2.1 :Input Output Control System Learning Outcomes • Distinguish between Directory Management and Disk Space Management • Identify the primary function perform by input / output control system • Describe boot process Directory Management vs Disk Space Management Directory Management The purpose is organize file, directory and operation on them Disk Space Management The purpose is manage files stored on disk. Differentiate between File System and IOCS File System File system provide facilities which enable a user to create files, assign meaningful name and specify how the files to be shared with others users of the system IOCS Implement efficient organization and access of data in files. Function Perform by File System and IOCS File System IOCS Directory structure and file naming facilities A set of mechanism for storage and access of data Protection of file against illegal forms access A library of modules to perform efficient file processing Static and dynamic sharing of files Reliable storage of files Boot Process • Booting up is a bootstrapping process that starts operating systems when the user turns on a computer system • Booting is the process of starting or restarting a computer Type of Boot Process 1. Cold Boot 2. Warm Boot Type of Boot Process : Cold Boot • When turning on a computer that has been powered off completely. • Example : by press power button. Type of Boot Process : Warm Boot • Is the process of restarting a computer that already is powered on. • Example : In Windows XP, warm boot can be perform by : – pressing combination of (CTRL + ALT +DEL) – selecting a button or an option from a list in a dialog box – pressing the reset button on the computer How a PC Boots Up 1. The power supply send a signal to the component s in the system unit 2. The processor finds the ROM chip(s) that contain the BIOS (basic input output system) 3. The BIOS performs the POST(power-on self test), which checks components such as mouse, keyboard and adapter cards. Cont… 4. The results of the POST are compared with data in a CMOS chip 5. The BIOS looks for the system file in drive A (floppy disk drive), sometimes a CD or DVD drive and then drive C (hard disk) 6. The system file and the kernel of the operating system load into memory (RAM) from storage (hard disk) 7. The operating system loads configuration information, may request user information and display the desktop on the screen.