This article details versions of MS-DOS, IBM PC DOS, and at least partially compatible disk operating systems. It does not include the many other operating systems called "DOS" which are unrelated to IBM PC compatibles.
Originally MS-DOS was designed to be an operating system that could run on any computer with a 8086-family microprocessor. It competed with other operating systems written for such computers, such as CP/M-86 and UCSD Pascal. Each computer would have its own distinct hardware and its own version of MS-DOS, a situation similar to the one that existed for CP/M, with MS-DOS emulating the same solution as CP/M to adapt for different hardware platforms. So there were many different original equipment manufacturer (OEM) versions of MS-DOS for different hardware. But the greater speed attainable by direct control of hardware was of particular importance, especially when running computer games. So very soon an IBM-compatible architecture became the goal, and before long all 8086-family computers closely emulated IBM hardware, and only a single version of MS-DOS for a fixed hardware platform was all that was needed for the market. This specific version of MS-DOS is the version that is discussed here, as all other versions of MS-DOS died out with their respective systems. One version of such a generic MS-DOS (Z-DOS) is mentioned here, but there were dozens more. All these were for personal computers that used an 8086-family microprocessor, but which were not fully IBM PC compatible.
Name | First public release date | Creator | Owner or maintainer as of 2021 [update] | License |
---|---|---|---|---|
86-DOS 0.42 | 1981-02-25 | Seattle Computer Products | Support ended | Proprietary |
86-DOS 1.00 | 1981-04-28 | |||
PC DOS 1.0 | 1981-08-12 | Microsoft (for IBM) | ||
PC DOS 1.1 | 1982-05-?? | |||
PC DOS 2.0 | 1983-03-?? | |||
PC DOS 2.1 | 1983-10-?? | |||
PC DOS 3.0 | 1984-08-?? | |||
PC DOS 3.1 | 1985 | |||
PC DOS 3.2 | 1986 | |||
PC DOS 3.3 | 1987 | |||
IBM DOS 4.0 (called PC DOS 4.0) | 1988 | |||
IBM DOS 5.0 (called PC DOS 5.0) | 1991 | |||
PC DOS 6.1, PC DOS 6.3 | 1993 | |||
PC DOS 7.0 (revision 0) | 1995 | |||
PC DOS 2000 (PC DOS 7.0 revision 1) | 1998 | |||
PC DOS 7.10 | 2003 | Support ended by IBM | ||
MS-DOS 1.25 [1] (first version named "MS-DOS") | 1982 | Microsoft | Support ended | Open source, MIT License [2] |
Z-DOS 1.25 | 1982-05-?? | OEM Zenith Data Systems | Proprietary | |
MS-DOS 2.0 | 1983-03-?? | Microsoft | Open source, MIT License [2] | |
MS-DOS 2.11 | 1983-12-?? | Proprietary | ||
MS-DOS 3.0 | 1984 | |||
MS-DOS 3.1 | ||||
MS-DOS 3.2 | 1986 | |||
MS-DOS 3.3 | 1987 | |||
MS-DOS 4.0 | 1988 | Open source, MIT License [2] | ||
MS-DOS 5.0 | 1991 | Proprietary | ||
MS-DOS 6.0 | 1993 | |||
MS-DOS 6.20 | ||||
MS-DOS 6.21 | March 1994 [3] | |||
MS-DOS 6.22 | April 1994 [3] | |||
MS-DOS 7.0 (Windows 95A) | 1995 | |||
MS-DOS 7.10 (Windows 95 OSRs 2 and 2.5, 98, 98 SE) | 1996 | |||
MS-DOS 8.0 (Windows ME and later) [4] | 2000 | Support ended by Microsoft [5] | ||
DOS Plus 1.1, 1.2/1.2a | 1985 | Digital Research | Support ended | |
DOS Plus 2.1 | 1986 | |||
DR DOS 3.31-3.35 | 1988 | |||
DR DOS 3.40-3.41 | 1989 | |||
DR DOS 5.0 | 1990 | |||
DR DOS 6.0 | 1991 | |||
Novell DOS 7 | 1993 | Novell | ||
Caldera OpenDOS 7.01 | 1997 | Caldera, Inc.; Caldera UK, Ltd. | Support ended officially; a derivative, Enhanced DR-DOS, was maintained by Udo Kuhnt until 2011 | Partial, free non-commercial use |
Caldera DR-OpenDOS 7.02 | Support ended | |||
Caldera DR-DOS 7.02 | 1998 | Proprietary | ||
Caldera DR-DOS 7.03 | 1999, 1998 prereleased | Caldera Thin Clients, Inc.; Caldera UK, Ltd; Lineo, Inc. | DRDOS, Inc. | |
DR-DOS 8.0 | 2004 | DeviceLogics | Support ended | |
DR-DOS 8.1 [6] | 2005 | DRDOS, Inc. | ||
FreeDOS 1.0 | 2006-09-03 | Jim Hall, et al. | The FreeDOS Project | Open source, GPL |
FreeDOS 1.1 | 2012-01-02 | |||
FreeDOS 1.2 | 2016-12-25 | |||
FreeDOS 1.3 | 2021-12-14 | |||
PTS-DOS 6.4 | 1993 | PhysTechSoft [7] | PhysTechSoft | Proprietary |
PTS-DOS 6.5 | ? | |||
PTS-DOS 6.6 | ||||
PTS-DOS 2000 (6.7) | ||||
PTS-DOS 32 (7.0) | ||||
PTS-DOS 6.51 | ca. 1995 | Paragon Technology Systems | Paragon Technology Systems | |
Paragon DOS 2000 Pro | ? | |||
ROM-DOS 6.22 [8] | Datalight | Datalight | ||
ROM-DOS 7.1 [8] | ||||
Embedded DOS | General Software | General Software | ||
DIP DOS 2.11 | 1989 | DIP Research, Atari Corporation | Support ended | |
RxDOS 6.2 | 1999 | Michael Podanoffsky | Support ended | Open source, GPL |
RxDOS 7.20-7.24 | 2018 | C. Masloch | C. Masloch | |
SISNE plus | ? | Itautec, Scopus Tecnologia | Support ended | Proprietary |
Name | Hard drive: partition size max | Native support: File systems | Native support: floppy capacities 3.5" | Native support: floppy capacities 5.25" | Native support: floppy capacities 8.0" | Integrated disk compression utility | Native support: long file names |
---|---|---|---|---|---|---|---|
86-DOS 0.42-1.00 | — | FAT12; (CP/M 2 through RDCPM) | — | NorthStar 87.5 KB; Cromemco 90 KB | Cromemco/Tarbell 250.25 KB;Tarbell 616 KB; Tarbell 1232 KB [9] | No | No |
MS-DOS 1.25 | — | FAT12 | — | 160 KB; 320 KB | 250.25 KB [10] | No | No |
MS-DOS 2.0-2.11 | 16 MB (32 MB with third-party FORMAT) [11] | FAT12 | — | 160 KB; 180 KB; 320 KB; 360 KB | 250.25 KB; [10] [12] [13] 500.5 KB; [10] [12] [13] 616 KB; [12] [13] 1232 KB [10] [12] [13] | No | No |
MS-DOS 3.0 | 32 MB | FAT12, FAT16 | — | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
MS-DOS 3.1 | 32 MB | FAT12, FAT16 | — | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
MS-DOS 3.2 | 32 MB | FAT12, FAT16 | 720 KB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
MS-DOS 3.3 | 32 MB | FAT12, FAT16 | 720 KB; 1.44 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
MS-DOS 3.31 | 512 MB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
MS-DOS 4.0 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
MS-DOS 5.0 | 2 GB | FAT12, FAT16, FAT16B | 720 KB, 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
MS-DOS 6.0 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | DoubleSpace | No |
MS-DOS 6.20 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | DoubleSpace | No |
MS-DOS 6.21 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
MS-DOS 6.22 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | DriveSpace | No |
MS-DOS 7.0 (Windows 95A) | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | DriveSpace | No |
MS-DOS 7.1 (Windows 95B/OSR2, Windows 95C/OSR2.5, Windows 98, and Windows 98SE) | 124.55 GB with FAT32 [14] | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | DriveSpace for Windows 95, none for Windows 98 | No |
MS-DOS 8.0 (Windows Me and later Windows versions) [4] | 124.55 GB with FAT32 [14] | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
PC DOS 1.0 | — | FAT12 | — | 160 KB | — | No | No |
PC DOS 1.1 | — | FAT12 | — | 160 KB; 320 KB (double-sided) | — | No | No |
PC DOS 2.0-2.1 | 16 MB (32 MB with third-party FORMAT) [11] | FAT12 | — | 160 KB; 180 KB; 320 KB; 360 KB | — | No | No |
PC DOS 3.0 | 32 MB | FAT12, FAT16 | — | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
PC DOS 3.1 | 32 MB | FAT12, FAT16 | — | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
PC DOS 3.2 | 32 MB | FAT12, FAT16 | 720 KB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
PC DOS 3.3 | 32 MB | FAT12, FAT16 | 720 KB; 1.44 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
IBM DOS 4.0 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
IBM DOS 5.0 | 2 GB | FAT12, FAT16, FAT16B | 720 KB, 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
PC DOS 6.1 (early version) | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
PC DOS 6.1 with Compression / PC DOS 6.3 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | SuperStor | No |
PC DOS 7.0 / PC DOS 2000 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 1.86 MB (XDF), 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB, 1.54 MB (XDF) | — | Stacker | No |
PC DOS 7.10 | ? | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 1.86 MB (XDF), 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB, 1.54 MB (XDF) | — | Stacker, not on FAT32 | No |
DOS Plus 1.1 | 32 MB | FAT12, FAT16, CP/M-86 | 315 KB; 720 KB; CP/M 315 KB; CP/M 720 KB; MSX-DOS 360 KB; MSX-DOS 720 KB | 160 KB; 180 KB; 320 KB; 360 KB; 800 KB; 1.2 MB; CP/M 160 KB; CP/M 320 KB | — | No | No |
DOS Plus 1.2-2.1 | 32 MB | FAT12, FAT16, CP/M-86 | Apricot 315 KB; [15] (720 KB [16] ) | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB; Acorn 640 KB; Acorn 800 KB; [17] CP/M 320 KB | — | No | No |
DR DOS 3.31-3.35 | 2 GB[ citation needed ] | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | — | No | No |
DR DOS 3.40-3.41 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | No | No |
DR DOS 5.0 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | No | No |
DR DOS 6.0 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | SuperStor | No |
PalmDOS 1.0 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | SuperStor | No |
Novell DOS 7 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | Stacker | No |
OpenDOS 7.01 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | Stacker | No |
DR-OpenDOS 7.02 | 2 GB | FAT12, FAT16, FAT16B | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | Stacker | No |
DR-DOS 7.02 | 2 GB | FAT12, FAT16, FAT16B, (FAT32 in FDISK only) | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | Stacker | Partial, COMMAND.COM and LONGNAME only |
DR-DOS 7.03 | 2 GB | FAT12, FAT16, FAT16B, (FAT32 in FDISK only) | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | Stacker | Partial, COMMAND.COM and LONGNAME only |
DR-DOS 7.04-7.05 | ? | FAT12, FAT16, FAT16B, FAT32 (non-bootable) | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | Stacker, not on FAT32 | Partial, COMMAND.COM and LONGNAME only |
DR-DOS 7.06-7.07 | ? | FAT12, FAT16, FAT16B, FAT32 (bootable) | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | Stacker, not on FAT32 | Partial, COMMAND.COM and LONGNAME only |
DR-DOS 8.0 | ? | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 2.88 MB | 160 KB; 180 KB; 320 KB; 360 KB; 1.2 MB | (250.25 KB [18] ) | Supported, not on FAT32 | Partial, COMMAND.COM only |
DR-DOS 8.1 | ? | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 2.88 MB | 360 KB; 1.2 MB | — | No | No |
FreeDOS 1.0 | 2 TB [ citation needed ] | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 2.88 MB | 360 KB; 1.2 MB | — | ? | No |
FreeDOS 1.1-1.3 | 2 TB [ citation needed ] | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 2.88 MB | 360 KB; 1.2 MB | — | No | Yes |
PTS-DOS 32 | ? | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 2.88 MB | 360 KB; 1.2 MB | — | No | No |
PTS-DOS 2000 | ? | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 2.88 MB | 360 KB; 1.2 MB | — | No | No |
PTS-DOS 2000 PRO | ? | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 2.88 MB | 360 KB; 1.2 MB | — | No | No |
Datalight ROM-DOS | ? | FAT12, FAT16, FAT16B, FAT32 | 720 KB; 1.44 MB, 2.88 MB | 360 KB; 1.2 MB | — | No | Yes |
DIP DOS | — | FAT12 | — | — | — | No | No |
In computing, booting is the process of starting a computer as initiated via hardware such as a button on the computer or by a software command. After it is switched on, a computer's central processing unit (CPU) has no software in its main memory, so some process must load software into memory before it can be executed. This may be done by hardware or firmware in the CPU, or by a separate processor in the computer system.
File Allocation Table (FAT) is a file system developed for personal computers and was the default filesystem for MS-DOS and Windows 9x operating systems. Originally developed in 1977 for use on floppy disks, it was adapted for use on hard disks and other devices. The increase in disk drives capacity required four major variants: FAT12, FAT16, FAT32, and ExFAT. FAT was replaced with NTFS as the default file system on Microsoft operating systems starting with Windows XP. Nevertheless, FAT continues to be used on flash and other solid-state memory cards and modules, many portable and embedded devices because of its compatibility and ease of implementation.
IBM PC DOS, also known as PC DOS or IBM DOS, is a discontinued disk operating system for the IBM Personal Computer, its successors, and IBM PC compatibles. It was manufactured and sold by IBM from the early 1980s into the 2000s. Developed by Microsoft, it was also sold by that company as MS-DOS. Both operating systems were identical or almost identical until 1993, when IBM began selling PC DOS 6.1 with new features. The collective shorthand for PC DOS and MS-DOS was DOS, which is also the generic term for disk operating system, and is shared with dozens of disk operating systems called DOS.
86-DOS is a discontinued operating system developed and marketed by Seattle Computer Products (SCP) for its Intel 8086-based computer kit.
Disk formatting is the process of preparing a data storage device such as a hard disk drive, solid-state drive, floppy disk, memory card or USB flash drive for initial use. In some cases, the formatting operation may also create one or more new file systems. The first part of the formatting process that performs basic medium preparation is often referred to as "low-level formatting". Partitioning is the common term for the second part of the process, dividing the device into several sub-devices and, in some cases, writing information to the device allowing an operating system to be booted from it. The third part of the process, usually termed "high-level formatting" most often refers to the process of generating a new file system. In some operating systems all or parts of these three processes can be combined or repeated at different levels and the term "format" is understood to mean an operation in which a new disk medium is fully prepared to store files. Some formatting utilities allow distinguishing between a quick format, which does not erase all existing data and a long option that does erase all existing data.
fdisk is a command-line utility for disk partitioning. It has been part of DOS, DR FlexOS, IBM OS/2, and early versions of Microsoft Windows, as well as certain ports of FreeBSD, NetBSD, OpenBSD, DragonFly BSD and macOS for compatibility reasons. Windows 2000 and its successors have replaced fdisk
with a more advanced tool called diskpart
.
In DOS memory management, conventional memory, also called base memory, is the first 640 kilobytes of the memory on IBM PC or compatible systems. It is the read-write memory directly addressable by the processor for use by the operating system and application programs. As memory prices rapidly declined, this design decision became a limitation in the use of large memory capacities until the introduction of operating systems and processors that made it irrelevant.
A bootloader, also spelled as boot loader or called bootstrap loader, is a computer program that is responsible for booting a computer. If it also provides an interactive menu with multiple boot choices then it's often called a boot manager.
In computing, the BIOS parameter block, often shortened to BPB, is a data structure in the volume boot record (VBR) describing the physical layout of a data storage volume. On partitioned devices, such as hard disks, the BPB describes the volume partition, whereas, on unpartitioned devices, such as floppy disks, it describes the entire medium. A basic BPB can appear and be used on any partition, including floppy disks where its presence is often necessary; however, certain filesystems also make use of it in describing basic filesystem structures. Filesystems making use of a BIOS parameter block include FAT12, FAT16, FAT32, HPFS, and NTFS. Due to different types of fields and the amount of data they contain, the length of the BPB is different for FAT16, FAT32, and NTFS boot sectors. Combined with the 11-byte data structure at the very start of volume boot records immediately preceding the BPB or EBPB, this is also called FDC descriptor or extended FDC descriptor in ECMA-107 or ISO/IEC 9293.
The Rainbow 100 is a microcomputer introduced by Digital Equipment Corporation (DEC) in 1982. This desktop unit had a monitor similar to the VT220 and a dual-CPU box with both 4 MHz Zilog Z80 and 4.81 MHz Intel 8088 CPUs. The Rainbow 100 was a triple-use machine: VT100 mode, 8-bit CP/M mode, and CP/M-86 or MS-DOS mode using the 8088. It ultimately failed to succeed in the marketplace which became dominated by the simpler IBM PC and its clones which established the industry standard as compatibility with CP/M became less important than IBM PC compatibility. Writer David Ahl called it a disastrous foray into the personal computer market. The Rainbow was launched along with the similarly packaged DEC Professional and DECmate II which were also not successful. The failure of DEC to gain a significant foothold in the high-volume PC market would be the beginning of the end of the computer hardware industry in New England, as nearly all computer companies located there were focused on minicomputers for large organizations, from DEC to Data General, Wang, Prime, Computervision, Honeywell, and Symbolics Inc.
MSX-DOS is a discontinued disk operating system developed by Microsoft's Japan subsidiary for the 8-bit home computer standard MSX, and is a cross between MS-DOS v1.25 and CP/M-80 v2.2.
A volume boot record (VBR) is a type of boot sector introduced by the IBM Personal Computer. It may be found on a partitioned data storage device, such as a hard disk, or an unpartitioned device, such as a floppy disk, and contains machine code for bootstrapping programs stored in other parts of the device. On non-partitioned storage devices, it is the first sector of the device. On partitioned devices, it is the first sector of an individual partition on the device, with the first sector of the entire device being a Master Boot Record (MBR) containing the partition table.
In computing, sys
is a command used in many operating system command-line shells and also in Microsoft BASIC.
In some operating systems, vol
is a command within the command-line interpreters (shells) such as COMMAND.COM
and cmd.exe
. It is used to display the volume label and volume serial number of a logical drive, such as a hard disk partition or a floppy disk, if they exist.
MS-DOS is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few operating systems attempting to be compatible with MS-DOS, are sometimes referred to as "DOS". MS-DOS was the main operating system for IBM PC compatibles during the 1980s, from which point it was gradually superseded by operating systems offering a graphical user interface (GUI), in various generations of the graphical Microsoft Windows operating system.
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.
A master boot record (MBR) is a type of boot sector in the first block of partitioned computer mass storage devices like fixed disks or removable drives intended for use with IBM PC-compatible systems and beyond. The concept of MBRs was publicly introduced in 1983 with PC DOS 2.0.
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.
MS-DOS 7 is a real mode operating system for IBM PC compatibles. Unlike earlier versions of MS-DOS, it was not released separately by Microsoft, but included in the Windows 9x family of operating systems. Windows 95 RTM reports it as MS-DOS 7.0, and Windows 95 OSR 2.x and Windows 98 report as 7.1. The real-mode MS-DOS 7.x is contained in the IO.SYS file.
FORMAT /S
command, that can be substituted by formatting HDD/FDD and then copying IO.SYS from CD-ROM boot A: image, as first ever file onto drive; loss of SYS A:
(or SYS B:
) command for floppies, that can be substituted too in the same way as FORMAT /S
; inability to boot to a command prompt without substitution/modification of IO.SYS (other than CD-ROM boot version) and COMMAND.COM. For purpose of booting from C: drive, an unmodified IO.SYS from simulated A: boot diskette image, that is placed on Windows Me OEM CD-ROM, from which that CD boots, can be used, and English COMMAND.COM can be modified by replacing in this file at hex offset 00006510h byte 75h by byte EBh, or substituted by (now freeware) 4DOS http://www.jpsoft.com/download.htm Archived 2006-09-01 at the Wayback Machine PTS-DOS 32 [..] Memory Manager himem.sys, included in PTS-DOS 32, supports up to 4 GB of RAM.
PTS-DOS 2000 [..] PTS-DOS is a powerful and fast 16-bit disk operating system, fully compatible with MS-DOS and all its applications.
6.22 and 7.1 kernels
E5h
. DR DOS 3.31 does not support this format. The format is similar, but not identical to the two 250.25 KB formats with FAT IDs FDh
and FEh
supported by MS-DOS 1.25/2.x.