Transcript Most modern operating systems incorporate these five components

Most modern operating systems incorporate
these five components
User interface
(shell)
Device
management
File
management
Memory
management
Processor
management
User Interface (Shell)

Provides a mechanism for the user and application
programs to communicate with the operating system.
– Types Of User Interfaces:
 Command – Executes single line commands
 Menu – Presents a list of single line commands
 GUI – Allows the user to issue commands by
clicking on icons or selecting options from a
menu
 Voice – User issues commands orally
 Web
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The User Interface
Fig. 7.1:
People
communicate
with the
operating
system through
the user
interface or
shell by issuing
commands.
User
Application
program
User interface
Interrupt
Operating system
Hardware
Command
User Interface Functions

Identify user
 Specify program to be executed
 Specify peripheral device requirements
 Support run-time intervention
Types of User Interfaces

Command interface
 Menu interface
 Graphic user interface
 Expert system (voice-activated) interface
 Web-form interface
Types of User Interfaces

Command Interface
– Requires the user to type brief, cryptic commands.


MS-DOS Line Commands.
Application program function-key commands.
– Require considerable user training.

Menu Interface
– Presents the user with a list of available options.
– Easier to learn and easier to use.
– Traversing multiple menus can be time-consuming.
Types of User Interfaces

Graphic User Interface
– Presents the user with a selection of windows, icons,
menus, and pointers.


Macintosh
Microsoft Windows
– Easy to understand, learn, and use
– Consume considerable processor time and memory
– Sometimes called an object-oriented interface or an
icon-based interface.
Types of User Interfaces

Expert System Interface
– Voice-activated
– Utilizes natural-language processing.
 Voice recognition
 Voice data entry
– Requires a very powerful computer with a great
deal of memory and a fast processor.
Types of User Interfaces

Web-Form Interface
– Follows the metaphor established by the
Internet and the World Wide Web.
Summary
Most modern operating systems incorporate
these five components
User interface
(shell)
Device
management
File
management
Memory
management
Processor
management
Device Management

Responsible for controlling communications with the
system’s peripheral devices.
 Interface Board
• Translates between internal and external
form
 Channel
• Performs peripheral device-independent
functions on large computers
Device Management

Responsible for controlling communications with the
system’s peripheral devices.
 Blocking Data
• Provides better utilization of disk/tape space
Most modern operating systems incorporate
these five components
User interface
(shell)
Device
management
File
management
Memory
management
Processor
management
Processor Management

Efficiently managing the processor’s time.
 Machine Cycle
• ICU
• ALU
 Object Code – Machine language version of the
source program
 Concurrency – Multiple programs are loaded and
executed concurrently
 Interrupt – An electronic signal that causes the
system to save a link to the current program and
start and operating system routine
Most modern operating systems incorporate
these five components
User interface
(shell)
Device
management
File
management
Memory
management
Processor
management
File Management

Incorporates routines that allow the user or programmer to
create, delete, modify, and manipulate files by name.
 Logical Records
• Programmer’s view of I/O
 Physical Records
• Input – Transferring data into memory from
a peripheral device
• Output – Transferring data from memory to
a peripheral device
 Directory
• FAT - File Allocation Table
• VTOC – Volume Table of Contents
File Management

Incorporates routines that allow the user or programmer to
create, delete, modify, and manipulate files by name.
 Access Techniques
• Sequential – Accessing data in physical
order
• Random – Accessing data without regard for
physical order
• Data Base
Centralized
Programmer can ignore physical data
structure
Most modern operating systems incorporate
these five components
User interface
(shell)
Device
management
File
management
Memory
management
Processor
management
Memory Management

Concerned with managing the system’s main
memory resources as the computer runs, allocating
space to applications as needed and ensuring that
those applications do not interfere with each other.
 Data is stored in memory in Binary form
 Absolute Address – A physical location in
memory
 Relative Address
• An address relative to a base location
• Allows a routine to be loaded into a different
location in memory
Memory Management

Concerned with managing the system’s main
memory resources as the computer runs, allocating
space to applications as needed and ensuring that
those applications do not interfere with each other.
 Concurrency
• Multiple programs are loaded into memory
and executed concurrently
Cache Memory
 Object Code

Memory Management

Concerned with managing the system’s main
memory resources as the computer runs, allocating
space to applications as needed and ensuring that
those applications do not interfere with each other.
 Resident Routines
• A routine that stays in memory

Transient Routines
• A routine that is loaded into memory as
needed

Transient Area
• Memory for application programs and
transient routines
Memory Management

Concerned with managing the system’s main
memory resources as the computer runs, allocating
space to applications as needed and ensuring that
those applications do not interfere with each other.
 Fixed-Partition Management
• Divides the Transient Area into fixed-length
partitions

Dynamic Memory
• The Transient Area is treated as a pool of
free space.
Memory Management

Concerned with managing the system’s main
memory resources as the computer runs, allocating
space to applications as needed and ensuring that
those applications do not interfere with each other.
 Segmentation
• Programs are divided into independently
addressed segments and stored in noncontiguous memory

Paging
• Programs are divided into fixed-length pages
and loaded into noncontiguous memory
Memory Management

Concerned with managing the system’s main memory
resources as the computer runs, allocating space to
applications as needed and ensuring that those applications
do not interfere with each other.
 Overlay Structures
• Developed when the amount of available
memory was limited
 Virtual Memory
• Real Memory
• External Paging Device
• Virtual Memory
Memory Management

Concerned with managing the system’s main memory
resources as the computer runs, allocating space to
applications as needed and ensuring that those applications
do not interfere with each other.
 Virtual Storage
• Uses an external device as an extension of
real memory
 Time Sharing
• Managing multiple concurrent users
designed with interactive processing in mind
Memory Management

Concerned with managing the system’s main memory
resources as the computer runs, allocating space to
applications as needed and ensuring that those applications
do not interfere with each other.
 Spooling
• Copying data from a slow input device to
disk for subsequent processing