Systems Engineering Laboratories

Systems Engineering Laboratories
Company type	Private
Industry	Computer hardware, Real-time computing
Founded	January 1, 1959; 67 years ago in Fort Lauderdale, Florida, United States
Fate	Acquired by Gould Electronics in 1981
Successor	Gould Computer Systems Division, later Encore Computer Corporation
Headquarters	Fort Lauderdale, United States
Products	16-bit, 24-bit, and 32-bit real-time minicomputers; proprietary operating systems (RTM, MPX-32, UTX-32)
Number of employees	2500 (1989)

Systems Engineering Laboratories (SEL), established in 1959 in Fort Lauderdale, Florida, was a trailblazer in the development of 32-bit real-time minicomputers, with a focus on process control and monitoring solutions. By 1966, SEL significantly contributed to the evolution of minicomputer technology by advancing from 16-bit to 24-bit architectures.

In 1981, Gould Electronics acquired SEL, integrating it as the Gould Computer Systems Division. After Gould itself was purchased by Nippon Mining in 1988, U.S. government regulations mandated the divestiture of defense-related components, including this division. As a result, Encore Computer Corporation took over the Computer Systems Division in 1989, inheriting a workforce of approximately 2,500 employees.

Encore gradually sold off several business units, culminating in the 1997 sale of its Storage Products Group to Sun Microsystems. Refocusing on SEL’s original expertise in real-time computing, the company rebranded as Encore Real Time Computing. In 2002, Compro Computer Services acquired Encore Real Time Computing’s assets and continues to provide support for legacy SEL systems through offerings such as the Legacy Computer Replacement System (LCRS), which prioritizes compatibility with existing platforms while preparing for future needs.

Throughout its history, SEL and its successors encountered fierce competition from general-purpose Unix-based microprocessor systems developed by companies like Sun Microsystems and Silicon Graphics. This competition gradually diminished their dominance in the specialized real-time computing market.

SEL 800 series

The first computers produced by SEL—the 810 and 840 models—utilized all-silicon monolithic integrated circuits. The 810 operated with a 16-bit word length, whereas the 840 employed 24-bit words. Both systems supported core memory capacities ranging from 4,096 to 32,768 words with a full cycle time of 1.75 microseconds. They included comprehensive software suites tailored for real-time applications as well as FORTRAN compilers designed for scientific tasks. Optional external storage devices such as disks or drums and standard peripheral equipment were also available.

Upgraded versions like the 810A and 840A followed these initial models. The 810B offered enhanced performance through a faster cycle time of 750 nanoseconds and expandable memory options from 8K up to 32K words. The multiprocessing variant, the 840MP, supported configurations of up to three CPUs, each featuring 32K words of 24-bit memory sharing a common 64K core bank while running the same software and utilizing peripherals compatible with the 840A.

SEL 32 series

Launched in 1975, the Model 32/55 introduced the innovative SelBUS architecture and stood among the earliest true 32-bit superminicomputers on the market, alongside PerkinElmer's 8/32 system. At debut, its bus achieved an unprecedented speed of 26.6 megabytes per second. The CPU design consisted of three wire-wrapped circuit boards, which simplified assembly processes and lowered manufacturing expenses compared to conventional backplane designs.

Later variants such as the 32/75 incorporated multilayer printed circuit boards, while the single-board CPU design was introduced with the Model 32/27. These systems transitioned from using core memory to semiconductor memory technologies.

The SEL 32 series captured significant market share within technical fields including aircraft simulation, petroleum exploration, electric power grid management, and pioneering computer animation efforts. A notable example includes Gould/SEL computers being utilized in creating the opening animation sequence for Steven Spielberg's television program Amazing Stories.

SEL 32/x7 and 6000-9000 series

During the early 1980s, SEL introduced the Thunderbird system, which utilized emitter-coupled logic (ECL) technology and was marketed under the Concept series name. This lineup included three models: the Concept 32/67, 32/87, and 32/97. These systems operated on the proprietary MPX-32 operating system. With the addition of virtual memory hardware, the 32/67 and 32/97 models were further developed into the Powernode 6000 and Powernode 9000 series, respectively. These newer systems ran UTX-32, a Unix variant derived from BSD 4.2 and developed at Gould's Urbana-Champaign UNIX center, designed to support multiprocessor configurations. The Powernode 9080 stood out by featuring symmetrical dual processors with equal access to memory and I/O buses, marking it as a pioneer in commercial Unix multiprocessor technology.

Due to the use of low-density ECL chips, each CPU consisted of roughly a dozen circuit boards, which limited system expansion to two CPUs per SELbus. The cache memory was modular and could be upgraded as needed. ECL technology required high current at low voltage levels, necessitating robust power supplies and heavy cabling, especially in larger cabinet setups. By the mid-1990s, the introduction of the RSX board brought RISC processing capabilities along with high-speed static RAM while preserving binary compatibility with existing software environments.

Gould/SEL’s High Speed Data (HSD) interface became widely recognized as an industry standard within process control applications.

Other

Gould made a notable contribution to real-time computing through its Reflective Memory technology, which allowed up to eight computers to share memory efficiently at high speeds.

Following Gould’s divestiture of its Computer Systems division, Encore Computer adopted Motorola 88100 processors along with a Unix-based operating system to develop the Encore-91 system. This product featured real-time extensions including a micro-MPX environment. Leveraging Gould’s reflective memory architecture combined with their own hardware and Umax operating system, Encore created the Infinity-90 line—a series of high-density storage devices functioning as storage area networks (SANs) compatible with Unix, Windows, and mainframe platforms. In 1997, this product line was sold to Sun Microsystems, rebranded as the A7000; however, it was eventually discontinued. Approximately 200 employees from Encore transitioned to Sun as part of this acquisition.

Due to ongoing requirements for long-term support in nuclear facilities and military flight simulators, service providers continue maintaining Gould/SEL systems today.

Software

To complement its hardware offerings and business strategy, SEL developed several proprietary operating systems. Initially, the Real Time Monitor (RTM) provided rapid performance but featured a limited user interface, supporting up to sixteen users via the ALIM interface. With the launch of SEL 32 systems, SEL introduced MPX-32, which enabled both multiprocessing and multiuser functionality. In the early 1980s, through its Gould Computer System Division, SEL embraced Unix by releasing UTX-32—an operating system that merged features from both BSD and System V Unix variants. This hybrid environment allowed users to select or combine utilities from either Unix flavor, enhancing operational flexibility and competitive positioning. Of particular note was UTX-32S, a secure iteration that became one of the first Unix-based systems certified at NSA’s C2 security level, highlighting SEL’s dedication to delivering secure enterprise solutions.

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