Mentec

Mentec was an Irish technology company established in 1978. Its original business focused on monitoring and control software and systems, placing it within the industrial-computing and process-control sector rather than the consumer electronics market. The company became a significant reseller and original-equipment manufacturer associated with Digital Equipment Corporation, or DEC, in Ireland. This relationship gave Mentec access to DEC’s hardware and software ecosystem while allowing it to build specialized systems and products for industrial and technical customers. A major part of Mentec’s early activity involved remote terminal units. During the early 1980s, the company offered a family of units based on DEC’s SBC/11-21, known by the Falcon designation. These systems reflected Mentec’s practical focus on connecting computing equipment to industrial processes and remote operational environments. The company subsequently developed its own PDP-11-compatible processor products after DEC’s J-11 PDP-11 chipset became available in 1982. Mentec’s first major PDP-11 single-board computer was the M70, developed between 1982 and 1984. It was followed by related boards including the M71, M80, M90, and M100. These products used Q-Bus-compatible architectures and integrated features such as error-correcting or parity memory, serial communications, bootstrap firmware, EPROM, parallel interfaces, and optional floating-point hardware. The M71 was tailored particularly toward process-control applications, while the M100 represented a later and faster redesign of the DEC 11/93 concept. Mentec’s hardware was aimed at extending the useful life of PDP-11 systems and supplying compatible processing platforms for industrial and original-equipment applications. The company also pursued more ambitious processor technology. The M11 implemented the PDP-11 instruction set through a microcoded design using Texas Instruments arithmetic and sequencing components, with an Intel i960 used for microcode loading, floating-point functions, and console support. The later M1 translated the M11 concept into an ASIC-based implementation. These designs demonstrated Mentec’s engineering effort to preserve and advance a mature minicomputer architecture as original DEC processor technology evolved. Mentec’s relationship with DEC expanded beyond hardware. In 1994, DEC transferred ownership of several PDP-11 operating systems to Mentec Inc. The transferred software included RSX-11S, RSX-11M, RSX-11M Plus, and Micro/RSX. Mentec therefore became an important commercial and custodial entity for parts of the PDP-11 software legacy. In 1997, DEC and Mentec also provided no-cost licenses for non-commercial hobby use of RSTS 9.6 and earlier versions on the SIMH PDP-11 emulator. In May 1998, Mentec Inc. granted hobbyists a free license for specified versions of RSX-11M and RSX-11M Plus on SIMH. The corporate history later diverged between Mentec Inc. and Mentec Ltd. Mentec Inc. was declared bankrupt in 2006. Mentec Ltd. was acquired by the Irish firm Calyx in December 2006. The PDP-11 software held by Mentec Inc. was subsequently acquired by XX2247 LLC, although the availability of new commercial licenses has been unclear. The surviving software and hardware references mean that Mentec remains significant in the history of PDP-11-compatible computing, industrial control, and legacy-system preservation, even though the original corporate businesses are no longer active as a unified operating company.

Mentec was founded in Ireland in 1978 and initially developed monitoring and control software and systems. Its early commercial identity was closely connected with Digital Equipment Corporation. Mentec became a substantial DEC reseller and OEM in Ireland, combining distribution and integration work with its own engineering activity. The company’s early-1980s products included remote terminal units built around DEC’s SBC/11-21 architecture, also referred to as Falcon systems. These units were intended for remote and industrial applications, consistent with Mentec’s original concentration on control and monitoring environments. The availability of DEC’s J-11 PDP-11 chipset in 1982 enabled Mentec to begin designing its own PDP-11 single-board computers. The first of these was the M70, developed from 1982 to 1984. The M70 used four Q-Bus modules and incorporated the J-11 chipset, onboard ECC DRAM, bootstrap EPROMs, and four serial lines implemented with DEC DC319 DLART components. Mentec extended the design into the M71, a process-control variant. It supported configurable ECC DRAM and EPROM, four serial ports, and two parallel ports based on 8255 components. The product was initially developed for Mentec’s own remote terminal units. The M80 introduced parity memory and a higher clock rate than the M70, while software configuration through the bootstrap reduced the need for physical wire-wrap configuration. The M90 was essentially a clock-enhanced version of the M80. The M100 became the final Mentec processor board based on the J-11 chipset. It was a redesigned and faster version of the DEC 11/93 concept, operating the J-11 at 19.66 MHz and offering four integrated serial ports, one to four megabytes of onboard memory, and an optional floating-point unit. Some later variants used daughter cards that replaced the DLART implementation with a Xilinx device and added FIFO buffering for OEM applications. Other late examples substituted SRAM for onboard DRAM. Mentec also investigated a more original processor implementation. The M11 was a microcoded PDP-11 instruction-set processor designed as an upgrade for the M100. It used two Texas Instruments TI8832 arithmetic logic units and a TI8818 microsequencer. One arithmetic unit served as the processor ALU and the other implemented memory management. An Intel i960 handled microcode loading, IEEE-format floating-point operations, and ODT functions. Serial interfaces were emulated through a Xilinx device, and SRAM was used for both microcode and main memory. The design was written in VHDL and simulated before hardware construction, with DEC PDP-11/23 diagnostic software used during validation. The M1 followed as an ASIC implementation of the M11’s PDP-11 architecture. Although implemented in silicon rather than assembled from the M11’s discrete microcoded components, it retained a microcoded design and used an Atmel 0.85-micrometre ASIC process for five-volt operation. Mentec’s role expanded in software preservation and licensing. In March 1994, DEC transferred RSX-11S, RSX-11M, RSX-11M Plus, and Micro/RSX to Mentec Inc. Other operating systems, including RSX-11A through RSX-11D and IAS, did not follow the same ownership path and remained associated with DEC and its successors. In 1997, DEC and Mentec made RSTS 9.6 and earlier available under a no-cost license for non-commercial hobby use with SIMH. In May 1998, Mentec Inc. similarly granted hobbyist access to specified versions of RSX-11M and RSX-11M Plus through SIMH. The later corporate history involved separate entities. Mentec Inc. was declared bankrupt in 2006. Mentec Ltd. was acquired by Calyx, an Irish company, in December of that year. The software owned by Mentec Inc. was subsequently acquired by XX2247 LLC. The exact availability of new commercial licenses has remained uncertain. Mentec is therefore best understood as a defunct or no-longer-unified specialist technology company whose historical importance rests on industrial control, DEC resale and OEM activity, PDP-11-compatible hardware, and preservation of legacy operating systems.

• 2006

  Corporate restructuring and bankruptcy

  [1]Mentecen.wikipedia.org

  Mentec Inc. is declared bankrupt, while Mentec Ltd. is acquired by Calyx in December; the Mentec Inc. PDP-11 software assets subsequently move to XX2247 LLC.

• 1998

  Selected RSX systems receive hobbyist licensing

  [1]Mentecen.wikipedia.org

  Mentec Inc. grants free hobbyist use of specified RSX-11M and RSX-11M Plus versions on SIMH.

• 1997

  RSTS hobby license is established

  [1]Mentecen.wikipedia.org

  DEC and Mentec provide a no-cost non-commercial license for RSTS 9.6 and earlier releases when run on the SIMH emulator.

• 1994

  DEC transfers selected PDP-11 operating systems

  [1]Mentecen.wikipedia.org

  DEC transfers RSX-11S, RSX-11M, RSX-11M Plus, and Micro/RSX to Mentec Inc.

• 1984

  M70 development is completed

  [1]Mentecen.wikipedia.org

  Mentec completes development of the M70, a J-11-based Q-Bus processor board developed between 1982 and 1984.

• 1982

  J-11 chipset becomes available and Mentec begins PDP-11 board development

  [1]Mentecen.wikipedia.org

  The availability of DEC’s J-11 PDP-11 chipset leads Mentec to start designing its own PDP-11-compatible single-board computers.

• 1978

  Mentec is founded

  [1]Mentecen.wikipedia.org

  Mentec International Ltd. is established in Ireland with an initial focus on monitoring and control software and systems.

A specialist industrial-computing and legacy DEC technology company focused on monitoring and control systems, PDP-11-compatible hardware, OEM integration, and stewardship of PDP-11 operating systems.

• Industrial control equipment

  Falcon remote terminal units

  Mentec’s early-1980s remote terminal units were based on DEC’s SBC/11-21 architecture. They represented the company’s original emphasis on monitoring and control, providing a DEC-compatible computing foundation for remote industrial and process-control applications.

• PDP-11-compatible processor board · 1984

  M70

  Developed between 1982 and 1984, the M70 was Mentec’s first PDP-11 single-board computer. It used the DEC J-11 chipset in a four-module Q-Bus design and included ECC DRAM, bootstrap EPROMs, and four serial interfaces based on DEC DC319 DLART components.

• Process-control processor board

  M71

  The M71 was a process-control-oriented version of the M70. It supported selectable ECC DRAM, substantial EPROM capacity, four serial connections, and two parallel ports implemented with 8255 devices. Mentec first designed it for its own remote terminal units.

• PDP-11-compatible processor board

  M80

  The M80 developed the M70 design with parity memory, a somewhat higher clock rate, and software configuration through the bootstrap process. The latter feature substantially reduced dependence on manual wire-wrap configuration during system setup.

• PDP-11-compatible processor board

  M90

  The M90 was primarily a clock-enhanced continuation of the M80. It retained the general Mentec PDP-11-compatible board approach while providing a faster processor implementation for systems that required additional performance.

• PDP-11-compatible processor board

  M100

  The M100 was Mentec’s final J-11-based processor board and a redesign of the DEC 11/93 concept. It ran the J-11 at 19.66 MHz, provided four onboard serial ports, supported one to four megabytes of onboard memory, and offered an optional floating-point unit. Some later units added Xilinx-based serial buffering or SRAM daughter cards for OEM configurations.

• Microcoded PDP-11 processor upgrade

  M11

  The M11 was a new microcoded implementation of the PDP-11 instruction set intended as an upgrade-board replacement for the M100. It used two TI8832 ALUs and a TI8818 microsequencer, with an Intel i960 supporting microcode loading, floating-point operations, and ODT. Mentec designed it in VHDL and simulated the architecture before producing hardware.

• ASIC PDP-11 processor upgrade

  M1

  The M1 was an ASIC realization of the M11’s PDP-11 implementation. It remained microcoded despite its ASIC form and used an Atmel 0.85-micrometre device designed for five-volt operation.

• Operating-system software · 1994

  RSX-11 operating systems

  Mentec Inc. held the transferred rights to RSX-11S, RSX-11M, RSX-11M Plus, and Micro/RSX from 1994. Selected versions later became available to hobbyists under free licenses for use with the SIMH PDP-11 emulator. Commercial licensing after the later transfer of ownership is not clearly established.

• Operating-system software licensing · 1997

  RSTS licensing

  In 1997, DEC and Mentec made RSTS version 9.6 and earlier available for non-commercial hobby use on SIMH at no cost. The license was distributed with authorized software kits associated with the emulator.

• 2006

  Separate corporate outcomes for Mentec Ltd. and Mentec Inc.M&A

  Background

  The Irish Mentec Ltd. and United States-based Mentec Inc. were separate corporate entities with different assets and obligations.

  Action taken

  Mentec Ltd. was acquired by Calyx, while Mentec Inc. entered bankruptcy and its PDP-11 software assets were later acquired by XX2247 LLC.

  Aftermath

  Mentec ceased to function as a unified operating brand, and ownership of its historical software and corporate assets became divided.

  Source

• 1998

  Grant hobbyist access to selected RSX releasesStrategy

  Background

  Mentec controlled several RSX operating-system rights and the SIMH emulator provided a practical environment for legacy PDP-11 software.

  Action taken

  Mentec Inc. granted free licenses for specified versions of RSX-11M and RSX-11M Plus for hobbyist use on SIMH.

  Aftermath

  The license helped preserve selected RSX releases, although it did not establish unrestricted commercial licensing for the broader RSX family.

  Source

• 1997

  Support non-commercial preservation of RSTSStrategy

  Background

  PDP-11 systems were becoming legacy platforms, while emulator-based preservation offered a way to keep historical software usable.

  Action taken

  Mentec and DEC granted a no-cost hobby license for RSTS 9.6 and earlier versions on the SIMH PDP-11 emulator.

  Aftermath

  The decision supported the preservation and non-commercial use of RSTS within the retrocomputing community.

  Source

• 1994

  Accept transfer of selected PDP-11 operating-system rightsM&A

  Background

  DEC was reorganizing responsibility for parts of its PDP-11 software portfolio, while Mentec already had a close hardware and OEM relationship with DEC.

  Action taken

  Mentec Inc. accepted ownership of RSX-11S, RSX-11M, RSX-11M Plus, and Micro/RSX.

  Aftermath

  The transfer made Mentec a key commercial custodian of several PDP-11 operating systems and later enabled selected hobbyist licensing through SIMH.

  Source

1. 1Mentecen.wikipedia.org