Operating Systems Basic PC Maintenance, Upgrade and Repair Mods 1 & 2

What is an Operating System ► An operating system (OS) provides a computer user with a file system structure and a means of communicating with the computer system hardware. ► It communicates with disk storage units, screen displays, printers, memory, and other computer components. ► It allows application software to communicate with the BIOS, which in turn translates the request into instructions the hardware can understand. ► It provides the user with the ability to interact with the computer hardware and peripherals.

Operating System Characteristics ► Defined as, “The way an operating system handles activities such as storing data, interfacing with the user, and presenting information on the screen.” ► Multitasking – the ability of an operating system to support two or more programs running at the same time. ► Although it seems that both programs are running simultaneously, they are not. The PC switches control between the programs and gives the illusion of simultaneous operation.  Preemptive Multitasking – also referred to as time slicing, allows multiple programs to share control of the operating system. ► No single program can totally take control. ► All programs running in this mode are sharing RAM. ► If two programs attempt to use the same area of RAM at the same time, the computer will lock up. ► Windows 95, 98, Me, 2000, NT and XP use this type of multitasking.

Operating System Characteristics ► User Interface – The way in which a user interfaces with the operating system. ► The two dominant user interfaces are text line command and graphical user interface (GUI).  Text line command interface means that commands for the computer are issued by typing in text at a command prompt ► Examples of this are DOS, PC-DOS, and UNIX.  Graphical user interface, pronounced “gooey”, is a user friendly interface used in most all computers today. ► Macintosh invented this interface in the 80’s. ► Microsoft, in response, created Windows 3.1 ► The GUI displays the file system consisting of folders, icons, and names. ► The file structure is easily displayed and interpreted. ► Allows the user to perform functions by selecting on-screen icons rather than issuing text line commands.

File System Structure ► The basic structure is made up of directories, subdirectories, and files.  File – a collection of data that forms a single unit  Directory – a file used to group other files together in a hierarchical file structure. ► Is similar to a file folder in a conventional paper filing system. ► Are referred to as “folders” in many operating system.  Subdirectory – a file that subdivides the contents of a directory. ► Is similar to a folder within a folder in a conventional paper filing system. ► Are referred to as subfolders in many operating systems.  Pathname – used to identify the location of a specific file in a directory structure. ► Example: C:\PC Maintenance\Computer Pics

The Microsoft Windows Family ► In 1990, Windows was introduced as the first Microsoft graphic user interface for the PC operating system. ► It was built on top of the MS-DOS system ► It was not really a new type of system, it just displayed the file structure on the screen differently than text only systems. ► This new system was Windows 3.0. ► Improved versions of this over the years were Windows 3.1 and 3.11 Windows 3.x

The Microsoft Windows Family ► The release of Windows 95 produced many changes in the Microsoft operating system. Some significant changes were....  Plug and Play (PnP)  Right mouse click  32-bit operating system  Enhanced CD player ► PnP allows hardware devices to be configured automatically (detection, configuration, assignment of system resources). ► Right mouse click displayed a shortcut menu with access to features such a Open, Explore, Find, Create Shortcut, Rename, Properties, etc. Windows 95

The Microsoft Windows Family ► The release of Windows 98 was delayed several times. ► It was originally a project code named Memphis, and later called Windows 97. ► It offered support for new technologies such as DVD, MMX, AGP, and FAT32. ► It also introduced the integration of a Web Browser (Internet Explorer) as part of the operating system  This caused a lot of controversy and helped involve Microsoft in an antitrust suit that made it all the way to the United States Supreme Court. Windows 98

The Microsoft Windows Family ► Short for “New Technology”, it was originally developed to replace MS-DOS systems, but became too large and powerful for the typical PC at the time. ► Is similar in appearance to other Windows operating systems. ► Comes in two different versions:  Stand-alone PC  File server. ► Security is enhanced, limiting access to users. Even single user had to set up their own security system in order to access files. Windows NT

The Microsoft Windows Family ► Windows Me was more stable than its Windows 95 and 98 predecessors. ► Although the basic operating system remained the same, several necessary changes were made.  Introduced an advanced network wizard designed specifically for the home or small office user (sharing between PC’s.)  Included more sophisticated data compression techniques for video files.  A system restore tool was added to the system that allowed the user to restore the PC back to a previous working configuration if a problem exists. Windows Me

The Microsoft Windows Family ► Windows 2000 continues to improve the many features of the Windows operating system. ► One major change was the switch from FAT to NTFS, the new file system also known as the dynamic file system. ► This system provided added security and allows multiple hard drives to be handled as one large volume. To the user, the multiple drives appear as one. Windows 2000

The Microsoft Windows Family ► In October of 2001, the first versions of Windows XP were released. ► XP = eXPerience ► Was the first major change in the Windows operating system since Windows 95 came on the market. ► Windows XP is written using a modified NT kernel  Kernel is the core of the operating system ► This modified NT kernel is much more stable when compared to the typical Windows 95 and 98 kernels. ► Two XP operating systems were created; Home Edition and Professional. ► XP is the dominant replacement for all Windows systems. ► Computers running Windows 98, NT, Me, or 2000 should be easily upgraded to XP Windows Xp

Other Operating Systems ► Linux  A derivative of UNIX, a mainframe computer operating system originally developed in the 1970’s.  Can run on Intel and Motorola processors, so....  It can be loaded on Mac’s as well as PC’s. ► OS/2  Developed by Microsoft for IBM computer systems.  Similar to the Windows operating system. ► OS/9  Was developed jointly by Microware Systems and Motorola in the early 80’s.  Motorola manufactures the CPU found in Mac computers. ► OS/10 

Operating System Terminology ► There are several common technical terms associated with operating systems.  File Allocation Tables (FAT) – a table used by the operating system to record and recall the locations of files on a hard disk.  Configuration – Setup for use with specific hardware and software. Configuration files contain information such as the amount of memory and the type of floppy drive, modem, and video adapter present in the system.  Registry – Found in Windows 95, 98, Me, NT, 2000, and XP. Essentially a database that stores configuration information  Application Software – software designed for a specific purpose such as creating databases or spreadsheets, word processing, producing graphics, or just for entertainment.

Operating System Terminology ► There are several common technical terms associated with operating systems.  Drivers – software that enables proper communication between the PC and peripheral and installed devices. Many drivers are located in the Windows directory and are known as cabinet (cab) files.  Cab Files – Compressed files that contain the operating system software.  Software Patches – are fixes for operating systems and application software that have already been released. They also contain system updates that can remove bugs.  Bugs – errors in programming.