most modern operating systems incorporate these five components
TRANSCRIPT
Most modern operating systems incorporate Most modern operating systems incorporate these five componentsthese five components
User interface(shell)
Devicemanagement
Filemanagement
Memorymanagement
Processormanagement
User Interface (Shell)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: Fig. 7.1: People People communicate communicate with the with the operating operating system through system through the user the user interfaceinterface oror shell by issuing shell by issuing commands.commands.
Applicationprogram
User interface
Operating system
Hardware
User
Interrupt Command
User Interface FunctionsUser Interface Functions
Identify userSpecify program to be executedSpecify peripheral device requirementsSupport run-time intervention
Types of User InterfacesTypes of User Interfaces
Command interfaceMenu interfaceGraphic user interfaceExpert system (voice-activated) interfaceWeb-form interface
Types of User InterfacesTypes 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 InterfacesTypes 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 InterfacesTypes 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 InterfacesTypes of User Interfaces
Web-Form Interface– Follows the metaphor established by the
Internet and the World Wide Web.
SummarySummary
Most modern operating systems incorporate Most modern operating systems incorporate these five componentsthese five components
User interface(shell)
Devicemanagement
Filemanagement
Memorymanagement
Processormanagement
Device ManagementDevice 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 ManagementDevice 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 Most modern operating systems incorporate these five componentsthese five components
User interface(shell)
Devicemanagement
Filemanagement
Memorymanagement
Processormanagement
Processor ManagementProcessor 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 Most modern operating systems incorporate these five componentsthese five components
User interface(shell)
Devicemanagement
Filemanagement
Memorymanagement
Processormanagement
File ManagementFile 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 ManagementFile 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 Most modern operating systems incorporate these five componentsthese five components
User interface(shell)
Devicemanagement
Filemanagement
Memorymanagement
Processormanagement
Memory ManagementMemory 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 ManagementMemory 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 concurrentlyCache MemoryObject Code
Memory ManagementMemory 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
neededTransient Area
• Memory for application programs and transient routines
Memory ManagementMemory 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
partitionsDynamic Memory
• The Transient Area is treated as a pool of free space.
Memory ManagementMemory 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 non-contiguous memory
Paging• Programs are divided into fixed-length pages
and loaded into noncontiguous memory
Memory ManagementMemory 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 ManagementMemory 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 ManagementMemory 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