Data General
Data General Corporation was an American minicomputer manufacturer founded in 1968 by former Digital Equipment Corporation (DEC) engineers Edson de Castro, Henry Burkhardt III, and Herbert Richman, which became a major player in the minicomputer industry during the 1970s and 1980s through innovative, affordable systems like the Nova and Eclipse lines, before pivoting to storage solutions and being acquired by EMC Corporation in 1999 for $1.1 billion.[1][2] The company originated from frustration at DEC, where de Castro's proposal for a 16-bit computer was rejected, leading the trio—aged 29, 23, and another young engineer—to establish Data General in Westborough, Massachusetts, with initial funding to develop their vision of accessible computing.[1] In 1969, Data General released the Nova, a groundbreaking 16-bit minicomputer using medium-scale integration (MSI) TTL logic circuits, priced under $10,000, which sold 500 units in its first 15 months and found applications in scientific, educational, and even agricultural settings, such as optimizing feed at a poultry farm processing millions of birds.[1][3] This success propelled rapid growth, positioning Data General as a key competitor to DEC and establishing it as a Fortune 500 company with over 125,000 systems deployed worldwide by the early 1980s.[4] Building on the Nova series, which evolved through versions up to the Nova 4 in 1978, Data General introduced the 16-bit Eclipse line in 1974, designed to outperform DEC's PDP-8 at a lower cost with features like up to 256KB of addressable memory and general-purpose processing capabilities.[5][6] By the 1980s, the company expanded into multi-processor systems like the Eclipse MV family, desktop generations, and even portable computing with the Data General/One laptop in 1984—a 9-pound breakthrough featuring an Intel 8088 processor, 256KB RAM, and a flip-up 9-inch screen.[7][8] As the minicomputer market declined, Data General shifted focus to storage, launching the CLARiiON disk system in 1992, which grew into a $500 million business by the late 1990s and facilitated its acquisition by EMC to bolster midrange storage offerings.[2]History
Founding and Early Years (1968–1969)
Data General Corporation was founded in 1968 in Hudson, Massachusetts, by former Digital Equipment Corporation (DEC) employees Edson de Castro, Henry Burkhardt III, Richard Sogge, and Herbert Richman.[9][10] De Castro, who had led the design of DEC's PDP-8 minicomputer, grew frustrated with DEC's reluctance to develop a successor 16-bit system, prompting him and his colleagues to leave and establish an independent venture focused on innovation in minicomputer technology.[1] The company secured initial funding of $400,000 upfront as part of a larger $800,000 investment to support its operations.[11] Initially headquartered in the former mill town of Hudson, with operations later moving to Westborough, Data General adopted a lean startup approach, operating from modest rented space to foster a culture of engineering-driven agility and rapid development.[10][12] This setup emphasized cost efficiency and close collaboration among a small team of engineers, reflecting the founders' vision of building affordable computing solutions without the bureaucratic constraints they experienced at DEC.[13] From its inception, Data General targeted scientific and industrial markets with a design for a 16-bit minicomputer intended to outperform and undercut DEC's PDP-8 in performance and price.[1] The team developed the first prototype in 1968, culminating in the announcement of the Nova system at the 1969 national Computer Conference, marking the company's entry into the competitive minicomputer industry.[10][6]Nova Era and Initial Success (1969–1974)
Data General achieved its breakthrough with the launch of the Nova minicomputer in 1969, a 16-bit word-addressable system designed to compete directly with Digital Equipment Corporation's PDP-8 by offering superior performance at a lower cost.[1] The initial model featured 4K words of core memory, basic input/output capabilities via a bi-directional bus, and was priced at a base of $3,995, making it accessible for scientific and educational applications.[14] This compact design, utilizing medium-scale integration TTL logic on a single large printed circuit board, marked a significant advancement in minicomputer architecture and quickly positioned Data General as an innovator in the field.[3] The Nova's market reception was swift and strong, with approximately 500 units sold in its first 15 months and contributing to the company's total Nova family sales exceeding 50,000 units over its lifetime.[10] This rapid adoption helped Data General capture a notable portion of the growing minicomputer sector, particularly in process control, laboratory automation, and academic settings, where its reliability and affordability shone.[6] By 1971, annual revenues had reached $10 million, reflecting doubled sales from the previous year and underscoring the Nova's role in establishing Data General as a major player.[15] In response to demand for enhanced performance, Data General introduced the Supernova series in 1970, followed by the Supernova SC model in 1971, which incorporated faster 800-nanosecond core memory and optional semiconductor memory with a 300-nanosecond cache for improved speed in demanding computations. These upgrades targeted high-performance needs in scientific computing and education, enabling more complex simulations and data processing tasks while maintaining compatibility with the original Nova architecture.[16] Concurrently, the company expanded internationally by establishing sales operations in Europe in 1970, laying the groundwork for broader global distribution.[17]Mid-1970s Challenges and Eclipse Development
By the early 1970s, Data General's rapid expansion strained its manufacturing capabilities, particularly in scaling production for Nova upgrades during 1973 and 1974. These scaling issues resulted in significant delivery delays, frustrating customers and enabling competitors like Digital Equipment Corporation (DEC) to capture market share with more reliable offerings such as the PDP-11 series.[18][19] In response, Data General launched the Eclipse line in October 1974, with the C/300 model marking the company's entry into more advanced 16-bit minicomputers designed for both scientific and commercial applications. The Eclipse C/300 introduced innovative features including virtual memory support and demand paging, allowing for efficient memory management in multitasking environments, while maintaining compatibility with existing Nova software to ease customer transitions. Although the architecture supported configurations with up to 16 processors in later expansions, initial models like the C/300 focused on single-processor performance with eight accumulators and microprogrammable control for flexibility.[10][18][20] Despite these advancements, the Eclipse rollout faced substantial hurdles, including hardware bugs and immature software that hindered reliability until major fixes were implemented by 1976. Production problems, stemming from overambitious internal projects and managerial discord under founder Edson de Castro, exacerbated these issues and delayed widespread adoption.[19][18][10] The broader economic turmoil of the 1973–1974 oil crisis further compounded these challenges, as soaring energy prices disrupted industrial clients who formed a key segment of Data General's customer base, leading to reduced demand for computing equipment. Company revenues dipped to $108 million in fiscal 1975, prompting aggressive cost-cutting measures such as streamlining research initiatives and tightening operational controls to stabilize finances.[21][22] In parallel, Data General began a strategic pivot toward business computing markets, developing software like Business BASIC to target administrative and data processing applications beyond traditional scientific uses, aiming to diversify revenue streams and compete more directly with IBM in enterprise settings.[10][18]Fountainhead Project and Eagle Computer (Late 1970s)
In response to Digital Equipment Corporation's 1976 announcement of its 32-bit VAX minicomputer, Data General initiated Project Fountainhead that year as a highly secretive effort to develop an advanced 32-bit architecture capable of outperforming competitors in the emerging high-end minicomputer market.[23] The project, headquartered in Research Triangle Park, North Carolina, aimed to create a groundbreaking system using innovative design principles, including high-level language support and variable-word-length processing, but it encountered significant management challenges and fell behind schedule.[24][25] Faced with Fountainhead's delays and the urgent need to counter the VAX—particularly after its commercial launch in 1978—Data General engineering manager Tom West launched a clandestine parallel initiative codenamed Eagle in late 1977 or early 1978, operating as a skunkworks project from the company's Westborough, Massachusetts, facilities.[23][24] West, skeptical of Fountainhead's ambitious approach, directed his team to extend the existing 16-bit Eclipse architecture to 32 bits while ensuring backward compatibility, leveraging off-the-shelf components for faster development.[23] This effort produced the Eagle CPU, which powered the MV/8000 minicomputer—a system featuring a 32-bit CISC design with a 4 GB virtual address space divided into privilege rings, virtual memory support via an Address Translation Unit, and compatibility with Unix-like operating systems through XENIX integration on top of Data General's AOS/VS.[26][27] The MV/8000 achieved approximately 1.3 MIPS performance, competitive with the VAX-11/780, and was released in April 1980 after Eagle outpaced the still-delayed Fountainhead, which was ultimately canceled.[26][23] The Eagle project's development was marked by an intense, high-pressure team culture under West's leadership, involving around two dozen young engineers divided into hardware ("Hardy Boys") and microcode ("Microkids") subgroups, who endured grueling schedules—often seven days a week—with limited resources and internal corporate rivalries.[24] This dynamic, characterized by burnout, fierce dedication, and West's aloof yet protective management style, was vividly chronicled in Tracy Kidder's 1981 Pulitzer Prize-winning book The Soul of a New Machine, which portrayed the engineers' rivalries and the existential stakes of the effort as Data General's potential salvation.[24][28] Initial production faced challenges, including component sourcing issues common to the era's semiconductor shortages, but the MV/8000 began shipping in 1980 and saw brisk early sales, with Data General delivering systems that solidified its position as a key player in multi-user minicomputer environments.[23] The Eagle design laid the foundation for the broader MV series, enabling Data General's temporary market recovery in the early 1980s.[23]MV Series and 1980s Recovery
The MV series emerged from the Eagle project, a high-priority effort to develop a 32-bit minicomputer capable of competing with Digital Equipment Corporation's VAX line. The Eclipse MV/8000, codenamed Eagle, was released in April 1980 as the flagship model, featuring advanced architecture for improved performance over prior Eclipse systems.[10] This was followed by the MV/6000 in 1981, a mid-range system designed for broader market accessibility, and the MV/4000 in 1983, a compact entry-level option that enhanced the line's scalability for smaller installations.[29][30] The series incorporated enhancements in reliability through modular design and supported clustering configurations of up to 15 processors connected via high-speed local links, enabling distributed processing up to 150 feet apart.[29] The commercialization of the MV series drove a significant recovery for Data General in the early 1980s, stabilizing the company after financial strains from 1970s overexpansion and development delays. Revenue grew to over $800 million by fiscal 1983, with sales rebounding 40% in early 1984 to exceed $1 billion, largely attributed to MV adoption in sectors like government and finance.[17][10] Notable implementations included the U.S. Forest Service's distributed processing network, which deployed over 900 MV-series superminicomputers across 880 field sites to support administrative and scientific applications, boosting operational efficiency.[31] The MV line became a bestseller, with an installed base reaching 40,000 machines by 1990, generating $600 million in annual revenue at its peak.[32] This focus on the MV series resolved short-term crises, averting bankruptcy risks from earlier losses—such as a 51% profit drop to $24.6 million in fiscal 1982—by prioritizing high-volume sales of reliable, multi-user systems.[10] Workforce expansion accompanied the recovery, growing to approximately 17,700 employees by 1984 to support increased production and global distribution.[28] Data General also pursued international manufacturing to meet demand, including operations in Scotland tied to disk drive production via Rodime Ltd. in Glenrothes, established in 1979.[33] These efforts provided a temporary lifeline, allowing the company to refocus on core minicomputer strengths before transitioning toward Unix-based systems like AViiON in the late 1980s.[10]Late 1980s to 1990s: Diversification and Decline
In the mid-1980s, Data General sought to diversify into the burgeoning personal computing market with the introduction of the Desktop Generation series in 1985, a family of desktop professional computers designed for compatibility with its minicomputer ecosystem and upward scalability.[34] These systems aimed to counter the microcomputer revolution but struggled due to high pricing and limited software availability, failing to gain significant traction against competitors.[10] Similarly, the company launched the Data General/One portable computer in 1984, an IBM PC-compatible laptop weighing nine pounds with MS-DOS, dual 3.5-inch floppy drives, and a monochrome LCD display, intended to capture mobile computing demand.[7] However, its poor display readability and the rapid rise of more affordable IBM PC clones overshadowed it, resulting in overestimated demand and commercial underperformance.[35] By the late 1980s, Data General pivoted toward open systems to address declining minicomputer sales, introducing the AViiON series of Unix workstations and servers in 1989, initially powered by Motorola 88000 RISC processors.[10] This line marked a strategic embrace of Unix and scalable architectures, transitioning from proprietary designs to compete in the workstation market; by fiscal 1991, AViiON generated $200 million in revenue, with projections for further growth to $500 million.[32] Later iterations incorporated x86 processors, broadening its appeal amid the "Unix wars" where vendors vied for open systems dominance. In December 1990, founder Edson de Castro was removed as CEO and chairman amid ongoing financial challenges.[36] In 1992, Data General debuted the CLARiiON storage system, a mid-range disk array using RAID technology to provide high-capacity, fault-tolerant data storage for Unix environments, supporting up to 20 drives in a compact enclosure.[37] Targeted at memory-intensive applications, it gained market traction through original equipment manufacturer (OEM) partnerships, including deals with Storage Technology Corporation, Hewlett-Packard, NEC, Bull, and Silicon Graphics by 1994, positioning it as a key diversification into enterprise storage.[38] Despite these efforts, Data General faced persistent financial challenges in the 1990s as the PC boom eroded minicomputer demand and intense competition in the Unix server market squeezed margins.[39] Company revenue stagnated around $1.12 billion by the mid-1990s, with cumulative losses exceeding $547 million from 1986 to 1995, prompting significant cost-cutting measures including the layoff of 1,000 employees in 1992 and an overall workforce reduction of two-thirds to approximately 6,900 by 1993.[10][40]Acquisition by EMC (1999)
In August 1999, EMC Corporation announced its intent to acquire Data General Corporation in a stock-for-stock transaction valued at approximately $1.1 billion, or $19.58 per share based on EMC's closing stock price on August 6.[41] The primary motivation was to expand EMC's presence in the rapidly growing $10 billion midrange storage market by incorporating Data General's CLARiiON disk array technology, which provided scalable, Fibre Channel-based storage solutions that complemented EMC's high-end Symmetrix enterprise systems.[41][42] This move also brought Data General's AViiON server lineup and research expertise in network-attached storage, enabling EMC to offer integrated solutions for UNIX and Windows NT environments.[41] The acquisition faced no major regulatory hurdles and closed on October 12, 1999, with each Data General share exchanged for 0.3125 shares of EMC common stock.[43] At the time, Data General employed about 5,000 people worldwide, including 1,800 in Massachusetts, all of whom were integrated into EMC's operations based in nearby Hopkinton.[44] EMC immediately discontinued Data General's legacy minicomputer lines, such as the Eclipse and MV series, which had become obsolete amid the industry's pivot to Intel-based architectures and client-server models.[45] However, the company retained the AViiON workstation and server teams, as well as the CLARiiON development and sales groups, relocating key personnel to facilities in Maynard, Massachusetts, to focus on high-value storage and compute innovations.[43][45] Data General's decision to sell stemmed from ongoing financial pressures, including quarterly net losses reported throughout fiscal 1998—such as $4.5 million in the second quarter—and broader challenges from heavy investments in Y2K compliance for legacy systems alongside the market's rapid shift toward Windows NT and open systems.[46] Post-acquisition, EMC rebranded several Data General offerings to align with its portfolio, while the CLARiiON line remained a cornerstone product, continuing sales and evolution until its end-of-life in 2012 under the Dell EMC banner following Dell's 2016 acquisition of EMC.[47] This integration marked the end of Data General as an independent entity and bolstered EMC's dominance in enterprise storage.[48]Products
Minicomputers
The Nova family represented Data General's foundational line of 16-bit minicomputers, featuring a word length of 16 bits with support for 8-bit bytes and four accumulators (two of which could function as index registers).[49] The architecture included a 15-bit program counter and instruction sets for jumps/modify memory, data moves, I/O operations, and arithmetic/logic functions.[49] Early models like the Nova 1200 series offered a memory cycle time of 1.2 microseconds, enabling efficient processing for scientific and industrial tasks.[50] Memory was based on magnetic core technology, expandable in increments of 1K, 2K, 4K, 8K, or 16K words, up to a maximum of 32K words in standard configurations.[49] The Nova 3, introduced in October 1975, enhanced this lineup with standard direct memory access (DMA) capabilities for high-speed I/O transfers and an optional floating-point unit that added 31 specialized instructions, supporting up to 128K words of memory with a memory management unit (MMU).[51] Supernova variants built on the Nova design by introducing overlapped instruction fetch and execution, along with early adoption of bipolar semiconductor memory for improved speed in demanding environments.[52] These systems achieved a core memory cycle time of 0.8 microseconds, dropping to 0.3 microseconds with read-only memory (ROM), which allowed for faster arithmetic and logical operations.[52] Memory capacity extended up to 32K words, with options for mixing core and semiconductor modules, and included hardware for multiply/divide operations as well as memory protection features.[49] Supernovas were particularly suited for real-time control applications, such as high-speed laboratory monitoring and precision manufacturing, due to their enhanced throughput—over three times that of the original Nova.[52] The Eclipse series advanced Data General's minicomputer offerings with a more sophisticated 16-bit architecture featuring eight accumulators and built-in support for virtual memory, marking a shift toward multitasking and larger-scale processing.[53] The C/300 model, released in 1974, utilized a microprogrammed design with an effective cycle time as low as 0.2 microseconds through memory interleaving, enabling high-performance commercial applications. Virtual memory was implemented via a memory allocation and protection (MAP) unit that supported up to 256K bytes (128K words) of physical memory, with segmentation into eight regions for security and resource management. The S/130, introduced in 1976, provided a compact configuration for smaller installations, offering 128K bytes (64K words) of maximum main memory and compatibility with the full Eclipse instruction set, including stack management and queue operations.[29]| Model Family | Cycle Time (μs) | Max Memory Capacity (words) | Key Performance Notes |
|---|---|---|---|
| Nova | 1.2 (1200 series); 0.8 (later) | 32K (standard); 128K (extended) | Load/store: 1.6–2.55 μs; Add/subtract: 0.8–1.35 μs; Relative power index: 2.5–4.5[49][54] |
| Supernova | 0.8 (core); 0.3 (ROM) | 32K | >3x original Nova speed; DMA rates up to 1.25M words/sec[52][54] |
| Eclipse | 0.2 (effective, C/300) | 128K (C/300); 64K (S/130) | Virtual memory support; Interleaved access for 0.3 μs effective in some ops[29] |
Servers and Workstations
Data General's MV series marked a significant advancement in 32-bit computing for multi-user server applications, deriving from the Eclipse CPU architecture to support demanding enterprise workloads. The initial MV/8000 model, launched in 1980, achieved approximately 1 MIPS of performance while offering up to 14 MB of RAM, enabling efficient handling of business processing tasks in multi-user configurations. Later expansions in the series introduced Symmetric Multi-Processing (SMP) capabilities, scaling from 2 to 15 CPUs to distribute workloads across multiple processors for enhanced throughput in server environments. For instance, the MV/40000 HA models delivered up to 50 MIPS with 4 processors and supported up to 256 MB of RAM, facilitating clustered configurations for high-transaction loads such as database operations.[56][57][58] Early MV systems employed emitter-coupled logic (ECL) for rapid signal propagation and high-speed execution, contributing to their competitive edge in performance-critical applications. Over time, the series transitioned to complementary metal-oxide-semiconductor (CMOS) technology in models like the MV/35000, which supported six-way multiprocessing using custom CMOS designs for improved power efficiency, reduced heat, and greater integration density without sacrificing speed. This evolution allowed the MV line to bridge proprietary minicomputer roots with emerging open systems standards, powering servers in sectors like finance and manufacturing. The MV series' clustering features further enabled transaction processing rates suitable for online systems, with configurations handling thousands of users through load-balanced nodes.[59][60][58] In 1989, Data General introduced the AViiON line of UNIX-based workstations and entry-level servers, targeting engineering and scientific computing with support for multi-user access. These systems utilized the Motorola 88000 RISC processor at clock speeds up to 25 MHz, paired with the DG/UX operating system for robust multitasking and networking. Subsequent AViiON models shifted to Intel Pentium Pro processors, retaining DG/UX compatibility while boosting performance for workstation clusters in collaborative environments. Hardware innovations included integrated cache and memory management units from the 88000 family, enabling seamless handling of graphics-intensive and simulation workloads. Performance metrics highlighted the line's strengths, with a 40 MHz 88110-based model achieving 37.8 SPECint92 and 50.5 SPECfp92 ratings, underscoring its efficiency in integer and floating-point computations relative to contemporaries.[61][62][63] The Xodiac servers, debuted in 1988, offered fault-tolerant computing akin to Tandem systems, optimized for online transaction processing (OLTP) in mission-critical settings. Featuring hot-swappable modules for minimal downtime and non-stop processing via redundant hardware paths, Xodiac ensured continuous operation even during component failures, with integrated network buses supporting distributed fault recovery. These servers emphasized reliability through modular design, allowing real-time reconfiguration without interrupting services, and were particularly suited for high-availability applications like banking and telecommunications.[64][65]Storage Systems
Data General entered the storage market in 1992 with the introduction of the CLARiiON line of RAID-based disk arrays, marking one of the earliest commercial implementations of redundant array of independent disks technology tailored for open systems like UNIX and Windows environments.[38] The initial models, such as the deskside Series 2000, featured modular architectures comprising a Disk Processor Enclosure (DPE) for controllers and cache, paired with Disk Array Enclosures (DAEs) for drive expansion, offering capacities up to 24 GB in configurations suited for memory-intensive applications like imaging and voice recognition.[18] These systems emphasized high availability through fault-tolerant designs derived from earlier High Availability Disk Array (HADA) prototypes, including data integrity checks via SNiiFER monitoring that appended 8 extra bits per block for error detection.[38] Key features of the early CLARiiON arrays included dual controllers for redundancy, enabling failover to maintain operations during hardware faults, and support for snapshot capabilities in evolving models to facilitate point-in-time data copies for backup and recovery.[18] Scalability was a core strength, allowing configurations to expand from small deskside units to larger rack-mounted setups, with later iterations under Data General reaching multi-terabyte capacities before the 1999 acquisition by EMC Corporation, which extended growth to petabyte scales in subsequent releases.[38] The systems initially used SCSI interfaces for both front-end host connectivity and back-end drive access, providing reliable performance in mid-range environments. To broaden market reach, Data General forged OEM partnerships in the mid-1990s, reselling CLARiiON through vendors including Hewlett-Packard, IBM, Storage Technology Corporation, NEC, Bull, Sun Microsystems, and Silicon Graphics, which integrated the arrays into their UNIX-based server ecosystems for mid-range storage area networks (SANs).[18][38] By 1997, these efforts propelled CLARiiON to generate approximately $500 million in annual revenue, with nearly 60% derived from partner channels, establishing Data General as a leader in sub-$100,000 storage segments for enterprise applications.[39] The CLARiiON platform evolved technically from SCSI-dominant designs to incorporate Fibre Channel interfaces, transitioning front-end connectivity to 2 Gb/s Fibre Channel Arbitrated Loop (FC-AL) for improved bandwidth and distance in SAN deployments.[38] Drive capacities advanced from 3.5-inch 4 GB units to 73 GB models, while controller processing upgraded to configurations with up to four Intel Pentium CPUs at 2 GHz. Following the EMC acquisition in 1999, the lineage continued with the CLARiiON CX series introduced around 2001–2002, which supported 10,000 RPM drives for enhanced input/output operations per second (IOPS) in high-performance scenarios.[2] CLARiiON implemented multiple RAID levels to balance redundancy, capacity, and performance: RAID 0 for striping to maximize throughput at the cost of fault tolerance; RAID 1 for mirroring to ensure data duplication and quick recovery; and RAID 5 for distributed parity, offering efficient storage utilization with single-drive fault tolerance suitable for random I/O workloads.[38] These levels enabled tunable performance, with RAID 0 delivering the highest IOPS for sequential reads (up to drive-limited speeds), RAID 1 providing balanced read/write symmetry around 100–200 IOPS per spindle in typical 1990s configurations, and RAID 5 achieving comparable reads but reduced writes due to parity calculations, often 50–75% of RAID 0 rates in mid-range arrays. Such implementations positioned CLARiiON as a versatile solution for database and file-serving applications demanding both reliability and scalability.Peripherals and Terminals
Data General developed a range of peripherals and terminals to complement its minicomputer systems, emphasizing compatibility with Nova and Eclipse architectures through standardized interfaces like RS-232. These devices facilitated data input, output, and interaction in multi-user environments, supporting operating systems such as RDOS.[66] The Dasher series represented Data General's primary line of CRT-based display terminals, starting with the Dasher D2 introduced in October 1976. The D2 featured a 12-inch diagonal CRT display capable of showing 1,920 characters in a 24-line by 80-column format, using a 96-character ASCII set with options for highlighting such as blink and underscore. It included a detachable typewriter-style keyboard with tactile feedback, N-key rollover, and up to 11 user-defined function keys, connected via a standard RS-232-C interface supporting transmission rates from 110 to 19,200 baud; an optional 20 mA current loop was available, along with a printer interface at 110-1,200 bps. Priced at approximately $1,990 for the base model, the D2 was designed for interactive use with Data General systems, including buffered transmission and compatibility with AOS and RDOS.[66] Evolutions in the Dasher series included the Dasher D3, released in March 1979, which built on the D2 with enhanced editing capabilities and a more advanced keyboard featuring 18 user-defined function keys (expandable to 72 functions), a dedicated numeric pad, and screen management controls. The D3 maintained the 12-inch display with 1,920-character capacity and added programmable attributes like dual-intensity, reverse video, and block fill, while supporting a standard RS-232-C printer interface up to 2,400 baud. Priced at $2,590, it emphasized operator convenience through its sculptured, detachable design and compatibility with earlier Dasher models. Subsequent models like the D4, introduced around 1982, incorporated bitmap graphics support on a 14-inch screen, enabling 80-column text display alongside vector drawing capabilities, further extending the series' utility for graphical applications in Eclipse-based environments.[66][67] Data General's output peripherals included line printers and magnetic tape drives optimized for Nova and Eclipse systems. The model 4326 line printer operated at 300 lines per minute (LPM) with 132 columns and a 96-character set supporting upper- and lower-case text, using a programmed input/output (PIO) interface; it was compatible with Eclipse-based CS/200 series computers and offered optional multilingual fonts for international use. For backups and data transfer, the 6026 9-track tape transport and controller provided densities of 800 or 1,600 bits per inch (bpi) on 10.5-inch reels, supporting up to eight drives per controller at 75 inches per second; it was designed for microEclipse and Eclipse systems in the CS/100 and CS/200 series. An additional 1,600 bpi streaming tape drive handled 8.5-inch reels at 30 inches per second offline, ensuring reliable archival storage integrated with RDOS batch operations.[68][69] Keyboards for Data General terminals adopted custom QWERTY layouts tailored to RDOS prompts, featuring a main typewriter-style array, a 14-key numeric section, a 12-key screen management keypad for cursor and editing functions, and a 15-key user function keypad for system-specific commands. These capacitively switched, solid-state keys ensured reliability in multi-user setups. Expansion cards, such as general-purpose interface boards, allowed integration of custom peripherals into Nova and Eclipse I/O buses, supporting asynchronous terminal subsystems and RDOS device drivers without altering core system architecture.[70][71] Dasher terminals integrated seamlessly with later Data General systems like the MV and AViiON series through serial ports, enabling console and keyboard operations. The following table outlines key compatibility aspects:| System | Interface | Key Features Supported | Notes |
|---|---|---|---|
| MV Series | RS-232 Serial | Keyboard entry, SCM commands (e.g., ATTACH, BOOT) | Up to 19,200 baud; Dasher D3/D4 for interactive processing[17] |
| AViiON 530/4600 | RS-232 Asynchronous (DB9/DB25) | Terminal attachment, baud rate configuration via SCM | Dasher keyboards compatible; avoids ports B/C for console; supports job processors[72] |