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MS-DOS (an acronym of Microsoft Disk Operating System) is Microsoft's clone of the CP/M disk operating system for the Intel 8088 processor, used by the original IBM Personal Computer. It has also been referred to as PC-DOS or simply DOS, though there had already been other OSes with that name since the mid-1960s, starting with IBM's first disk operating system for the IBM System/360. It has also been called "MS-DOG" and "mess-dos" by its critics.[1]
Description[]
MS-DOS is a single-user operating system that ran one program at a time and was limited to working with one megabyte of memory, 640 kilobytes of which is usable for the application program. Special add-on Expanded Memory Specification (EMS) boards allowed EMS-compliant software to exceed the 1 MB limit. Add-ons to DOS, such as Microsoft Windows and DESQview, took advantage of EMS and allowed the user to have multiple applications loaded at once and switch between them.[1]
History[]
Clip from a commercial comparing a PC's manual with that of a Mac.
MS-DOS originated as 86-DOS, written in 6 weeks by hacker Tim Paterson, who is said to have regretted selling it to Microsoft, which then licensed it to IBM. Many of the original DOS functions were calls to BASIC (in ROM on the original IBM PC), e.g. format and mode. People with non-IBM PCs had to buy MS BASIC (which later became GW-BASIC). Most versions of DOS included some compatible version of BASIC.
Numerous features, including vaguely Unix-like but rather broken support for subdirectories, I/O redirection and pipelines, were hacked into MS-DOS 2.0 and subsequent versions. As a result, there are two or more incompatible versions of many system calls, and MS-DOS programmers could never agree on basic things like what character to use as an option switch ("-" or "/"). Despite the various issues, its use by many IBM PC-compatibles with Intel 16 and 32-bit microprocessors led to it becoming the highest-unit-volume operating system in history until its eventual replacement by Microsoft Windows.[1]
MS-DOS on Apple hardware[]
PowerPC-based Macs running classic Mac OS or Mac OS X can use a software emulator such as Virtual PC, or a hardware emulator like a DOS Compatibility Card, to run MS-DOS or PC-DOS.[2][3] Macs running Mac OS X or macOS on PowerPC, Intel, or Apple processors can also use DOSBox as an open source alternative to run vintage DOS software and games.[4]
References[]
- ↑ 1.0 1.1 1.2 Microsoft Disk Operating System at the Free On-Line Dictionary Of Computing. 2007-05-21.
- ↑ Connectix Corporation Ships Connectix Virtual PC, Connectix. 1997-06-11.
- ↑ Before there was Boot Camp, there were DOS Compatibility Cards by Steven Sande, Engadget. 2009-12-10.
- ↑ Information, DOSBox. Accessed 2021-10-03.
External links[]
- The original sources of MS-DOS 1.25 and 2.0 by Microsoft at GitHub
- MS-DOS at Computer Hope
- MS-DOS at Wikipedia
