Editing Digital Research (section)

=== 1980–1990:  CP/M, CP/M-86 ===

After Microsoft presented [[MS-DOS]] that was based on [[CP/M]], Digital Research released [[CP/M-86]], which was the first [[16-bit computing|16-bit system]] (1981, adapted to the IBM PC in early 1982), which was meant as direct competitor to [[MS-DOS]]. There followed the multi-tasking [[MP/M-86]] (1981), and [[Concurrent CP/M]] (1982), a single-user version featuring virtual consoles from which applications could be launched to run concurrently.<ref name="Kildall_1982_8-bit"/> The company's documentation had a poor reputation, with [[Jerry Pournelle]] in 1982 describing it as seemingly "encrypted and translated into Swahili".<ref name="pournelle198205">{{Cite magazine |last=Pournelle |first=Jerry |date=May 1982 |title=Supercalc, Spelling Programs, BASIC Compilers, and Home-Grown Accounting |url=https://archive.org/details/eu_BYTE-1982-05_OCR/page/n227/mode/1up?view=theater |access-date=2024-12-28 |magazine=BYTE |page=226}}</ref> and ''[[InfoWorld]]'' calling its CP/M manuals incomplete, incomprehensible, and poorly indexed.<ref name = "InfoWorld 1981">{{cite journal | last = Hogan | first = Thom| title = Microsoft's Z80 SoftCard | journal = InfoWorld | volume = 3 | issue = 4 | pages =20–21 | publisher = Popular Computing| date = March 3, 1981| url = https://books.google.com/books?id=jT4EAAAAMBAJ&pg=PT14 | issn = 0199-6649}}</ref>

In May 1983 Digital Research announced that it would offer PC&nbsp;DOS versions of all of its languages and utilities.<ref name="hughes198307"/> It remained influential, with {{currency|amount=45|code=USD|fmt=gaps|linked=yes}}&nbsp;million in 1983 sales making Digital Research the fourth-largest microcomputer software company.<ref name="caruso19840402"/> Admitting that it had "lost" the 8088 software market but hoped to succeed with the [[Intel 80286]] and [[Motorola 68000]], by 1984 the company formed a partnership with [[AT&T Corporation]] to develop software for [[Unix System V]] and sell its own and third-party products in retail stores.<ref name="shea19840220"/> Pournelle warned later that year, however, that "Many people of stature seem to have left or are leaving Digital Research. DR had better get its act together."<ref name="byte198503"/>

In a parallel development Digital Research also produced a selection of [[programming language]] [[compiler]]s and [[interpreter (computing)|interpreter]]s for their OS-supported platforms, including [[C (programming language)|C]], [[Pascal (programming language)|Pascal]], [[COBOL]], [[FORTRAN]], [[PL/I]], [[PL/M]], [[CBASIC]], [[BASIC]], and [[Logo (programming language)|Logo]].

Digital Research developed [[CP/M-86]] as an alternative to MS-DOS and it was made available through IBM in early 1982. The company later created an MS-DOS clone with advanced features called [[DR&nbsp;DOS]], which pressured Microsoft to further improve its own DOS.

At the time the [[IBM Personal Computer]] was being developed, Digital Research's CP/M was the dominant operating system of the day. In 1980, IBM asked Digital Research to supply a version of CP/M written for the [[Intel 8086]] microprocessor as the standard operating system for the PC, which would use the code-compatible [[Intel 8088]] chip. Digital Research, uneasy about the conditions related to making such an agreement with IBM, refused.{{Citation needed|date=August 2024}}

[[Microsoft]] seized this opportunity to supply an OS, in addition to other software (e.g., [[BASIC]]) for the new IBM PC. When the IBM PC arrived in late 1981, it came with [[PC&nbsp;DOS]], an OEM version of [[MS-DOS]], which was developed from [[86-DOS]], which Microsoft had acquired for this purpose. By mid-1982, [[MS-DOS]] was also marketed for use in hardware-compatible non-IBM computers. This one decision resulted in Microsoft becoming the leading name in computer software.

This story is detailed from the point of view of Microsoft and IBM in the [[PBS]] series ''[[Triumph of the Nerds]]'',<ref name="Triumph"/> and from the point of view of Gary Kildall's friends and coworkers in ''[[The Computer Chronicles]]''.<ref name="Chronicles"/>

The competition between MS-DOS and DR&nbsp;DOS is one of the more controversial chapters of microcomputer history. Microsoft offered better licensing terms to any computer manufacturer that committed to selling MS-DOS with every system they shipped, making it uneconomical for them to offer systems with another OS, since the manufacturer would still be required to pay a license fee to Microsoft for that system. This practice led to a US Department of Justice investigation, resulting in a decision in 1994 that barred Microsoft from "per-processor" licensing.<ref name="Corcoran_1994"/>

Successive revisions of Concurrent CP/M incorporated [[PC-MODE|MS-DOS API emulation]] (since 1983), which gradually added more support for DOS applications and the [[FAT file system]]. These versions were named [[Concurrent DOS]] (1984), with [[Concurrent PC&nbsp;DOS]] (1984) being the version adapted to run on IBM compatible PCs.{{Citation needed|date=August 2024}}

In 1985, soon after the introduction of the [[80286]]-based [[IBM PC/AT]], Digital Research introduced a real-time system, initially called [[Concurrent DOS 286]].

Other single-user operative systems were launched: [[DOS Plus]] (1985) and [[DR&nbsp;DOS]] (1988). The latter system was marketed as a direct MS-DOS/PC DOS replacement with added functionality. In order to achieve this, it gave up built-in support to run CP/M applications and was changed to use DOS-compatible internal structures. It became a successful product line in itself.{{Citation needed|date=August 2024}}