86-DOS (1981) 9 DOS

86-DOS is a "quick and dirty" operating system clone of CP/M created by Seattle Computer Products for their 8086 S-100 systems. It was later bought by Microsoft and used as the basis for IBM PC-DOS and MS-DOS

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IBM Macro Assembler (1981) 2 DOS

IBM Macro Assembler is an IBM OEM rebranded release of Microsoft Macro Assembler, and was intended only for use with the IBM PC.

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IBM Pascal Compiler (1981) 0 DOS

The IBM PASCAL Compiler, is a tool that compiles Pascal source code in to binaries for IBM PC-DOS. The IBM PASCAL Compiler is an IBM OEM version of the Microsoft Pascal Compiler.

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IBM PC Diagnostics (1981) 7 DOS

These are the diagnostic disks (and cassette) provided by IBM with their PC computers. They are used to verify the basic functionality of the hardware. These are only intended for use with genuine IBM computers.

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IBM Typing Tutor (1981) 0 Education DOS Other

IBM Typing Tutor is an educational program sold by IBM alongside their original IBM PC. The software itself was licensed from Microsoft, and is notable as being one of only two known commercial programs that were sold for the IBM PC on cassette tape. (The other being IBM PC Diagnostics )

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Microsoft Adventure (1981) 1 DOS

Microsoft Adventure is a text based interactive fiction game based on "Colossal Cave Adventure" by Will Crowther. It was one of the first games for the IBM PC.

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Microsoft BASIC (1981) 50 DOS CPM

Although Microsoft did not invent BASIC, their founding product was a BASIC interpreter for the Altair computer. The descendants below includes Microsoft's BASIC-80 (MBASIC), BASIC-86 (pre-GWBasic), BASIC for Mac, BASIC Compiler 86/88, Basic Compiler for Mac, and Professional Development System 7.x. IBM Personal Computer Basic Compiler, GW-BASIC, QuickBasic, and Visual Basic are listed separately.

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Microsoft Macro Assembler (1981) 20 DOS

The Microsoft Macro Assembler (MASM) is an x86 assembler that uses the Intel syntax for MS-DOS and Microsoft Windows. For a time, it competed with Borland Turbo Assembler. IBM re-branded early versions under the name IBM Macro Assembler. Later versions were bundled with Microsoft Visual Studio.

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Microsoft Pascal (1981) 5 DOS

The Microsoft Pascal Compiler is Microsoft's implementation of the ISO Pascal language for DOS, Xenix, and OS/2. It was among Microsoft's early language products provided for DOS. It was superseded by Microsoft QuickPascal. The Microsoft Pascal Compiler was licensed to IBM, who sold it as the IBM Pascal Compiler.

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MS-DOS (1981) 685 DOS

Originally 86-DOS, written by Tim Paterson of Seattle Computer Products, DOS was a rough clone of CP/M for 8086 based hardware. Microsoft purchased it and licensed it to IBM for use with Microsoft's IBM PC language products. In 1982, Microsoft began licensing DOS to other OEMs that ported it to their custom x86 hardware and IBM PC clones.

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PC-DOS (1981) 64 DOS

IBM PC-DOS was an IBM branded version of MS-DOS licensed from Microsoft for use on the IBM PC system. Versions of PC-DOS paralleled that of MS-DOS up until version 6.1, where PC-DOS was independently maintained by IBM up until 7.1, the last version. Although not the only OS available for the IBM PC when it came out, it quickly became popular due to its low cost in comparison to the others. Its direct competitors on the PC at the time were CP/M-86 and UCSD p-System. The major differences between PC-DOS and MS-DOS were only in terms of driver support and built in programs until version 6.1 where development diverged.

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