Question: Who founded the company which makes DECSYSTEM-20?

full_context: Document 1: Robert Adamson (software pioneer): Adamson graduated in Computer Science from the University of Utah in 1971. In 1981, he founded Software Generation Technology Corp. and wrote, one of the first fully interpretive languages for IBM mainframe computers. SGT was sold to Pansophic Systems where the product was renamed GENER/OL. and later acquired by Computer Associates
Document 2: Marc Andreessen: Marc Lowell Andreessen ( ; born July 9, 1971) is an American entrepreneur, investor, and software engineer. He is the co-author of Mosaic, the first widely used Web browser; co-founder of Netscape; and co-founder and general partner of Silicon Valley venture capital firm Andreessen Horowitz. He founded and later sold the software company Opsware to Hewlett-Packard. Andreessen is also a co-founder of Ning, a company that provides a platform for social networking websites. He sits on the board of directors of Facebook, eBay, and Hewlett Packard Enterprise, among others. Andreessen was one of six inductees in the World Wide Web Hall of Fame announced at the First International Conference on the World-Wide Web in 1994..
Document 3: VT100: The VT100 is a video terminal, introduced in August 1978 by Digital Equipment Corporation (DEC). It was one of the first terminals to support ANSI escape codes for cursor control and other tasks, and added a number of extended codes for special features like controlling the status lights on the keyboard. This led to rapid uptake of the ANSI standard, becoming the de facto standard for terminal emulators.
Document 4: PDP-7: The PDP-7 was a minicomputer produced by Digital Equipment Corporation as part of the PDP series. Introduced in 1964, shipped since 1965, it was the first to use their Flip-Chip technology. With a cost of , it was cheap but powerful by the standards of the time. The PDP-7 is the third of Digital's 18-bit machines, with essentially the same instruction set architecture as the PDP-4 and the PDP-9.
Document 5: DECSYSTEM-20: The DECSYSTEM-20 was a 36-bit Digital Equipment Corporation PDP-10 mainframe computer running the TOPS-20 operating system (products introduced in 1977).
Document 6: TRS-80: The TRS-80 Micro Computer System (TRS-80, later renamed the Model I to distinguish it from successors) is a desktop microcomputer launched in 1977 and sold by Tandy Corporation through their RadioShack stores. The name is an abbreviation of "Tandy/RadioShack, Z80 microprocessor". It is one of the earliest mass-produced and mass-marketed retail home computers.
Document 7: The Macintosh Way: The Macintosh Way was the first book written by former Apple evangelist Guy Kawasaki. Subtitled "the art of guerilla management", the book focused on technology marketing and management and includes many anecdotes culled from Kawasaki's experience during the early development of the Macintosh.
Document 8: Commodore VIC-20: The VIC - 20 (in Germany: VC - 20; In Japan: VIC - 1001) is an 8 - bit home computer that was sold by Commodore Business Machines. The VIC - 20 was announced in 1980, roughly three years after Commodore's first personal computer, the PET. The VIC - 20 was the first computer of any description to sell one million units.
Document 9: The Ultimate Entrepreneur: The biographical book, The ultimate entrepreneur: the story of Ken Olsen and Digital Equipment Corporation, chronicles the experiences of Ken Olsen racing to design minicomputers at the company of his own founding, Digital Equipment Corporation. At the time the book was published by two computer journal writers, Ken Olsen was competing with other Massachusetts computing companies such as Data General (founded by his former employee), Prime Computer, Wang Laboratories, Symbolics, Lotus Development Corporation, and Apollo Computer. While believing in the value of software, he did not believe in the value of software separate from hardware, and missed the opportunity to fund Lotus 1-2-3 or Visicalc. He also missed the importance of the personal computer, but his futuristic vision of the Client–server model helped to launch Ethernet.
Document 10: DECsystem: DECsystem was a line of server computers from Digital Equipment Corporation. They were based on MIPS architecture processors and ran DEC's version of the UNIX operating system, called Ultrix. They ranged in size from workstation-style desktop enclosures to large pedestal cabinets.
Document 11: DECmate: DECmate was the name of a series of PDP-8-compatible computers produced by the Digital Equipment Corporation in the late 1970s and early 1980s. All of the models used an Intersil 6100 (later known as the Harris 6100) or Harris 6120 (an improved Intersil 6100) microprocessor which emulated the 12-bit DEC PDP-8 CPU. They were text-only and used the OS/78 or OS/278 operating systems, which were extensions of OS/8 for the PDP-8. Aimed at the word processing market, they typically ran the WPS-8 word-processing program. Later models optionally had Intel 8080 or Z80 microprocessors which allowed them to run CP/M. The range was a development of the VT78 which was introduced in July 1977.
Document 12: Macintosh: As for Mac OS, System 7 was a 32-bit rewrite from Pascal to C++ that introduced virtual memory and improved the handling of color graphics, as well as memory addressing, networking, and co-operative multitasking. Also during this time, the Macintosh began to shed the "Snow White" design language, along with the expensive consulting fees they were paying to Frogdesign. Apple instead brought the design work in-house by establishing the Apple Industrial Design Group, becoming responsible for crafting a new look for all Apple products.
Document 13: Software Arts: Software Arts was a software company founded by Dan Bricklin and Bob Frankston in 1979 to develop VisiCalc, which was published by a separate company, Personal Software Inc., later named VisiCorp.
Document 14: Macintosh: Burrel's innovative design, which combined the low production cost of an Apple II with the computing power of Lisa's CPU, the Motorola 68K, received the attention of Steve Jobs, co-founder of Apple. Realizing that the Macintosh was more marketable than the Lisa, he began to focus his attention on the project. Raskin left the team in 1981 over a personality conflict with Jobs. Team member Andy Hertzfeld said that the final Macintosh design is closer to Jobs' ideas than Raskin's. After hearing of the pioneering GUI technology being developed at Xerox PARC, Jobs had negotiated a visit to see the Xerox Alto computer and its Smalltalk development tools in exchange for Apple stock options. The Lisa and Macintosh user interfaces were influenced by technology seen at Xerox PARC and were combined with the Macintosh group's own ideas. Jobs also commissioned industrial designer Hartmut Esslinger to work on the Macintosh line, resulting in the "Snow White" design language; although it came too late for the earliest Macs, it was implemented in most other mid- to late-1980s Apple computers. However, Jobs' leadership at the Macintosh project did not last; after an internal power struggle with new CEO John Sculley, Jobs resigned from Apple in 1985. He went on to found NeXT, another computer company targeting the education market, and did not return until 1997, when Apple acquired NeXT.
Document 15: Personal computer: 1974 saw the introduction of what is considered by many to be the first true ``personal computer '', the Altair 8800 created by Micro Instrumentation and Telemetry Systems (MITS). Based on the 8 - bit Intel 8080 Microprocessor, the Altair is widely recognized as the spark that ignited the microcomputer revolution as the first commercially successful personal computer. The computer bus designed for the Altair was to become a de facto standard in the form of the S - 100 bus, and the first programming language for the machine was Microsoft's founding product, Altair BASIC.
ground_truth: Ken Olsen
sub_queries: What company makes DECSYSTEM-20? Answer: Digital Equipment Corporation
Digital Equipment Corporation >> founded by Answer: Ken Olsen