MS-DOS

MS-DOS (acronym for Microsoft Disk Operating Ssystem, Microsoft Disk Operating System or Microsoft DOS) was the most popularly known member of Microsoft's DOS family of operating systems, and the primary operating system for personal computers. compatible with the IBM PC in the 1980s and mid-1990s, until it was gradually replaced in version 8.0 in 2000 by operating systems that offered a graphical user interface, notably by several generations of Microsoft Windows. Since Windows XP, a version of MS-DOS was no longer included and was replaced by CMD.

MS-DOS was born in 1980 when Microsoft was commissioned to produce an operating system for IBM's IBM PC range of personal computers. At this time, Microsoft purchased the rights to QDOS, Quick Disk Operating System, also known as 86-DOS, from Seattle Computer Products which was written by Tim Paterson, and began work on modifications for it. be able to meet IBM's requirements.

History

MS-DOS was not an Operating System made from scratch, it was developed from QDOS, Quick Disk Operating System, also known as 86-DOS. Its development officially started in 1981 and was released in 1982 as MS-DOS 1.0. It had eight major releases and was widely distributed, but was gradually superseded by S.S.O.O. which offered a graphical user interface (GUI), in particular, for several generations of the Microsoft Windows operating system.

Versions

• MS-DOS 1.0 (1981)
• MS-DOS 1.1 (1982)
• MS-DOS 1.25 (1982)
• MS-DOS 2.0 (1983)
• MS-DOS 3.0 (1984)
• MS-DOS 3.30 (1987)
• MS-DOS 4.0 (1988)
• MS-DOS 5.0 (1991)
• MS-DOS 5.2 (1992)
• MS-DOS 6.0 (1993)
• MS-DOS 6.22 (1994)
• MS-DOS 7.0 (1995)
• MS-DOS 8.0 (2000)

Source code

The source code for MS-DOS 1.1 (1982) and 2.0 (1983), along with Word for Windows 1.1 (1989) was released by Microsoft on March 25, 2014.

Features

As its name "Disk Operating System" indicates MS-DOS is installed on the hard drive of an IBM or PC compatible computer, however it is able to be fully MS-DOS ready in seconds; unlike Apple's Macintosh, AMIGA Commondore, and UNIX systems of the same era. The Macintosh and AMIGA required starting their operating system from a floppy disk and loading everything into RAM, a process called a "Kickstart".

The kernel consists of IO.SYS, MSDOS.SYS, and COMMAND.COM. It is possible to start DOS with only these three files, but most commands and functions will not be available.. The names of the files had a maximum of 8 characters, a period and an extension of a maximum of three letters, in total a maximum of 12 characters of the ASCII Code that allowed distinguishing some files from others within the same directory. Finally in Windows 95, DOS supports a larger number of characters. Not all ASCII code characters were allowed to name a file, as some (example: /*?+ and others) were reserved for other functions. This reserved character limitation is still in effect today.

Basic Commands

Here are some of the commands used by MS-DOS, and which can currently be used from the command line in Windows operating systems, which is CMD. To access the help of these, MS-DOS, from version 6.2 allows the following: command to consult /? (eg: copy /?).

They can be internal (included within COMMAND.COM itself) or external (executable files in the MSDOS directory):

Internal commands

Internal or resident commands are those that are transferred to memory when the Operating System is loaded and can be executed without having DOS present in the default drive from which the command can be executed. The default drive is the drive you are on, for example A:>_; and the specified drive is the one to which we address or specify being in another drive, for example A:>B: the specified drive is B.

These are some internal MS-DOS commands:

• CD or CHDIR - Change the current directory.
• CD.. - Change to the hierarchically superior directory.
• CLS - Cleans all commands and all the information on screen except the command incitator (prompt) usually the letter and route of the used unit (e.g. C:/2005)
• COPY - Copying a directory file to another
• COPY Copy to a file the characters entered on screen
• DATE - Visualize or change the date of the system.
• OF THE - Used to delete files.
• DIR - List the directories and files of the current drive or directory.
• FOR - Repeat a command
• PROMPT- Change the command display line.
• MD or MKDIR - Create a directory
• RD or RMDIR- Delete a directory.
• REM - Allows to insert comments in batch process files.
• REN or RENAME - Rename files and directories.
• SET - Attend values to environment variables.
• IT - Visualize or change the time of the system.
• TYPE - Shows the contents of a file. It is mainly used to view contents of files in text format.
• VIEW - Show the operating system version.
• VOL - Shows the label of the hard drive and its volume (if any)
• BREAK - Activate or deactivate extended CTRL+C verification.
• EDIT - Open a kind of text editor.
• EXIT - Get out.

External commands

External commands as opposed to internal commands are stored in command files called transient or external, and they need these files to be executed, also external commands have their own name and can be copied from one disk to another.

Here are some of the commands that were used by MS-DOS, and that can now be used from the command line in Windows operating systems. To access the help of these, MS-DOS, from version 6.2 allows the following: command to consult /? (Ex: dir /?). They can be internal (included within COMMAND.COM itself) or external (executable files in the MSDOS directory):

• ATTRIB - No parameters visualizes the attributes of directories and files. With parameters changes the attributes of directories and files.

The attributes of the directories, and the files are: read (r), write (w), file (a), hidden (h), system (s). Parameters: signs (plus or minus) and letters r, w, a, and h " v". Example: Attrib +r *.* (read-only attribute, for all files in that directory)

• APPEND - It serves to specify trajectories for data files.
• BACKUP - Run a backup of one or more files from a hard drive to a floppy.
• CHKDSK - Verify if there are errors on the hard drive. (You can also use to correct them with the "/F" parameter)
• DELTREE - Delete a directory no matter what it contains subdirectories with all its contents.
• DISKCOMP - After a copy of floppy disks we can perform a check, to see if you have copied all the contents, comparing. This command compares disks or floppy disks.
• DISKCOPY - Allows to make an identical copy of one floppy to another, belongs to the group of external orders.
• DOSKEY - It allows to maintain residents in RAM the orders that have been executed at the indicative point.
• FC - Compare files.
• FORMAT - It allows to create the logical structure in a physical storage unit (hard disks, floppy disks and mass storage units).
• FORMAT /U - Format an unconditionally formatted disk repairing errors and marking bad sectors.
• FORMAT /s - Format a disk and convert it into system disk.
• PRINT - Allows to print files.

These parameters can be used in combination.

• KEYB - Set the keyboard language according to the added parameter (Example: KEYB SP for the Spanish keyboard).
• LABEL - Show or change the label of the hard drive.
• MEM - Shows RAM, occupied space and free space.
• MOVE - Move or change position a directory and/or files. He also renames deputy directors.
• SUBST - Create a virtual logical drive from a directory.
• TREE - Shows the directories in tree shape.
• XCOPY - This command has the same function as your counterpart. resident COPY, with the saving that performs coping operations of the entire directory structure if the wild character is used ♪ and modifier /s. It's an improved version of the previous one.

Redirects

• . - Redirecting the standard input. Your syntax is command;.
• ▪ - Redirecting the standard output. Your syntax is command  file. If the file doesn't exist, it creates it. If it already existed, it overwrites its content.
• ◊ - Redirecting the standard output to an existing file. Your syntax is command  file. If the file doesn't exist, it creates it. If it already existed, add the command result below the previous file content.