OPERATING SYSTEMS

OPERATING SYSTEMS

Software - a set of electronic instructions that tell a PC what to do
Types of software are application software and OS
Examples of application software are MS Word, Adobe Photoshop and Intuit QuickBooks
Examples of OS are Windows 2K, Linux and MS DOS
OS - manages the hardware, resources and application software. An OS also provides the following services to computer hardware and peripherals.
Disk and file management
Provides API's, which stands for Application Programming Interface, a sort of rulebook for programmers in order to write programs for a particular OS.
Device access
User interface GUI-Graphical User Interface (Icons, click mouse) examples are Windows and Mac OS and Command Interface or Command Line OS examples are MS DOS and UNIX
Memory management
Output format
OS terms
Version - A particular revision of a piece of software, in relations to other versions of the product
Source - Code use to write particular software. Open source means that the OS can be examined and modified by users for example Linux and close source means that the actual code cannot be modified like Windows OS
Shell - A program that runs on top of an OS. The two examples of shells are DOS (command shell) and Windows (GUI)
GUI- GUI's use a mouse and touch pad to move in an OS
Multitasking
Cooperative Multitasking - A method in which the application itself is responsible for using and then freeing access to the processor (Windows 3.x)
Preemptive Multitasking - A method in which the OS allots each application a certain amount of processor time and then forcibly takes back control and gives another application or task access to the processor
Multithreading - The ability of a single application to have multiple requests in to the processor at one time, which results in faster performance
Types of OS and NOS


MS DOS-A OS developed by MS from Quick and Dirty DOS
Version 1.0 - First version very archaic
Version 1.1 - Supported 320KB floppy drives
Version 2.0 - Hard drive and subdirectory support
Version 3.0- 1.2 MB floppy support
Version 4.0 - Provided a DOS shell feature
Version 5.0 - Provided memory management support and improved utilities
Version 6.0 - Added MEMMAKER
Version 6.22 - Added DriveSpace disk compression utility
Windows - A GUI OS perfected and marketed by MS
Versions of Windows include:


Windows 3.x (not really an OS) more of an operating shell which runs on top of DOS
Windows 95 - PnP, very user friendly
Windows 98 - More stable than Windows 95, also adds more features
Windows 2000 - PnP, supports administrative tools and disk management
Windows NT 4.0 - Use for a client/server model, only drawback is its not PnP
Windows Me - A patch up OS with decent support for graphics
Windows XP - The new OS flagship from MS targeting end users
Windows 2003 - Microsoft's new operating system
Linux - A free and stable OS invented by Linus Torvald


Different vendors of Linux include:
Red Hat Linux
Caldera Linux
Mandrake Linux
SuSe Linux
VaLinux
Corel Linux
UNIX - The oldest and most powerful OS around
Most UNIX systems are descendants of the System V and BSD Models
Most popular UNIX versions are as follows:
Sun Solaris UNIX
HP AIX
IBM UNIX
Free BSD
Novell Netware - A Network OS known for its file and print capabilities
Novell Netware 3.x
Novell Netware 4.x
Novell Netware 5.x
Novell Netware 6.x
OS/2 - A 32-bit GUI OS from IBM

Mac OS - A GUI OS from Apple developed for Macintosh and i-Mac computers
Mac OS 7.x
Mac OS 8.x
Mac OS 9.x
Mac OS X