2.1 Input Output Control System

2.1 :Input Output Control
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
Implement efficient organization
and access of data in files.
Function Perform by File System
and IOCS
File System
Directory structure and file naming
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
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
3. The BIOS performs the POST(power-on self
test), which checks components such as
mouse, keyboard and adapter cards.
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.