Utility software Software Category

Utility software is a kind of system software designed to help analyze, configure, optimize and maintain the computer. A single piece of utility software is usually called a utility (abbr. util) or tool.
Utility software should be contrasted with application software, which allows users to do things like creating text documents, playing games, listening to music or surfing the web. Rather than providing these kinds of user-oriented or output-oriented functionality, utility software usually focuses on how the computer infrastructure (including the computer hardware, operating system, application software and data storage) operates. Due to this focus, utilities are often rather technical and targeted at people with an advanced level of computer knowledge.
Most utilities are highly specialized and designed to perform only a single task or a small range of tasks. However, there are also some utility suites that combine several features in one software.
Most major operating systems come with several pre-installed utilities.

Utility software categories

• Disk storage utilities
• Disk defragmenters can detect computer files whose contents are broken across several locations on the hard disk, and move the fragments to one location to increase efficiency.
• Disk checkers can scan the contents of a hard disk to find files or areas that are corrupted in some way, or were not correctly saved, and eliminate them for a more efficiently operating hard drive.
• Disk cleaners can find files that are unnecessary to computer operation, or take up considerable amounts of space. Disk cleaner helps the user to decide what to delete when their hard disk is full.
• Disk space analyzers for the visualization of disk space usage by getting the size for each folder (including sub folders) & files in folder or drive. showing the distribution of the used space.
• Disk partitions can divide an individual drive into multiple logical drives, each with its own file system which can be mounted by the operating system and treated as an individual drive.
• Backup utilities can make a copy of all information stored on a disk, and restore either the entire disk (e.g. in an event of disk failure) or selected files (e.g. in an event of accidental deletion).
• Disk compression utilities can transparently compress/uncompress the contents of a disk, increasing the capacity of the disk.
• File managers provide a convenient method of performing routine data management tasks, such as deleting, renaming, cataloging, uncataloging, moving, copying, merging, generating and modifying data sets.
• Archive utilities output a stream or a single file when provided with a directory or a set of files. Archive utilities, unlike archive suites, usually do not include compression or encryption capabilities. Some archive utilities may even have a separate un-archive utility for the reverse operation.
• System profilers provide detailed information about the software installed and hardware attached to the computer.
• Anti-virus utilities scan for computer viruses.
• Hex editors directly modify the text or data of a file. These files could be data or an actual program.
• Data compression utilities output a shorter stream or a smaller file when provided with a stream or file.
• Cryptographic utilities encrypt and decrypt streams and files.
• Launcher applications provide a convenient access point for application software.
• Registry cleaners clean and optimize the Windows registry by removing old registry keys that are no longer in use.
• Network utilities analyze the computer's network connectivity, configure network settings, check data transfer or log events.
• Command line interface (CLI) and Graphical user interface (GUI) Allows the user to contact and make changes to the operating system.

Different Types of Operating Systems

Operating systems that create a link between users and the applications form the core of computer systems. It dissociates the programs and the hardware and simplifies resource management. Let us look at the different types of operating systems.

An operating system is a software component of a computer system that is responsible for the management of various activities of the computer and the sharing of computer resources. It hosts the several applications that run on a computer and handles the operations of computer hardware. Users and application programs access the services offered by the operating systems, by means of system calls and application programming interfaces. Users interact with operating systems through Command Line Interfaces (CLIs) or Graphical User Interfaces known as GUIs. In short, operating system enables user interaction with computer systems by acting as an interface between users or application programs and the computer hardware. Here is an overview of the different types of operating systems.

Real-time Operating System: It is a multitasking operating system that aims at executing real-time applications. Real-time operating systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The main object of real-time operating systems is their quick and predictable response to events. They either have an event-driven or a time-sharing design. An event-driven system switches between tasks based of their priorities while time-sharing operating systems switch tasks based on clock interrupts.

Multi-user and Single-user Operating Systems: The operating systems of this type allow a multiple users to access a computer system concurrently. Time-sharing system can be classified as multi-user systems as they enable a multiple user access to a computer through the sharing of time. Single-user operating systems, as opposed to a multi-user operating system, are usable by a single user at a time. Being able to have multiple accounts on a Windows operating system does not make it a multi-user system. Rather, only the network administrator is the real user. But for a Unix-like operating system, it is possible for two users to login at a time and this capability of the OS makes it a multi-user operating system.

Multi-tasking and Single-tasking Operating Systems: When a single program is allowed to run at a time, the system is grouped under a single-tasking system, while in case the operating system allows the execution of multiple tasks at one time, it is classified as a multi-tasking operating system. Multi-tasking can be of two types namely, pre-emptive or co-operative. In pre-emptive multitasking, the operating system slices the CPU time and dedicates one slot to each of the programs. Unix-like operating systems such as Solaris and Linux support pre-emptive multitasking. Cooperative multitasking is achieved by relying on each process to give time to the other processes in a defined manner. MS Windows prior to Windows 95 used to support cooperative multitasking.

Distributed Operating System: An operating system that manages a group of independent computers and makes them appear to be a single computer is known as a distributed operating system. The development of networked computers that could be linked and communicate with each other, gave rise to distributed computing. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system.

Embedded System: The operating systems designed for being used in embedded computer systems are known as embedded operating systems. They are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources. They are very compact and extremely efficient by design. Windows CE, FreeBSD and Minix 3 are some examples of embedded operating systems.

The operating systems thus contribute to the simplification of the human interaction with the computer hardware. They are responsible for linking application programs with the hardware, thus achieving an easy user access to the computers.

The History of Computers( Year Wise)

"Who invented the computer?" is not a question with a simple answer. The real answer is that many inventors contributed to the history of computers and that a computer is a complex piece of machinery made up of many parts, each of which can be considered a separate invention.
This series covers many of the major milestones in computer history (but not all of them) with a concentration on the history of personal home computers.

Computer History Year/Enter	Computer History Inventors/Inventions	Computer History Description of Event
1936	Konrad Zuse - Z1 Computer	First freely programmable computer.
1942	John Atanasoff & Clifford Berry ABC Computer	Who was first in the computing biz is not always as easy as ABC.
1944	Howard Aiken & Grace Hopper Harvard Mark I Computer	The Harvard Mark 1 computer.
1946	John Presper Eckert & John W. Mauchly ENIAC 1 Computer	20,000 vacuum tubes later...
1948	Frederic Williams & Tom Kilburn Manchester Baby Computer & The Williams Tube	Baby and the Williams Tube turn on the memories.
1947/48	John Bardeen, Walter Brattain & Wiliam Shockley The Transistor	No, a transistor is not a computer, but this invention greatly affected the history of computers.
1951	John Presper Eckert & John W. Mauchly UNIVAC Computer	First commercial computer & able to pick presidential winners.
1953	International Business Machines IBM 701 EDPM Computer	IBM enters into 'The History of Computers'.
1954	John Backus & IBM FORTRAN Computer Programming Language	The first successful high level programming language.
1955 (In Use 1959)	Stanford Research Institute, Bank of America, and General Electric ERMA and MICR	The first bank industry computer - also MICR (magnetic ink character recognition) for reading checks.
1958	Jack Kilby & Robert Noyce The Integrated Circuit	Otherwise known as 'The Chip'
1962	Steve Russell & MIT Spacewar Computer Game	The first computer game invented.
1964	Douglas Engelbart Computer Mouse & Windows	Nicknamed the mouse because the tail came out the end.
1969	ARPAnet	The original Internet.
1970	Intel 1103 Computer Memory	The world's first available dynamic RAM chip.
1971	Faggin, Hoff & Mazor Intel 4004 Computer Microprocessor	The first microprocessor.
1971	Alan Shugart &IBM The "Floppy" Disk	Nicknamed the "Floppy" for its flexibility.
1973	Robert Metcalfe & Xerox The Ethernet Computer Networking	Networking.
1974/75	Scelbi & Mark-8 Altair & IBM 5100 Computers	The first consumer computers.
1976/77	Apple I, II & TRS-80 & Commodore Pet Computers	More first consumer computers.
1978	Dan Bricklin & Bob Frankston VisiCalc Spreadsheet Software	Any product that pays for itself in two weeks is a surefire winner.
1979	Seymour Rubenstein & Rob Barnaby WordStar Software	Word Processors.
1981	IBM The IBM PC - Home Computer	From an "Acorn" grows a personal computer revolution
1981	Microsoft MS-DOS Computer Operating System	From "Quick And Dirty" comes the operating system of the century.
1983	Apple Lisa Computer	The first home computer with a GUI, graphical user interface.
1984	Apple Macintosh Computer	The more affordable home computer with a GUI.
1985	Microsoft Windows	Microsoft begins the friendly war with Apple.
SERIES	TO BE	CONTINUED

Short History about IBM Computer and DOS Operating System

The History of the IBM PC - International Business Machines

In July of 1980, IBM representatives met for the first time with Microsoft's Bill Gates to talk about writing an operating system for IBM's new hush-hush "personal" computer. IBM had been observing the growing personal computer market for some time. They had already made one dismal attempt to crack the market with their IBM 5100. At one point, IBM considered buying the fledgling game company Atari to commandeer Atari's early line of personal computers. However, IBM decided to stick with making their own personal computer line and developed a brand new operating system to go with. The secret plans were referred to as "Project Chess". The code name for the new computer was "Acorn". Twelve engineers, led by William C. Lowe, assembled in Boca Raton, Florida, to design and build the "Acorn". On August 12, 1981, IBM released their new computer, re-named the IBM PC. The "PC" stood for "personal computer" making IBM responsible for popularizing the term "PC".The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. The PC came equipped with 16 kilobytes of memory, expandable to 256k. The PC came with one or two 160k floppy disk drives and an optional color monitor. The price tag started at $1,565, which would be nearly $4,000 today. What really made the IBM PC different from previous IBM computers was that it was the first one built from off the shelf parts (called open architecture) and marketed by outside distributors (Sears & Roebucks and Computerland). The Intel chip was chosen because IBM had already obtained the rights to manufacture the Intel chips. IBM had used the Intel 8086 for use in its Displaywriter Intelligent Typewriter in exchange for giving Intel the rights to IBM's bubble memory technology.
Less than four months after IBM introduced the PC, Time Magazine named the computer "man of the year"

The History of the MS-DOS Operating Systems, Microsoft, Tim Paterson, and Gary Kildall 


On August 12, 1981, IBM introduced its new revolution in a box, the "Personal Computer" complete with a brand new operating system from Microsoft and a 16-bit computer operating system called MS-DOS 1.0.

Operating System : /n./ [techspeak] (Often abbreviated `OS') The foundation software of a machine, of course; that which schedules tasks, allocates storage, and presents a default interface to the user between applications. The facilities an operating system provides and its general design philosophy exert an extremely strong influence on programming style and on the technical cultures that grow up around its host machines. - The Jargon Dictionary*
In 1980, IBM first approached Bill Gates and Microsoft, to discuss the state of home computers and Microsoft products. Gates gave IBM a few ideas on what would make a great home computer, among them to have Basic written into the ROM chip. Microsoft had already produced several versions of Basic for different computer system beginning with the Altair, so Gates was more than happy to write a version for IBM.As for an operating system (OS) for the new computers, since Microsoft had never written an operating system before, Gates had suggested that IBM investigate an OS called CP/M (Control Program for Microcomputers), written by Gary Kildall of Digital Research. Kindall had his Ph.D. in computers and had written the most successful operating system of the time, selling over 600,000 copies of CP/M, his OS set the standard at that time


IBM tried to contact Kildall for a meeting, executives met with Mrs. Kildall who refused to sign a non-disclosure agreement. IBM soon returned to Bill Gates and gave Microsoft the contract to write the new operating system, one that would eventually wipe Kildall's CP/M out of common use.

The "Microsoft Disk Operating System" or MS-DOS was based on QDOS, the "Quick and Dirty Operating System" written by Tim Paterson of Seattle Computer Products, for their prototype Intel 8086 based computer.QDOS was based on Gary Kildall's CP/M, Paterson had bought a CP/M manual and used it as the basis to write his operating system in six weeks, QDOS was different enough from CP/M to be considered legal.Microsoft bought the rights to QDOS for $50,000, keeping the IBM deal a secret from Seattle Computer Products.Gates then talked IBM into letting Microsoft retain the rights, to market MS DOS separate from the IBM PC project, Gates proceeded to make a fortune from the licensing of MS-DOS.In 1981, Tim Paterson quit Seattle Computer Products and found employment at Microsoft.

Access to various networks on Linux

Big corporations often sub-divide their networks into small networks, hidden behind gateways. To access
them, you need to tell your Linux system that there is a gateway to use to access the networks.
The route program makes it easy to add networks, hosts and gateways to your routing table. To add a default
gateway, for example to access the Internet, you can set it as default with the following line:
route add default gw 10.0.0.1
This will work if you need to access the Internet via the 10.0.0.1 gateway. Now, if you want to access
networks 10.1.0.0 and 10.2.0.0 through other gateways, here is what you will want to do:
route add -net 10.1.0.0 gw 10.0.0.10
route add -net 10.2.0.0 gw 10.0.0.20

Changing file permissions on Linux Operating System

To change a file's permissions, you need to use a program called chmod. With that command you can change
one or multiple file permissions. Here are a few examples:
$ chmod 755 file
$ ls -l file
-rwxr-xr-x 1 root users 1656 Mar 22 00:27 file
$ chmod 700 file
$ ls -l file
-rwx------ 1 root users 1656 Mar 22 00:27 file
$ chmod 664 file
$ ls -l file
-rw-rw-r-- 1 root users 1656 Mar 22 00:27 file
The numbers are based on the 3 types of permissions. Read = 4, write = 2 and execute = 1. A permission of
755 means the user will have read, write and execute permissions (4 + 2 + 1 = 7), and everyone else will have
read and execute permissions (4 + 1 = 5).

Mouse problems(in Linux OS)

The mouse is a very important part of a computer. In X, you can't do much without it. Even in console some
applications will allow you to use it. You must first configure it.
Like every other device, the mouse has a device file in the /dev directory. Depending on your mouse type, it
will be either /dev/psaux for a PS/2 mouse, or /dev/cua0 for a serial mouse on COM1.
To make it easy to use in the future, you should link the right device file to /dev/mouse:
ln -s /dev/cua0 /dev/mouse
Then, when you configure X Window or any other program that requires a mouse, you can specify
/dev/mouse.

TV on Linux

A number of cards exist allowing you to watch and record TV on your PC. Most come with software for
Windows only, like so many things, but it is possible to do the same thing on Linux.
Linux comes with several drivers which make up the Video4Linux drivers. Several cards are supported by
these drivers, and a list of them is available at http://roadrunner.swansea.linux.org.uk/v4l.shtml. This is the
driver side. You also need software to use the devices.
Several programs are available to watch TV, capture images and even Web applications. A list of some of the
programs is available at http://www.thp.uni-koeln.de/~rjkm/linux/bttv.html including datasheets

Linux without a hard drive

Modern Linux distributions require around 100 megs to 200 megs of hard disk space to install. But is it
possible to run Linux on a system without a hard drive? Yes it is.
The Linux Router Project is a full-featured Linux distribution that fits on one diskette. It was made for
routers, and use modules to add the software packages you need, including DNS servers, Web servers, email
and routing. You can find more information on the Linux Router Project at http://www.linuxrouter.org

Can't mount root fs(Linux OS)

When you boot a system, this is an error that will halt the system. This error means that the kernel can't
mount the root file system, so it can't get all of its configuration files.
There are a few cases where this happens:
·  No IDE support in the kernel. If your main hard drive is an IDE, and you have recompiled
without including "Enhanced IDE/MFM/RLL disk/cdrom/tape/floppy support" or some other
basic IDE device drivers.
·  File system not supported. Usually the root file system should be of type ext2. You need to
make sure that ext2 is compiled in the kernel, and not as a module because you can't load
modules without first mounting the root file system.
·  The drive is not ready. If you have removed the drive, the hard disk died or the BIOS didn't
detect the device for some reason, then the kernel won't be able to mount it.

Use Windows special keys in Linux

Why are all the new keyboards sold with Win95 keys on them? How about making them do real keyboard
functions while in X Window? Here is how.
First you need to find out which key mapping you are using. Usually it will be US, it might also be en_US, ca
or else. Locate the file, usually in /usr/X11/lib/X11/xkb and edit it with your favorite editor. For me the file is
called /usr/X11/lib/X11/xkb/symbols/ca.
The file lists all the key codes and what they do. The key codes for the Win95 special keys are LWIN, RWIN
and MENU. All you need to do is add them to the list, with the functions for them. I decided to map the left
WIN key to "@" and the right WIN key and MENU keys to "{" and "}". Here are the lines I added:
key <RWIN> { [ braceleft ] };
key <LWIN> { [ at ] };
key <MENU> { [ braceright ] };
By browsing the file you can find all the other symbols and what they do. You can also add multiple
functions to a key, by using ALT and SHIFT.
The changes will take effect when you restart X Window. With the XKB extension (you do need to have it
enabled in /etc/XF86Config btw) it's easy to change the mapping of any key.

Making CD-ROM images(Linux OS)

With other operating systems, such as Microsoft Windows or IBM OS/2, you are not allowed in the license to
make your own CD-ROM with the OS on it and then distribute it.
Linux, being Open Source and free, can be copied. You can download a distribution or buy it from an online
store and burn your own copy, and then install it on many computers, or give it to your friends. Usually, you
will find instructions on how to do that on the FTP server for your favorite distribution. You will need the
main directory on the CD-ROM. The sources are not needed since they are available from the FTP site.
Some distributions also come with ISO images of their CD-ROM. This is a single file that can be put onto a
CD-ROM, and will create a full file system with files on it.
One thing you have to be careful is not to copy commercial programs. The basic CD-ROM where the Linux
distribution is located is composed of free software. But some distributions may come with other commercial
programs, and you should read the license first.

LILO and boot problems(Linux OS)

When a computer starts, the number of beeps the BIOS outputs tells you the state of the computer. On some
computers, one beep means all is ok, but 2 beeps mean there is an error. LILO uses the same kind of codes.
The number of letters you see from the word LILO on the screen says what is wrong. The whole word means
everything is fine, only LI means only the first part of LILO could be loaded. A full description of this is
available from the Bootdisk HOWTO.
When LILO can't load, it's a major problem. This often means that the boot code was corrupted. The only
way to boot is from a floppy disk. In RedHat, you can use the rescue disk, in Slackware, you can use the boot
disk with the "mount" image.
When LILO is fine, it's often easier to figure a boot problem. If the kernel panics when it tries to boot, it is
usualy due to a configuration error. You can tell LILO to mount another kernel you may have, like a "safe" or
"old" image you kept for these cases. If the problem is in initialization scripts, you can tell LILO to boot
directly into a shell with the following boot command line:
LILO boot: linux init=/bin/sh
Where "linux" would be your kernel image

Default boot mode(Linux OS)

When a Linux system boots, it loads the kernel, all its drivers, and the networking servers, then the system
will display a text login prompt. There, users can enter their user names and their passwords. But it doesn't
have to boot this way.
There are 3 modes defined in most Linux distributions that can be used for booting. They are defined in
/etc/inittab and have specific numbers. The first mode, also called runlevel 1, is single user mode. That mode
will only boot the system for 1 user, with no networking. Runlevel 3 is the default mode. It will load the
networking servers and display a text login prompt. Runlevel 5 is the graphical mode. If you have X Window
installed and configured, you can use it to display a graphical login prompt.
The way to change this is to edit /etc/inittab and change the initdefault line:
id:3:initdefault:
Changing a 3 to a 5 will make the system display a xdm graphical screen on bootup

Default file permissions(Linux OS)

When you create a file, the system gives it default permissions. On most systems the permissions are 755
(read, write and execute for the owner, and read and execute for others).
This default is setup with the umask command. To use the command, you need to find the right octal number
to give it. The permissions in the umask are turned off from 666. This means that a umask of 022 will give
you the default of 755. To change your default permissions from 755 to 700, you would use this command:
umask 077