History of Dos

History of DOS
Missed Meeting, missed opportunities, When Gary Kildall President of CPM OS missed his meeting with IBM representatives, this opened the door to a small software developer company called Microsoft. Led by its Co founders Bill Gates and Paul Allen they were able to purchase the rights to QDOS and later renamed it to MS DOS. Microsoft were able to license the OS to IBM and other computer manufacturers. The rest as they say were History.
Fundamental concepts of MS DOS

DOS version 1.0 (1981)
DOS version 6.22 (1994)
ASSIGN
(External)

ASSIGN x=y [...] /sta

Redirects disk drive requests to a different drive.

ATTRIB
(External)

ATTRIB [d:][path]filename [/S]
ATTRIB [+R|-R] [+A|-A] [+S|-S] [+H|-H] [d:][path]filename [/S]

Sets or displays the read-only, archive, system, and hidden attributes of a file or directory.

BACKUP
(External)

BACKUP d:[path][filename] d:[/S][/M][/A][/F:(size)] [/P][/D:date] [/T:time] [/L:[path]filename]

Makes a backup copy of one or more files. (In DOS Version 6, this program is stored on the DOS supplemental disk.)

BREAK
(Internal)

BREAK =on|off

Used from the DOS prompt or in a batch file or in the CONFIG.SYS file to set (or display) whether or not DOS should check for a Ctrl + Break key combination.

BUFFERS
(Internal)

BUFFERS=(number),(read-ahead number)

Used in the CONFIG.SYS file to set the number of disk buffers (number) that will be available for use during data input.

CALL
(Internal)

CALL [d:][path]batchfilename [options]

Calls another batch file and then returns to current batch file to continue.

CHCP
(Internal)

CHCP (codepage)

Displays the current code page or changes the code page that DOS will use.

CHDIR
(Internal)

CHDIR (CD) [d:]path
CHDIR (CD)[..]

Displays working (current) directory and/or changes to a different directory.

CHKDSK
(External)

CHKDSK [d:][path][filename] [/F][/V]

Checks a disk and provides a file and memory status