The continuing development of various modern mass storage options for the
8-bit Atari computers has necessitated ongoing development of supporting
disk operating systems. This section describes full-featured disk operating
systems (DOS) for the Atari that remain actively developed today.
RealDOS v1.0a Build 0031 (November 2012)
- Shareware from Integrated Logic Systems (ILS, Stephen J. Carden)
- Disk utilization/filesystem: SpartaDOS File System (SDFS) version 2.0
- XL/XE with 64KiB RAM required. Also designed to run on APE software and
hardware, or with an emulator.
- RealDOS contains both the MUX- and non-MUX SIOV.
This DOS will realize how it is being called and will load the proper SIOV
handler for your needs. RealDOS will configure itself by detecting your
- Fully supports: Black Box (all versions), ICD MIO, Ken Jones MIO, KPI
interface, Supra Interface, IDEa, SIO2PC, APE Registered Version, SIO2SD,
SIO2IDE, SIO2USB, S-Drive and The Multiplexer.
- RealDOS was also designed to work with the Atari800Win emulator.
- RealDOS does not support at this time the cartridge version of the MyIDE
Old version/Release history:
RealDOS (or Real.DOS) shares its development heritage with disk-based
SpartaDOS version 3.2c from ICD (which is described elsewhere in this FAQ
list). The features and capabilities of RealDOS may thus be further
described in terms of changes and improvements made since ICD SpartaDOS
(NOTE: Prior to Real.Dos Build 0026, distribution of RealDOS was private.
Exception: the Video 61 SpartaDOS 3.3C cartridge described below.)
-- SpartaDOS Ver 3.2p "30-Jan-86 Copyright (C) 1986 by ICD, Inc."
o Support for the CSS Multiplexer ("MUX") in the form of a MUX-specific
o Being based on SpartaDOS 3.2c, does not have the open file/directory
bug/error found in later official SpartaDOS versions (3.2d, 3.2f, 3.2g,
3.2gx), a problem known to be capable of trashing a hard drive
o What was privately distributed as SpartaDOS 3.2p was initially
developed from SpartaDOS 3.2c source code that was privately shared by
ICD. During the development process all new/modified sources were
lost, so new sources were then reverse-engineered (by Ken Ames for
Steve Carden) from surviving working executables and from memory,
leading finally to SpartaDOS 3.2p.
o Date of distribution unknown -- unreflected in the Version info
-- SpartaDOS Pro Ver 3.3a 3-Nov-94 "Copyright (C) 1994 by FTe"
o Support for a Drive 9
o MS-DOS work-alike command set
-- SpartaDOS Pro Ver 3.3b 25-Dec-95 "(S)hareware 1995 by IFYB, Inc."
o Same as 3.3a but includes the Sparta High Speed SIOV (for US Doubler &
compatible) instead of the MUX SIOV as in 3.3a.
-- SpartaDOS Pro Ver 3.3c 19-Dec-97 "(S)hareware 1997 by IFYB, Inc."
o Same as 3.3a or 3.3b, but includes both SIOV versions, auto-selected
based on hardware detected
-- Sparta DOS 3.3C "(c) 1998 Video 61"
o Same as Ver 3.3c 19-Dec-97 but modified by Video 61 to operate from a
16KiB ROM cartridge. Available: http://www.atarisales.com/
o According to Lance Ringquist of Video 61:
K-Products (Bob Klaas) contracted with FTe (Mike Hohman) to develop
SpartaDOS Pro 3.3 for exclusive use and distribution with K-Products'
BBS Express! Pro. When Video 61 purchased all rights associated with
BBS Express! Pro from K-Products, the rights to SpartaDOS Pro 3.3
o According to Stephen Carden:
The SpartaDOS Pro 3.3 versions were developed privately as hacks to
ICD SpartaDOS 3.2c, the rights to which remain with FTe to this day.
-- SpartaDOS Ver 3.3d 1-Jan-98 "(S)hareware 1998 by IFYB, Inc."
o Same as 3.3c, but further debugged for use with the ICD MIO
-- Real.dos Builds 0003 through 0031, 2002-2012
SpartaDOS X 4.48 with Toolkit (23 Jul. 2016), by DLT Ltd.
- Often abbreviated: SDX
- No source code in common with disk-based SpartaDOS, nor with RealDOS
- 48KiB RAM required; more recommended
- A 128KiB ROM cartridge (v.4.40+ ; earlier versions 64KiB)
- Can run on the following platforms: intSDX128 and intSDX128 "flash", Altirra
and Atari800 emulators, IDE Plus 2.0 interface, Ultimate1MB, Incognito
board, SIDE HDD cartridge, SIC! Cartridge, Turbo Freezer 2005, Maxflash 1Mb,
Maxflash 8Mb, Maxflash MyIDE+Flash, MyIDE II, an upgraded SpartaDOS X
cartridge from ICD, SDX 128 "flash" cartridge, AtraX SDX 128 cartridge
- Proprietary kernel does not rely on the Central Input/Output (CIO)
portion of the Atari OS to communicate with devices. Standard Atari CIO
communication is also supported for full software compatibility.
- Disk utilization/filesystems:
1) SpartaDOS File System (SDFS) version 2.1 (SDX native filesystem)
(v.4.40+ ; SDFS 2.0 in prior versions)
- Supports sector sizes larger than 256 bytes
- "All DOS using SDFS 2.0 work with SDFS 2.1 and vice versa."
2) Atari DOS 2
- Supports subdirectories in MYDOS up to a size of ~16MiB
(65535 sectors, 256 bytes each)
- Supports the extended sectors of DOS 2.5 for read only.
- Does not support the ability to create/delete, or set a working
directory on MYDOS media
3) CP/M (as of SDX 4.46)
- Read Indus CP/M 2.2 disks on Indus GT/LDW Super 2000/CA-2001)
4) MS-DOS FAT12 (as of SDX 4.46) or FAT16 (as of SDX 4.47)
- Read-only; hardware device must support 512-byte sectors
- Number of drives or partitions: up to 15 (8 before v.4.40)
- Logical sector size: 128, 256, or 512 bytes (128 or 256 before v.4.40)
- Number of sectors per disk: up to 65535
- Disk size: up to 32MiB (16MiB in versions before v.4.40)
- Directory size: up to 32KiB
- Number of directories: unlimited
- Number of entries per directory: up to 1423
- File size: up to 16MiB
- Number of files open at a time: up to 16
- Path length: up to 64 characters
- Extended memory: up to 1024KiB with Port B type; 4032KiB with Axlon type
- High speed support: Happy/Warp Speed, US Doubler/UltraSpeed,
Indus GT/Synchromesh, XF551, 1050 Speedy
- RS232.COM provided for loading the R: handler from the 850 interface ROM
Old versions/release history:
SpartaDOS X was originally developed by Mike Gustafson for ICD.
ICD SpartaDOS X release history: (version numbering started with 4.0)
- SpartaDOS X 4.17 ??-??-88
- SpartaDOS X 4.18 10-29-88
- SpartaDOS X 4.19 1-16-89
- SpartaDOS X 4.20 2-06-89
- SpartaDOS X 4.21 7-10-89
The rights to SpartaDOS X were purchased from ICD by Fine Tooned Engineering
(FTe, Mike Hohman) in 1993 (November?).
FTe SpartaDOS X release history:
- SpartaDOS X 4.22 11-05-95
DLT Ltd. (Draco, Lizard, Trub) chose to carry the development of SDX forward.
DLT SpartaDOS X release history:
- SpartaDOS X 4.39RC (1 Oct. 2006)
- SpartaDOS X 4.41 (8 Feb. 2008)
- SpartaDOS X 4.42 (25 Dec. 2008)
- SpartaDOS X 4.43 (updated 14 Apr. 2011; first released 10 Apr. 2011)
- SpartaDOS X 4.45 (4 Nov. 2011)
- SpartaDOS X 4.46 with Toolkit (2 Jan. 2013)
- SpartaDOS X 4.47 with Toolkit (10 Feb. 2015)
http://sdx.atari8.info/ or http://spartados.com or http://spartadosx.com
- Atarimax http://www.atarimax.com/
- Candle http://spiflash.org/
- Lotharek http://lotharek.pl/
XDOS 2.43 (c) 2009 by Stefan Dorndorf
- "Extended Disk Operating System"
- A compact yet more capable alternative to Atari DOS 2.5
- Two versions:
1) XDOS 2.4N supports all standard Atari drives (810, 1050, XF551), and
supports XF551 and Hyper-XF Hyper Speed high speed input/output.
2) XDOS 2.4F adds high speed input/output with:
SIO2USB, SIO2SD, Speedy 1050, Happy 1050, 1050 Turbo
- Disk utilization/filesystems:
1) DOS 1 (not append)
2) DOS 2.0
3) DOS 2.5
4) DOS 2.2/2.3 (931 sectors format)
5) DOS XL
6) (Happy) DOS II + / D (All versions)
7) BIBO-DOS (except 360KiB "Quad" format)
8) Turbo-DOS (except 360KiB "Quad format)
9) MyDOS (except sub-directories, disks with more than 1040 sectors, and
append to MyDOS files)
- RAM disks: 14KiB-256KiB
- Command driven
- Can use batch files
- D: Disk File Manager supports D1: through D9:
- H: device of Atari800Win emulator is supported
- Happy-Computer DOS II+/D V:4.5M Copyright 1985 by Stefan Dorndorf
- Commonly known as "Happy-DOS"
- Published in issue 3/1986 of Happy Computer magazine
- DOS II+/D - Version 6.1 Copyright 1987 by Stefan Dorndorf
- DOS II+/D - Version 6.4 (c) '87 by S.D.
- XDOS 2.3 (p) 1990 S.Dorndorf
- Adds DOS 2.5/MYDOS enhanced density compatibility