86-DOS

86-DOS was an operating arrangement developed and marketed by Seattle Computer Products for its Intel 8086-based computer kit. Initially accepted as QDOS (Quick and Dirty Operating System) the name was afflicted to 86-DOS already SCP started licensing the operating system

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86-DOS had a command anatomy and appliance programming interface that apish that of Digital Research's (abbreviated DR or DRI) CP/M operating system, which fabricated it accessible to anchorage programs from the latter. The arrangement was purchased by Microsoft and developed added as PC-DOS and MS-DOS.

Origins

86-DOS was created because sales of the Seattle Computer Products (SCP) 8086 computer kit, approved in June 1979 and alien in November, were admiring due to the absence of an operating system. The alonecomputer application which SCP could advertise with the lath was the stand-alone Microsoft BASIC-86, which Microsoft had developed on a ancestor of SCP's hardware. SCP capital to action the 8086 adaptation of CP/M that Digital Research had announced, but its absolution date was uncertain. This was not the aboriginal time Digital Research had lagged abaft accouterments developments; two years beforehand it had been apathetic to acclimate CP/M for fresh billowing deejay formats and adamantine disks. In April 1980 SCP assigned 24-year-old Tim Paterson to advance a acting for CP/M-86.

Paterson advised 86-DOS with an API that was accordant with bequest CP/M programs. At the aforementioned time he fabricated a cardinal of changes and enhancements to abode what he saw as CP/M's shortcomings. CP/M buried book arrangement advice in anamnesis for speed, but this appropriate a user to force an amend to a deejay afore removing it; if the user forgot, the deejay would be corrupt. Paterson took the safer but slower access of afterlight the deejay with anniversary operation. CP/M's PIP command, which affected files, accurate several appropriate book names that referred to accouterments accessories such as printers and advice ports. Paterson congenital these names into the operating arrangement as accessory files so that any affairs could use them. He gave his artful affairs the added automatic name COPY. Rather than implementing CP/M's book system, he acclimated BASIC-86's FAT filesystem to advance affinity with systems that SCP had already shipped.

IBM interest

In October 1980, IBM was developing what would become the aboriginal IBM Personal Computer. CP/M was by far the best accustomed operating arrangement in use at the time, and IBM acquainted it bare CP/M in adjustment to compete. IBM's assembly visited Digital Research and discussed licensing with Digital Research's licensing representative, Dorothy McEwen Kildall, who hesitated to assurance IBM's non-disclosure agreement. Although the NDA was after accepted, Digital Research would not acquire IBM's angle of $250,000 in barter for as abounding copies as IBM could sell, insisting on the accepted royalty-based plan.1 In after discussions amid IBM and Bill Gates, Gates mentioned the actuality of 86-DOS and IBM adumbrative Jack Sams told him to get a authorization for it.citation needed

Creation of PC-DOS

Microsoft purchased a all-encompassing authorization for 86-DOS from Seattle Computer Products in December 1980 for $25,000. In May 1981, it assassin Tim Paterson to anchorage the arrangement to the IBM-PC, which acclimated the slower and beneath big-ticket Intel 8088 processor and had its own specific ancestors of peripherals. IBM watched the developments daily, submitted over 300 change requests afore it accustomed the artefact and wrote the user chiral for it.

In July 1981, a ages afore the PC's release, Microsoft purchased all rights to 86-DOS from SCP for $50,000. It met IBM's capital criteria: it looked like CP/M, and it was accessible to acclimate absolute 8-bit CP/M programs to run beneath it, conspicuously acknowledgment to the TRANS command which would construe antecedent files from 8080 to 8086 apparatus instructions. Microsoft accountant 86-DOS to IBM, and it became PC-DOS 1.0. This authorization additionally acceptable Microsoft to advertise DOS to added companies, which it did. The accord was spectacularly successful, and SCP after claimed in cloister that Microsoft had buried its accord with IBM in adjustment to acquirement the operating arrangement cheaply. SCP ultimately accustomed a 1 actor dollar adjustment payment.

Intellectual property dispute

When Digital Analysis architect Gary Kildall advised PC-DOS and begin that it bifold CP/M's programming interface, he capital to sue IBM, which at the time claimed that PC-DOS was its own product. However, Digital Research's advocate did not accept that the accordant law was bright abundant to sue. Nonetheless, Kildall confronted IBM and abiding them to action CP/M-86 with the PC in barter for a absolution of liability.

Controversy has connected to beleaguer the affinity amid the two systems. Perhaps the best amazing affirmation comes from Jerry Pournelle, who claims that Kildall alone approved to him that DOS independent CP/M cipher by entering a command in DOS that displayed Kildall's name;2 as of 2006 Pournelle has not appear the command and cipher has appear advanced to approve his story. A 2004 book about Kildall says that he acclimated such an encrypted bulletin to authenticate that added manufacturers had affected CP/M, but does not say that he begin the bulletin in DOS;3 instead Kildall's account (a antecedent for the book) acicular to the acclaimed interface similarity. Paterson insists that the 86-DOScomputer application was his aboriginal work, and has denied apropos to or contrarily application CP/M cipher while autograph it.4 After the 2004 book appeared, he sued the authors and publishers for defamation.5 The cloister disqualified in arbitrary judgement that no aspersion had occurred, as the book's claims were opinions based on analysis or were not provably false.6

EDLIN

By 1982, back IBM asked Microsoft to absolution a adaptation of DOS that was accordant with a adamantine disk, PC-DOS 2.0 was an about complete carbon of DOS, so by March 1983, actual little of QDOS remained. The best constant aspect of 86-DOS was its archaic band editor, EDLIN, which remained the alone editor supplied with Microsoft versions of DOS until the June 1991 absolution of MS-DOS 5.0, which included a TUI-based editor, MS-DOS Editor based on QBasic. EDLIN can still be acclimated on abreast machines, back it is arranged with the emulated DOS ambiance up to Windows 7.