Types Of Operating System

Examples of Application Suites

Microsoft Office Lotus Smart Suite

OPERATING SYSTEMS • They enable access to programs, accessories and other hardware. An operating system is just as essential to a computer as the computer’s hardware. • An Operating System (OS) is the actual software that controls the allocation and use of a computer’s hardware. • The OS keeps components workinf in unison, acting as a communicator between the user the computer’s hardware and software

• Operating Systems basic tasks like recognizing input from the keyboard or mouse, sending output to the video screen or printer, keeping track of files on the drives, and controlling peripherals such as printers and modems.

OPERATING SYSTEM’S COMPONENTS • User Interface • Kernel (OS Executive) • File Management System

The User Interface • It is what users see onscreen and interact with when giving a computer either by typing and commands. • Communicates to the computer either by typing commands at a command prompt or by issuing commands through a graphical user interface (GUI)

The Kernel • Its job is to regulate disk files, memory management, program objectives and tasks, and program execute and process. • It is considered the operating system’s core because it controls a computer’s hardware, and is responsible for either directly activating computer hardwar e or for interfacing with software that drives the hardware.

The File Management System • It is the operating system’s organizer, arraging files inheirarchical tree-like structure the root directky. • Filename extensions declare files’ type: txy indentifies text data; jpg,bmp and gif extensions identify graphic files.

HOW DOES AN OPERATING SYSTEM WORK? • It takes charge of important activities from the boot up process to the shutdown process.Once up an running, the operating system manages memory; saves, deletes, and retrieves data; arranges to display data on the monitor; sends data to the printer; responds to kestrokes; recognizes mouse clicks; and reads and writes data to the hard and floopy disks.

MAJOR OPERATING SYSTEMS • • • • • • •

CP/M: An Early Operating System MS-DOS and PC-DOS Microsoft Windows OS 2 MAC OS Unix Linux

CP/M: An Early Operating System • In 1973, a man named Gary Kildall wrote the first PC operating system (using the PL/M program language he invented) called Control Program for Microcomputer (or CP/M). Initially CP/M ran on the Intel 8008 chip, and later translated to the 8080 chip.

• IBM approached Kildall to discuss licensing terms for his CP/M operating system. When Kildall missed that oppointment, the IBM executive went on to his next appointment—with a company named Microsoft. (kildall denies the accuracy of the missed-appointment story) Microsoft’s Bill Gates seized the licensing opportunity immediately. The rest—Gates’ licensing DOS to IBM—is history.

MS-DOS and PC-DOS • The ‘Quick and Dirty Operating System,’ first developed by Tim Patterson of Seattle Computer Products, was purchased by Microsoft for$100,00. Microsoft then rifened Q-DOS and named it microsoft Disk Operating System.

MS-DOS 2.x • -it accompanied IBM's PC XT computer,offering a 10 MB hard drive, three new expansion slots, and a serial interface. • - the PC XT gave users more flexibility with 128 KB of RAM and a floppy drive. • - MS-DOS 2 introduced the DOS file system's familiar heirarchical "tree" structure.This "tree" structure is a cornerstone for other operating systems like Unix and Linux as well as Windows.

MS-DOS 3.x • in this version the hard drive grew: MsDOS 3 accommodated that growth. • - IBM's PC AT computer--available with a 20 MB hard drive--included the MS-DOS 3 with its 256 KB of RAM, 6 MHz processor, and 1.2 MB floppy drive. • - MS-DOS 3.1 included IBM's PC network, a workgroup- like networking structure. • - by the late 1980s, DOS had evolved through two more versions: • 3.2 and 3.3.

• - by the way of those upgrades, hard disk partition size had grown to 32 MB. • - the "new" DOS now supported Token Ring networks, and a more compact 3.5"floppy disc which could accommodate up to 1.4 MB of space.

MS-DOS 4.x • - it was a significant change from its predecessors.The imployed DOS shell gave the users to manage files, run programs and perform basic maintenance included a limited graphical interface and DOS shell access via a mouse.

MS-DOS 5.x • it is introduced in early 1990s that some new utilities that users have come to depend on. • - UNFORMAT.EXE and UNDELETE.COM make accidentally "lost" data easier to retrieve. • - DOSKEY.COM makes it possible to use the up arrow key to scroll through the list of previously issued commands, saving users from having to re-type the same thing over and over.

• -EDIT.COM replaced the former EDLIN.COM (a very basic and unfriendly text editor) to provide a popular simple text editor. • - QBASIC was also introduced to create an interface for writing and running BASIC programs. • -once more upgrade featured in version 5.x gave users the option of loading drivers into upper memory-thereby expanding conventional memory.

MS-DOS 6.x this version was introduced in the early 90's led to new computing heights. The improvements was highlighted by new anti-virus software, backup software, defragmenting ability, new configuration possibilities, and additional commands. • - DriveSpace is a disk compression program.it is a built-in Windows compression utility that was introduced a part of MS-DOS 6.x. Compression utilities are used optimize available hard drive space by "intercepting" files, then compressing them prior to actually storing them. It is also possible to buy third party disk compression utilities like WinZip. •

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WINDOWS • - by 1974 Xerox had developed the friendly systems we take for granted today. Xerox's Alto workstation featured the first graphical user interface, mouse, and computer-to-computer communication. • - Unfornately, their short-sighted executives saw no future for the personal computer, and chose to bank on their copier business rather than their improvements to personal computing and

• networking. And this turned out to be a big mistake. • - by the late 1980's, even as the DOS was evolving and improving, its limitations were becoming obvious. • - Computer- using customer (especially the at-home, technically unsophisticated users) wanted machines and software designed and written for no- technical consumers. Without a graphical interface, MS-DOS did not meet the ease -ofaccess and ease-of-use needs of the growing modern computer customer base. • - Apple and Microsoft caught on to the

• market early, incorporating Alto's userfriendly technology into their own software development, modifying the Macintosh and Windows operating system software to accommodate user needs. The result: Macintosh's and Windows' now familiar, user-friendly graphical interfaces that takes technical monotony out of computer access.

WINDOWS' EVOLUTION:

Windows 1.x • - it is looking more "graphical" than its DOS underpinnings. It is still did not feature the icons we ahve come to recognize in today's graphical user interfaces. • - some Window 1 features, however-menu systems, tiled windows, and mouse access-created a benchmark for future, even more advanced Windows versions. • - Windows 1.x also introduced limited multitasking to the PC world.

• - multitasking gave personal computer users the illusion that multiple tasks could simultaneously be managed. In actuality, multitasking manages multiple tasks by spending a fraction of a second of each task, before switching to another, eventually cycling through all the task currently running. At no time is the system actually managing more than one process at a single time, it just appears that way.

Windows 2.x • in the late 1980's came the familiar access- making icons of today's interfaces with Windows 2. Along the icons, Windows 2 allowed overlapping (not just tiled) application windows. In the Windows 2 supported program information files (PIF), giving users configuring power to run DOS application more efficiently. An enhanced version of Windows 2Windows/386, designed to be compatible with Intel’s 386 processor- permitted multiple extended memory DOS sessions.

Windows 3.x • In 1990, Windows 3 brought its File Manager, Program Manager, and network support to its ever-adapting functions. Windows 3.0’s 386 Enhanced mode opened up the hard drive to virtual memory, supplementing the computer’s RAM. • Better graphical and multimedia capability, improved error-protection, and easier application cooperation with object linking and embedding (OLE) accompanied Windows 3.1’s 1992 introduction.

• Windows 3.11 did not add any features, but fixed bugs present in Windows 3.1. • Windows for Workgroups added support for peer-to-peer networks into Windows 3.x (Windows 3.1 and Windows 3.11 are both referred to as Windows 3.x). Users could share files and printers while setting limited security to resources. Windows for Workgroups also added an e-mail application and a schedule sharing application.

Windows 95 • As hardware and software continued to improve, DOS became an obsolete foundation to the Windows graphical interface. In a move to accommodate ever- expanding modern software and hardware capabilities, Microsoft integrated its friendly Windows shell with its operating system to create a major breakthrough in the operating system market. • Up this point, Windows was simply a management program that ran on top of DOS. Windows users still had to boot their machines to a DOS prompt before

• accessing the Windows interface. The core operating system that started with Windows 95 is the Windows 9x-based operating system. Windows 95,98, and ME are all Windows 9x-based operating system. • Windows 95 was released in August of 1995; Microsoft has made numerous changes and additions to the operating system. There are four versions A, B, and C. • Windows 95 is a hybrid 16-bit/32-bit operating system. 32-bit code is used as often as possible for speed and stability, but 16-bit code is present to ensure

• compatibility with older DOS and Windows 3.x software (backward compatibility). • Windows 95 encourages the use of 32-bit hardware drivers, despite its support for 16-bit DOS, which enables compatibility with old hardware. While the 32-bit code in Windows 95 provides increased stability over Windows 3.1, the legacy 16-bit code still leaves the operating system vulnerable to crashes. • Windows 95 can be used as a complete product for new system or as an upgrade to Windows 3.x.

Windows 98 • Major revisions to Windows 95 culminated in Microsoft’s introduction of Windows 98. Operating intuitively, much like its Windows 95 predecessor, Windows 98 is a more polished version of Windows 95 offering enhanced features. • Enhanced support for multimedia hardware and software, multiple monitor support, and a helpful Maintenance Wizard are a few of Windows 98 features that distance it from its Windows 95 cousin.

• Windows 98’s most notable change was to integrate the Internet Explorer 4.0 browser into the operating system. This has since become the center for a lot of litigation. • Windows 98 brings FAT32 support to the retail customer. A conversion program (CVT.EXE) is provided to allow users to upgrade their FAT partitions to FAT32.

Windows Millennium Edition (Windows ME) • While still a hybrid 16-bit/32-bit operating system, Windows ME takes extensive steps to hide the DOS environment from users in an attempt to make the system even more friendly. • Windows ME introduces system recovery features that allow the computer to recover from corrupted system files.

Windows XP • It is formerly known by its code name Whistler, which is the Microsoft’s major operating system release. • Windows XP is the end of the line for the six-year-old Windows 9x operating system core. • Microsoft intends to combine all the ease of-use, multimedia, and gaming features that were brought to life in the Windows 9x core with the stability, 32-bit performance, and security of the NT core

OS/2 • IBM operating system upgrade led to the emergence of the OS/2 family. • OS/2 was one of the most powerful operating systems available when it was initially released, but lack of support has forced this operating system to disappear from the mainstream market. • The first OS/2 incarnation was designed to accommodate the 286-processor. • OS/2 version 2 needed at least a 386 processor and offered a 32-bit code.

• OS/2 version 3 was called OS/2 Warp, featured 32-bit code, graphical interface, and preemptive multitasking. OS/2 Warp was also designed to take advantage of the 486 processor. OS/2’s development has paralleled its Windows counterpart, and holds on to some loyal users.

MAC OS • Apple Computer gave its system 7 operating system a new name in 1997: The Apple Computer operating system has held on to a piece of the operating system market despite of Microsoft’s dominance. • Mac OS’s easy-to-use GUI interface and standard Plug-and-Play hardware configuration have made it very popular among its legion of dedicated users. The Mac OS has proven to be a great tool for

• graphics development and multimedia applications; however, the Mac OS suffers because it lacks compatibility with software applications enjoyed by PC users. • Mac OS X was a newest operating system for the Macintosh which introduced in the year 2000 that builds its users-friendly graphical interface on a more robust/ stable UNIX based foundation.

UNIX • UNIX operating system offers major complexity, stability and power that is for users whose power needs are huge and complex. • Despite its cryptic, text-based interface, UNIX still maintains a loyal following because it rarely “crashes”. UNIX system administrators speak sometimes of UNIX based computers that run for years without needing a reboot. Newer innovations for UNIX, like graphical

• interface, have made it even more popular among personal computer purists.

LINUX • It is a free UNIX-type operating system originally created by Linus Torvalds with the assistance of developers around the world. Developed under he GNU General Public License, which is the source code for Linux, is freely available to everyone. • Linux’s gaining popularity is no doubt due to its reputable UNIX lineage and unbeatable price. Linux suffers from the same barrier that prevents UNIX from being accepted as a consumer operating system: its cryptic command line interface.

• Fortunately, Linux has a large community of hardcore users who are constantly improving the operating system. These improvements include a graphical interface and greater networking capabilities. As a sign of the times Linux operating system will continue to gain in popularity and challenge the computing industry’s dependence on Microsoft’s line of network operating system.

BITS & BYTES • The computer only understand two things; those two things are • ON and OFF • On is represented by the number (1) while off is represented by (0). • This is based on the Binary number system and these digits are known as bits. • Bits- is a contraction of the words Binary DigiT in order for the computer to save information it saves it in terms of Bytes.

• Bytes – is a contraction of the word BinarY digiTs Eight. This means that one BYTE consists of eight bits. A byte is necessary in order for the computer to store a character of information. So, in terms of storage space a byte can be considered to be the size of a character. • Kilobyte Approximately 1000 bytes. A kilobyte can store up to 1000 characters of Information. • Megabyte Approximately 1 Million bytes. A megabyte can store up to 1 Million character of information. • Gigabyte Approximately 1 Billion bytes. Gigabytes can store up to 1 Billion characters of information.

FILES • Files are clumps of computer data stored somewhere in your computer. Each file has a name, a location, and a length, and usually a date of when it was last changed. • Files are stored in several places • On floppy disks • On hard drives • On CD’s • In the computers memory (RAM)

• In the computers special read only memory (ROM) • On tapes of a tape back- up device • Any files that are in the memory of the computer are lost when the power is turned off. That is not as scary as it sounds because what you usually have in memory is only a temporary copy of the file, the original stays on the hard drive or floppy drive or wherever it is usually kept. Pretty well the only time the original is in memory is when you are creating a new file and haven’t saved it yet.

What do files do? • Files hold and store information that can be read by the computer.

What kinds of files are there? • All files are the same, they all have a name, a location, a date and they all hold information. However, they can hold lots of different kinds of information, so we often think of this as different kinds of files. • TABLE

What do you do with the files? • What you do with the file depend on the type of information that it holds, but some things can be done with all files. • Run them- if they hold a program. • Look inside them- if they hold graphics information or text.

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