Atari DOS is the
disk operating system used with the
Atari 8-bit family
The Atari 8-bit family is a series of 8-bit home computers introduced by Atari, Inc. in 1979 as the Atari 400 and Atari 800. The series was successively upgraded to Atari 1200XL , Atari 600XL, Atari 800XL, Atari 65XE, Atari 130XE, Atari 800XE, ...
of computers.
Operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
extensions loaded into memory were required in order for an Atari computer to manage files stored on a
disk drive
Disk storage (also sometimes called drive storage) is a general category of storage mechanisms where data is recorded by various electronic, magnetic, optical, or mechanical changes to a surface layer of one or more rotating disks. A disk drive is ...
. These extensions to the operating system added the disk handler and other file management features.
The most important extension is the disk handler. In Atari DOS 2.0, this was the File Management System (FMS), an implementation of a
file system
In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one larg ...
loaded from a
floppy disk
A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined w ...
. This meant at least an additional
RAM
Ram, ram, or RAM may refer to:
Animals
* A male sheep
* Ram cichlid, a freshwater tropical fish
People
* Ram (given name)
* Ram (surname)
* Ram (director) (Ramsubramaniam), an Indian Tamil film director
* RAM (musician) (born 1974), Dutch
* Ra ...
was needed to run with DOS loaded.
Versions
There were several versions of Atari DOS available, with the first version released in 1979.
Atari
Atari was using a cross assembler
In computer programming, assembly language (or assembler language, or symbolic machine code), often referred to simply as Assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence be ...
with Data General AOS
Data General AOS (an abbreviation for Advanced Operating System) was the name of a family of operating systems for Data General 16-bit Eclipse C, M, and S minicomputers, followed by AOS/VS and AOS/RT32 (1980) and later AOS/VS II (1988) for the ...
.
DOS 1.0
In the first version of DOS from Atari
Atari () is a brand name that has been owned by several entities since its inception in 1972. It is currently owned by French publisher Atari SA through a subsidiary named Atari Interactive. The original Atari, Inc. (1972–1992), Atari, Inc., ...
all commands were only accessible from the menu. It was bundled with the ''810
__NOTOC__
Year 810 ( DCCCX) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar.
Events
By place Byzantine Empire
* Spring – The Venetian dukes change sides again, submitting to Kin ...
'' disk drives. This version was entirely memory resident, which made it fast but occupied memory space.
DOS 2.0
:Also known as ''DISK OPERATING SYSTEM II VERSION 2.0S''
The second, more popular version of DOS from Atari was bundled with the ''810'' disk drives and some early ''1050
Year 1050 (Roman numerals, ML) was a common year starting on Monday (link will display the full calendar) of the Julian calendar.
Events
By place
Europe
* Hedeby is sacked by King Harald Hardrada, Harald III (Hardrada) of Kingdom of ...
'' disk drives. It is considered to be the lowest common denominator for Atari DOSes, as any Atari-compatible disk drive can read a disk formatted with ''DOS 2.0S''.
''DOS 2.0S'' consisted of DOS.SYS
and DUP.SYS
. DOS.SYS
was loaded into memory, while DUP.SYS
contained the disk utilities and was loaded only when the user exited to DOS.
In addition to bug fixes, ''DOS 2.0S'' featured improved NOTE/POINT
support and the ability to automatically run an Atari executable file named AUTORUN.SYS
. Since user memory was erased when DUP.SYS
was loaded, an option to create a MEM.SAV
file was added. This stored user memory in a temporary file (MEM.SAV
) and restored it after DUP.SYS
was unloaded. The previous menu option from ''DOS 1.0'', N. DEFINE DEVICE
, was replaced with N. CREATE MEM.SAV
in ''DOS 2.0S''.
Version ''2.0S'' was for single-density disks, ''2.0D'' was for double-density
Disk density is a capacity designation on magnetic storage, usually floppy disks. Each designation describes a set of characteristics that can affect the areal density of a disk or the efficiency of the encoded data. Such characteristics include ...
disks. 2.0D shipped with the ''815
__NOTOC__
Year 815 (Roman numerals, DCCCXV) was a common year starting on Monday (link will display the full calendar) of the Julian calendar.
Events
By place Byzantine Empire
* Byzantine–Bulgarian Treaty of 815, Byzantine–Bulgaria ...
'' Dual Disk Drive, which was both expensive and incompatible with the standard 810, and thus sold only a small number; making DOS version ''2.0D'' rare and unusual.
DOS 3
A new version of DOS that came originally bundled with the 5.25-inch Atari 1050
The Atari 1050 was a floppy disk drive for the Atari 8-bit family home computers, released in June 1983. It was compatible with the 90 kB single-density mode of the original Atari 810 it replaced, and added a new "enhanced" or "dual density" ...
disk drive. This made use of the new '' Enhanced Density'' (ED) capability, also referred to by Atari as ''Dual Density''. This increased storage from 88 KB to 130 KB per disk. There was a single density (88 KB) formatting option to maintain compatibility with older Atari 810 disk drives.
By organizing sector
Sector may refer to:
Places
* Sector, West Virginia, U.S.
Geometry
* Circular sector, the portion of a disc enclosed by two radii and a circular arc
* Hyperbolic sector, a region enclosed by two radii and a hyperbolic arc
* Spherical sector, a po ...
s into blocks, Atari was anticipating larger capacity floppy disks, but this resulted in incompatibility with ''DOS 2.0S''. Files converted to DOS 3 could not be converted back to ''DOS 2.0''. As a result, DOS 3 was extremely unpopular and did not gain widespread acceptance amongst the Atari user community.
DOS 3 provided built-in help via the Atari HELP key and/or the inverse key. Help files needed to be present on the system DOS disk to function properly. DOS 3 also used special XIO commands to control disc operations within BASIC programs.
DOS 2.5
:Also known as ''DISK OPERATING SYSTEM II VERSION 2.5''
Version 2.5 is an upgrade to 3.0. After listening to complaints by their customers, Atari released an improved version of their previous DOS. This allowed the use of Enhanced Density disks, and there was a utility to read DOS 3 disks. An additional option was added to the menu (P. FORMAT SINGLE
) to format single-density disks. DOS 2.5 was shipped with ''1050'' disk drives and some early '' XF551'' disk-drives.
Included utilities were DISKFIX.COM
, COPY32.COM
, SETUP.COM
and RAMDISK.COM
.
DOS 4.0
:Codename during production: ''QDOS''
DOS 4.0 was designed for the never-released '' 1450XLD''. The rights were returned to the author, Michael Barall, who placed it in the public domain
The public domain (PD) consists of all the creative work
A creative work is a manifestation of creative effort including fine artwork (sculpture, paintings, drawing, sketching, performance art), dance, writing (literature), filmmaking, ...
. It was later published by Antic Software
Antic Software was a software company associated with ''Antic'', a magazine for the Atari 8-bit family of computers. Bound into issues of the magazine, the Antic Software catalog initially sold Atari 8-bit games, applications, and utilities from t ...
. DOS 4.0 used blocks instead of single sectors, and supported single, enhanced, and double density, as well as both single- and double-sided drives. DOS 4.0 was not compatible with DOS 2 or 3 disks but could read files from them. It also did not automatically switch densities, and it was necessary to go to the menu and manually select the correct density.
DOS XE
:Codename during production: ADOS
DOS XE supported the double-density
Disk density is a capacity designation on magnetic storage, usually floppy disks. Each designation describes a set of characteristics that can affect the areal density of a disk or the efficiency of the encoded data. Such characteristics include ...
and double-sided capabilities of the Atari XF551
The XF551 was the last floppy disk drive produced by Atari for the 8-bit series home computers. It was the first drive from the company that officially supported double-density, adding double-sided support, providing 360 kB of storage per ...
drive, as well as its burst I/O. DOS XE used a new disk format which was incompatible with DOS 2.0S and DOS 2.5, requiring a separate utility for reading older 2.0 files. It also required bank-switched RAM, so it did not run on the 400/800 machines. It supported date-stamping of files and sub-directories.
DOS XE was the last DOS made by Atari for the Atari 8-bit family.
Third-party DOS programs
Many of these DOSes were released by manufacturers of third-party drives, anyone who made drive modifications, or anyone who was dissatisfied with the available DOSes. Often, these DOSes could read disks in higher densities, and could set the drive to read disks faster (using ''Warp Speed'' or ''Ultra-Speed'' techniques). Most of these DOSes (except SpartaDOS) were DOS 2.0 compatible.
SmartDOS
Menu driven DOS that was compatible with DOS 2.0. Among the first third-party DOS programs to support double-density
Disk density is a capacity designation on magnetic storage, usually floppy disks. Each designation describes a set of characteristics that can affect the areal density of a disk or the efficiency of the encoded data. Such characteristics include ...
drives.
Many enhancements including sector copying and verifying, speed checking, turning on/off file verifying and drive reconfiguration.
Published by Rana Systems. Written by John Chenoweth and Ron Bieber, last version 8.2D.
OS/A+ and DOS XL
DOS produced by Optimized Systems Software
Optimized Systems Software (OSS) was a company that produced disk operating systems, programming languages with integrated development environments, and applications primarily for the Atari 8-bit family of home computers. OSS was best known fo ...
. Compatible with DOS 2.0 - Allowed the use of Double Density floppies. Unlike most ATARI DOSses, this used a command line instead of a menu. DOS XL
DOS XL is a discontinued Disk Operating System (DOS) written by Paul Laughton, Mark Rose, Bill Wilkinson, and Mike Peters and published by Optimized Systems Software (OSS) for the Atari 8-bit family of home computers. It was designed to be com ...
provided a menu program in addition to the command line.
SuperDOS
This DOS could read SS/SD, SS/ED, SS/DD and DS/DD disks, and made use of all known methods of speeding up disk-reads supported by the various third-party drive manufacturers.
Published by Technical Support. Written by Paul Nicholls.
Top-DOS
Menu driven DOS with enhanced features. Sorts disk directory listings and can set display options. File directory can be compressed. Can display deleted files and undelete them. Some advanced features required a proprietary TOP-DOS format.
Published by Eclipse Software. Written by R. K. Bennett.
Turbo-DOS
This DOS supports Turbo 1050, Happy, Speedy, XF551 and US Doubler highspeed drives. XL/XE only.
Published by Martin Reitershan Computertechnik. Written by Herbert Barth and Frank Bruchhäuser.
MyDOS
This DOS adds the ability to use sub-directories, and supports hard-drives.
Published by Wordmark Systems, includes complete source code.
SpartaDOS
This DOS used a command-line interface. Was not compatible with DOS 2.0, but could read DOS 2.0 disks. Supports subdirectories and hard drives being capable of handling filesystems sized up to 16 MB. Included the capability to create primitive batch files.
SpartaDOS X
A more sophisticated version of SpartaDOS
Atari DOS is the disk operating system used with the Atari 8-bit family of computers. Operating system extensions loaded into memory were required in order for an Atari computer to manage files stored on a disk drive. These extensions to ...
, which strongly resembles MS-DOS in its look and feel. It was shipped on a 64 KB ROM cartridge
A ROM cartridge, usually referred to in context simply as a cartridge, cart, or card, is a replaceable part designed to be connected to a consumer electronics device such as a home computer, video game console or, to a lesser extent, electroni ...
.
RealDOS
A SpartaDOS compatible DOS (in fact, a renamed version of SpartaDOS 3.x, due to legal reasons).
''RealDOS'' is Shareware by Stephen J. Carden and Ken Ames.
BW-DOS
A SpartaDOS compatible DOS, the last version 1.30 was released in December 1995. It has a much lower memory footprint compared to the original SpartaDOS and does not use the RAM under the ROM of XL/XE machines, allowing it to be used on the older Atari 400
The Atari 8-bit family is a series of 8-bit home computers introduced by Atari, Inc. in 1979 as the Atari 400 and Atari 800. The series was successively upgraded to Atari 1200XL , Atari 600XL, Atari 800XL, Atari 65XE, Atari 130XE, Atari 800XE ...
/800
__NOTOC__
Year 800 ( DCCC) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar. It was around this time that the Anno Domini calendar era became the prevalent method in Europe for naming years, so ...
models.
BW-DOS is Freeware by Jiří Bernasek.
XDOS
XDOS is Freeware by Stefan Dorndorf.
Disk formats
A number of different formats existed for Atari disks. Atari DOS 2.0S, single-sided, single-density disk had 720 sectors divided into 40 tracks. After formatting, 707 sectors were free. Each 128-byte sector used the last 3 bytes for housekeeping data (bytes used, file number, next sector), leaving 125 bytes for data. This meant each disk held 707 × 125 = 88,375 bytes of user data.
The single-density disk holding a mere 88 KB per side remained the most popular Atari 8-bit disk format throughout the series' lifetime, and almost all commercial software continued to be sold in that format (or variants of it modified for copy protection
Copy protection, also known as content protection, copy prevention and copy restriction, describes measures to enforce copyright by preventing the reproduction of software, films, music, and other media.
Copy protection is most commonly found on ...
), since it was compatible with all Atari-made disk drives.
* ''Single-Sided, Single-Density'': 40 tracks with 18 sectors per track, 128 bytes per sector. 90 KB capacity.
* ''Single-Sided, Enhanced-Density'': 40 tracks with 26 sectors per track, 128 bytes per sector. 130 KB capacity. Readable by the 1050 and the XF551.
* ''Single-Sided, Double-Density'': 40 tracks with 18 sectors per track, 256 bytes per sector. 180 KB capacity. Readable by the XF551, the 815, or modified/upgraded 1050.
* ''Double-Sided, Double-Density'': 80 tracks (40 tracks per side) with 18 sectors per track, 256 bytes per sector. 360 KB capacity. Readable by the XF551 only.
Percom standard
In 1978, Percom
Percom Data was an early microcomputer company formed in 1976 to sell peripherals into the emerging microcomputer market. They are best known for their floppy disk systems, first for S-100 machines, and the later for other platforms like the TRS-8 ...
established a double-density layout standard which all other manufacturers of Atari-compatible disk drives such as Indus
The Indus ( ) is a transboundary river of Asia and a trans-Himalayan river of South and Central Asia. The river rises in mountain springs northeast of Mount Kailash in Western Tibet, flows northwest through the disputed region of Kashmir, ...
, Amdek
is a Japanese manufacturer of electronic musical instruments, electronic equipment, and software. It was founded by Ikutaro Kakehashi in Osaka on 18 April 1972. In 2005, its headquarters relocated to Hamamatsu in Shizuoka Prefecture. It has fa ...
, and Rana —except Atari itself— followed. A configuration block of 12 bytes defines the disk layout.
References
;Notes
*
Online version
Mapping the Atari, Revised Edition
by Ian Chadwick
External links
— Reference manual for DOS 3.
Everything You Wanted To Know About Every DOS
Atari Dos 4 (aka ANTIC Dos aka QDOS)
Documentation on Atari DOS 4
from Wordmark Systems.
{{Disk operating systems
Atari 8-bit family software
Atari operating systems
Disk operating systems
Discontinued operating systems
1979 software