IT Introduction to Information Technology CHAPTER 08 – Operating System

System Software System Software? Programs that control or maintain the operations of the computer and its devices. The interface between the user, application software, and the computer’s hardware.

System Software Two Types of System Software Operating Systems Utility Programs

System Software Operating System Software Coordinates all the activity of the computer hardware

System Software Operating System Software Resides on the Hard Drive usually found on the 1 st Hard Drive Partition or Drive C:\

System Software Operating System Functions Starting A Computer Providing a User Interface Managing Programs Managing Memory Scheduling Jobs Configuring Devices Establishing Network Connections Monitoring Performance File Management Controlling a Network Administering Security

System Software Starting A Computer Booting a Computer Cold Boot – Turning on the computer Warm Boot – Restarting the computer

System Software How does a personal computer boot up? Step 1. Power supply sends signal to com- ponents in system unit Step 4. Results of POST are compared with data in CMOS chip Step 2. Processor accesses BIOS to start computer Step 3. BIOS runs tests, called the POST, to check components such as mouse, keyboard, and adapter cards Step 5. BIOS looks for system files in floppy disk drive or CD/DVD drive, and then hard disk Step 6. Kernel (core) of operating system loads into RAM Step 7. Operating system loads configuration information and displays desktop on screen

System Software Providing a User Interface Controls how data is entered and how information is displayed Three Types: Command-Line Interface Menu-Driven Interface Graphical User Interface (GUI)

System Software Command-Line Interface

System Software Menu-Driven Interface

System Software Graphical User Interface (GUI)

System Software Managing Programs There are four ways an OS manages programs:

System Software Real-time operating system (RTOS) Real-time operating systems are used to control machinery, scientific instruments and industrial systems. An RTOS typically has very little user-interface capability, and no end-user utilities, since the system will be a "sealed box" when delivered for use. A very important part of an RTOS is managing the resources of the computer so that a particular operation executes in precisely the same amount of time every time it occurs. In a complex machine, having a part move more quickly just because system resources are available may be just as catastrophic as having it not move at all because the system is busy.

System Software Single-user, single task As the name implies, this operating system is designed to manage the computer so that one user can effectively do one thing at a time. The Palm OS for Palm handheld computers is a good example of a modern single-user, single-task operating system.

System Software Single-user, multi-tasking This is the type of operating system most people use on their desktop and laptop computers today. Microsoft's Windows and Apple's MacOS platforms are both examples of operating systems that will let a single user have several programs in operation at the same time. For example, it's entirely possible for a Windows user to be writing a note in a word processor while downloading a file from the Internet while printing the text of an message.

System Software Multi-user A multi-user operating system allows many different users to take advantage of the computer's resources simultaneously. The operating system must make sure that the requirements of the various users are balanced, and that each of the programs they are using has sufficient and separate resources so that a problem with one user doesn't affect the entire community of users. Unix, VMS and mainframe operating systems, such as MVS, are examples of multi-user operating systems

System Software Multi-Processing Supports two or more processors (CPU) Aysmmetric: one CPU does the work of the system, the other CPUs service user requests. Symmetric: All processors can be used by the system and users alike. No CPU is special.

System Software Managing Memory To optimize the use of random access memory or RAM. One way to do this is to utilize Virtual Memory

System Software Virtual Memory The OS allocates a portion of storage (usually the hard drive) to function as additional RAM.

System Software Virtual Memory The OS allocates a portion of storage (usually the hard drive) to function as additional RAM. Step 1. The operating system transfers the least recently used data and program instructions to disk because memory is needed for other functions. Step 2. The operating system transfers data and program instructions from disk to memory when they are needed.

System Software Windows Vista ReadyBoost Windows ReadyBoost lets users use a removable flash memory device, such as a USB thumb drive, to improve system performance without opening the box. Windows ReadyBoost can improve system performance because it can retrieve data kept on the flash memory more quickly than it can retrieve data kept on the hard disk, decreasing the time you need to wait for your PC to respond.

System Software Windows Vista ReadyBoost ReadyBoost does not cache file writes—it's a write-through cache. That way, you never lose any precious data that's meant to be written to a hard drive. After all, a flash memory key can get yanked out of a system at any time. The cache itself is encrypted using AES-128 encryption, so no one can steal your flash memory key and casually browse through the cache file to see what you've been doing.

System Software Scheduling Jobs Determines the order in which jobs are processed. A job is an operation the processor manages. Utilizes a Buffer – a segment of memory for temporary storage of items until needed Utilizes Spooling – sending a job to a buffer instead of directly to a device (printers) Utilizes a Queue – a list in the buffer of jobs waiting to be completed

System Software Configuring Devices The OS configures through a Device Driver or Driver. Each hardware component of a computer has a device driver. It is how the OS communicates with the hardware. Plug-N-Play – the OS automatically configures any new devices connected to the computer

System Software Establishing a Network Connection Provides the means of making a connection to a network including the Internet Usually a Web Browser is provided for the Internet connection function

System Software Monitoring Performance A part of the OS that shows the performance statistics of the system. Useful for troubleshooting problems or just seeing how well your system works. (In Windows XP it is located under the Task Manager Dialog Box)

System Software File Management Saving, Reading, Copying, Moving, Deleting Windows Explorer is the primary file manager in Windows XP

System Software Controlling a Network Some Operating Systems are specifically designed to control networks. These types are called Network Operating Systems (NOS). They coordinate the activities of the network

System Software Administering Security The OS provides a way to control user access through security authentication. Example: Logging into this labs computers

System Software System Utilities A program that allows us to perform maintenance or management of our computers. These include File Managers, Image Viewers, Uninstallers, Disk Scanners, Disk Defragmenters, Diagnostics, Backup, Screen Savers, Spyware/Adware Removers, and Antivirus Utilities.

System Software Stand-Alone Operating Systems DOSWINDOWS MAC OS X UNIXLINUX

System Software Network Operating System NETWARE WINDOWS SERVER UNIXLINUXSOLARIS

System Software Embedded Operating System WINDOWS CE WINDOWS MOBILE PALM OS SYMBIAN OS

System Software Types of Utility Software Antivirus Programs Personal Firewalls File Compression Personal Computer Maintenance

System Software Personal Firewall

System Software QUESTIONS ?

System Software BUYERS GUIDE 2006 PAGE 444

System Software ASSIGNMENT 06 Buy a New PC Computer (Pretend) You can choose whatever components you want from any supplier or retailer. Explain to me why you chose this computer and what it will do for you. Also list the individual components of the computer and the final total cost of the system. You have a budget of: $ 5,000.00

System Software Some Starting Points: System Resellers Parts Resellers