History DOS

1 history

1.1 origins
1.2 decline
1.3 continued use

1.3.1 embedded systems
1.3.2 emulation

history

origins

ibm pc dos (and separately sold ms-dos) , predecessor, 86-dos, resembled digital research s cp/m—the dominant disk operating system 8-bit intel 8080 , zilog z80 based microcomputers. dos instead ran on intel 8086 16-bit processors. starting ms-dos 1.28 , pc dos 2.0 operating system incorporated various features inspired xenix, microsoft s variant of unix.

when ibm introduced ibm pc, built intel 8088 microprocessor, needed operating system. seeking 8088-compatible build of cp/m, ibm approached microsoft ceo bill gates (possibly believing microsoft owned cp/m due microsoft z-80 softcard, allowed cp/m run on apple ii). ibm sent digital research, , meeting set up. however, initial negotiations use of cp/m broke down; digital research wished sell cp/m on royalty basis, while ibm sought single license, , change name pc dos . digital research founder gary kildall refused, , ibm withdrew.

ibm again approached bill gates. gates in turn approached seattle computer products. there, programmer tim paterson had developed variant of cp/m-80, intended internal product testing scp s new 16-bit intel 8086 cpu card s-100 bus. system named qdos (quick , dirty operating system), before being made commercially available 86-dos. microsoft purchased 86-dos, allegedly $50,000. became microsoft disk operating system, ms-dos, introduced in 1981.

within year microsoft licensed ms-dos on 70 other companies, supplied operating system own hardware, under own names. microsoft later required use of ms-dos name, exception of ibm variant. ibm continued develop version, pc dos, ibm pc. digital research became aware operating system similar cp/m being sold ibm (under same name ibm insisted upon cp/m), , threatened legal action. ibm responded offering agreement: give pc consumers choice of pc dos or cp/m-86, kildall s 8086 version. side-by-side, cp/m cost $200 more pc dos, , sales low. cp/m faded, ms-dos , pc dos becoming marketed operating system pcs , pc compatibles.

microsoft sold ms-dos original equipment manufacturers (oems). 1 major reason not pcs 100% ibm pc compatible. dos structured such there separation between system specific device driver code (io.sys) , dos kernel (msdos.sys). microsoft provided oem adaptation kit (oak) allowed oems customize device driver code particular system. 1990s, pcs adhered ibm pc standards microsoft began selling ms-dos in retail ms-dos 5.0.

in mid-1980s microsoft developed multitasking version of dos. version of dos referred european ms-dos 4 because developed icl , licensed several european companies. version of dos supports preemptive multitasking, shared memory, device helper services , new executable ( ne ) format executables. none of these features used in later versions of dos, used form basis of os/2 1.0 kernel. version of dos distinct released pc dos 4.0 developed ibm , based upon dos 3.3.

digital research attempted regain market lost cp/m-86, concurrent dos, flexos , dos plus (both compatible both ms-dos , cp/m-86 software), later multiuser dos (compatible both ms-dos , cp/m-86 software) , dr dos (compatible ms-dos software). digital research bought novell, , dr dos became novell dos 7; later, part of caldera (under names opendos , dr-dos 7.02/7.03), lineo, , devicelogics.

gordon letwin wrote in 1995 dos was, when first wrote it, one-time throw-away product intended keep ibm happy d buy our languages . microsoft expected interim solution before xenix. company planned on time improve ms-dos indistinguishable single-user xenix, or xedos, run on motorola 68000, zilog z-8000, , lsi-11; upwardly compatible xenix, byte in 1983 described multi-user ms-dos of future .

ibm, however, did not want replace dos. after at&t began selling unix, microsoft , ibm began developing os/2 alternative. 2 companies later had series of disagreements on 2 successor operating systems dos, os/2 , windows. split development of dos systems result. last retail version of ms-dos ms-dos 6.22, after ms-dos became part of windows 95, 98 , me. last retail version of pc dos pc dos 2000 (a.k.a. pc dos 7 revision 1) though ibm did later develop pc dos 7.10 oems , internal use.

the freedos project began 26 june 1994, when microsoft announced no longer sell or support ms-dos. jim hall posted manifesto proposing development of open-source replacement. within few weeks, other programmers including pat villani , tim norman joined project. kernel, command.com command line interpreter (shell) , core utilities created pooling code had written or found available. there several official pre-release distributions of freedos before freedos 1.0 distribution released on 3 september 2006. made available under gnu general public license (gpl), freedos not require license fees or royalties.

decline

early versions of microsoft windows ran on separate version of dos. 1990s, windows graphical shell saw heavy use on new dos systems. in 1995, windows 95 bundled standalone operating system did not require separate dos license. windows 95 (and windows 98 , me, followed it) took on default os kernel, though ms-dos component remained compatibility. windows 95 , 98, not me, ms-dos component run without starting windows. dos no longer required use windows, majority of pc users stopped using directly.

continued use

dosbox

available dos systems in 2012 freedos, dr-dos, rom-dos, pts-dos, rxdos , real/32. computer manufacturers, including dell , hp, sell computers freedos oem operating system.

embedded systems

dos s structure of accessing hardware directly makes ideal use in embedded devices. final versions of dr-dos still aimed @ market. rom-dos used embedded system on canon powershot pro 70.

emulation

on linux, possible run copies of dos , many of clones on dosemu, linux-native virtual machine running dos programs @ near native speed. there number of other emulators running dos on various versions of unix , microsoft windows such dosbox. dosbox designed legacy gaming (e.g. king s quest, doom) on modern operating systems.