Editing Disk operating system (section)

==History==
Before modern storage such as the disk drive, floppy disk, and [[flash storage]], early computers used storage such as [[Analog delay line|delay line]], [[core memory]], [[punched card]], [[punched tape]], [[magnetic tape]], and [[magnetic drum]]. Early microcomputers and [[home computer]]s used paper tape, [[audio cassette tape]] (such as [[Kansas City standard]]), or no permanent storage at all. Without permanent storage, program and data entry is input at [[front panel]] switches directly into memory or through a [[computer terminal]] or keyboard, sometimes controlled by a [[BASIC]] interpreter in [[read-only memory|ROM]]. When power is turned off, all information is lost.

In the early 1960s, as disk drives became larger and more affordable, various mainframe and minicomputer vendors introduced disk operating systems and modified existing operating systems to use disks.

[[Hard disk]]s and floppy disk drives require software to manage rapid access to block storage of sequential and other data. For most microcomputers, a disk drive of any kind was an optional peripheral. Systems could be used with a tape drive or booted without a storage device at all. The disk operating system component of the operating system was only needed when a disk drive was used.

By the time IBM announced the [[System/360]] mainframes, the concept of a disk operating system was well established. Although IBM did offer [[IBM Basic Programming Support|Basic Programming Support]] (BPS/360) and TOS/360 for small systems, they were out of the mainstream and most customers used either DOS/360 or OS/360.

Most home and personal computers of the late 1970s and 1980s used a disk operating system; most often with "DOS" in the name and simply referred to as "DOS" in the context of its user community. For example, [[Commodore DOS|CBM DOS]], [[Atari DOS]], [[TRS-DOS]], [[Apple DOS]], [[Apple ProDOS]], and [[MS-DOS]]. [[CP/M]] is also a disk operating system, despite not having "DOS" in the name.<ref name="byte1983_07">{{cite magazine |author-last=Dahmke | author-first=Mark |title=CP/M Plus: The new disk operating system is faster and more efficient than CP/M |magazine=BYTE Magazine | url= https://archive.org/details/byte-magazine-1983-07/page/n359/mode/2up?view=theater |date=1983-07-01 |volume=8 |issue=7 |pages=360 |issn= }}</ref>

A DOS is usually loaded from a disk, but there are exceptions, such as [[Commodore 1541|Commodore's disk drive]] for the [[Commodore 64]] and [[VIC-20]] which contain the DOS in [[ROM]]. Some versions of [[AmigaDOS]] mostly resides in ROM, as a part of a [[Kickstart (Amiga)|Kickstart]] firmware.