Editing Digital Research (section)

==History==
{{pic|Digital Research logo 1974.svg|The original Digital Research logo, used from 1977 to the early 1980s}}

=== 1974–1979: Founding and incorporation ===
In 1972, [[Gary Kildall]], an instructor at the [[Naval Postgraduate School]] in [[Monterey, California]], began working at [[Intel]] as a [[consultant]] under the business name '''Microcomputer Applications Associates''' (MAA).<ref name="collegial"/> By 1974, he had developed Control Program/Monitor, or [[CP/M]], the first [[disk operating system]] for [[microcomputer]]s. 

In 1974 he incorporated as '''Intergalactic Digital Research''', with his wife handling the business side of the operation.<ref name="collegial"/> The company soon began operating under its shortened name Digital Research.<ref name="collegial"/> The company's operating systems, starting with [[CP/M]] for [[Intel 8080|8080]]/[[Zilog Z80|Z80]]-based microcomputers, were the [[de facto]] standard of their era. Digital Research's product suite included the original 8-bit CP/M and its various offshoots like [[MP/M]] (1979), a multi-tasking multi-user version of CP/M.{{Citation needed|date=August 2024}}

=== 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}}

===Graphics Environment Manager (1985)===

[[File:IBM PC GEM.jpg|240px|thumb|right|Graphics Environment Manager (GEM) Graphic User Interface (GUI) in 1985]]

In 1985 Digital Research also produced a microcomputer version of the [[Graphical Kernel System|GKS]] graphics standard (related to [[NAPLPS]]) called [[Graphics System Extension|GSX]], and later used this as the basis of their [[Graphics Environment Manager|GEM]] [[graphical user interface|GUI]]. Less known are their application programs, limited largely to the GSX-based DR DRAW and a small suite of GUI programs for GEM. After the development of GEM, Microsoft introduced [[Windows 1.0]].

Digital Research (and later its successor [[Caldera (company)|Caldera]]) accused Microsoft of announcing [[vaporware]] versions of MS-DOS to suppress sales of DR&nbsp;DOS.{{Citation needed|date=December 2014}}

===FlexOS, Concurrent DOS XM and Concurrent DOS 386 ===

[[Concurrent PC&nbsp;DOS]] later evolved into the modular [[FlexOS]] (1986). This exploited the greater memory addressing capability of the new [[CPU]] to provide a more flexible multi-tasking environment. There was a small but powerful set of system [[Application programming interface|API]]s, each with a synchronous and an asynchronous variant. [[Named pipe|Pipe]]s were supported, and all named resources could be aliased by setting [[environment variable]]s. This system was to enjoy enduring favour in point-of-sale systems.{{Citation needed|date=August 2024}}

Other successors of Concurrent DOS were [[Concurrent DOS XM]] (1986<!-- 1985? -->) and the 32-bit [[Concurrent DOS 386]] (1987).

=== 1990 and 1991: Multiuser DOS ===
{{pic|Digital Research logo 1990.svg|Logo of Digital Research used briefly toward the end of its independent existence, from March 1990<ref>{{cite journal | last=von Simson | first=Charles | date=March 26, 1990 | url=https://books.google.com/books?id=cAmo4wSwQJ0C&pg=PP37 | title=DRI adds graphics update | journal=Computerworld | publisher=IDG Publications | volume=XXIV | issue=13 | page=37 | via=Google Books}}</ref> to 1991}}
In 1991 DR presented [[Multiuser DOS]].  Digital Research's multi-user family of operating systems was sidelined with the previous single user operative systems.{{Citation needed|date=August 2024}}

In one [[beta release]] of [[Windows 3.1]], Microsoft included hidden code (later called the [[AARD code]]) that detected DR&nbsp;DOS and displayed a cryptic error message.<ref name="Schulman_1993_AARD"/><ref name="Schulman_1994_Undocumented-DOS"/>