System Programming Blog: Disk Operating System

 

 Disk Operating System (DOS)

What is DOS?

The phrase also can talk over a specific circle of relatives of disk operating systems, usually MS-DOS, an acronym for Microsoft DOS, an OS that runs on Disk.

An OS is the software program that controls a laptop`s hardware and peripheral gadgets and lets in different software program packages to function. Early computer systems of the 1940s and 1950s no longer have disk drives. Instead, they had been hard-stressed out to perform precise computations.

Later, computer systems had been capable of shop commands loaded into the laptop's reminiscence the usage of punch playing cards and then, after that, magnetic tapes. Computer reminiscence area became limited, and whilst the commands to govern a laptop had been moved onto a disk drive, inclusive of a floppy disk or inner HDD, it became taken into consideration modern-day technology. Also DOS is likewise used to explain numerous comparable command-line disk working systems.

History is DOS.

The disk operating system was originally referred to as the QDOS software package and was initial developed in April one980 by Tim Paterson (born Gregorian calendar month 1, 1956. He redesigned the 8086 central processing unit SCP card, and upon completion, Digital analysis visited the SCP to examine if the 8086 central processing unit card might add management Program / Monitor (CP / M). Microsoft needed the program to run on their computers; thus, at the last quarter of 1979, Paterson approached Microsoft, and among every week more or less, he discharged all 32K Microsoft Basic 8086 cards.

In April 1980, Paterson began in operation on the 8086 SCP card software package. Now, within the last half of 1980, IBM was in a very hurry to search out software system for its coming laptop computer, which might become the initial IBM computer.

In July, IBM contacted Microsoft to develop AN software package for his or her computers. At the time, CP / M was the foremost standard in operation system; thus, Bill Gates transferred IBM to Digital analysis (DRI), manufacturers of the foremost wide used CP / M. IBM felt the requirement, that is CP / M, to compete. Therefore, IBM representatives visited DRI and mentioned the licenses. However, the 2 have not entered into AN agreement as Digital analysis rejected IBM's $ 250,000 proposal to induce a lot of copies that IBM might sell and insisted on a typical royalty-based system.

After a disagreement, IBM came back to Microsoft in October 1980, requesting a replacement software package. However, in December 1980, Microsoft bought a special 86-DOS license from SCP for $ 25,000. In July 1981, Microsoft purchased all the rights to 86-DOS for $ fifty,000. Since then, it's developed into a stronger software package over the years.

D O S Versions	Date	About the Version
86 – DOS 0.10	Aug 1980	The original author of this version was Tim Paterson and it was the first owned by Seattle Computer Products (SCP).
PC – DOS 1.0	Aug 1981	Microsoft developed it and was the first IBM release for its personal computers.
PC DOS 2.0	Mar 1983	The primary developer was Microsoft. This version resided on a hard disk drive, subdirectories, and device drivers.
PC DOS 3.0	Aug 1984	The primary developer was Microsoft and had the large disk support feature. Designed for IBM Personal Computer/AT.
IBM DOS 4.0	July 1988	The original author was IBM and was developed for DOS Shell EMS 4.0 usage.
MS-DOS 5.0	June 1991	Developed by Microsoft and was designed to support with MS-DOS Editor and QBasic features
MS-DOS 6.0	Mar 1993	Developed by Microsoft and had disk utilities and double space disk compression features.

How DOS works??

The computer goes through various steps which is called the boot process. There are mainly six steps involved in the running of Disk Operating system viz,.:

The read-only memory (ROM) bootstrap loader reads the Master Boot Record and passes control over to it.

The boot record loads the disk operating system into memory, and it takes control of the machine.

The computer transfers data stored on a magnetic disk to its main memory, the random access memory.

It also transfers data to external devices attached to the computer, such as a computer screen or printer.

The computer provides various applications programming interfaces for programs like character input/output, memory management, program loading, termination, and handling input from the user through a keyboard.

The OS also provides file management that organizes, reads, and writes files on storage. The files are organized in a hiera
rchical structure of directories, subdirectories, and files.

A disk operating system doesn't have a graphical user interface (GUI). Its interface is character-based, so users must type commands in the command line to indicate what actions they want.

MS-DOS is not case-sensitive so that commands can type in either uppercase or lowercase. However, other disk operating systems have case-sensitive CLIs. DOS commands include the following.

Commands	Description
Dir	List all files of specific directories or subdirectories.
CD or CHDIR	Navigate or move to a specific directory.
RD or RMDIR	Remove directory.
TREE	Display all directory paths.
PATH	Set sequential search path for executable files.
SUBST	Substitutes a string alias for the pathname.
FORMAT	Formats a disk for DOS files.
COPY	Copies one or more files to another location.
XCOPY	Copy files and directories and their subdirectories.
Del	Delete files.
Ren or rename	Rename the name of a file or directory.
ATTRIB	Set or show file attributes.
BACKUP	Backup files and directories.
PROMPT	Customize DOS prompt.
Deltree	Deletes all files and subdirectories from a computer.
Help	Lists the available commands or more information about a specific command.
mkdir or md	Creates a new subdirectory.
Move	Moves files or directories from one directory to another or from one drive to another.
Type	Displays the contents of a file on the screen.
*	A wildcard character that represents one or more characters a group of files has in common.
?	A wildcard character that represents a single character a group of files has in common.

Advantages of DOS - 

MS-DOS also known as Microsoft Disk Operating System is a computer operating system by the Redmond giant Microsoft Corporation. This was used as the main OS before Windows OS came out and still is in some places today. In fact, the MS-DOS was the framework behind Windows operating systems until Windows XP.

1. Direct access to the BIOS calls and the underlying hardware is simple.

2. This will run on smaller systems and will "boot" far faster than any Windows version due to its size.

3. MS-DOS is a lightweight operating system that gives you direct access to most devices. It lacks the overhead of a multitasking operating system, though.

4. In addition, MS-DOS is useful for creating workarounds, integrating programs, and managing/administering a Microsoft system.

When it comes to disadvantage -

1. When it comes to the disadvantages, the OS does not support multitasking. 2. When addressing more than 640 MB of RAM, it has challenging memory access. 3. You may need to handle the interrupt levels for hardware yourself, as the OS does not enable automatic IRQ ordering.

Conclusion-

As a result, when Windows 3.0 was released, it was on the verge of extinction. The use of MS DOS was heavily criticized by the GUI. With the advent of Windows 95, it was no longer released as a standalone product and was only used for booting, debugging, and backwards compatibility with previous software, particularly games. So that was MS DOS's entire overview. Finally, I'd like to point out that it has a strong element of exposure, which means it will never become obsolete. As a result, individuals who work on it will always be profitable because it is free and contains all of the features of commercial versions of operating systems such as IOS, Windows 10, and so on. Apart from that, it's a Microsoft-licensed operating system, so we can trust it as it is one of the biggest software companies.