Mentec

M70 The M70 was developed between 1982 and 1984. It was a quad Q-bus module based on the J-11 chipset incorporating onboard ECC DRAM, bootstrap EPROMs and 4 serial lines implemented using DEC DC319 DLART chips. M71 The M71 was a version of the M70 intended for process control. It provided for 1/4 or 1 M Byte of ECC DRAM, up to 1/2 MB of EPROM, lines (DC-319 DLARTs) and two parallel ports implemented using 8255 chips. It was initially designed by Mentec for use in its own Remote Terminal Units. M80 The M80 was a further development of the M70 but using parity memory and a slightly higher clock rate. It also introduced software configuration via the bootstrap which all but eliminated wire-wrap configuration. M90 This was effectively merely a clock tweaked version of the M80. M100 The M100, a redesign of the 11/93, was the last of Mentec's J-11 based processor boards. The M1 used an Atmel 0.85 μm ASIC for 5 V operation. ==PDP-11 operating systems==

RSX-11 Ownership of RSX-11S, RSX-11M, RSX-11M Plus and Micro/RSX was transferred from DEC to Mentec Inc. in March 1994 as part of a broader agreement. In 2006 Mentec Inc. was declared bankrupt while Mentec Ltd. was acquired by Irish firm Calyx in December 2006. The PDP-11 software, which was owned by Mentec Inc. was then bought by XX2247 LLC, which is the owner of the software today. It is unclear if new commercial licenses are possible to buy at this time. Hobbyists can run RSX-11M (version 4.3 or earlier) and RSX-11M Plus (version 3.0 or earlier) on the SIMH emulator thanks to a free license granted in May 1998 by Mentec Inc. Legal ownership of RSX-11A, RSX-11B, RSX-11C, RSX-11D, and IAS never changed hands; therefore it passed to Compaq when it acquired DEC in 1998 and then to Hewlett-Packard in 2002. In late 2015 Hewlett-Packard split into two separate companies (HP Inc. and Hewlett Packard Enterprise), so the current owner cannot be firmly established. New commercial licenses have not been issued at least since October 1979 (RSX-11A, RSX-11B, RSX-11C) or 1990 (IAS), and none of these operating systems was ever licensed for hobbyist use. RSTS In 1997 DEC and Mentec granted anyone wishing to use RSTS 9.6 or earlier for non-commercial, hobby purposes a no-cost license. The license is only valid on the SIMH PDP-11 emulator. The license also covers some other DEC operating systems. Copies of the license are included in authorized software kit available for download on the official website of the SIMH emulator. ==References==