Data General
Industry | Computer |
---|---|
Fate | Acquired |
Successor | EMC Corporation |
Founded | 1968 |
Defunct | 1999 |
Headquarters | Westborough, Massachusetts |
Products | Minicomputers, disk arrays |
Data General was one of the first minicomputer firms from the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation. Their first product, the Data General Nova, was a 16-bit minicomputer. This used their own operating system, Data General RDOS (DG/RDOS), and in conjunction with programming languages like "Data General Business Basic" they provided a multi-user operating system with record locking and built-in databases far ahead of many contemporary systems. The Nova was followed by the Supernova and Eclipse product lines, all of which were used in many applications for the next two decades. The company employed an original equipment manufacturer (OEM) sales strategy to sell to third parties who incorporated Data General computers into the OEM's specific product lines. A series of missteps in the 1980s, including missing the advance of microcomputers despite the launch of the microNOVA in 1977, and the Data General-One portable computer in 1984, led to a decline in the company's market share. The company did continue into the 1990s, however, and was eventually acquired by EMC Corporation in 2002.
History
Origin, founding and early years: Nova and SuperNova
Data General (DG) was founded by several engineers from Digital Equipment Corporation who were frustrated with DEC's management and left to form their own company. The chief founders were Edson de Castro,[1] Henry Burkhardt III, and Richard Sogge of Digital Equipment (DEC), and Herbert Richman of Fairchild Semiconductor.[2] The company was founded in Hudson, Massachusetts in 1968.[3]
Edson de Castro was the chief engineer in charge of the PDP-8, DEC's line of inexpensive computers that created the minicomputer market.[1] It was designed specifically to be used in laboratory equipment settings; as the technology improved, it was reduced in size to fit into a 19-inch rack. Many PDP-8s still operated decades later. De Castro, convinced he could do one better, began work on his new 16-bit design.
The result was released in 1969 as the Nova. Designed to be rack-mounted similarly to the later PDP-8 machines, it was smaller in height and ran considerably faster. Announced as "the best small computer in the world",[4] the Nova quickly gained a following, especially in scientific and educational markets,[1] and made the company flush with cash, although Data General had to defend itself from misappropriation of its trade secrets.[5] With the initial success of the Nova, Data General went public in the fall of 1969. The Nova, like the PDP-8, used a simple accumulator-based architecture. It lacked general registers and the stack-pointer functionality of the more advanced PDP-11, as did competing products, such as the HP 1000; compilers used hardware-based memory locations in lieu of a stack pointer.
The original Nova was soon followed by the faster SuperNova, then later by several minor versions based on the SuperNova core. The last major version, the Nova 4, was released in 1978. During this period the Nova generated 20% annual growth rates for the company, becoming a star in the business community and generating US$ 100 million in sales in 1975.[3] In 1977, DG launched a 16-bit microcomputer called the microNOVA to poor commercial success.
The Nova series plays a very important role as instruction-set inspiration to Charles P. Thacker and others at Xerox PARC during their construction of the Xerox Alto.[6]
Late 1970s to late 1980s: crisis and a short term solution
In 1974, the Nova was supplanted by their upscale 16-bit machine, the Eclipse. Based on many of the same concepts as the Nova, it included support for virtual memory and multitasking more suitable to the small office environment. For this reason, the Eclipse was packaged differently, in a floor-standing case resembling a small refrigerator.
Production problems with the Eclipse led to a rash of lawsuits in the late 1970s. Newer versions of the machine were pre-ordered by many of DG's customers, which were never delivered. Many customers sued Data General after more than a year of waiting, charging the company with breach of contract, while others simply canceled their orders and went elsewhere. The Eclipse was originally intended to replace the Nova outright, evidenced by the fact that the Nova 3 series, released at the same time and utilizing virtually the same internal architecture as the Eclipse, was phased out the next year. Strong demand continued for the Nova series, resulting in the Nova 4, perhaps as a result of the continuing problems with the Eclipse.
In 1976, Digital announced the VAX series, their first 32-bit minicomputer line, described as "super-minis". The first products would not ship until February 1978. This coincided with the aging 16-bit products (notably the PDP-11), which were coming due for replacement. Data General immediately launched their own 32-bit effort in 1976 to build what they called the "world's best 32-bit machine", known internally as the "Fountainhead Project". When Digital's VAX-11/780 was shipped in February 1978, however, Fountainhead was not yet ready to deliver a machine, due mainly to problems in project management. DG's customers left quickly for the VAX world.
Soon afterwards, Data General launched a hyperactive 32-bit effort based on the Eclipse known as the "Eagle Project". By late 1979, it became clear that Eagle would deliver before Fountainhead, igniting an intense turf war within the company for constantly shrinking project funds. In the meantime, customers abandoned Data General in droves, driven not only by the delivery problems with the original Eclipse (including very serious quality control and customer service problems), but also the power and versatility of Digital's new VAX line.
The Eagle Project was the subject of Tracy Kidder's Pulitzer prize-winning book, The Soul of a New Machine, making the MV line the best-documented computer project in recent history. The MV/8000 was a straightforward, 32-bit extension of the Nova-based Eclipse, yet still lacking a hardware stack pointer adopted by most new computers since the late 1960s. It was backwards-compatible with 16-bit Eclipse applications, used the same command-line interpreter as the 16-bit Eclipse, and achieved improved 32-bit performance over the VAX 11/780 while using fewer components.
MV series
In 1980, the Eclipse MV/8000 was released. The MV systems generated an almost miraculous turnaround for Data General. Through the early 1980s sales picked up, and by 1984 the company had over a billion dollars in annual sales.
One of Data General's significant customers at this time was the United States Forest Service, which starting in the mid-1980s used DG systems installed at all levels from headquarters in Washington, D.C. down to individual ranger stations and fire command posts. This required equipment of high reliability and generally rugged construction that could be deployed in a wide range of places, often to be maintained and used by people with no computer background at all. The intent was to create new kinds of functional integration in an agency that had long prized its decentralized structure. Despite some tensions, the implementation was effective and the overall effects on the agency notably positive. The introduction, implementation, and effects of the DG systems in USFS were documented in a series of evaluative reports prepared in the late 1980s by the RAND Corporation.
The MV series came in various iterations, from the MV/2000 (later MV/2500), MV/4000, MV/10000, MV/15000, MV/20000, MV/30000, MV/40000 and ultimately concluded with the MV/60000HA minicomputer. The MV/60000HA was intended to be a High Availability system, with many components duplicated to eliminate the single point of failure. Yet, there were failures among the system's many daughter boards, back-plane, and mid-plane. DG technicians were kept quite busy replacing boards and many blamed poor quality control at the DG factory in Mexico where they were made and refurbished.
In retrospect, the nicely performing MV series was too little, too late. At a time when DG invested its last dollar into the dying minicomputer segment, the microcomputer was rapidly making inroads to the lower-end market segment, and the introduction of the first workstations wiped out all 16-bit machines, once DG's best customer segment. While the MV series did stop the erosion of DG's customer base, this now smaller base was no longer large enough to allow DG to develop their next generation. DG had also changed their marketing to focus on direct sales to Fortune 100 companies and thus alienated many resellers.
Software
Data General developed operating systems for its hardware: DOS and RDOS for the Nova, RDOS and AOS for the 16-bit Eclipse C, M, and S lines, AOS/VS and AOS/VS II for the Eclipse MV line, and a modified version of UNIX System V called DG/UX for the Eclipse MV and AViiON machines. The AOS/VS software was the most commonly used DG software product and included CLI (Command Line Interpreter) allowing for complex scripting, DUMP/LOAD, and other custom components.
Related system software also in common use at the time included such packages as X.25, Xodiac, and TCP/IP for networking, Fortran, COBOL, RPG, PL/I, C and Data General Business Basic for programming, INFOS II and DG/DBMS for databases, and the nascent relational database software DG/SQL.
Data General also offered an office automation suite named Comprehensive Electronic Office (CEO), which included a mail system, a calendar, a folder-based document store, a word processor, a spreadsheet processor, and other assorted tools. All were crude by today's standards, but were revolutionary for their time.
Some software development from the early 1970s is notable. PLN (created by Robert Nichols) was the host language for a number of DG products, making them easier to develop, enhance, and maintain than macro assembler equivalents. PLN smacked of a micro-subset of PL/I, in sharp contrast to other languages of the time, such as BLISS. The RPG product (shipped in 1976) incorporated a language runtime system implemented as a virtual machine which executed pre-compiled code as sequences of PLN statements and Eclipse commercial instruction routines. The latter provided microcode acceleration of arithmetic and conversion operations for a wide range of now-arcane data types such as overpunch characters. The DG Easy product, a portable application platform developed by Nichols and others from 1975 to 1979 but never marketed, had roots easily traceable back to the RPG VM created by Stephen Schleimer.
Also notable were several commercial software products developed in the mid to late 1970s in conjunction with the commercial computers. These products were popular with business customers because of their screen design feature and other ease-of-use features. The first product was IDEA (Interactive Data Entry/Access), which consisted of a screen design tool (IFMT), TP Controller (IMON), and a program development language (IFPL). The second was the CS40 line of products, which used COBOL and their own ISAM data manager. The COBOL variant used included an added screen section. Both of these products were a major departure from the transaction monitors of the day which did not have a screen design tool and used subroutine calls from COBOL to handle the screen. IDEA was identified by some market watchers as a precursor to fourth-generation programming languages.
The original IDEA ran on RDOS and would support up to 24 users in an RDOS Partition. Each user could use the same or a different program. Eventually, IDEA ran on every commercial hardware product from the MicroNova (4 users) to the MV series under AOS/VS, the same IDEA program running all those systems. The CS40 (the first of this line) was a package system which supported four terminal users, each running a different COBOL program. These products also led to the development of a third product, TPMS (Transaction Processing Monitoring System (announced in 1980)) which could capably run a large number of COBOL or PL/I users with a smaller number of processors, a major resource and performance advantage on AOS and AOS/VS systems. TPMS had the same screen design tool as the earlier products. TPMS used defined subroutine calls for screen functions from COBOL or PL/I, which in some users' eyes made it more difficult to use. However, this product was aimed at the professional IS Programmers as were its competitors—IBM’s CICS and DEC’s TRAX. As with IDEA, TPMS used INFOS for information management and DG/DBMS for database management.
Xodiac
Data General's proprietary networking architecture was known as Xodiac.[7]:247 Data General software packages supporting Xodiac included Comprehensive Electronic Office (CEO).[7]:247 In 1987, Data General announced its intention to replace Xodiac with the Open Systems Interconnection (OSI) protocol suite.[8]
Dasher terminals
Data General produced a full range of peripherals, sometimes by rebadging printers for example, but Data General's own series of CRT-based and hard-copy terminals, were high quality and featured a generous number of function keys, each with the ability to send different codes, with any combination of control and shift keys, which influenced WordPerfect design. The model 6053 Dasher 2 featured an easily tilted screen, but used many integrated circuits; the smaller, lighter D100, D200 and eventually the D210 replaced it as the basic user terminal, while graphics models such as the D460 (with ANSI X3.64 compatibility) occupied the very high end of the range. Terminal emulators for the D2/D3/D100/D200/D210 (and some features of the D450/460) do exist, including the Freeware 1993 DOS program in D460.zip.
Most Data General software was written specifically for their own terminals (or the terminal emulation built into the Desktop Generation DG10, but the Data General One built-in terminal emulator is not often suitable), although software using Data General Business BASIC could be more flexible in terminal handling, because logging into a Business BASIC system would initiate a process whereby the terminal type would (usually) be auto-detected.
Data General-One
Data General's introduction of the Data General-One (DG-1) in 1984 is one of the few cases of a minicomputer company introducing a truly breakthrough PC product. Considered genuinely "portable", rather than "luggable", as alternatives often were called, it was a nine-pound battery-powered MS-DOS machine equipped with dual 3½-inch diskettes, a 79-key full-stroke keyboard, 128K to 512K of RAM, and a monochrome liquid-crystal display (LCD) screen capable of either the full-sized standard 80×25 characters or full CGA graphics (640×200). The DG-1 was considered a modest advance over similar Osborne-Kaypro systems overall.
Despite the memorable advertisements ("The first computer able to fit inside the IBM PC"), the DG-1 was, however, only a modest success. One problem was the use of 3½" diskettes, which were slightly ahead of their time; popular software titles were not available in 3½-inch format, and this was a serious issue, because then-common diskette copy-protection schemes made it difficult for users to copy the software into that format. Additionally, the diskettes used a proprietary formatting scheme not compatible with products from other companies. Although Creative Computing termed the price of US$2895 "competitive", it was a very expensive system and optional additions, such as expanded RAM and an external 5¼-inch floppy drive, drove the price considerably higher. The 4.0 MHz CPU speed was fractionally slower than the then-current 4.77 MHz IBM PC. The Achilles' heel, however, was the LCD, which was not backlit, had poor contrast, and was frequently accused of serving better as a mirror than as a display screen. Usable outdoors or in bright offices only, a flashlight, it was joked, was often necessary to see the contents of the screen.
Another product killer was the incompatible serial port chip, an Intel 82C51, which was used to conserve power, instead of the 8250 used in the IBM PC. For a portable system, this was a critical flaw: PC programs that used the serial port wouldn't run on the DG-1 due to the non-standard register arrangement within the 82C51.
An updated version of the DG-1 appeared later with a much improved electroluminescent screen. However, the light-producing display could be washed out by bright sunlight. Additionally, the new screen was power hungry and consumed so much power that the battery option was removed, thereby causing the DG-1 to lose its status as a true portable.
Desktop Generation
Data General also brought out a small-footprint "Desktop Generation" range, starting with the DG10 that included both Data General and Intel CPUs in a patented closely coupled arrangement, able to run MS-DOS or CP/M-86 concurrently with DG/RDOS, with each benefiting from the hardware acceleration given by other CPU as a co-processor that would handle (for instance) screen graphics or disk operations concurrently. Other members of the Desktop Generation range, the DG20 and DG30, were aimed more at traditional commercial environments, such as multi-user COBOL systems, replacing refrigerator-sized minicomputers with toaster-sized modular microcomputers based around the microECLIPSE CPUs and some of the technology developed for the microNOVA-based "Micro Products" range such as the MP/100 and MP/200 that had struggled to find a market niche. The Single-processor version of the DG10, the DG10SP, was the entry-level machine with, like the DG20 and 30, no ability to run Intel software. Despite having some good features and having less direct competition from the flood of cheap PC compatibles, the Desktop Generation range also struggled, partly because they offered an economical way of running what was essentially "legacy software" while the future was clearly either slightly cheaper Personal Computers or slightly more expensive "super minicomputers" such as the MV and VAX computers.
Lock-in or no lock-in?
Throughout the 1980s, the computer market had evolved dramatically. Large installations in the past typically ran custom-developed software for a small range of tasks. For instance, IBM often delivered machines whose only purpose was to generate accounting data for a single company, running software tailored for that company alone.
By the mid-1980s, the introduction of new software development methods and the rapid acceptance of the SQL database was changing the way such software was developed. Now developers typically linked together several pieces of existing software, as opposed to developing everything from scratch. In this market, the question of which machine was the "best" changed; it was no longer the machine with the best price–performance ratio or service contracts, but the one that ran all of the third-party software you intended to use.
This change forced changes on the hardware vendors as well. Formerly, almost all computer companies attempted to make their machines different enough that when their customers sought a more powerful machine, it was often cheaper to buy another from the same company. This was known as "vendor lock-in", which helped guarantee future sales, even though the customers detested it.
With the change in software development, combined with new generations of commodity processors that could match the performance of low-end minicomputers, lock-in was no longer working. When forced to make a decision, it was often cheaper for the users to simply throw out all of their existing machinery and buy a microcomputer product instead. If this was not the case at present, it certainly appeared it would be within a generation or two of Moore's law.
In 1988, two company directors put together a report showing that if the company were to continue existing in the future, DG would have to either invest heavily in software to compete with new applications being delivered by IBM and DEC on their machines, or alternately exit the proprietary hardware business entirely.
Thomas West's report outlined these changes in the marketplace, and suggested that the customer was going to win the fight over lock-in. They also outlined a different solution: Instead of trying to compete against the much larger IBM and DEC, they suggested that since the user no longer cared about the hardware as much as software, DG could deliver the best "commodity" machines instead.
"Specifically", the report stated, "DG should examine the Unix market, where all of the needed software already exists, and see if DG can provide compelling Unix solutions." Now the customer could run any software they wished as long as it ran on Unix, and by the early 1990s, everything did. As long as DG's machines outperformed the competition, their customers would return, because they liked the machines, not because they were forced; lock-in was over.
AViiON
De Castro agreed with the report, and future generations of the MV series were terminated. Instead, DG released a technically interesting series of Unix servers known as the AViiON. The name "AViiON" was a reversed play on the name of DG's first product, Nova, implying "Nova II". In an effort to keep costs down, the AViiON was originally designed and shipped with the Motorola 88000 RISC processor. The AViiON machines supported multi-processing, later evolving into NUMA-based systems, allowing the machines to scale upwards in performance by adding additional processors.
CLARiiON
An important element in all enterprise computer systems is high speed storage. At the time AViiON came to market, commodity hard disk drives could not offer the sort of performance needed for data center use. DG attacked this problem in the same fashion as the processor issue, by running a large number of drives in parallel. The overall performance was greatly improved and the resulting innovation was marketed originally as the HADA (High Availability Disk Array) and then later as the CLARiiON line. The CLARiiON arrays, which offered SCSI RAID in various capacities, offered a great price/performance and platform flexibility over competing solutions.
The CLARiiON line was marketed not only to AViiON and Data General MV series customers, but also to customers running servers from other vendors such as Sun Microsystems, Hewlett Packard and Silicon Graphics. Data General also embarked on a plan to hire storage sales specialists and to challenge EMC's Symmetrix in the wider market.
Joint venture with Soviet company
On December 12, 1989, DG and Soviet Union software developer NPO Parma announced Perekat, the first joint venture between an American computer company and a Soviet company. DG would provide hardware and NPO Parma the software, and Austrian companies Voest Alpine Industrieanlagenbau GmbH and their marketing group Voest Alpine Vertriebe would build the plant.[9]
Final downturn and EMC takeover
Despite Data General's betting the AViiON farm on the Motorola 88000, Motorola decided to end production of that line. The 88000 had never been very successful, and DG was the only major customer. When Apple Computer and IBM proposed their joint solution based on POWER architecture, the PowerPC, Motorola picked up the manufacturing contract and killed the 88000.
DG quickly responded and introduced new models of the AViiON series based on a true commodity processor, the Intel x86 series. By this time a number of other vendors, notably Sequent Computer Systems, were also introducing similar machines. The lack of lock-in now came back to haunt DG, and the rapid commoditization of the Unix market led to shrinking sales. DG did begin a minor shift toward the service industry, training their technicians for the role of implementing a spate of new x86-based servers and the new Microsoft Windows NT domain-driven, small server world. This never developed enough to offset the loss of high margin server business however.
Data General also targeted the explosion of the internet in the latter 1990s with the formation of the THiiN Line business unit, led by Tom West, which had a focus on creation and sale of so-called "internet appliances". The product developed was called the SiteStak web server appliance and was designed as an inexpensive website hosting product.
CLARiiON did better after finding a large niche for Unix storage systems, and its sales were still strong enough to make DG a takeover target. EMC Corporation, a major data storage company, announced that they would buy Data General and its assets in January 2002 for $1.1 Billion or $19.58 a share.[10] Although details of the acquisition specified that EMC had to take the entire company, and not just the storage line, EMC quickly ended all development and production of DG computer hardware and parts, effectively ending Data General's presence in the segment. The maintenance business was sold to a third party, who also acquired all of DG's remaining hardware components for spare parts sales to old DG customers. The CLARiiON line continued to be a major player in the market, and was marketed under that name until January 2012.[11] CLARiiON was also widely sold by DELL through a worldwide OEM deal with EMC. The Clariion and Celerra storage products evolved into EMC's unified storage platform, the VNX platform.
Data General would be only one of many New England based computer companies, including the original Digital Equipment Corporation that collapsed or were sold to larger companies after the 1980s. On the Internet, even the old Data General domain (dg.com), which contained a few EMC webpages that only mentioned the latter company in passing, was sold to the Dollar General discount department store chain in October 2009.
Alumni
- DJ Delorie designed PC motherboards and BIOS code for Data General for four years. He authored DJGPP, and currently works for Red Hat on GCC.[12]
- Peter Darnell was a developer of DG/L and went on to develop C compilers for Unix and Windows. He wrote a book on C and is the developer of the visual programming language VisSim by Visual Solutions.
- Jean-Louis Gassée was with Data General in France before moving to Apple Computer and Be Inc.
- Ronald H. Gruner was head of Data General's Fountainhead project which competed with the MV/8000. After leaving DG he co-founded Alliant Computer Systems along with former DG colleague Craig Mundie.[13]
- David C. Mahoney founded Banyan Systems and pioneered Local Area network technologies in late 1980s along with Novell.
- Craig Mundie was a software developer at Data General. He is now Chief Technologist at Microsoft.
- Mike Nash worked on AOS/VS kernel virtual terminal services for PCI and was a Corporate Vice President at Microsoft and is currently Vice President, Consumer PC & Solutions, Printing and Personal Systems Group, Hewlett-Packard Company.[14][15]
- Ray Ozzie was a software developer at Data General. He subsequently worked for Software Arts, Lotus Development, Iris Associates, and Groove Networks. Groove Networks was acquired by Microsoft in 2005, and Ozzie replaced Bill Gates as chief software architect at Microsoft from 2006 until 2010.
- Jonathan Sachs co-founded Lotus Development where he authored 1-2-3.
- Jit Saxena founded Netezza, search technology company
- Christopher Stone founded Object Management Group (created CORBA) and became vice chairman/CEO of Novell.
- Asher Waldfogel was a software engineer in Special Systems who later went on to found Redback Networks, Tollbridge Technologies and PeakStream.[16]
- Steve Wallach Cofounder of Convex computer company.
- Joshua Weiss was a manager in the Xodiac Networking group who went on to co-found Prominet (bought by Lucent Technologies) and later was founder and CEO of Nauticus (bought by Sun Microsystems).
- Tom West was the manager for the MV/8000 and later projects. He was the main protagonist of the Pulitzer Prize winning non-fiction book The Soul of a New Machine.[17]
- Edward Zander was product marketing manager at Data General before his positions at Apollo Computer, Sun Microsystems and Motorola as CEO.
Notes
- 1 2 3 "Computer History Museum - Data General Corporation (DG) - 840 the loaded nova". www.computerhistory.org. Retrieved 27 July 2016.
- ↑ White, Donald (July 28, 1968). "The Data General Corp., New firm, new line of computers". The Boston Globe. p. B-25.
- 1 2 "The Business That Time Forgot Data General is gone. But does that make its founder a failure? - April 1, 2003". money.cnn.com. Retrieved 27 July 2016.
- ↑ "Nova brochure" (PDF). 1968. Retrieved 12 August 2014.
- ↑ Data General Corp. v. Digital Computer Controls, Inc.
- ↑ Charles P. Thacker; Edward M. McCreight (December 1974). "Alto: A Personal Computer System" (PDF). p. 13.
- 1 2 Eriksen, Denise C. (1984). "A synopsis of present day practices concerning decision support systems". Information & Management. 7 (5): 243–252. ISSN 0378-7206. doi:10.1016/0378-7206(84)90048-X.
- ↑ King, Julia (14 September 1987), "Open Systems: How open are they?", Network World, IDG Network World Inc, 4 (37), pp. 1, 35–38, 40, ISSN 0887-7661
- ↑ Donker, Peter P. (13 December 1989). "DG to Enter Soviet Market 'Foothold' in Untapped Area". Worcester Telegram & Gazette.
- ↑ "EMC buys Data General for $1.1 billion". CNET. Retrieved 27 July 2016.
- ↑ Connor, Deni (23 August 2011). "EMC Discontinues Clariion, Celerra Storage Lines". InformationWeek. Retrieved 23 January 2012.
- ↑ "dj delorie".
- ↑ "Ron Gruner: Geek of the Week - Simple Talk". 25 July 2012.
- ↑ Microsoft PressPass - Microsoft Executives and Images
- ↑ http://www.hp.com/hpinfo/newsroom/press_kits/bios/Mike_Nash_bio.pdf
- ↑ http://www2.cla.umn.edu/clatoday/W2003/waldfogel.html Archived March 10, 2008, at the Wayback Machine.
- ↑ Kidder, Tracy (1981) [1997]. The Soul of a New Machine. Modern Library. ISBN 978-0-316-49170-9.
References
- Kidder, Tracy (1981). The Soul of a New Machine. Little, Brown and Company. Reprint edition July 1997 by Modern Library. ISBN 0-679-60261-5.
External links
- Official Website, circa 1996
- SimuLogics ("dedicated to preserving the history and legacy of the Data General Nova, Eclipse, MV and compatible computers")
- Carl Friend's Computer Museum (has pages for over a dozen DG systems)
- data general facebook alumni group