The Apple II disk operating system, known simply as DOS, thus intercepted all input typed at the BASIC command prompt to determine whether it was a DOS command.

A few years later, in 1981, IBM introduced the first DOS based IBM PC, and due to the overwhelming popularity of PCs and their clones, DOS soon became the operating system on which the majority of BBS programs were run.

MS-DOS continued to be the most popular operating system for BBS use up until the mid-1990s, and in the early years most multi-node BBSes were running under a DOS based multitasker such as DESQview or consisted of multiple computers connected via a LAN.

With open software specifications and the possibility of software licensing, new opportunities arose for software tools that then became the de facto standard, such as DOS for operating systems, but also various proprietary word processing and spreadsheet programs.

The drive's built-in disk operating system was CBM DOS 2. 6.

Disk Operating System ( specifically ) and disk operating system ( generically ), most often abbreviated as DOS, refer to an operating system software used in most computers that provides the abstraction and management of secondary storage devices and the information on them ( e. g., file systems for organizing files of all sorts ).

In some cases, the disk operating system component ( or even the operating system ) was known as DOS.

On the PC compatible platform, an entire family of operating systems was called DOS.

Mature versions of the Commodore, SWTPC, Atari and Apple home computer systems all featured a disk operating system ( actually called ' DOS ' in the case of the Commodore 64 ( CBM DOS ), Atari 800 ( Atari DOS ), and Apple II machines ( Apple DOS )), as did ( at the other end of the hardware spectrum, and much earlier ) IBM's System / 360, 370 and ( later ) 390 series of mainframes ( e. g., DOS / 360: Disk Operating System / 360 and DOS / VSE: Disk Operating System / Virtual Storage Extended ).

* The DOS / 360 initial / simple operating system for the IBM System / 360 family of mainframe computers ( it later became DOS / VSE, and was eventually just called VSE ).

* The DOS operating system for DEC PDP-11 minicomputers.

: The best known family of operating systems named " DOS " is that running on IBM PCs type hardware using Intel x86 CPUs or their compatible cousins from other makers.

Doom became a " killer app " that all capable consoles and operating systems were expected to have, and versions of Doom have subsequently been released for the following systems: DOS, Microsoft Windows, Linux, Apple Macintosh, Super NES, Sega 32X, Sony PlayStation, Game Boy Advance, iOS, Symbian OS, RISC OS, Atari Jaguar, Sega Saturn, Nintendo 64, Tapwave Zodiac, 3DO, Xbox, and Xbox Live Arcade.

A double-sided disk on the 1571 would have a capacity of 340 KB ( 70 tracks, 1, 360 disk blocks of 256 bytes each ); as 8 KB are reserved for system use ( directory and block availability information ) and, under CBM DOS, 2 bytes of each block serve as pointers to the next logical block, 254 x 1, 328 = 337, 312 B or about 329. 4 KB were available for user data.

They are used to emulate a hardware device, particularly in virtualization environments, for example when a DOS program is run on a Microsoft Windows computer or when a guest operating system is run on, for example, a Xen host.

" In an appendix he called DOS " plain and simple theft " because its first 26 system calls worked the same as CP / M's.

Microsoft had a double gain from its release: first, it made it impossible for consumers to run Windows 95 on a cheaper, non-Microsoft DOS ; secondly, although traces of DOS were never completely removed from the system and MS DOS 7 would be loaded briefly as a part of the booting process, Windows 95 applications ran solely in 386 enhanced mode, with a flat 32-bit address space and virtual memory.

As Steve Wozniak, the creator of Integer BASIC and the only person who understood it well enough to add floating point features, was busy with the Disk II drive and controller and with Apple DOS, Apple turned to Microsoft, who was the BASIC vendor of choice after their success with Altair BASIC, and licensed a 10 KB assembly language version of BASIC dubbed " Applesoft.

Similarly, all output was scrutinized for a Control-D character ( ASCII 4 ), which BASIC programs would send before seemingly PRINTing a disk command to get DOS's attention ( the disk commands would not really get PRINTed but were intercepted by DOS and prevented from making it to the screen output ).

Civilization was originally developed for DOS running on a PC.

Accordingly, when a disk was formatted or a disk error occurred, the unit would try to physically move the head 40 times in the direction of track zero ( although the 1541 DOS only used 35 tracks, the drive itself was a 40 track unit, so this ensured track zero would be reached no matter where the head was before ).

However, one track was reserved by DOS for directory and file allocation information ( so-called BAM, Block Allocation Map ).

The embedded OS in the 1571 was CBM DOS V3. 0 1571, an improvement over the 1541's V2. 6.

Usually, it was called Apple DOS to distinguish it from MS-DOS.

* Commodore DOS, which was used by 8-bit Commodore computers.

Unlike most other DOS systems, it was integrated into the disk drives, not loaded into the computer's own memory.

* Atari DOS, which was used by the Atari 8-bit family of computers.

The Atari OS only offered low-level disk-access, so an extra layer called DOS was booted off a floppy that offered higher level functions such as filesystems.

Digital Research produced a compatible variant known as DR DOS, which was eventually taken over ( after a buyout of Digital Research ) by Novell, then by Caldera.

The game was made available on Steam on August 3, 2007, running on the DOSBox DOS emulator.

While a few short-lived DOS based EDuke projects emerged, it was not until the release of EDuke32, an extended version of Duke3D incorporating variants of both Fowler's Microsoft Windows JFDuke3D code and Saettler's EDuke code, by one of 3D Realms ' forum moderators in late 2004 that EDuke's scripting extensions received community focus.

The primary operating systems in use on current IBM mainframes include z / OS ( which followed MVS and OS / 390 ), z / VM ( previously VM / CMS ), z / VSE ( which is in the DOS / 360 lineage ), z / TPF ( a successor of Airlines Control Program ), and Linux on System z such as SUSE Linux Enterprise Server and others.

# DOS 5. 0 and higher: Assign drive letters to all remaining primary partitions, beginning with the first hard drive and proceeding through successive physical hard disk drives.

Some versions of DOS don't assign the drive letter, beginning with C :, to the first active primary partition recognized upon the first physical hard disk, but on the first primary partition recognized of the first hard disk, even if it is not set active.

CONFIG. SYS is the primary configuration file for the DOS, OS / 2 as well as similar operating systems.

Oracle's primary application development tool, Oracle Forms 3, was character-based and did not run under Microsoft Windows ( although it could run in a DOS window or natively on DOS without Windows ).

With the introduction of version 4. 0, the name was changed to PC Tools Deluxe, and the primary interface became a colorful graphical DOS shell ( previously the DOS shell resembled PC BOSS and was monochrome.

Squish is both the name of a FidoNet mail tossing application originally designed for DOS and OS / 2, and the name of the primary mail storage format in which this application stores FidoNet and other local BBS messages.

Three emulators of the machine exist, ElectrEm for Windows / Linux / Mac OS X, Elkulator for Windows / DOS and the Multi-system emulator MESS.

There were many successful commercial BBS programs developed for DOS, such as PCBoard BBS, RemoteAccess BBS, and Wildcat!

( Around 1990, OS / 2 came out with " preemptive multitasking " of DOS, an alternative to DESQview for multi-node BBS.

For those more nostalgic for the true BBS experience, one can use NetSerial ( Windows ) or DOSBox ( Windows /* nix ) to redirect DOS COM port software to telnet, allowing them to connect to Telnet BBSes using 1980s and 1990s era modem terminal emulation software, like Telix, Terminate, Qmodem and Procomm Plus.

And since for normal files, two bytes of each physical sector were used by DOS as a pointer to the next physical track and sector of the file, only 254 out of the 256 bytes of a block were used for file contents.

The version of Commodore DOS built into the 1581 added support for partitions, which could also function as fixed-allocation subdirectories.

Like the 1571, its built-in DOS provided a data burst mode for transferring data to the C128 computer at a faster speed than a 1541.

Most home computer DOS ' es were stored on a floppy disk always to be booted at start-up, with the notable exception of Commodore, whose DOS resided on ROM chips in the disk drives themselves ( the computer itself had no DOS, just a form of a BIOS for communicating with peripherals ).

The Lt. Kernal hard disk subsystem for the Commodore 64 and Commodore 128 models stored its DOS on the disk, as is the case with modern systems, and loaded the DOS into RAM at boot time.

* GDOS and G + DOS, for the + D and DISCiPLE disk interfaces for the ZX Spectrum.