Unix Operating System

1. Operating System Application is not
A computer with no Operating System is the same as having a Walkman cassette without, which means the same alone lying. Operating System INSTEAD of the application. The public often confused between the understanding of Software and applications. The sense of easy, the software is all kinds of kinds of programs used to operate computers and equipment.

While the software is divided into two:
  • Operating Systems: software used to operate the computer
  • Applications: the program operated in an environment for Operating System-specific purposes,
example: Programming, Office Work, and Gaming.

2. Operating System Up-to-date
Developing operating System following the development of technology and human needs. In General Operating System created for a particular type of computer, among others, as follows:
  • Microsoft Windows for Personal Computer (PC)
  • VMS for DEC · OS/2, AIX, OS/390 to IBM
  • MacOS for Apple Macintosh
  • SunOS for Sun Computers
  • Microsoft Windows CE Palmtop to UNIX Operating System is the parent who is able to be implemented for all types of computer machines that exist to this day.

A list of Operating System with its final version (with random sequence):
1. Microsoft Windows Me
2. Microsoft Windows 2000
3. Novell Netware 5
4. MacOS 9 and MacOS X Server Beta
5. Linux RedHat 7.0, Mandrake 7.2, 1.2, YellowDog MkLinux R1, LinuxPPC 2000, Slackware, Caldera OpenLinux 2.4 7.1, SuSE 7.0, Debian 2.2 6. FreeBSD 4.2 7. Solaris 7 8. BeOS Release 5

3. Concept of the Kernel and Shell
The kernel is the bridge between hardware and applications that translates the language of the software so that it is able to understand by the hardware and the hardware will soon process it in accordance with the request. As a result it is possible for users to use or work with their computers via software. Things that are done by the Kernel:
  • interrupt handler that handles i/o request
  • memory management to do such things, some people or groups have landing and considerations of development are different.
This causes the Operating System to appear in many different types, such as:
  • Windows 3.11 with the method the non pre-emptive multitasking that later developed in Windows 9 x into pre-emptive MultiTasking.
  • Windows that use Drivers to access hardware, unlike other Unix that put it into the kernel. Linux, MacOS X and BeOS is a hybrid of these two concepts, most (which is essential) is inserted into the kernel and the rest made module-module (because not all computers need/same). While the shell is a bridge between the User Input with the Kernel function gives the facilities on the user to interact with a computer (Software or Hardware). Shell: Shell illustration in Windows95 is known as Windows Explorer, while for Windows 98 has been transformed into a Internet Explorer (4.0 and 5.0). An alternative shell for Windows is a LiteStep, which gives the display Windows resembling the XWindow Afterstepnya Unix. Shell is better known by the users of Unix, among others: csh, tcsh, bash, pdksh, sh, and others.
4. Unix???
UNIX is an Operating System that was originally developed by Bell Labs in 1969 as a system concept ' interactive time-sharing '. The creators of Unix is Ken Thompson and Dennis Ritchie. In 1974, became the first Operating System Unix, written in C language and operating system which is open or standard. UNIX has terstandardisasi by the IEEE as the Portable Operating System Interface (POSIX). Characteristics Of The Unix
1. Multitasking – it can run more than one application at the same time.
2. Multiuser – can be used by more than one user at the same time.
3. Line/Text Command Based – resembling a DOS uses commands that are typed as a means ' to rule ' of the computer. Even so has developed a GUI applications that can replace the type ' command ' by running Windows. Analogous to DOS and Win311, where the Win311 have yet to be described as an Operating System.
4. Secure – have sufficient security level than any other Operating System. Where each file, user and group has a ' set ' permissions, so it does not allow a user to remove or meng'edit ' without having sufficient permissions.
5. Ready for Network - since its creation history has a purpose as a means of communication between computers, then Unix up to now still excels in terms of Computer-Networking.

4.1 history of Unix
  • 1965 Bell Laboratories joined the MIT and General Electric to support the development of a new operating system, Multics, which could provide multi-user, multi-processors and multi-level file system.
  • 1969 AT&T feel less confident and out of Multics project. Some programmers that project, Ken Thompson, Dennis Ritchie, Doug McIlroy and Rudd Canaday to design and implement the first unix system files, and given the name of UNIX by Brian Kernighan.
  • January 1970 1 set as UNIX time 0
  • 1971 system starts to run on the PDP-11 with 16 KB of memory, including 8 kb for program and EMC disk. The use of significantly used in the laboratory of Bell as a word processing tool.
Widely used among UNIX programmers because:
  • functioning in the environment the programmer
  • easy user interface
  • them simple with high performance
  • hierarchical file systems
  • a simple interface in the format file
  • multi-user and multi-prosesing
  • independent architecture and transparent to the user.
  • 1973 the code of Unix was rewritten in the C language, a new programming language developed by Dennis Ritchie. Rewritten into a high-level language making it easier for ported to the computer/machine new.
  • 1974 Thompson and Ritchie popularized the new Unix operating system that results in a high enthusiasm in academic circles as a potential tool in the development of system programming. Since AT&T of interest from the public in 1956, they were licensed to a university education and also for use as a commercial product.
  • 1977 there are 500 Unix sites around the world.
  • 1980 4.1 BSD (Berkeley Software Development)
  • 1983 SunOS 4.2 BSD, SysV,
  • 1984 there are about 100,000 Unix sites with different platforms.
  • 1988 AT&T and Sun Microsystems join in designing the System V Release 4. This system was further developed into the UnixWare and Solaris 2.
  • 1993 Novell bought UNIX from AT&T
  • 1994 Novell gave the name "UNIX" into the X/OPEN
  • 1995 Santa Cruz Operations (SCO) UnixWare from Novell purchase. SCO and HP announced it would join the Unix 64 bit build.
  • 1996 International Data Corporation predicted in 1997 will be spread over three million of the Unix system around the world. Introduction to Unix: ftp://wks.uts.ohio-state.edu/unix_course/unix_book.ps
4.2 of the GNU project
The GNU project's aim was to develop a complete free Unix-like system. GNU stands for GNU'S not Unix. The project was launched in 1984 to develop a unix-like operating systems, in other words the GNU System. One of the variants of this GNU using Linux kernel and is often referred to as GNU/Linux. This project will continue to be developed with the creation of software and utilities are free. Development was done on a fragmentary, for instance Linus Torvalds continued to write kernel code, Donald Knuth made the standard text-formatter (TeX), Bob Scheifler developing the X Window system and others get to the programs and utilities. In addition to the GNU project also exists independently generate unix-like operating system which is free. This system is known by the name of BSD developed by UC Berkeley. The free operating system that exists now in General is a variant of the GNU system or BSD systems.

4.3 What does the Free Software?
Free software is a form of freedom, referring to the user to use, copy, distribute, study, change or improve the software. Specifically there are 4 meaning of freedom:
1. Free running program.
2. Free learn and adapt the program according to your needs.
3. Free to redistribute.
4. Non enhancing programs and publish it.

In the GNU project used two licenses to protect legally freedom:
1. Copyleft: anyone who redistribute the program with or without the changes should give freedom to also be distributed again or modified. Copyleft guarantees every user has freedom.
2. Non-copyleft: anyone who distributes or change must get permission from the makers of the program. The free Software Foundation: http://www.fsf.org/

Click here for Comments