Systems Engineering Laboratories

Last updated

Systems Engineering Laboratories (also called SEL) was a manufacturer of minicomputers in Fort Lauderdale, Florida. It was one of the first 32-bit realtime computer system manufacturers. Realtime computers are used for process control and monitoring.



Systems Engineering Laboratories was founded and incorporated in Fort Lauderdale, Florida in 1959, [1] [2] at the beginning of the breakout of minicomputers from 16-bit to larger architectures.

SEL was purchased by Gould Electronics in 1981 [3] and was operated essentially unchanged as the Gould Computer Systems Division (CSD). The parent company was acquired by Nippon Mining in 1988, but as part of the U.S. government approval of the deal, Nippon Mining was required to divest the Gould divisions that did work for the Department of Defense, including the Computer Systems Division. [4] Later, in 1989, Encore Computer Corporation (about 250 employees) bought the computer division (about 2500 employees) from Nippon Mining. Parts of Encore were sold off over the years, with the last major spin-off being their Storage Products Group, sold to Sun Microsystems in 1997. This left the company consisting primarily of their real-time group (the original SEL core) and returned to this business niche after renaming themselves Encore Real Time Computing. In 2002, Compro Computer Services, Inc. (a former service competitor, and later service partner) obtained SEL/Gould/Encore real-time technological assets through its acquisition of Encore Real Time Computing, Inc., and continues support of the legacy SelBUS-based product line as far back as the 32/55 and offers an upgrade path using the Legacy Computer Replacement System (LCRS) hardware simulator. Compro Computer Services, Inc continue trading as Encore in Europe, COMPRO continues the tradition of long-term product support by offering replacement solutions (e.g., the Legacy Computer Replacement System, or LCRS) that emphasize backward-compatibility coupled with future-proofing. Gould (as well as its primary competitors MASSCOMP, Harris and Concurrent) were driven into the ground by general purpose microprocessor Unix designs such as those by Sun and SGI.

Computer products

SEL 800 series

SEL's first computers the 810 & 840 use all silicon monolithic integrated circuits. The 810 has a 16 bit word size while the 840 has a 24 bit word size. Core memory for both is in 4096 word increments up to 32,768 words with a 1.75 μsec machine full cycle time. They featured a complete software package for real-time applications and a FORTRAN package for off-line scientific computation. Options included external disk or drum storage and any "standard" peripheral. [5]

The 810A [6] and 840A [7] are somewhat enhanced versions of the earlier models.

The 810B [8] has a 750 nanosec full cycle time with an 8K work memory expandable to 32K.

The multiprocessing 840MP can be configured for up to three CPUs with 32k 24-bit words each and sharing a 64K core bank. It uses the 840A software and peripherals. [9]

SEL 32 series

In 1975, the Model 32/55 computer was introduced along with a new bus architecture called the SelBUS. [10] This system was one of the industry's first true 32-bit superminicomputers along with the PerkinElmer 8/32. [11]

The bus speed was 26.6 megabytes per second, which was a record at the time of its introduction. The CPU of the 32/55 was composed of three wire-wrapped boards bolted together. The use of a bus instead of a wire-wrapped backplane simplified manufacturing, lowered costs, and made system enhancements easier. Multilayer printed circuit boards were introduced with the 32/75 about a year later, and single-board CPUs were introduced as the 32/27 [12] shortly thereafter. Core memory was replaced by semiconductor memory.

The SEL 32 series became extremely popular in many technical markets such as aircraft simulation, oil exploration, electric power system control, and the beginnings of computer animation. Gould/SEL computers were used to animate the opening sequence for Steven Spielberg's television series "Amazing Stories".

SEL 32/x7 and 6000-9000 series

In the early 1980s, SEL introduced a system based on emitter-coupled logic (ECL) technology code named the Thunderbird. Its official marketing name became the Concept series, consisting of three models: the low-end Concept 32/67 [13] , and the refrigerator-sized Concept 32/87 [14] and 32/97. These ran the company's proprietary MPX-32 operating system. With the additional of virtual memory hardware, the 32/67 and 32/97 models took on the designations of Powernode 6000 and Powernode 9000, with several variants of each available. These ran UTX-32, Gould's version of Unix based on a BSD 4.2 kernel developed by Purdue University to support multiprocessor systems. [15] The Powernode 9080 was a symmetrical dual processor system, with both processors having full access to memory and the I/O bus, and capable of being booted up from either processor. It was the first such commercially available system to run any version of Unix.

The CPU for these system ballooned to about a dozen boards because of the low-density ECL chip footprint. As a result, CPUs could only be placed at each end of the SELbus, limiting computer systems to two CPUs. It had modular cache memory that could be upgraded. The ECL circuitry consumed huge amount of current at a very low voltage; the cabinets of the larger models contained extra rack space which held stacks of 400-amp power supplies, and heavy-gauge wiring leading to the backplane. In the mid-1990s, the RSX computer board featured RISC processing capabilities and high speed 75 ns static RAM design (essentially an all-cache design) while maintaining complete binary compatibility with existing programs.

Gould/SEL's "High Speed Data interface" or HSD was considered an industry standard in the process control industry.[ according to whom? ]


One of Gould's primary contributions to the real-time computing world was its "Reflective Memory" technology which allowed up to eight computers to share memory at a very high speed.

When Encore Computer acquired Gould's Computer Systems division, the new Encore switched to using Motorola 88100 series of chips and a Unix-based OS. They built a small Unix based system known as the Encore-91 which included a number of RT extensions including a "micro-MPX environment."

Encore used the real-time reflective memory design from Gould along with their 88100 based systems and Umax OS to create a line of high-density storage devices. Known as the Infinity-90 product these acted as large SANs for Unix, Windows and Mainframe computers with data sharing capabilities. In 1997 Encore sold this product line to Sun Microsystems where it was marketed as the A7000. It was not very successful and eventually canceled by Sun. About 200 Encore employees went to Sun in this exchange.

Because of the long-life support requirements of nuclear plants and military flight simulators, there are still companies in existence today providing support and parts for Gould/SEL systems.


SEL had a proprietary operating system called Real Time Monitor (RTM) which, although extremely fast, had limited user interface. It supported a console for command entry, and would support up to 16 users via the ALIM interface. When the SEL 32 systems were introduced, SEL created another operating system called MPX-32 which supported multiprocessing and multiple users. Later, in the early 1980s, SEL adopted the Unix operating system. As "Gould CSD" (Computer System Division) then introduced the UTX-32 Unix-based OS that included both BSD and System V characteristics. At a time when there was a "religious war" between BSD and System V advocates, Gould developed this "dual universe" system that contained nearly all of the features of both BSD 4.2 and System V.4. The user made the selection of which environment would be used by setting a few shell variables. (However, clever programmers soon discovered that by customizing search paths, they could mix utilities, system calls and libraries from both environments.) A special secure version, designated UTX-32S , was one of the first Unix based systems to receive NSA's C2 security level certification. [16]

See also

Related Research Articles

Microprocessor Computer processor contained on an integrated-circuit chip

A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit (IC) of MOSFET construction. The microprocessor is a multipurpose, clock driven, register based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory and provides results as output. Microprocessors contain both combinational logic and sequential digital logic. Microprocessors operate on numbers and symbols represented in the binary number system.

Operating system Software that manages computer hardware resources

An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.


The DECSYSTEM-20 was a 36-bit Digital Equipment Corporation PDP-10 mainframe computer running the TOPS-20 operating system.

PA-RISC instruction set architecture developed by Hewlett-Packard

PA-RISC is an instruction set architecture (ISA) developed by Hewlett-Packard. As the name implies, it is a reduced instruction set computer (RISC) architecture, where the PA stands for Precision Architecture. The design is also referred to as HP/PA for Hewlett Packard Precision Architecture.

VAX Computer architecture, and a range of computers

VAX is a line of computers developed by Digital Equipment Corporation (DEC) in the mid-1970s. The VAX-11/780, introduced on October 25, 1977, was the first of a range of popular and influential computers implementing the VAX instruction set architecture (ISA).

The NS32000, sometimes known as the 32k, is a series of microprocessors produced by National Semiconductor. The first member of the family, the 32016, came to market in 1982, making it the first 32-bit general-purpose microprocessor on the market. However, the 32016 contained a large number of bugs and often could not be run at its rated speed. These problems, and the presence of the similar Motorola 68000, led to almost no use in the market.

The 88000 is a RISC instruction set architecture (ISA) developed by Motorola during the 1980s. The MC88100 arrived on the market in 1988, some two years after the competing SPARC and MIPS. Due to the late start and extensive delays releasing the second-generation MC88110, the m88k achieved very limited success outside of the MVME platform and embedded controller environments. When Motorola joined the AIM alliance in 1991 to develop the PowerPC, further development of the 88000 ended.

Amiga 3000

The Commodore Amiga 3000, or A3000, is a personal computer released by Commodore in June 1990. It features improved processing speed, improved graphics rendering, and a new revision of the operating system. It is the successor to the Amiga 2000.

Ultrix is the brand name of Digital Equipment Corporation's (DEC) discontinued native Unix operating systems for the PDP-11, VAX, MicroVAX and DECstations.

Version 7 Unix

Seventh Edition Unix, also called Version 7 Unix, Version 7 or just V7, was an important early release of the Unix operating system. V7, released in 1979, was the last Bell Laboratories release to see widespread distribution before the commercialization of Unix by AT&T Corporation in the early 1980s. V7 was originally developed for Digital Equipment Corporation's PDP-11 minicomputers and was later ported to other platforms.

DECstation brand of computers

The DECstation was a brand of computers used by DEC, and refers to three distinct lines of computer systems—the first released in 1978 as a word processing system, and the latter two both released in 1989. These comprised a range of computer workstations based on the MIPS architecture and a range of PC compatibles. The MIPS-based workstations ran Ultrix, a DEC-proprietary version of UNIX, and early releases of OSF/1.

XNU computer operating system kernel

XNU is the computer operating system (OS) kernel developed at Apple Inc. since December 1996 for use in the macOS operating system and released as free and open-source software as part of the Darwin OS, which is the basis for the Apple TV Software, iOS, iPadOS, watchOS, and tvOS OSes. XNU is an abbreviation of X is Not Unix.

Atari TT030 personal computer model

The Atari TT030 is a member of the Atari ST family, released in 1990. It was originally intended to be a high-end Unix workstation, however Atari took two years to release a port of Unix SVR4 for the TT, which prevented the TT from ever being seriously considered in its intended market.


The Sun-2 series of UNIX workstations and servers was launched by Sun Microsystems in November 1983. As the name suggests, the Sun-2 represented the second generation of Sun systems, superseding the original Sun-1 series. The Sun-2 series used a 10 MHz Motorola 68010 microprocessor with a proprietary Sun-2 Memory Management Unit (MMU), which enabled it to be the first Sun architecture to run a full virtual memory UNIX implementation, SunOS 1.0, based on 4.1BSD. Early Sun-2 models were based on the Intel Multibus architecture, with later models using VMEbus, which continued to be used in the successor Sun-3 and Sun-4 families.

NEC V60 microprocessor model

NEC V60 was a CISC microprocessor manufactured by NEC starting in 1986. It has an MMU, and RTOS support both for Unix-based user-application-oriented systems and for I‑TRON based hardware-control-oriented embedded systems. This article also describes V70 and V80 as these share the same ISA as the V60. In addition, dedicated co-FPP, multi-cpu lockstep fault-tolerant mechanism named FRM, development tools including Ada certified system MV‑4000, and ICE are described. Their successor the V800 Series product families are briefly introduced.

Encore Computer was an early pioneer in the parallel computing market, based in Marlborough, Massachusetts. Although offering a number of system designs beginning in 1985, they were never as well known as other companies in this field such as Pyramid Technology, Alliant, and the most similar systems Sequent and FLEX.

VAX 8000

The VAX 8000 is a discontinued family of minicomputers developed and manufactured by Digital Equipment Corporation (DEC) using processors implementing the VAX instruction set architecture (ISA).

The PowerNode 9080 was a dual processor 32-bit Superminicomputer produced by Fort Lauderdale, Florida based electronics company Gould Electronics in the 1980s. Its UTX/32 4.3BSD Berkeley Unix-based operating system was one of the very first multi-processor shared memory implementations of Unix, although the processors operated in a Master-Slave configuration with a Mutual Exclusion (MutEx) lock on all Kernel IO resources. Machines could be configured for either single or dual processor operation.

Honeywell Level 6

The Honeywell Level 6 was a line of 16-bit minicomputers, later upgraded to 32-bit, manufactured by Honeywell, Inc. from the mid 1970s. In 1979 the Level 6 was renamed the DPS 6, subsequently DPS 6 Plus and finally DPS 6000.


  1. Peterson's Engineering, Science, & Computer Jobs. Peterson's Guides. 1986. ISBN   978-0-87866-348-4.
  2. Modern Data Products, Systems, Services. Delta Publications. 1969.
  3. The Economist. Economist Newspaper Limited. 1984.
  4. Markoff, John (31 August 1988). "Gould To Be Acquired By Nippon Mining". New York Times. Retrieved 22 April 2016.
  5. Datamation, April 1975, p.75
  6. "SEL 810A General Purpose Computer" (PDF). Systems Engineering Laboratories. 1967. Retrieved April 3, 2020.
  7. "SEL 840A General Purpose Digital Computer" (PDF). Systems Engineering Laboratories. April 1966. Retrieved April 3, 2020.
  8. Reference Manual SEL 810B General Purpose Computer (PDF). Systems Engineering Laboratories. November 1968. Retrieved April 3, 2020.
  9. Datamation, November 1966, p.19
  10. Surden, Esther; Lundell, Jr., E. Drake (31 December 1975 — 5 January 1976). "Rapid Growth at Top and Bottom of Range Marks Year". Computerworld. Newton, Massachusetts: Computerworld, Inc. 9 (53): 33. Retrieved 9 November 2011.Check date values in: |date= (help)
  11. "32-Bit Mini Becomes Hot Topic Among Users". Computerworld. 27 July 1981. p. 7.
  12. "Concept 32/27" (PDF). Gould. 307323420-002.
  13. "SEL Introduces Line of 32-Bit Minis". Computerworld. 28 February 1983. p. 51.
  14. "Gould Speeds Up 32-Bit Concept Mini Line". Computerworld. 21 June 1982. p. 5.
  15. "Employees Who Made Early Contributions: George Goble". Purdue University. Retrieved 22 April 2016.
  16. "A Guide to Understanding Design Documentation in Trusted Systems". National Computer Security Center. 2 October 1988. p. 29. NSC-TG-007.