Operating Systems n241.tplt Historical Perspective Prior to the 1950's, computers such as ENIAC (Electronic Numerical Integrator and Computer), had no operating system
-many people were required to manually connect wires and set switches so the program could run PCs (Personal Computers) 1969 - UNIX was developed by Bell Labs, a research facility for AT&T 1981 - IBM began selling the PC and MS-DOS (Microsoft Disk Operating System) was selected as the standard for the system 1983 - Apple introduced the first publicly available computer using a GUI (graphical user interface) - the Apple Lisa 1984 - Apple released the Macintosh DOS did not embrace the GUI approach until the advent of Windows Operating Systems Controls the input, output and process activities for a computer Acts as a traffic cop to control the resources of the computer
- computer memory
- file storage space
- the computer processor (CPU) Operating System Is a software program that helps the user interact with the computer Helps the all the hardware components communicate with each other Acts as a Box of Tools
-utility programs allow you to move files, create directories, copy files, etc. Is a self-starter - "booting" Command Lines The Operating System gives you an interface C:\> indicates a command line interface DOS and UNIX are both command line operating systems GUIs Graphical User Interface Has nice pictures with descriptive words underneath Allows you to 'click' with the mouse to start a program and other computer tasks Picture concepts are easier to understand
- "A picture is worth a 1,000 words" Without the pictures you would have to know the exact command required to move a file instead of clicking and dragging with the mouse Examples of Operating Systems DOS UNIX Windows 3.1 Windows 95 and 98 Mac System 7.0 Problems Operating Systems are Good at Solving Organization An interface you can interact with efficiently Helps all parts of your system to communicate with each other The "Tree" Think of the file structure of an operating system like a "tree" The Root A general starting point on each drive Directories Next level after root directory Programs usually install their own directory Subdirectories Next level after Directories There may be several levels of subdirectories before you get to the files. Files May be considered an organized collection of computer information Are stored on the computer with the help of the operating system Each operating system has its own convention for naming files Operating Tools from the Operating System User Interface
-command line
-GUI Management tools to help you manage your files Multitasking The ability to run more than one program at a time Active program is the one currently getting your attention Any program that is visible is "open", but may not be the active program File Management Programs A utility of the Operating System Things you can find in a file manager program
- indicator of the current drive
- a way to change drives
- a picture of the tree structure
- an indicator of the current directory
- a list of subdirectories on the current directory
- a way to change directories
- list of files on the current directory
- and a way to back up to the previous directory Common File Management Programs File Manager (Windows 3.1) Explorer (Windows 95) My Computer (Windows 95/98) The Mac Desktop (Macintosh) File management in a command line system Problem Solving with File Management Systems Organizing your disk
- directory, subdirectories, files Finding where things are located Manipulating files - copying, deleting, etc. Manipulating directories - making new ones and naming them Tools File Management Programs Give You Visual Representation of directory structure Drag and drop features Graphic representation of files and directories Menus and toolbars (file and directory manipulation tools) Symbolic Representation Schemes Common programs
- Program Manager (Windows 3.1)
- Start button (Windows 95/98)
- Desktop (Windows 95/98)
- Apple Menu (Mac System 7+) Problems Symbolic Schemes are Good at Solving A custom file system Virtual files, Virtual Directories