Operating System Tutorial

Operating System Tutorial Types of Operating System Evolution of Operating System Functions of Operating System Operating System Properties Operating System Services Components of Operating System Needs of the Operating System

Operating Systems

Linux Operating System Unix Operating System Ubuntu Operating System Chrome Operating Systems Fedora Operating System MAC Operating System MS Windows Operating System Solaris Operating System Cooperative Operating System CorelDRAW Operating System CentOS FreeBSD Operating Systems Batch Operating System MS-DOS Operating System Commercial Mobile Operating Systems


Difference Between Multi-programming and Multitasking Difference between C-LOOK and C-SCAN Difference between Rotational Latency and Disk Assess Time Trap vs Interrupt Difference between C-SCAN and SSTF Difference between SCAN and FCFS Difference between Seek Time and Disk Access Time Difference between SSTF and LOOK Difference between Process and Program in the Operating System Difference between Protection and Security in Operating System

How To

How to implement Monitors using Semaphores How to Install a Different Operating System on a PC


What is Kernel and Types of Kernel What is DOS Operating System What is Thread and Types of Thread What is Process Scheduler and Process Queue What is Context Switching What is CPU Scheduling What is Producer-Consumer Problem What is Semaphore in Operating System Monitors in Operating System What is Deadlock What is Paging and Segmentation What is Demand Paging What is Virtual Memory What is a Long term Scheduler What is Page Replacement in Operating System What is BSR Mode What is Convoy Effect What is Job Sequencing in Operating System Why is it critical for the Scheduler to distinguish between I/O-bound and CPU-bound programs Why is there a Need for an Operating System


Process Management Process State Scheduling Algorithm FCFS (First-come-First-Serve) Scheduling SJF (Shortest Job First) Scheduling Round-Robin CPU Scheduling Priority Based Scheduling HRRN (Highest Response Ratio Next) Scheduling Process Synchronization Lock Variable Mechanism TSL Mechanism Turn Variable Mechanism Interested Variable Mechanism Deadlock Avoidance Strategies for Handling Deadlock Deadlock Prevention Deadlock Detection and Recovery Resource Allocation Graph Banker’s Algorithm in Operating System Fixed Partitioning and Dynamic Partitioning Partitioning Algorithms Disk Scheduling Algorithms FCFS and SSTF Disk Scheduling Algorithm SCAN and C-SCAN Disk Scheduling Algorithm Look and C-Look Disk Scheduling Algorithm File in Operating System File Access Methods in Operating System File Allocation Method Directory Structure in Operating System N-Step-SCAN Disk Scheduling Feedback Queue in Operating System Contiguous Memory Allocation in Operating System Real-time Operating System Starvation in Operating System Thrashing in Operating System 5 Goals of Operating System Advantages of Operating System Advantages of UNIX Operating System Bit Vector in Operating System Booting Process in Operating System Can a Computer Run Without the Operating System Dining Philosophers Problem in Operating System Free Space Management in Operating System Inter Process Communication in Operating System Swapping in Operating System Memory Management in Operating System Multiprogramming Operating System Multitasking Operating Systems Multi-user Operating Systems Non-Contiguous Memory Allocation in Operating System Page Table in Operating System Process Scheduling in Operating System Segmentation in Operating System Simple Structure in Operating System Single-User Operating System Two Phase Locking Protocol Advantages and Disadvantages of Operating System Arithmetic operations in binary number system Assemblers in the operating system Bakery Algorithm in Operating System Benefits of Ubuntu Operating System CPU Scheduling Criteria in Operating System Critical Section in Operating System Device Management in Operating System Linux Scheduler in Operating System Long Term Scheduler in Operating System Mutex in Operating System Operating System Failure Peterson's Solution in Operating System Privileged and Non-Privileged Instructions in Operating System Swapping in Operating System Types of Operating System Zombie and Orphan Process in Operating System 62-bit operating system Advantages and Disadvantages of Batch Operating System Boot Block and Bad Block in Operating System Contiguous and Non - Contiguous Memory Allocation in Operating System Control and Distribution Systems in Operations Management Control Program in Operating System Convergent Technologies in Operating System Convoy Effect in Operating System Copy Operating Systems to SSD Core Components of Operating System Core of UNIX Operating System Correct Value to return to the Operating System Corrupted Operating System Cos is Smart Card Operating System Cosmos Operating Systems Examples Generation of Operating System Hardware Solution in Operating System Process Control Block in Operating System Function of Kernel in Operating System Operating System Layers History of Debian Operating Systems Branches and Architecture of Debian Operating Systems Features and Packages of Debian Operating Systems Installation of Operating System on a New PC Organizational Structure and Development in Debian Operating Systems User Interface in Operating System Types Of Memory in OS Operating System in Nokia Multilevel Paging in OS Memory Mapping Techniques in OS Memory Layout of a Process in Operating System Hardware Protection in Operating System Functions of File Management in Operating System Core of Linux Operating System Cache Replacement Policy in Operating System Cache Line and Cache Size in Operating System What is Memory Mapping? Difference Between Network Operating System And Distributed Operating System What is the difference between a Hard link and a Soft Link? Principles of Preemptive Scheduling Process Scheduling Algorithms What is NOS? What is the Interrupt I/O Process? What is Time Sharing OS What is process termination? What is Time-Sharing Operating System What is Batch File File system manipulation What is Message-passing Technique in OS Logical Clock in Distributed System

MS-DOS Operating System

It is also referred to occasionally as "DOS", an abbreviation for disc operating systems. Operating systems with a graphical user interface (GUI) in different iterations of the graphical Microsoft Windows operating system eventually replaced it. Several comparable command-line disc operating systems are sometimes referred to as DOS.

MS-DOS Operating System

Several rival products were made available during the x86 platform's existence, and MS-DOS went through eight versions before development stopped in 2000. The operating system, application software, and user data were first stored and accessed using floppy discs and Intel 8086 CPUs running on computer hardware.

Microsoft's transformation from a provider of programming languages to a multifaceted software development organization was an important product, supplying crucial financial and promotional resources. Additionally, it served as the foundational operating system on which early GUI versions of Windows ran. Progressive version updates brought feature support for newer CPUs, quickly changing computer architectures and compatibility for additional mass storage devices in ever-larger sizes and formats.

Working of DOS

The procedure a computer goes through to start up is called the boot process. For a machine running one of the six-disc operating systems listed below, for example:

  1. The Master Boot Record is read by the read-only memory (ROM) bootstrap loader before it transfers control to it.
  2. The boot record starts the computer by loading the disc operating system into memory and giving it control.
  3. Data from a magnetic disc is transferred to the computer's primary memory, the random access memory.
  4. The computer offers several application programming interfaces (APIs) for applications, such as character input/output, memory management, program loading, termination, and managing user input through a keyboard.
  5. The OS further offers file management, which groups, reads, and writes data stored on storage. A hierarchical system comprising folders, subdirectories, and files is used to arrange the files.

An interface for a disc operating system is not graphical (GUI). Users must put instructions in the command line to specify their desired activities because the interface is character-based.

Features of DOS

Here are some characteristics that make a disc operating system stand out:

  1. MS-DOS does not support GUIs and does not recognize mouse inputs.
  2. A disc operating system controls files and directories and enables the loading and running of programs. It can manage resource allocation and manage hardware like discs and memory.
  3. It is an operating system designed for a single user that performs several functions to ensure systems are running properly.
  4. The File Allocation table is a tabular structure used to hold these IDs.
  5. MS-DOS needs a concept of user responsibilities, supports a multiuser operating system, and is less secure. Due to its simple interface and few functionalities, it is incredibly light.

Limitations of DOS

Here are certain restrictions placed on the disc operating system, including:

  1. Built-in security: Built-in security features like file ownership and permissions are not present in DOS.
  2. No multiuser or multitasking: It is also non-multiuser and non-multitasking compatible. Although it can only run one application simultaneously, it offers direct access to the underlying hardware and fundamental I/O system.
  3. Difficult user interface: To execute applications and other OS activities, a user must input instructions and memorize commands. It is tough for novices to utilize because of this method.

Types of MS-DOS Commands

A command is a directive issued to a computer to carry out a certain task. Each operation can be carried out by one of the several MS-DOS commands, which are kept on the disc in the DOS directory. There are two categories of MS-DOS commands: internal commands and external commands.

  1. Internal Command: The command interpreter file stores internal commands, which are built-in into MS-DOS (COMMAND.COM). DATE, TIME, DIR, VER, and other internal commands are a few of them. If the system runs at the prompt (C:>) level, these commands are stored in memory.
  2. External Command: A separate program file (.com) called an external command is located in the DOS directory.

Other disc operating systems, however, offer CLIs that are case-sensitive. The following are DOS commands.

dirList every file in a given directory or subdirectory.
CD or CHDIR  Move or go to a certain directory.
RD or RMDIRDelete the directory.
TREEShow every directory route.
PATH  Determine the order of the executable files' search path.
SUBST  A string alias is used in place of the pathname.
FORMAT  A disk's formatting for DOS files.
COPY  Copy all of the files, folders, and subdirectories.
Del  Removing files.
Ren or rename ATTRIB  Change a file's or directory's name. To display or set file characteristics.
BACKUP  Back up your folders and files.
PROMPT  Alter the DOS prompt.
Delete  Removes all folders, files, and files from a machine.
Help  Lists the available commands or provides extra details regarding a particular command.
Mkdir or md  Establishes a fresh subfolder.
Move  Transfers files or folders across drives or between directories.
Type  Shows a file's contents on the screen.
*  A character that acts as a wildcard and stands in for one or more characters shared by several files.
?  A character that acts as a wildcard and stands in for any character that is shared by several files.

MS-DOS files and file names

Handling disc files is one of the OS's main responsibilities. A file may be made up entirely of data, or it may include software that instructs the computer on how to carry out a certain operation. Every file has a distinct filename used to locate it on the disc. In MS-DOS, a filename consists of a name and an extension.

An extension of three characters is allowed for each filename. There is a period after the name and before the extension. As a delimiter, the period shows where one part of the filename finishes and the following one starts. When identifying files that are connected in some way, an extension is typically utilized. The following characters may be used in a filename and extension according to MS-DOS:

  1. Letters A–Z in uppercase and lowercase.
  2. 0 through 9 numbers o $ # & @ () special characters! ^ ` ~ { }

Any additional characters, including spaces, used in a filename will result in the name ending there. Because certain applications could employ them as delimiters or for other specific functions, it is generally recommended to avoid using special characters in filenames.

Additionally, MS-DOS assigns unique meanings to the extensions BAT, COM, EXE, and SYS, which is why you should only sometimes use them with your data files. Examples of acceptable and undesirable filenames are shown below.

Valid MS-DOS Filenames:

  2. DAT.
  3. 1.