Unix - Operating Systems

The uniqueness of UNIX

The features that made UNIX a hit from the start are:

* Multitasking capability

* Multi-user capability

* Portability

* UNIX programs

* Library of application software

* Security

1. Multitasking Capability

Many computers do just one thing at a time, as anyone who uses a PC or laptop can attest. Try logging onto your company's network while opening your browser while opening a word processing program. Chances are the processor will freeze for a few seconds while it sorts out the multiple instructions.

UNIX, on the other hand, lets a computer do several things at once, such as printing out one file while the user edits another file. This is a major feature for users, since users don't have to wait for one application to end before starting another one.

2. Multi-user

The same design that permits multitasking permits multiple users to use the computer. The computer can take the commands of a number of users -- determined by the design of the computer -- to run programs, access files, and print documents at the same time.

The computer can't tell the printer to print all the requests at once, but it does prioritize the requests to keep everything orderly. It also lets several users access the same document by compartmentalizing the document so that the changes of one user don't override the changes of another user.

3. System portability

A major contribution of the UNIX system was its portability, permitting it to move from one brand of computer to another with a minimum of code changes. At a time when different computer lines of the same vendor didn't talk to each other -- yet alone machines of multiple vendors -- that meant a great savings in both hardware and software upgrades.

It also meant that the operating system could be upgraded without having all the customer's data inputted again. And new versions of UNIX were backward compatible with older versions, making it easier for companies to upgrade in an orderly manner.

4. UNIX Programs

UNIX comes with hundreds of programs that can divide into two classes:

Integral utilities

These are absolutely necessary for the operation of the computer, such as the command interpreter, and Tools that aren't necessary for the operation of UNIX but provide the user with additional capabilities, such as typesetting capabilities and e-mail.

UNIX Communications

E-mail is commonplace today, but it has only come into its own in the business community within the last 10 years. Not so with UNIX users, who have been enjoying e-mail for several decades.

UNIX e-mail at first permitted users on the same computer to communicate with each other via their terminals. Then users on different machines, even made by different vendors, were connected to support e-mail. And finally, UNIX systems around the world were linked into a world wide web decades before the development of today's World Wide Web.

5. Applications libraries

UNIX as it is known today didn't just develop overnight. Nor were just a few people responsible for it's growth. As soon as it moved from Bell Labs into the universities, every computer programmer worth his or her own salt started developing programs for UNIX.

Today there are hundreds of UNIX applications that can be purchased from third-party vendors, in addition to the applications that come with UNIX.

6. Security

It is safe, preventing one program from accessing memory or storage space allocated to another, and enables protection, requiring users to have permission to perform certain functions, i.e. accessing a directory, file, or disk drive.

UNIX at HOME

A few of the many advantages of using Unix at home are:

 Unix runs on older, less powerful machines. If your machine does not have enough CPU speed and memory for Windows, it can still run Unix.

 Several Unix flavors such as FreeBSD are free. Additionally high quality, free applications like the emacs text editor, Apache web server and GIMP image editor are available for Unix platforms. Equivalent Windows software costs hundreds of dollars

 Unix provides a flexible multi-user environment. Each member of the family can have their own account with personal settings and secure files. You can keep the kids from reading your work, financial or personal files, while allowing your spouse to access financial files but not work or personal files.

 Unix provides the ultimate in computer programming environments. Powerful C, C++, Fortran and Java compilers along with development tools are available for free. Furthermore, the Internet is littered with libraries of free code for these compilers. It would cost over $1,000 to create a comparable programming environment for a machine running Windows.

On the downside:

You should only consider Unix if you are willing to spend a lot of time working on your operating system. Unix is harder to install, maintain and upgrade than Windows or the MacOS.

More home oriented applications run under Windows than Unix. If you need educational software for the kids or love computer games, Windows is a better choice than Unix. Dual booting (running Windows and Unix on the same machine) overcomes this disadvantage.

UNIX Evaluation

In making a decision on which OS is better, we must finally evaluate the abundant advantages of UNIX over the disadvantages. As programs continue to become larger and more complex, and as computers become faster and increase in complexity, operating systems must become more and more stable. In comparison with Windows NT, UNIX maintains this stability very well.

NASA, who relies very heavily on their equipment, prefers UNIX because if its stability in complex,