there are some drawbacks , among others : Multi - tasking is not perfect , limited memory management , and conflict on some embedded programs . Fixing Mac system OS sometimes be a very tiring job . On Mac OS X ( latest version ) , all the weaknesses in the old version has been try eliminated . Multi - tasking has been going well and management memory is much better . In addition to its GUI display is touted as the best among the existing operating system .

5 . Linux

Linux is very similar to UNIX systems , this is due compatibility with UNIX is a primary design goal of the Linux project . Linux development started in 1991 , when a Finnish student named Linus Torvalds wrote Linux , a kernel for the 80386 processor , The first 32 - bit processor in the Intel CPU is a collection fit for the PC . In many ways , the Linux kernel is the core of the Linux project , but that other components that make up a complete Linux operating system . where Linux kernel consists of the codes that are made ​​specifically for the Linux project , most of the supporting software is not exclusive to Linux , but usually used in a UNIX -like operating systems .

For example , from Berkeley BSD operating system , the X Window System from MIT , and GNU project of the Free Software Foundation . Division ( sharing ) tools have worked in two directions . system The main library Linux was originally started by the GNU project , but improved library development through cooperation of community Linux primarily on addressing , inefficiency , and bugs . another component such as the GNU C compiler , gcc , high enough quality to be used directly in Linux . The tools under Linux network administration derived from code developed for 4.3BSD , but newer BSD , one FreeBSD only , the borrowed code from Linux , for example, is Intel math library floating-point emulation .

Currently , Linux is one operating system The most rapid development . The presence of several groups of developers , spread all over the world , which always improves the feature, help advance the Linux operating system . At the same time , many developers who are working to move applications to Linux ( can be run on Linux ) . The main problem faced is the first Linux interface in the form of text ( text-based interface ) . It does not make people interested using Linux as it should be first carefully to understand how to use ( not user-friendly ) . but This situation has begun to change with the presence of KDE and GNOME . both has an interesting desktop display that change the perception of the world on Linux .