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IBM ships the PC with Microsoft’s DOS

On 12 August 1981 IBM announced the IBM PC with Microsoft’s MS-DOS, a completed licensing instrument that made Gates’s firm the default PC operating-system vendor. US v. Microsoft 1998 is later monopoly litigation. In the causal graph this event strengthens the driver Industrial-Policy Activism.

Sources: [1][2]

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On 12 August 1981 IBM announced the IBM PC with Microsoft’s MS-DOS, a completed licensing instrument that made Gates’s firm the default PC operating-system vendor.

Context

IBM chose Microsoft over others. Neighbouring founding is 1975. Neighbouring Windows 95 is later GUI. He did not write IBM’s board minutes.

Founding 1975 is neighbouring. US v. Microsoft 1998 is later monopoly litigation.

Bill Gates was Microsoft CEO until January 2000, chairman until February 2014, then a technical adviser until 2020, and a Gates Foundation co-chair. That is not authorship of every Windows copy, every GAVI dose, or every IRS schedule. Melinda French Gates is a different person. Bill Clinton is PER-000772, a different person. A pledge is not a coverage rate. A docket is not a personality.

Why it matters

The path is digital-platform-power and industrial-policy: a completed default-OS licence is a platform instrument with later tying costs stored separately.

Who was responsible

Contribution type and responsibility level for each recorded actor — not sole-author shorthand.

  • Bill Gates

    Person

    Direct responsibility

    responsibility level 0.55 · verified

    He licensed DOS. IBM shipped the PC. Clone makers later copied the interface. Courts later sat.

What changed

Fact → Driver → Indicator. Relationship strength orders the paths; it is not the observed indicator movement.

    1. FactIBM ships the PC with Microsoft’s DOS
    2. strengthensDriverIndustrial-Policy Activism

    impact weight 0.3 · Effect from 12 August 1981 · verified

    A completed PC-standard OS is an industrial software-capacity instrument.

    1. FactIBM ships the PC with Microsoft’s DOS
    2. strengthensDriverDigital-Platform Power Concentration
    3. weakensIndicators (2)Having a say in government
    Worsening path

    impact weight 0.45 · Effect from 12 August 1981 · verified

    Becoming the IBM PC default OS is a completed platform-concentration instrument.

Evidence

The sources behind this fact and its verification state.

Verified2 sources on file
  1. 1.Reuters — IBM PC launches with Microsoft DOSReuters · High credibility · verified
  2. 2.IBM — IBM Personal Computer announcement, 12 August 1981IBM · High credibility · verified
What the sources establish

IBM carries the official instrument or communique. Reuters records the same dated act independently.

Established: 12 August 1981 IBM PC with MS-DOS, independently reported.

Not established: that competition vanished that day, or a unique later consumer-surplus coefficient.

IBM shipped the PC. Clone makers later copied the interface. Courts later sat.. A later repeal, court stay, or successor order would be a different Fact with a different date. That pair identifies IBM ships the PC with Microsoft’s DOS, not a later speech about IBM ships the PC with Microsoft’s DOS.

Co-authors and later implementers named in Context remain on the file. If a later repeal, stay, or successor instrument exists, it needs its own date and its own row. The contribution described on this Person row is limited to He licensed DOS. IBM shipped the PC. Clone makers later copied the interface. Courts later sat. That limit is the alternative to treating office-holding as authorship of every later series.

Causal path

How this event connects to drivers and indicators in the graph.

  1. ActorBill Gates
  2. contributed toFactIBM ships the PC with Microsoft’s DOS
  3. strengthensDrivers (2)Industrial-Policy Activism

Cite this page

Factrail. (2026). IBM ships the PC with Microsoft’s DOS. Factrail. https://factrail.ai/facts/ms-ibm-dos-1981

https://factrail.ai/facts/ms-ibm-dos-1981

Accessed 15 October 2026.

By the Factrail desk · Method: how we source and score · Last reviewed

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