Atari DOS

Last updated
Atari DOS
Ataridos-2.5.PNG
Atari DOS version 2.5, main menu
Developer Atari, Inc., Atari Corporation
Working stateDiscontinued
Source model Closed source
Initial release1979;45 years ago (1979)
Latest release XE 1.0 / 1987;37 years ago (1987)
Available in English
Platforms Atari 8-bit computers
Default
user interface 		Menu
License Proprietary EULA

Atari DOS is the disk operating system used with the Atari 8-bit 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 the operating system added the disk handler and other file management features.

Contents

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 loaded from a floppy disk. This meant at least an additional 32 KB RAM was needed to run with DOS loaded.

Versions

There were several versions of Atari DOS available, with the first version released in 1979. [1] Atari was using a cross assembler with Data General AOS.

DOS 1.0

In the first version of DOS from Atari, all commands were only accessible from the menu. It was bundled with the Atari 810 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 Atari 1050 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 disks. 2.0D shipped with the 815 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

DOS 3 diskette as supplied with a 1050 disk drive Atari Master Diskette 3 DOS 3 Floppy Disk in Sleeve.jpg
DOS 3 diskette as supplied with a 1050 disk drive

The 1050 was the first drive from Atari to offer higher recording density. For reasons unknown, they did not take advantage of the 180 kB "double density" mode the hardware in the 1050 was capable of using, and instead introduced a new "Dual Density" mode. To avoid confusion, Atari users soon began referring to this as Enhanced Density to differentiate it from real double density systems.

Initially, this increased density mode was not able to be used as Atari shipped the drives with 2.0, which only supported the original 90 kB mode. This was addressed not long after with the release of DOS 3.0. When formatted with DOS 3.0, the disk held 40 tracks of 27 sectors, up from 18 on DOS 2.0. Each sector holds 128 bytes, for a total of 133,120 bytes of storage, up from DOS 2.0's 92,160.

In DOS 2.0, a 10-bit number was used to store sector numbers in the directory. This limited disks to a maximum of 1024 sectors. The new format had 1080 sectors, so 2.0 would not be able to use all of its capability. To address this, and to offer the possibility of working with even larger formats in the future, DOS 3.0 grouped sectors together in groups of eight, known as a block, each holding 1,204 bytes. The number in the directory was reduced to 8-bits, meaning it could address up 256 kB on a single disk. The boot information and directory used three blocks, leaving 130 kB free for user storage on the 1050. [2]

Unfortunately, the new directory format made the disks unreadable on DOS 2.0. The DOS 3.0 Master Diskette included a small utility program to copy a 2.0 disk to 3.0, but not one to copy it back. A separate utility allowed disks to be formatted in 2.0 format if compatibility was needed. [3] As a result of this decision, 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. [4] 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 1450XLD. It was designed to operate with larger disk formats, adding double density and double sided support while also supporting the older single and enhanced density formats from DOS 2 and 2.5. To support the newer modes, it returned to the blocks concept used in DOS 3.0 when used to format enhanced or double density disks, but this time using slightly smaller 6-sector format, which held 768 bytes in enhanced density and 1536 bytes in double density.

Like DOS 3, disks formatted in the new higher-density formats were not compatible with older drives and DOSes. It could read and write to those disks to retain compatibility. However, it could not determine the format of a disk automatically, and the user had to select the format of the disks from the DOS menu.

The 1450XLD was never released, and the rights for DOS 4 were returned to the author, Michael Barall, who placed it in the public domain. It was published by Antic Software in 1984, and is sometimes referred to as "Antic DOS" for this reason.

DOS XE

Codename during production: ADOS

DOS XE supported the double-density and double-sided capabilities of the Atari XF551 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 computers.

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 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. 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 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[ clarification needed ]. 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. [5] [6] [7] [8]

Published by Wordmark Systems, includes complete source code under copyleft license, with an exception on distributing commercially only if it included in software or derivated software made of it would cost less than $50. [9] [10] [11] [12]

There is number of free addons and extensions for MyDOS created by users. [13] [14] [15] [16]

MyPicoDOS

This is a fork of MyDOS, intended to be used as game laucher. [17]

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

Screenshot of SpartaDOS X by FTE & DLT SpartaDOS X prompt.png
Screenshot of SpartaDOS X by FTE & DLT

A more sophisticated version of SpartaDOS, which strongly resembles MS-DOS in its look and feel. It was shipped on a 64 KB ROM cartridge.

RealDOS

A SpartaDOS compatible DOS (in fact, a renamed version of SpartaDOS 3.x, for legal reasons).

RealDOS is shareware by Stephen J. Carden and Ken Ames.

BW-DOS

Screenshot of BW-DOS by Jiri Bernasek Bwdos.png
Screenshot of BW-DOS by Jiří Bernasek

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 400/800 models.

BW-DOS is freeware by Jiří Bernasek.

XDOS

XDOS is freeware by Stefan Dorndorf.

LiteDOS

Minimalistic DOS for Atari, supporting files formats of various other DOS software, such as files of Atari DOS and MyDOS. [18]

Disk formats

A number of different formats existed for Atari disks. [8] 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), since it was compatible with all Atari-made disk drives.

Percom standard

In 1978, Percom established a double-density layout standard which all other manufacturers of Atari-compatible disk drives such as Indus, Amdek, and Rana —except Atari itself— followed. A configuration block of 12 bytes defines the disk layout. [11] [19] [20]

RAMCART

It is ramdisk for Atari XL, compatible with many DOS software. [21]

IDE Plus 2.0

It is an utility to work with Atari disks and diskettes, based on MyDOS and SpartaDOS. [16]

Related Research Articles

<span class="mw-page-title-main">Atari 8-bit computers</span> 1979-1991 home computer series

The Atari 8-bit computers, formally launched as the Atari Home Computer System, are a series of home computers introduced by Atari, Inc., in 1979 with the Atari 400 and Atari 800. The architecture is designed around the 8-bit MOS Technology 6502 CPU and three custom coprocessors which provide support for sprites, smooth multidirectional scrolling, four channels of audio, and other features. The graphics and sound are more advanced than most of its contemporaries, and video games are a key part of the software library. The 1980 first-person space combat simulator Star Raiders is considered the platform's killer app.

<span class="mw-page-title-main">Apple ProDOS</span> Apple II disk operating system

ProDOS is the name of two similar operating systems for the Apple II of personal computer. The original ProDOS, renamed ProDOS 8 in version 1.2, is the last official operating system usable by all 8-bit Apple II computers, and was distributed from 1983 to 1993. The other, ProDOS 16, was a stop-gap solution for the 16-bit Apple IIGS that was replaced by GS/OS within two years.

A boot disk is a removable digital data storage medium from which a computer can load and run (boot) an operating system or utility program. The computer must have a built-in program which will load and execute a program from a boot disk meeting certain standards.

<span class="mw-page-title-main">TRSDOS</span> Operating system for Tandy TRS-80 computers

TRSDOS is the operating system for the Tandy TRS-80 line of eight-bit Zilog Z80 microcomputers that were sold through Radio Shack from 1977 through 1991. Tandy's manuals recommended that it be pronounced triss-doss. TRSDOS should not be confused with Tandy DOS, a version of MS-DOS licensed from Microsoft for Tandy's x86 line of personal computers (PCs).

Optimized Systems Software (OSS) was a company that produced disk operating systems, programming languages with integrated development environments, and applications primarily for Atari 8-bit computers. The founders of OSS previously developed Atari DOS, Atari BASIC, and the Atari Assembler Editor for Atari, Inc., and many OSS products are substantially improved versions. OS A+ and DOS XL are based on Atari DOS. BASIC A+, BASIC XL, and BASIC XE are based on Atari BASIC. EASMD and MAC/65 are modeled on the Atari Assembler Editor. Action! is an ALGOL-inspired compiled programming language with an integrated full-screen editor. OSS also sold some software for the Apple II.

<span class="mw-page-title-main">DOS XL</span>

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 computers. It was designed to be compatible with Atari DOS which shipped with Atari, Inc.'s disk drives, which had also been written by the same team.

A disk compression software utility increases the amount of information that can be stored on a hard disk drive of given size. Unlike a file compression utility, which compresses only specified files—and which requires the user to designate the files to be compressed—an on-the-fly disk compression utility works automatically through resident software without the user needing to be aware of its existence. On-the-fly disk compression is therefore also known as transparent, real-time or online disk compression.

The Atari Message Information System (AMIS) was one of the first BBS software packages available for the Atari 8-bit computers. It was known to crash pretty often and could not be left unattended for more than a few days. The autorun.sys file which contained the modem handler was at cause. Versions of the AMIS BBS were modified with the modem handler supplied with the Atari XM301 modem and was deemed much more stable.

Atari 8-bit computer peripherals include floppy drives, printers, modems, and video game controllers for Atari 8-bit computers, which includes the 400/800, XL, XE, and XEGS.

<span class="mw-page-title-main">Atari TOS</span> Operating system of the Atari ST range of computers

TOS is the operating system of the Atari ST range of computers. This range includes the 520ST and 1040ST, their STF/M/FM and STE variants and the Mega ST/STE. Later, 32-bit machines were developed using a new version of TOS, called MultiTOS, which allowed multitasking. More recently, users have further developed TOS into FreeMiNT.

<span class="mw-page-title-main">SpartaDOS X</span> Disk operating system

SpartaDOS X is a disk operating system for the Atari 8-bit computers that closely resembles MS-DOS. It was developed and sold by ICD in 1987-1993, and many years later picked up by the third-party community SpartaDOS X Upgrade Project, which still maintains the software.

Happy drives are series of disk drive enhancements for the Atari 8-bit and Atari ST computer families produced by a small company called Happy Computers. Happy Computers is most noted for the add-in boards for the Atari 810 and Atari 1050 floppy disk drives, which achieved a tremendous speed improvement for reading and writing, and for the ability to backup floppies. Happy's products were among the most popular Atari computer add-ons. They were still in use and active in the aftermarket as of 2009.

<span class="mw-page-title-main">DOS</span> Family of IBM PC-compatible operating systems

DOS is a family of disk-based operating systems for IBM PC compatible computers. The DOS family primarily consists of IBM PC DOS and a rebranded version, Microsoft's MS-DOS, both of which were introduced in 1981. Later compatible systems from other manufacturers include DR-DOS (1988), ROM-DOS (1989), PTS-DOS (1993), and FreeDOS (1998). MS-DOS dominated the IBM PC compatible market between 1981 and 1995.

<span class="mw-page-title-main">MAC/65</span> Atari 8-bit family 6502 assembler

MAC/65 is a 6502 assembler written by Stephen D. Lawrow for Atari 8-bit computers. MAC/65 was first released on disk by Optimized Systems Software in 1982, with the program requiring 16 KB RAM. A bank switched "SuperCartridge" from OSS followed in January 1984 for US$99, occupying only 8 KB.

<span class="mw-page-title-main">Floppy disk variants</span> Types of floppy disk formats

The floppy disk is a data storage and transfer medium that was ubiquitous from the mid-1970s well into the 2000s. Besides the 3½-inch and 5¼-inch formats used in IBM PC compatible systems, or the 8-inch format that preceded them, many proprietary floppy disk formats were developed, either using a different disk design or special layout and encoding methods for the data held on the disk.

The Indus GT is a 5+1⁄4-inch floppy disk drive that was introduced by Indus Systems in 1983 for the Atari 8-bit computers. It was later released for the Apple II and Commodore 64. On the Atari, it was widely regarded as the best drive of the era, with the most features, highest performance, and even best industrial design. They were known for the advertising slogan, "Turn your Atari into a Ferrari." The GT was sold until around 1987, at which point the rights were sold to Logical Design Works and reintroduced as the LDW Super 2000, sold primarily into Poland, and the CA-2001, sold into the US.

<span class="mw-page-title-main">Atari 810</span> Disk drive for the Atari 8-bit computers

The Atari 810 is the official floppy disk drive for the Atari 400 and 800, the first two models of Atari 8-bit computers. It was released by Atari, Inc. in 1980.

<span class="mw-page-title-main">Atari 1050</span> Floppy disk drive for Atari 8-bit computers

The Atari 1050 is a floppy disk drive for Atari 8-bit computers released in June 1983. It is compatible with the 90 kB single-density mode of the original Atari 810 it replaced, and added a new "enhanced" or "dual density" mode that provided 130 kB. Based on a half-height Tandon mechanism, it was smaller than the 810 and matched the styling of the new 600XL and 800XL machines.

The FAT file system is a file system used on MS-DOS and Windows 9x family of operating systems. It continues to be used on mobile devices and embedded systems, and thus is a well-suited file system for data exchange between computers and devices of almost any type and age from 1981 through to the present.

<span class="mw-page-title-main">Atari XF551</span> Floppy disk drive

The XF551 is a 5 1/4 inch floppy disk drive produced by Atari, Inc. for the Atari 8-bit computers. Introduced in 1987, it matches the gray design language of the XE models. It was the first drive from the company with official support for double-density and double-sided floppy disks—360 kB of storage per disk—and was also the final floppy disk drive Atari produced for the 8-bit computers. The XF551 allows faster transfer speed when used in double-density mode, doubling performance.

References

  1. ↑ Atari Archived February 21, 2009, at the Wayback Machine
  2. ↑ Reference 1982, p. 23.
  3. ↑ Reference 1982, p. 25.
  4. ↑ Chadwick, Ian (1985). "Appendix Seventeen: Dos 2.5 And The 1050 Drive". Mapping the Atari. Greensboro, North Carolina: Compute! Publications, Inc. ISBN   0-87455-004-1.
  5. ↑ Marslett, Charles; Puff, Robert (1988). MYDOS Version 4.50 (PDF) (User Guide). WORDMARK Systems. For Atari Home Computers.
  6. ↑ Miscellaneous PD Disks: MyDos Disk Operating System Replacement, utilities , retrieved 2024-09-14
  7. ↑ "Atari 400 800 XL XE MyDOS 5.0". www.atarimania.com. Retrieved 2024-09-14.
  8. 1 2 Fox-1, Sysop. "Disk Formats Explained". THUNDERDOME – the ATARI site. Retrieved 2024-09-14. There is no real important difference in the special boot bytes on a MyDos disk and an Atari Dos Disk.{{cite web}}: CS1 maint: numeric names: authors list (link)
  9. ↑ "MyDOS programs and tools". www.wordmark.org. Retrieved 2024-09-14.
  10. ↑ "Mathy's MyDOS page". www.mathyvannisselroy.nl. Retrieved 2024-09-14.
  11. 1 2 "ANTIC The Atari 8-bit Podcast: ANTIC Interview 393 - Charles Marslett, MYDOS and FastChip". ataripodcast.libsyn.com. Retrieved 2024-09-14. Charles Marslett wrote floppy disk and hard drive drivers for Percom, and was the creator of MYDOS, a disk operating system for the Atari 8-bit computers that offered support for double density sectors, subdirectories, and hard drives.
  12. ↑ "Index of /~archive/atari/8bit/Dos/Mydos". websites.umich.edu. Retrieved 2024-09-14.
  13. ↑ Fox-1, Sysop (2018-06-05). "Tag: mydos". THUNDERDOME – the ATARI site. Retrieved 2024-09-14.{{cite web}}: CS1 maint: numeric names: authors list (link)
  14. ↑ "Atari 400/800/XL/XE Miscellaneous Software & Utilities - Chebucto Community Net". www.chebucto.ns.ca. Retrieved 2024-09-14.
  15. ↑ "MyDOS". SourceForge. 2016-02-03. Retrieved 2024-09-14.
  16. 1 2 ":: drac030.atari8.info". drac030.krap.pl. Retrieved 2024-09-14. Utility disk for the interface. ATR format, side A for MyDOS, side B for SpartaDOS (updated 19 I 2011).
  17. ↑ Reichl, Matthias (2024-03-27), HiassofT/MyPicoDOS , retrieved 2024-09-14
  18. ↑ "LiteDOS (c) Mr.Atari". www.mr-atari.com. Retrieved 2024-09-14.
  19. ↑ Wilkinson, Bill (October 1985). "Atari Disk Drive Compatibility". Compute!. pp. 110–111. Retrieved 16 October 2013.
  20. ↑ Kay Savetz (2020-08-16), Charles Marslett, MYDOS and FastChip — interview , retrieved 2024-09-14
  21. ↑ Janz, Holger (2024-05-27), HolgerJanz/RAMCART , retrieved 2024-09-14
Notes
    This page is based on this Wikipedia article
    Text is available under the CC BY-SA 4.0 license; additional terms may apply.
    Images, videos and audio are available under their respective licenses.