Data General Corporation was one of the first minicomputer firms of the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation (DEC).
138-474: Their first product, 1969's Data General Nova , was a 16-bit minicomputer intended to both outperform and cost less than the equivalent from DEC, the 12-bit PDP-8 . A basic Nova system cost two-thirds or less than a similar PDP-8 while running faster, offering easy expandability, being significantly smaller, and proving more reliable in the field. Combined with Data General RDOS (DG/RDOS) and programming languages like Data General Business Basic , Novas provided
276-524: A 19-inch rack . Many PDP-8s still operated decades later in these roles. De Castro was watching developments in manufacturing, especially more complex printed circuit boards (PCBs) and wave soldering that suggested that the PDP-8 could be produced much more inexpensively. DEC was not interested, having turned its attention increasingly to the high-end market. Convinced he could improve the process, De Castro began work on his own low-cost 16-bit design. The result
414-461: A "prefetcher" to increase performance by fetching up to 11 instructions from memory before they were needed. Data General also produced a series of microNOVA single-chip implementations of the Nova processor. To allow it to fit into a 40-pin dual in-line package (DIP) chip, the address bus and data bus shared a set of 16 pins. This meant that reads and writes to memory required two cycles, and that
552-404: A centrally located "board-on-a-board", 5.25" wide by 6.125" high, and was covered by a protective plate. It was surrounded by the necessary support driver read-write-rewrite circuitry. All of the core and the corresponding support electronics fit onto a single standard 15 x 15-inch (380 mm) board. Up to 32K of such core RAM could be supported in one external expansion box. Semiconductor ROM
690-448: A consortium of venture capital funds from the Boston area, who agreed to provide an initial US$ 400,000 investment with a second US$ 400,000 available for production ramp-up. de Castro, Burkhart and Sogge quit DEC and started Data General (DG) on 15 April 1968. Green did not join them, considering the venture too risky, and Richman did not join until the product was up and running later in
828-533: 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
966-476: A demonstration of the power of their Micromatrix gate array technology, in 1968 Fairchild prototyped the 4711, a single-chip 4-bit ALU. The design was never intended for mass production and was quite expensive to produce. The introduction of the Signetics 8260 in 1969 forced their hand; both Texas Instruments and Fairchild introduced 4-bit ALUs of their own in 1970, the 74181 and 9341, respectively. In contrast to
1104-464: A desktop". The early AViiON servers were portrayed as powerful computing in the size of a pizza box. Data General Nova The Data General Nova is a series of 16-bit minicomputers released by the American company Data General . The Nova family was very popular in the 1970s and ultimately sold tens of thousands of units. The first model, known simply as "Nova", was released in 1969. The Nova
1242-509: 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. Data General exhibited a brash style of marketing and advertising, which acted to set the company in the spotlight. A memorable advertising campaign during the early 1980s Desktop Generation era, was issuance of T-shirts with the logo "We did it on
1380-504: A four-bit opcode can specify up to sixteen different ALU operations. Generally, an ALU opcode is not the same as a machine language instruction , though in some cases it may be directly encoded as a bit field within such instructions. The status outputs are various individual signals that convey supplemental information about the result of the current ALU operation. General-purpose ALUs commonly have status signals such as: The status inputs allow additional information to be made available to
1518-480: 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
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#17328442924571656-473: A large niche for Unix storage systems, and its sales were still strong enough to make DG a takeover target. EMC , the 800-pound gorilla in the storage market, announced in August 1999 that they would buy Data General and its assets for $ 1.1 billion or $ 19.58 a share. The acquisition was completed on October 12, 1999. Although details of the acquisition specified that EMC had to take the entire company, and not just
1794-454: A matching high-performance version. Gruner's low-cost model launched in 1970 as the Nova 1200 , the 1200 referring to the use of the original Nova's 1,200 ns core memory. It featured a 4-bit ALU based on a single 74181 chip, and was thus essentially a repackaged Nova. Seligman's repackaged four-ALU SuperNOVA was released in 1971 as the Nova 800 , resulting in the somewhat confusing naming where
1932-404: 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
2070-457: A multi-user platform far ahead of many contemporary systems. A series of updated Nova machines were released through the early 1970s that kept the Nova line at the front of the 16-bit mini world. The Nova was followed by the Eclipse series which offered much larger memory capacity while still being able to run Nova code without modification. The Eclipse launch was marred by production problems and it
2208-408: A new design effort known as "PDP-X" which included several advanced features. Among these was a single underlying design that could be used to build 8-, 16-, and 32-bit platforms. This progressed to the point of producing several detailed architecture documents. Ken Olsen was not supportive of this project, feeling it did not offer sufficient advantages over the 12-bit PDP-8 and the 18-bit PDP-9 . It
2346-418: A new generation of designs with word lengths that were multiples of 8 bits rather than multiples of 6 bits as in most previous designs. This led to mid-range designs working at 16-bit word lengths instead of DEC's current 12- and 18-bit lineups. de Castro was convinced that it was possible to improve upon the PDP-8 by building a 16-bit minicomputer CPU on a single 15-inch square board. In 1967, de Castro began
2484-410: 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
2622-408: A separate slot. An additional option allowed for memory mapping, allowing programs to access up to 128 kwords of memory using bank switching . Unlike the earlier machines, the Nova 4 did not include a front panel console and instead included a ROM containing machine code that allows a terminal to emulate a console when needed. There were three different versions of the Nova 4, the Nova 4/C,
2760-717: A single system. Following AViiON was the CLARiiON series of network-attached storage systems which became a major product line in the later 1990s. This led to a purchase by EMC , the major vendor in the storage space at that time. EMC shut down all of DG's lines except for CLARiiON, which continued sales until 2012. 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 , Henry Burkhardt III, and Richard Sogge of Digital Equipment (DEC), and Herbert Richman of Fairchild Semiconductor . The company
2898-550: 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,
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#17328442924573036-571: A very simple 8-bit ALU: Mathematician John von Neumann proposed the ALU concept in 1945 in a report on the foundations for a new computer called the EDVAC . The cost, size, and power consumption of electronic circuitry was relatively high throughout the infancy of the Information Age . Consequently, all early computers had a serial ALU that operated on one data bit at a time although they often presented
3174-596: A wider word size to programmers. The first computer to have multiple parallel discrete single-bit ALU circuits was the 1951 Whirlwind I , which employed sixteen such "math units" to enable it to operate on 16-bit words. In 1967, Fairchild introduced the first ALU-like device implemented as an integrated circuit, the Fairchild 3800, consisting of an eight-bit arithmetic unit with accumulator. It only supported adds and subtracts but no logic functions. Full integrated-circuit ALUs soon emerged, including four-bit ALUs such as
3312-500: A year earlier. Others within DEC had become used to the smaller boards used in earlier machines and were concerned about tracking down problems when there were many components on a single board. For the 8/I, the decision was made to stay with small boards, using the new " flip-chip " packaging for a modest improvement in density. During the period when the PDP-8 was being developed, the introduction of ASCII and its major update in 1967 led to
3450-453: Is a diverse but ardent group of people worldwide who restore and preserve original 16-bit Data General systems. The Nova, unlike the PDP-8 , was a load–store architecture . It had four 16-bit accumulator registers, two of which (2 and 3) could be used as index registers . There was a 15-bit program counter and a single-bit carry register. As with the PDP-8, current + zero page addressing
3588-436: Is an algorithm that operates on integers which are larger than the ALU word size. To do this, the algorithm treats each integer as an ordered collection of ALU-size fragments, arranged from most-significant (MS) to least-significant (LS) or vice versa. For example, in the case of an 8-bit ALU, the 24-bit integer 0x123456 would be treated as a collection of three 8-bit fragments: 0x12 (MS), 0x34 , and 0x56 (LS). Since
3726-415: Is in contrast to a floating-point unit (FPU), which operates on floating point numbers. It is a fundamental building block of many types of computing circuits, including the central processing unit (CPU) of computers, FPUs, and graphics processing units (GPUs). The inputs to an ALU are the data to be operated on, called operands , and a code indicating the operation to be performed; the ALU's output
3864-460: Is operating, external circuits apply signals to the ALU inputs and, in response, the ALU produces and conveys signals to external circuitry via its outputs. A basic ALU has three parallel data buses consisting of two input operands ( A and B ) and a result output ( Y ). Each data bus is a group of signals that conveys one binary integer number. Typically, the A, B and Y bus widths (the number of signals comprising each bus) are identical and match
4002-410: Is referred to as the "status register" or "condition code register". Depending on the ALU operation being performed, some status register bits may be changed and others may be left unmodified. For example, in bitwise logical operations such as AND and OR, the carry status bit is typically not modified as it is not relevant to such operations. In CPUs, the stored carry-out signal is usually connected to
4140-407: Is repeated for all operand fragments so as to generate a complete collection of partials, which is the result of the multiple-precision operation. In arithmetic operations (e.g., addition, subtraction), the algorithm starts by invoking an ALU operation on the operands' LS fragments, thereby producing both a LS partial and a carry out bit. The algorithm writes the partial to designated storage, whereas
4278-425: Is the result of the performed operation. In many designs, the ALU also has status inputs or outputs, or both, which convey information about a previous operation or the current operation, respectively, between the ALU and external status registers . An ALU has a variety of input and output nets , which are the electrical conductors used to convey digital signals between the ALU and external circuitry. When an ALU
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4416-462: The Am2901 and 74181 . These devices were typically " bit slice " capable, meaning they had "carry look ahead" signals that facilitated the use of multiple interconnected ALU chips to create an ALU with a wider word size. These devices quickly became popular and were widely used in bit-slice minicomputers. Microprocessors began to appear in the early 1970s. Even though transistors had become smaller, there
4554-489: 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 3 1 ⁄ 2 -inch diskettes, a 79-key full-stroke keyboard, 128 KB to 512 KB of RAM, and a monochrome LCD screen capable of either
4692-506: 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. 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
4830-592: The Open Systems Interconnection (OSI) protocol suite . 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 ;
4968-498: The PDP-11 , a much more complex design that was as different from the PDP-X as the Nova was. The two designs competed heavily in the market. Rumors of the new system from DEC reached DG shortly after the Nova began shipping. In spring 1970 they hired a new designer, Larry Seligman, to leapfrog any possible machine in the making. Two major changes had taken place since the Nova was designed; one
5106-508: The X.25 standard at the lower levels, and their own application layer protocols on top. Because it was based on X.25, remote sites could be linked together over commercial X.25 services like Telenet in the US or Datapac in Canada. Data General software packages supporting Xodiac included Comprehensive Electronic Office (CEO). In June 1987, Data General announced its intention to replace Xodiac with
5244-518: The Xerox Alto . 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
5382-487: The input/output circuitry and a complete system typically included another board with 4 kB of random-access memory . A complete four-card system fit in a single rackmount chassis. The boards were designed so they could be connected together using a printed circuit backplane , with minimal manual wiring, allowing all the boards to be built in an automated fashion. This greatly reduced costs over 8/I, which consisted of many smaller boards that had to be wired together at
5520-460: The "program load" switch was flipped. Versions were available with four ("2/4"), seven and ten ("2/10") slots. The Nova 3 of 1975 added two more registers, used to control access to a built-in stack. The processor was also re-implemented using TTL components, further increasing the performance of the system. The Nova 3 was offered in four-slot (the Nova 3/4) and twelve-slot (the Nova 3/12) versions. It appears that Data General originally intended
5658-546: The 8260, the new designs offered all common logic functions and further reduced the chip count. This led DG to consider the design of a new CPU using these more integrated ICs. At a minimum, this would reduce the CPU to a single card for either the basic Nova or the SuperNOVA. A new concept emerged where a single chassis would be able to host either machine simply by swapping out the CPU circuit board. This would allow customers to purchase
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5796-430: The ALU inputs. Typically, the external circuitry employs sequential logic to generate the signals that control ALU operation. The external sequential logic is paced by a clock signal of sufficiently low frequency to ensure enough time for the ALU outputs to settle under worst-case conditions (i.e., conditions resulting in the maximum possible propagation delay). For example, a CPU starts an addition operation by routing
5934-414: The ALU when performing an operation. Typically, this is a single "carry-in" bit that is the stored carry-out from a previous ALU operation. An ALU is a combinational logic circuit, meaning that its outputs will change asynchronously in response to input changes. In normal operation, stable signals are applied to all of the ALU inputs and, when enough time (known as the " propagation delay ") has passed for
6072-400: The ALU's carry-in net. This facilitates efficient propagation of carries (which may represent addition carries, subtraction borrows, or shift overflows) when performing multiple-precision operations, as it eliminates the need for software-management of carry propagation (via conditional branching, based on the carry status bit). In integer arithmetic computations, multiple-precision arithmetic
6210-464: The DG One Portable. 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
6348-510: 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
6486-547: 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. Throughout the 1980s, the computer market had evolved dramatically. Large installations in the past typically ran custom-developed software for
6624-613: 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
6762-512: The LS bit of each partial—which is conveyed via the stored carry bit—must be obtained from the MS bit of the previously left-shifted, less-significant operand. Conversely, operands are processed MS first in right-shift operations because the MS bit of each partial must be obtained from the LS bit of the previously right-shifted, more-significant operand. In bitwise logical operations (e.g., logical AND, logical OR),
6900-448: 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. 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
7038-570: 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
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#17328442924577176-506: 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. While DG was still struggling with Eclipse, in 1977, Digital announced the VAX series, their first 32-bit minicomputer line, described as " super-minis ". This coincided with
7314-469: The Nova 3 to be the last of its line, planning to replace the Nova with the later Eclipse machines. However, continued demand led to a Nova 4 machine introduced in 1978, this time based on four AMD Am2901 bit-slice ALUs . This machine was designed from the start to be both the Nova 4 and the Eclipse S/140, with different microcode for each. A floating-point co-processor was also available, taking up
7452-413: The Nova 4/S and the Nova 4/X. The Nova 4/C was a single-board implementation that included all of the memory (16 or 32 kwords). The Nova 4/S and 4/X used separate memory boards. The Nova 4/X had the on-board memory management unit (MMU) enabled to allow up to 128 kwords of memory to be used. The MMU was also installed in the Nova 4/S, but was disabled by firmware. Both the 4/S and the 4/X included
7590-436: The Nova computers, running under a range of consistent operating systems. FORTRAN IV , ALGOL , Extended BASIC, Data General Business Basic , Interactive COBOL , and several assemblers were available from Data General. Third-party vendors and the user community expanded the offerings with Forth , Lisp , BCPL , C , ALGOL , and other proprietary versions of COBOL and BASIC . The machine instructions implemented below are
7728-401: 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. In 1977, DG launched a 16-bit microcomputer called the microNOVA to poor commercial success. The Nova series played a very important role as instruction-set inspiration to Charles P. Thacker and others at Xerox PARC during their construction of
7866-456: The Nova simple compared to competing machines. In addition to its dedicated I/O bus structure, the Nova backplane had wire wrap pins that could be used for non-standard connectors or other special purposes. The instruction format could be broadly categorized into one of three functions: 1) register-to-register manipulation, 2) memory reference, and 3) input/output. Each instruction was contained in one word. The register-to-register manipulation
8004-406: The PDP-X, the new effort focused on a single machine that could be brought to market quickly, as de Castro felt the PDP-X concept was far too ambitious for a small startup company . Discussing it with the others at DEC, the initial concept led to an 8-bit machine which would be less costly to implement. The group began talking with Herbert Richman, a salesman for Fairchild Semiconductor who knew
8142-459: 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 original IDEA ran on RDOS and would support up to 24 users in an RDOS Partition. Each user could use
8280-510: The SuperNova. Future versions of the system added a stack unit and hardware multiply/divide. The Nova 4 / Eclipse S/140 was based on four AMD 2901 bit-slice ALUs, with microcode in read-only memory , and was the first Nova designed for DRAM main memory only, without provision for magnetic-core memory . The first models were available with 8 K words of magnetic-core memory as an option, one that practically everyone had to buy, bringing
8418-599: The aging of DEC's 16-bit products, notably the PDP-11 , which were coming due for replacement. It appeared there was an enormous potential market for 32-bit machines, one that DG might be able to "scoop". 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", or FHP for short (Fountain Head Project). Development took place off-site so that even DG workers would not know of it. The developers were given free rein over
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#17328442924578556-463: The backplane, which was itself connected together using wire wrap . The larger-board construction also made the Nova more reliable, which made it especially attractive for industrial or lab settings. The new design used a simple load–store architecture which would reemerge in the RISC designs in the 1980s. Because the complexity of a flip-flop was being rapidly reduced as they were implemented in chips,
8694-485: 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
8832-458: The common set implemented by all of the Nova series processors. Specific models often implemented additional instructions, and some instructions were provided by optional hardware. All arithmetic instructions operated between accumulators. For operations requiring two operands, one was taken from the source accumulator, and one from the destination accumulator, and the result was deposited in the destination accumulator. For single-operand operations,
8970-420: The company had annual sales of US$ 100 million . Ken Olsen had publicly predicted that DG would fail, but with the release of the Nova it was clear that was not going to happen. By this time, a number of other companies were talking about introducing 16-bit designs as well. Olsen decided these presented a threat to their 18-bit line as well as 12-bit, and began a new 16-bit design effort. This emerged in 1970 as
9108-460: The core with read-only memory ; lacking core's read–write cycle, this could be accessed in 300 ns for a dramatic performance boost. The resulting machine, known as the SuperNOVA , was released in 1970. Although the initial models still used core, the entire design was based on the premise that faster semiconductor memories would become available and the platform could make full use of them. This
9246-525: The design and selected a system that used a writable instruction set. The idea was that the instruction set architecture (ISA) was not fixed, programs could write their own ISA and upload it as microcode to the processor's writable control store . This would allow the ISA to be tailored to the programs being run, for instance, one might upload an ISA tuned for COBOL if the company's workload included significant numbers of COBOL programs. When Digital's VAX-11/780
9384-553: The design of both the Xerox Alto (1973) and Apple I (1976) computers, and its architecture was the basis for the Computervision CGP (Computervision Graphics Processor) series. Its external design has been reported to be the direct inspiration for the front panel of the MITS Altair (1975) microcomputer. Data General followed up on the success of the original Nova with a series of faster designs. The Eclipse family of systems
9522-468: The design offset the lack of addressing modes of the load–store design by adding four general-purpose accumulators , instead of the single register that would be found in similar low-cost offerings like the PDP series. Late in 1967, Richman introduced the group to New York-based lawyer Fred Adler, who began canvassing various funding sources for seed capital. By 1968, Adler had arranged a major funding deal with
9660-480: The end of the decade, the entire market had largely disappeared. The introduction of the Data General/One in 1984 did nothing to stop the erosion. In a major business pivot, in 1989 DG released the AViiON series of scalable Unix systems which spanned from desktop workstations to departmental servers . This scalability was managed through the use of NUMA , allowing a number of commodity processors to work together in
9798-513: The entire chipset to a single VLSI . This was offered in two machines, the microNOVA MP/100 and larger microNOVA MP/200 . The microNOVA was later re-packaged with a monitor in a PC-style case with two floppy disks as the Enterprise . Enterprise shipped in 1981, running RDOS , but the introduction of the IBM PC the same year made most other machines disappear under the radar. The Nova influenced
9936-527: 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 was the only product line that saw continued success through the later 1990s after finding
10074-487: 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 and their marketing group Voest Alpine Vertriebe would build the plant. Despite Data General's betting the AViiON farm on the Motorola 88000 , Motorola decided to end production of that CPU. The 88000 had never been very successful, and DG
10212-512: The first true minicomputer. He also led the design of the upgraded PDP-8/I, which used early integrated circuits in place of individual transistors. During the PDP-8/I process, de Castro had been visiting circuit board manufacturers who were making rapid advances in the complexity of the boards they could assemble. de Castro concluded that the 8/I could be produced using fully automated assembly on large boards, which would have been impossible only
10350-491: 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. 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
10488-446: 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
10626-416: The initial success of the Nova, Data General went public in the fall of 1969. The original Nova was soon followed by the faster SuperNova, which replaced the Nova's 4-bit arithmetic logic unit (ALU) with a 16-bit version that made the machine roughly four times as fast. Several variations and upgrades to the SuperNova core followed. The last major version, the Nova 4, was released in 1978. During this period
10764-492: The line went through several upgrades over the next five years, introducing the 800 and 1200, the Nova 2, Nova 3, and ultimately the Nova 4. A single-chip implementation was also introduced as the microNOVA in 1977, but did not see widespread use as the market moved to new microprocessor designs. Fairchild Semiconductor also introduced a microprocessor version of the Nova in 1977, the Fairchild 9440 , but it also saw limited use in
10902-409: The lower-cost system and then upgrade at any time. While Seligman was working on the SuperNOVA, the company received a letter from Ron Gruner stating "I've read about your product, I've read your ads, and I'm going to work for you. And I'm going to be at your offices in a week to talk to you about that." He was hired on the spot. Gruner was put in charge of the low-cost machine while Seligman designed
11040-502: The lower-numbered model has higher performance. Both models were offered in a variety of cases, the 1200 with seven slots, the 1210 with four and the 1220 with fourteen. By this time, the PDP-11 was finally shipping. It offered a much richer instruction set architecture than the deliberately simple one in the Nova. Continuing improvement in IC designs, and especially their price–performance ratio ,
11178-401: The machine ran about half the speed of the original Nova as a result. The first chip in the series was the mN601 , of 1977. This was sold both as a CPU for other users, a complete chipset for those wanting to implement a computer, a complete computer on a single board with 4 kB of RAM, and as a complete low-end model of the Nova. An upgraded version of the design, 1979's mN602 , reduced
11316-433: The machines, not because they were forced; lock-in was over. 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
11454-600: The market. The Nova line was succeeded by the Data General Eclipse , which was similar in most ways but added virtual memory support and other features required by modern operating systems . A 32-bit upgrade of the Eclipse resulted in the Eclipse MV series of the 1980s. Edson de Castro was the Product Manager of the pioneering Digital Equipment Corporation (DEC) PDP-8 , a 12-bit computer widely referred to as
11592-559: The meantime, customers were abandoning 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. Ultimately, Fountainhead was cancelled and Eagle became the new MV series, with the first model, the Data General Eclipse MV/8000 , announced in April 1980. The Eagle Project
11730-529: 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,
11868-458: The midst of a strike in the airline industry and the machine never arrived. They sent a second example, which arrived promptly as the strike had ended by that point, and in May the original one was finally delivered as well. The system was successful from the start, with the 100th being sold after six months, and the 500th after 15 months. Sales accelerated as newer versions were introduced, and by 1975
12006-417: 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 (CEOWrite), a spreadsheet processor, and other assorted tools. All were crude by today's standards, but were revolutionary for their time. CEOWrite was also offered on
12144-427: The native word size of the external circuitry (e.g., the encapsulating CPU or other processor). The opcode input is a parallel bus that conveys to the ALU an operation selection code, which is an enumerated value that specifies the desired arithmetic or logic operation to be performed by the ALU. The opcode size (its bus width) determines the maximum number of distinct operations the ALU can perform; for example,
12282-461: The new ICs allowed the ALU to be expanded to full 16-bit width on the same two cards, allowing it to carry out math and logic operations in a single cycle and thereby making the new design four times as fast as the original. In addition, new smaller core memory was used that improved the cycle time from the original's 1,200 ns to 800 ns, offering a further 1 / 3 improvement. Performance could be further improved by replacing
12420-567: The next clock, are allowed to propagate through the ALU and to the destination register while the CPU waits for the next clock. When the next clock arrives, the destination register stores the ALU result and, since the ALU operation has completed, the ALU inputs may be set up for the next ALU operation. A number of basic arithmetic and bitwise logic functions are commonly supported by ALUs. Basic, general purpose ALUs typically include these operations in their repertoires: ALU shift operations cause operand A (or B) to shift left or right (depending on
12558-406: The opcode) and the shifted operand appears at Y. Simple ALUs typically can shift the operand by only one bit position, whereas more complex ALUs employ barrel shifters that allow them to shift the operand by an arbitrary number of bits in one operation. In all single-bit shift operations, the bit shifted out of the operand appears on carry-out; the value of the bit shifted into the operand depends on
12696-588: The operand fragments may be processed in any arbitrary order because each partial depends only on the corresponding operand fragments (the stored carry bit from the previous ALU operation is ignored). Although it is possible to design ALUs that can perform complex functions, this is usually impractical due to the resulting increases in circuit complexity, power consumption, propagation delay, cost and size. Consequently, ALUs are typically limited to simple functions that can be executed at very high speeds (i.e., very short propagation delays), with more complex functions being
12834-462: The operand was taken from the source register and the result replaced the destination register. For all single-operand opcodes, it was permissible for the source and destination accumulators to be the same, and the operation functioned as expected. Arithmetic logic unit In computing , an arithmetic logic unit ( ALU ) is a combinational digital circuit that performs arithmetic and bitwise operations on integer binary numbers . This
12972-422: The operands from their sources (typically processor registers ) to the ALU's operand inputs, while simultaneously applying a value to the ALU's opcode input that configures it to perform an addition operation. At the same time, the CPU enables the destination register to store the ALU output (the resulting sum from the addition operation) upon operation completion. The ALU's input signals, which are held stable until
13110-416: The others through his contacts with DEC. At the time, Fairchild was battling with Texas Instruments and Signetics in the rapidly growing TTL market and were introducing new fabs that allowed more complex designs. Fairchild's latest 9300 series allowed up to 96 gates per chip, and they had used this to implement a number of 4-bit chips like binary counters and shift registers . Using these ICs reduced
13248-410: The partial is written to designated storage. This process repeats until all operand fragments have been processed, resulting in a complete collection of partials in storage, which comprise the multi-precision arithmetic result. In multiple-precision shift operations, the order of operand fragment processing depends on the shift direction. In left-shift operations, fragments are processed LS first because
13386-415: The processor's state machine typically stores the carry out bit to an ALU status register. The algorithm then advances to the next fragment of each operand's collection and invokes an ALU operation on these fragments along with the stored carry bit from the previous ALU operation, thus producing another (more significant) partial and a carry out bit. As before, the carry bit is stored to the status register and
13524-399: 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
13662-412: 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 the customer 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
13800-448: 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
13938-451: The responsibility of external circuitry. For example: An ALU is usually implemented either as a stand-alone integrated circuit (IC), such as the 74181 , or as part of a more complex IC. In the latter case, an ALU is typically instantiated by synthesizing it from a description written in VHDL , Verilog or some other hardware description language . For example, the following VHDL code describes
14076-543: 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
14214-462: 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. In 1979, DG introduced their Xodiac networking system. This was based on
14352-437: The signals to propagate through the ALU circuitry, the result of the ALU operation appears at the ALU outputs. The external circuitry connected to the ALU is responsible for ensuring the stability of ALU input signals throughout the operation, and for allowing sufficient time for the signals to propagate through the ALU circuitry before sampling the ALU outputs. In general, external circuitry controls an ALU by applying signals to
14490-432: The size of a fragment exactly matches the ALU word size, the ALU can directly operate on this "piece" of operand. The algorithm uses the ALU to directly operate on particular operand fragments and thus generate a corresponding fragment (a "partial") of the multi-precision result. Each partial, when generated, is written to an associated region of storage that has been designated for the multiple-precision result. This process
14628-697: 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
14766-440: 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. CLARiiON
14904-450: The system cost up to $ 7,995. This core memory board was organized in planar fashion as four groups of four banks, each bank carrying two sets of core in a 64 by 64 matrix; thus there were 64 x 64 = 4096 bits per set, x 2 sets giving 8,192 bits, x 4 banks giving 32,768 bits, x 4 groups giving a total of 131,072 bits, and this divided by the machine word size of 16 bits gave 8,192 words of memory. The core on this 8K word memory board occupied
15042-526: 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's introduction of
15180-459: The total IC count needed to implement a complete arithmetic logic unit (ALU), the core mathematical component of a CPU, allowing the expansion from an 8-bit design to 16-bit. This did require the expansion of the CPU from a single 15 by 15 inches (38 cm × 38 cm) printed circuit board to two, but such a design would still be significantly cheaper to produce than the 8/I while still being more powerful and ASCII-based. A third board held
15318-404: The type of shift. Upon completion of each ALU operation, the ALU's status output signals are usually stored in external registers to make them available for future ALU operations (e.g., to implement multiple-precision arithmetic ) and for controlling conditional branching . The bit registers that store the status output signals are often collectively treated as a single, multi-bit register, which
15456-504: The world." The basic model was not very useful out of the box, and adding 8 kW ( 16 kB ) RAM in the form of core memory typically brought the price up to US$ 7,995 . In contrast, an 8/I with 4 kW ( 6 kB ) was priced at US$ 12,800 . The first sale was to a university in Texas, with the team hand-building an example which shipped out in February. However, this was in
15594-552: The year. Work on the first system took about nine months, and the first sales efforts started that November. They had a bit of luck because the Fall Joint Computer Conference had been delayed until December that year, so they were able to bring a working unit to San Francisco where they ran a version of Spacewar! . DG officially released the Nova in 1969 at a base price of US$ 3,995 (equivalent to $ 33,193 in 2023), advertising it as "the best small computer in
15732-536: Was a straightforward, 32-bit extension of the Nova-based Eclipse. It was backwards-compatible with 16-bit Eclipse applications, used the same command-line interpreter, but offered improved 32-bit performance over the VAX 11/780 while using fewer components. 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
15870-443: Was almost RISC -like in its bit-efficiency; and an instruction that manipulated register data could also perform tests, shifts and even elect to discard the result. Hardware options included an integer multiply and divide unit, a floating-point unit (single and double precision), and memory management . The earliest Nova came with a BASIC interpreter on punched tape . As the product grew, Data General developed many languages for
16008-440: Was already available at the time, and RAM-less systems (i.e. with ROM only) became popular in many industrial settings. The original Nova machines ran at approximately 200 kHz , but its SuperNova was designed to run at up to 3 MHz when used with special semiconductor main memory. The standardized backplane and I/O signals created a simple, efficient I/O design that made interfacing programmed I/O and Data Channel devices to
16146-545: 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
16284-407: Was central. There was no stack register , but later Eclipse designs would utilize a dedicated hardware memory address for this function. The earliest models of the Nova processed math serially in 4-bit packets, using a single 74181 bitslice ALU . A year after its introduction, this design was improved to include a full 16-bit parallel math unit using four 74181s, this design being referred to as
16422-421: Was eroding the value of the original simplified instructions. Seligman was put in charge of designing a new machine that would be compatible with the Nova while offering a much richer environment for those who wanted it. This concept shipped as the Data General Eclipse series, which offered the ability to add additional circuitry to tailor the instruction set for scientific or data processing workloads. The Eclipse
16560-402: Was eventually canceled in the spring of 1968. Cancelation of the PDP-X prompted de Castro to consider leaving DEC to build a system on his own. He was not alone; in late 1967 a group of like-minded engineers formed to consider such a machine. The group included Pat Green, a divisional manager; Richard Sogge, another hardware engineer; and Henry Burkhardt III, a software engineer. In contrast to
16698-462: Was founded in Hudson, Massachusetts , in 1968. Harvey Newquist was hired from Computer Control Corporation to oversee manufacturing. Edson de Castro was the chief engineer in charge of the PDP-8 , DEC's line of inexpensive computers that created the minicomputer market. It was designed specifically to be used in laboratory equipment settings; as the technology improved, it was reduced in size to fit into
16836-479: Was introduced later the same year as the SuperNOVA SC , featuring semiconductor (SC) memory. The much higher performance memory allowed the CPU, which was synchronous with memory, to be further increased in speed to run at a 300 ns cycle time (3.3 MHz). This made it the fastest available minicomputer for many years. Initially the new memory was also very expensive and ran hot, so it was not widely used. As
16974-604: Was later introduced with an extended upwardly compatible instruction set, and the MV-series further extended the Eclipse into a 32-bit architecture to compete with the DEC VAX . The development of the MV-series was documented in Tracy Kidder 's popular 1981 book, The Soul of a New Machine . Data General itself would later evolve into a vendor of Intel processor-based servers and storage arrays, eventually being purchased by EMC . There
17112-505: 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 the EMC Symmetrix in the wider market. On December 12, 1989, DG and Soviet Union software developer NPO Parma announced Perekat (Перекат, “Rolling Thunder,”)
17250-405: Was packaged into a single 3U rack-mount case and had enough computing power to handle most simple tasks. The Nova became popular in science laboratories around the world. It was followed the next year by the SuperNOVA , which ran roughly four times as fast, making it the fastest mini for several years. Introduced during a period of rapid progress in integrated circuit (or "microchip") design,
17388-411: Was packaged on four PCB cards and was thus smaller in height, while also including a number of features that made it run considerably faster. Announced as "the best small computer in the world", the Nova quickly gained a following, especially in scientific and educational markets, and made the company flush with cash. DEC sued for misappropriation of its trade secrets, but this ultimately went nowhere. With
17526-459: Was released in 1969 by Data General as the Nova . 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. Designed to be rack-mounted similarly to the later PDP-8 machines, it
17664-507: 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. In the spring of 1978, with Fountainhead apparently in development hell , a secret skunkworks project was started to develop an alternative 32-bit system known as "Eagle" by a team led by Tom West . References to "the Eagle project" and "Project Eagle" co-exist. Eagle
17802-430: Was some time before it was a reliable replacement for the tens of thousands of Novas in the market. As the mini world moved from 16-bit to 32, DG introduced the Data General Eclipse MV/8000 , whose development was extensively documented in the popular book, The Soul of a New Machine . Although DG's computers were successful, the introduction of the IBM PC in 1981 marked the beginning of the end for minicomputers, and by
17940-530: Was sometimes insufficient die space for a full-word-width ALU and, as a result, some early microprocessors employed a narrow ALU that required multiple cycles per machine language instruction. Examples of this includes the popular Zilog Z80 , which performed eight-bit additions with a four-bit ALU. Over time, transistor geometries shrank further, following Moore's law , and it became feasible to build wider ALUs on microprocessors. Modern integrated circuit (IC) transistors are orders of magnitude smaller than those of
18078-607: Was successful in competing with the PDP-11 at the higher end of the market. Around the same time, rumors of a new 32-bit machine from DEC began to surface. DG decided they had to have a similar product, and Gruner was put in charge of what became the Fountainhead Project. Given the scope of the project, they agreed that the entire effort should be handled off-site, and Gruner selected a location at Research Triangle Park in North Carolina . This design became very complex and
18216-445: Was that Signetics had introduced the 8260, a 4-bit IC that combined an adder, XNOR and AND, meaning the number of chips needed to implement the basic logic was reduced by about three times. Another was that Intel was aggressively talking up semiconductor-based memories, promising 1024 bits on a single chip and running at much higher speeds than core memory. Seligman's new design took advantage of both of these improvements. To start,
18354-406: Was the Nova 2 , with the first versions shipping in 1973. The Nova 2 was essentially a simplified version of the earlier machines as increasing chip densities allowed the CPU to be reduced in size. While the SuperNOVA used three 15×15" boards to implement the CPU and its memory, the Nova 2 fitted all of this onto a single board. ROM was used to store the boot code, which was then copied into core when
18492-549: 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
18630-599: 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 by 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
18768-417: 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 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
18906-554: 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
19044-419: Was ultimately canceled years later. While these efforts were underway, work on the Nova line continued. The 840, first offered in 1973, also included a new paged memory system allowing for addresses of up to 17-bits. An index offset the base address into the larger 128 kword memory. Actually installing this much memory required considerable space; the 840 shipped in a large 14-slot case. The next version
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