Os- Its Type...and Features

MS-DOS (Microsoft Disk Operating System) is a single-user, single-tasking computer operating system that uses a command lineinterface. In spite of its very small size and relative simplicity, it is one of the most successful operating systems that has been developed to date.
Short for Disk Operating System. DOS was developed by Microsoft for IBM, and MS-DOS was for IBM compatible personal computers.
Disk Operating System - one of the first operating systems for the personal computer. When you turned the computer on all you saw was the command prompt which looked like c:\ >. You had to type all commands at the command prompt which might look like c:\>wp\wp.exe. This is called acommand-line interface.
It was not very "user friendly"
DOS is still a 16-bit operating system and does not support multiple users or multitasking.
Today, most computer users are only familiar with how to navigate Microsoft Windows using the mouse. Unlike Windows, MS-DOS is a command-line and is navigated by using MS-DOS commands. For example, if you wanted to see all the files in a folder in Windows you would double-click the folder to open the folder in Windows Explorer. In MS-DOS to view that same folder you would navigate to the folder using the cd command and then list the files in that folder using thedir command.
Maybe for you there are computer users who do not know what it is MS-DOS because in the present, MS-DOS has been rarely used because most use a more simple system like Windows.

Read more at BeZhare: MS-DOS the History Begins :: From BeZhare: Knowledge Which Must be Known http://bezhare.blogspot.com/2011/04/bezhare-ms-dos-history-begins.html#ixzz4OhJNEivd http://bezhare.blogspot.com/ Under Creative Commons License: Attribution

Topic | Command line | GUI | Ease | Because of the memorization and familiarity needed to operate a command line interface new users find it much more difficult to successfully navigate and operate a command line interface. | Although new users may have a difficult at time learning to use the mouse to operate and use a GUI most users pick up this interface much easier when compared to a command line interface. | Control | Users have much more control of their file system and operating system in a command line interface. For example, users can easily copy a specific file from one location to another with a one-line command. | Although a GUI offers plenty of control of a file system and operating system often advance users or users who need to do specific task may need to resort to a command line to complete that task. | Multitasking | Although many command line environments are capable of multitasking they do not offer the same ease and ability to view multiple things at once on one screen. | GUI users have windows that enable a user to easily view, control, and manipulate multiple things at once and is commonly much faster to do when compared to a command line. | Speed | Because command line users only need to use their keyboards to navigate a command line interface and often only need to execute a few lines to perform a task an advanced command line interface user would be able to get something done faster then an advance GUI user. | A GUI may be easier to use because of the mouse. However, using a mouse and keyboard to navigate and control your operating system for many things is going to be much slower than someone who is working in a command line.. |

copy myfile1.txt+myfile2.txt
Copy the contents in myfile2.txt and combines it with the contents in myfile1.txt. rename c:\chope hope
Rename the directory chope to hope. dir Lists all files and directories in the directory that you are currently in.
MS-DOS has a relatively small number of commands, and an even smaller number of commonly used ones. Moreover, these commands are generally inflexible because, in contrast to Linux and other Unix-like operating systems, they are designed to accommodate few options or arguments (i.e., values that can be passed to the commands).
CD - changes the current directory (cd)
COPY - copies a file (cp)
DEL - deletes a file (rm)
DIR - lists directory contents (ls)
EDIT - starts an editor to create or edit plain text files (vi, vim, ed, joe)
FORMAT - formats a disk to accept DOS files (mformat)
HELP - displays information about a command (man, info)
MKDIR - creates a new directory (mkdir)
RD - removes a directory (rmdir)
REN - renames a file (mv)
TYPE - displays contents of a file on the screen (more, cat)

Bootstrapping: the process of starting an inactive computer by using a small initialization program to load other programs.

Advantages:

1. will run on a much smaller system. (ENTIRE OS can be placed on a SINGLE MODERN ROM chip!)
2. gives you more "direct" control of the processes.
3. Because of smaller size will "boot" much faster than ANY windows version.
4. Is easier to write "special purpose" programs for, so long as they don't require "fancy" graphics.
5. Allows you to make use of the "old, slow" system you hid in the closet when you bought the "new" one.

Disadvantages:

1. Very few "new" programs available, therefore you need to be able to write programs in many cases.
2. Not nearly as fancy in the graphics department.
3. Not compatible with current "browsers" and most internet.
Disadvantages
1. Its a Single User OS (One User can Work at a time) 2. Its a Single Tasking OS (One application can run at a time) 3. It does not supports Graphics 4. It does not supports Networking 5. We can only make 2GB of Maximum partition as it supports only FAT 16

Read more: http://wiki.answers.com/Q/What_are_the_advantages_and_disadvantages_of_MS-DOS#ixzz1o2yEIhIq

MS-DOS is old, very old by computer standards. It is not compatible with most programs and applications now. It won't run right or at all on most newer computers, printers or anything else.
If you want to use dos you should have an older computer like 1993 and older. Dos will run older programs and software like 10+ years old but it will not run any windows program even old windows 3.1 programs unless it is installed. A few of those older programs were neat or were useful but most of of it is no where near as good as the new stuff now which is windows compatible.
Dos can also be useful for anyone who is into basic programing.

Read more: http://wiki.answers.com/Q/What_are_the_Disadvantages_of_using_MS-DOS_operating_system_over_windows_operating_systems#ixzz1o31itS3G

UNIX
Unix (officially trademarked as UNIX, sometimes also written as Unix) is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna. The Unix operating system was first developed in assembly language, but by 1973 had been almost entirely recoded in C

* multi-user more than one user can use the machine at a time supported via terminals (serial or network connection) * multi-tasking more than one program can be run at a time * hierarchical directory structure to support the organisation and maintenance of files * portability only the kernel ( <10%) written in assembler tools for program development a wide range of support tools (debuggers, compilers)
The major features/facilities of the UNIX operating system include the following: multi-user More than one user can use the machine at a time supported remote via terminals. multi-tasking More than one program can be run at a time.
Hierarchical directory structure
In order to support the organization and maintenance of files. portability Only the kernel is written in Assembler Language. This means that the operating system can be converted easily to run on different hardware.
Program development tools
A wide range of support tools: debuggers and compilers.

This UNIX operating system is structured in terms of three major components. kernel C Schedules programs.
C Manages data/file access and storage.
C Enforces security mechanisms.
C Performs all hardware access. shell C Presents each user with a prompt.
C Interprets command types by a user.
C Executes user commands.
C Supports a custom environment for each user.
Utilities C File management: rm, cat, ls, rmdir, mkdir
C User management: passwd, chmod, chgrp
C Process management: kill, ps
C Printing: lp, troff, pr
C Program development tools

Commands cd - change working directory cp - copy files mkdir - create a directory mv - move or rename files and directories rm - delete (remove) files rmdir - delete (remove) directories stat - status of file (i.e. last access) chmod - change the protection of a file or directory

Advantages * Full multitasking with protected memory. Multiple users can run multiple programs each at the same time without interfering with each other or crashing the system. * Very efficient virtual memory, so many programs can run with a modest amount of physical memory. * Access controls and security. All users must be authenticated by a valid account and password to use the system at all. All files are owned by particular accounts. The owner can decide whether others have read or write access to his files. * A rich set of small commands and utilities that do specific tasks well -- not cluttered up with lots of special options. Unix is a well-stocked toolbox, not a giant do-it-all Swiss Army Knife. * Ability to string commands and utilities together in unlimited ways to accomplish more complicated tasks -- not limited to preconfigured combinations or menus, as in personal computer systems. * A powerfully unified file system. Everything is a file: data, programs, and all physical devices. Entire file system appears as a single large tree of nested directories, regardless of how many different physical devices (disks) are included. * A lean kernel that does the basics for you but doesn't get in the way when you try to do the unusual. * Available on a wide variety of machines - the most truly portable operating system. * Optimized for program development, and thus for the unusual circumstances that are the rule in research.
Disadvantages
* The traditional command line shell interface is user hostile -- designed for the programmer, not the casual user. * Commands often have cryptic names and give very little response to tell the user what they are doing. Much use of special keyboard characters - little typos have unexpected results. * To use Unix well, you need to understand some of the main design features. Its power comes from knowing how to make commands and programs interact with each other, not just from treating each as a fixed black box. * Richness of utilities (over 400 standard ones) often overwhelms novices. Documentation is short on examples and tutorials to help you figure out how to use the many tools provided to accomplish various kinds of tasks.

Linux
In the 1980s, many people liked to use an operating system called Unix. But because it restricted the user from sharing and improving the system, some people made a new operating system that would work like Unix but which anybody could share or improve. MINIX, similar to Unix, was used as a teaching tool for university students to learn how operating systems worked. MINIX also restricted its sharing and improvement by its users.
A group of people called the GNU project wrote different parts of a new operating system called GNU, but it did not have all the parts an operating system needs to work. In 1991 Linus Torvalds began to work on a replacement for MINIX that would be free to use, and which would not cost anything. Linus started the project when he was attending the University of Helsinki.[2][3] This eventually became the Linux kernel. Kerneltype | Monolithic |
Linus Torvalds, who was then a student at the University of Helsinki in Finland, developed Linux in 1991. He released it for free on the Internet. Due to the far reach of the Free Software Foundation (FSF) and the GNU Project, Linux popularity increased rapidly, with utilities developed and released for free online. A commercial version of Unix was released by RedHat in the early 1990’s (combining the OS with technical support and documentation) and the popularity of Linux continued to skyrocket. advantages 1. Low cost: You don’t need to spend time and money to obtain licenses since Linux and much of its software come with the GNU General Public License. You can start to work immediately without worrying that your software may stop working anytime because the free trial version expires. Additionally, there are large repositories from which you can freely download high quality software for almost any task you can think of. 2. Stability: Linux doesn’t need to be rebooted periodically to maintain performance levels. It doesn’t freeze up or slow down over time due to memory leaks and such. Continuous up-times of hundreds of days (up to a year or more) are not uncommon. 3. Performance: Linux provides persistent high performance on workstations and on networks. It can handle unusually large numbers of users simultaneously, and can make old computers sufficiently responsive to be useful again. 4. Network friendliness: Linux was developed by a group of programmers over the Internet and has therefore strong support for network functionality; client and server systems can be easily set up on any computer running Linux. It can perform tasks such as network backups faster and more reliably than alternative systems. 5. Flexibility: Linux can be used for high performance server applications, desktop applications, and embedded systems. You can save disk space by only installing the components needed for a particular use. You can restrict the use of specific computers by installing for example only selected office applications instead of the whole suite. 6. Compatibility: It runs all common Unix software packages and can process all common file formats. 7. Choice: The large number of Linux distributions gives you a choice. Each distribution is developed and supported by a different organization. You can pick the one you like best; the core functionalities are the same; most software runs on most distributions. 8. Fast and easy installation: Most Linux distributions come with user-friendly installation and setup programs. Popular Linux distributions come with tools that make installation of additional software very user friendly as well. 9. Full use of hard disk: Linux continues work well even when the hard disk is almost full. 10. Multitasking: Linux is designed to do many things at the same time; e.g., a large printing job in the background won’t slow down your other work. 11. Security: Linux is one of the most secure operating systems. “Walls” and flexible file access permission systems prevent access by unwanted visitors or viruses. Linux users have to option to select and safely download software, free of charge, from online repositories containing thousands of high quality packages. No purchase transactions requiring credit card numbers or other sensitive personal information are necessary. 12. Open Source: If you develop software that requires knowledge or modification of the operating system code, Linux’s source code is at your fingertips. Most Linux applications are Open Source as well.

While we often talk about the benefits of Linux here at BrightHub, there are some drawbacks you should consider. Here are some of the biggest problems which some users may experience. 1. There’s no standard edition of Linux. Whereas Microsoft offers several different editions of each version of Windows, there are countless variations of Linux. For a new user it can be confusing to work out which is best for you. 2. Linux has patchier support for drivers (the software which coordinates your hardware and your operating system). This means you’ll sometimes find it trickier to get a new device set up. 3. Linux is, for new users at least, not as easy to use as Windows. That’s largely because Linux gives you more control, but does mean you’ll have to spend some time getting used to the way it works. 4. Because Linux is neither as popular as Windows, nor a commercial product, support works in a different way. You may have to look harder to find the answer to a problem and, while Linux supporters are more likely to offer help, it may not always match your own level of technical understanding. 5. Many of the programs you are used to in Windows will only run in Linux through a complicated emulator. These programs aren’t guaranteed to work perfectly, and in some cases may be noticeably slower. 6. While Linux can be suitable for an individual user, its small market share means it’s much harder to introduce in a corporate setting. With most office workers already familiar with Windows and Microsoft programs, there’ll likely be a notable time cost in converting staff to using a Linux system. 7. While there are perfectly passable alternatives to many popular Windows programs (such as the various Office components), some high-end applications such as Photoshop don’t have as close equivalents in Linux. 8. Fans of PC gaming may find Linux offers them a much more limited range. That’s partially because the latest games are nearly always a commercial operation and much harder to reproduce in Linux because they are much more individual than, for example, office software. 9. While there’s no specific reason why this should be the case, in practice quite a few users report finding printing can be troublesome to set up in Linux. 10. Because Linux is a free, open source system, there are no legal comebacks if you find software isn’t up to scratch or if it causes a problem. While there’s no guarantee you’d win, you do at least have some right of complaint with commercial products such as Windows. Understanding – Becoming familiar with the Linux operating system requires patience as well as a strong learning curve. You must have the desire to read and figure things out on your own, rather than having everything done for you. Check out the 20 must read howto’s and guides for Linux.

* Compatibility – Because of its free nature, Linux is sometimes behind the curve when it comes to brand new hardware compatibility. Though the kernel contributors and maintainers work hard at keeping the kernel up to date, Linux does not have as much of a corporate backing as alternative operating systems. Sometimes you can find third party applications, sometimes you can’t.

* Alternative Programs – Though Linux developers have done a great job at creating alternatives to popular Windows applications, there are still some applications that exist on Windows that have no equivalent Linux application. Read Alternatives to Windows Applications to find out some of the popular alternatives.

Now that you have an understanding of some of the advantages of Linux, its time get out there and experiment. Windows can be a great tool for the lazy and incompetent, but it takes a true scholar and one who wants to learn to run a robust operating system like Linux.

Key features of Linux Operating System:

Following are the key features of the Linux operating system: * Multitasking: several programs running at the same time. * Multiuser: several users on the same machine at the same time (and no two-user licenses!). * Multiplatform: runs on many different CPUs, not just Intel. * Multiprocessor/multithreading: it has native kernel support for multiple independent threads of control within a single process memory space. * It has memory protection between processes, so that one program can't bring the whole system down. * Demand loads executables: Linux only reads from disk those parts of a program that are actually used. * Shared copy-on-write pages among executables. This means that multiple process can use the same memory to run in. When one tries to write to that memory, that page (4KB piece of memory) is copied somewhere else. Copy-on-write has two benefits: increasing speed and decreasing memory use. * Virtual memory using paging (not swapping whole processes) to disk: to a separate partition or a file in the file system, or both, with the possibility of adding more swapping areas during runtime (yes, they're still called swapping areas). A total of 16 of these 128 MB (2GB in recent kernels) swapping areas can be used at the same time, for a theoretical total of 2 GB of useable swap space. It is simple to increase this if necessary, by changing a few lines of source code. * A unified memory pool for user programs and disk cache, so that all free memory can be used for caching, and the cache can be reduced when running large programs. * All source code is available, including the whole kernel and all drivers, the development tools and all user programs; also, all of it is freely distributable. Plenty of commercial programs are being provided for Linux without source, but everything that has been free, including the entire base operating system, is still free. * Multiple virtual consoles: several independent login sessions through the console, you switch by pressing a hot-key combination (not dependent on video hardware). These are dynamically allocated; you can use up to 64. * Supports several common file systems, including minix, Xenix, and all the common system V file systems, and has an advanced file system of its own, which offers file systems of up to 4 TB, and names up to 255 characters long. * Many networking protocols: the base protocols available in the latest development kernels include TCP, IPv4, IPv6, AX.25, X.25, IPX, DDP (AppleTalk), Netrom, and others. Stable network protocols included in the stable kernels currently include TCP, IPv4, IPX, DDP, and AX.25.

Windows xp
Additonal features * Windows XP includes various new features not found in previous versions of Microsoft Windows. Below is a listing of some of these new features. * New interface - a completely new look and ability to change the look. * Updates - new feature that automatically obtains updates from the Internet. * Internet Explorer 6 - Includes Internet explorer 6 and new IM. * Multilingual support - added support for different languages. * In addition to the above features, Windows XP does increase reliability when compared to previous versions of Microsoft Windows. | Minimum | Recommended | Processor | 233 MHz | 300 MHz or higher | Memory | 64 MB RAM (may limit performance and some features) | 128 MB RAM or higher | Video adapter and monitor | Super VGA (800 x 600) | Super VGA (800 x 600) or higher resolution | Hard drive disk free space | 1.5 GB | 1.5 GB or higher | Drives | CD-ROM or DVD-ROM | CD-ROM or DVD-ROM | Devices | Keyboard and mouse | Keyboard and mouse | Others | Sound card, speakers, and headphones | Sound card, speakers, and headphones |

Windows vista

Microsoft Windows Vista is an upgrade to Microsoft Windows XP and Windows 2000 users. Windows Vista contains a dramatic new look for users used to previous versions of Microsoft Windows that has been designed to help create an overall better experience.
Some of the key new features of Window Vista Include: * Windows Aero, a completely new GUI and unlike any previous version of Windows. * Basic file backup and restore. * Improved DVD support with the ability to easily create custom DVD movies. * Easy transfer, a feature that allows you to easily transfer files from an older computer to the new computer. * File encryption. * Instant search available through all Explorer windows. * Support for DirectX 10. * Self-healing, the ability to automatically detect and correct problems that may be encountered on the computer. * Shadow copy, a feature that allows you to recover deleted files. * Improved photo gallery and control of photographs. * Windows Sidebar and gadgets that allows you to add an almost endless list of different gadgets. * More parental control. * Improved Windows Calendar, with the ability to set tasks and appointments.
Windows home server

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Features
* Centralized backup - Allows backup of up to 10 PCs,[9] using Single-instance storage technology to avoid multiple copies of the same file, even if that file exists on multiple PCs.[10] * Health monitoring - Can centrally track the health of all PCs on the network, including antivirus and firewall status.[10] * File sharing - Creates and operates network shares for computers to store the files remotely, acting as a network-attached storage device. Separate categories are provided for common file types like Documents, Music, Pictures and Videos.[10] The files are indexed for fast searching.[11] * Printer sharing - Allows a print server to handle print jobs for all users.[10] * Shadow Copy - Uses Volume Shadow Copy Service to take point in time snapshots that allow older versions of files to be recovered.[12] * Headless operation - No monitor or keyboard is required to manage the device.[10] Remote administration is performed by using the Windows Home Server Console client software provided in the bundle. Remote Desktop Services[13] connections to the server are supported while connected to the same LAN.[14] * Remote access gateway - Allows remote access to any connected PC on the network, including the server itself, over the Internet.[14] * Media streaming - Can stream media to an Xbox 360 or other devices supporting Windows Media Connect.[10] * Selective data redundancy - Guards against a single drive failure by duplicating selected data across multiple drives.[10][dated info] * Expandable storage - Provides a unified single and easily expandable storage space, removing the need for drive letters.[10][dated info] * Extensibility through add-ins - Add-ins allow third-party developers to extend the features and functionality of the server. Add-Ins can be developed using the Windows Home Server SDK, to provide additional services to the client computers or work with the data already on the server. Add-ins can also be ASP.NET applications, hosted in IIS 6 running on WHS.[11] * Server backup - Backs up files which are stored within shared folders on the server to an external hard drive

Windows 7
d.
Aero Desktop (improved) * Aero Peek: A specific open window or all open windows can be made transparent * Aero Snaps: Open windows can be snapped to screen borders * Aero Shake: Desktop items can be minimized or maximized by shaking them * Maximize a window by dragging its border to the top of the screen * Dragging the bottom border expands the window vertically * Dragging two windows to opposite sides will resize them to fill half of the screen
Windows Taskbar (the Superbar) (improved) * Graphic thumbnails for open windows * Switch between multiple windows by just hovering over the taskbar thumbnail * Icons are big enough to be selected easily with the new touch feature * Applications can use the taskbar to provide information (a progress bar for example)

Libraries (new) * Libraries are containers similar to folders, but their content is based on file properties such as file type, pictures by date taken, or music by genre * There are default libraries (documents, music, pictures, etc.) and one can create personalized libraries * Libraries can contain files, not network shares, which are indexed by Windows Search
Jump lists (improved) * Jump lists are automatically populated links in the Start Menu to frequently accessed sources (apps, documents, etc.) * Taskbar items, the Internet Explorer, and Windows Media Player will have them too, allowing you to jump directly to a certain task of a program
Windows Sidebar (improved) * Is no longer a sidebar * Gadgets are now placed on the desktop * Gadgets are resizable * Aero Peek lets you see gadgets behind open windows
Windows Explorer (improved) * New user interface (have to find out more) * New copy engine: fewer prompts, shows file names being copied, more reliable
Scenic Ribbon (new) * Paint and WordPad now have a ribbon similar to the one in Office 2007 * Third-party developers can integrate ribbons into their apps
Start Menu Search (improved) * Searches in Libraries (also external files) * Search results are grouped according to Libraries * System administrator can define up to five external search destinations * Search will be executed on the server
Windows Search 4 (improved) * Input recommendations based on previous searches * Dynamic filters to narrow down results * New relevance algorithm * Word highlighting in results * Search Federation: search external resources (servers, Sharepoint, Web sites (OpenSearch))
Tablet PC enhancements (improved) * Supposed to have improved handwriting recognition * Supports handwritten math expressions * Personalized custom dictionaries, and supports new languages
Sticky Notes (improved) * Ink support * Paste support * Note colors * Resize possible
Accessibility (improved) * Improved speech recognition * Magnifier (whole desktop or portion of the screen) * Accessibility support tools for developers
Windows Touch (new) * Windows 7 can be controlled by touching the screen * It also supports multi-touch allowing you to use more than one finger