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= LinuxCNC History
[[cha:linuxcnc-history]] (((LinuxCNC History)))
EMC (the Enhanced Machine Controller) was created by
http://www.nist.gov/index.html[NIST] , the National Institute of Standards
and Technology, which is an agency of the Commerce Department of the United
States government.
NIST first became interested in writing a motion control package as a test
platform for concepts and standards. Early sponsorship from General Motors
resulted in an adaptation of the fledgling version of EMC using PMAC
intelligent control boards running under a 'real time' version of Windows NT
and controlling a large milling machine.
As is required of all 'work product' of US federal government employees,
the resulting software and the report about it are required to be in the
public domain and a report about it was duly published, including on the
Internet. It was there that Matt Shaver discovered EMC. He contacted NIST
and entered into discussions with Fred Proctor about adapting the code for
use in controlling less expensive hardware to be used for upgrades and
replacements of CNC controls that were obsolete or just plain dead. NIST
was intrigued because they too wanted something less expensive. In order to
launch a cooperative effort, a formal agreement was created which guaranteed
that the resulting code and design would remain in the public domain.
Early considerations focused on replacing the expensive and temperamental
'real time' Windows NT system. It was proposed that a relatively new (at the
time) real time extension of the Linux operating system be tried. This idea
was pursued with success. Next up was the issue of the expensive intelligent
motion control boards. By this time the processing power of a PC was
considered great enough to directly take control of the motion routines.
A quick search of available hardware resulted in the selection of a
http://www.servotogo.com/[Servo-To-Go] interface board as the first platform
for letting the PC directly control the motors. Software for trajectory
planning and PID loop control was added to the existing user interface and
RS274 interpreter. Matt successfully used this version to upgrade a couple
of machines with dead controls and this became the EMC system that first
caught the attention of the outside world. Mention of EMC on the
Rec.Crafts.Metalworking USENET discussion group resulted in early adopters
like http://pico-systems.com/motion.html[Jon Elson] building systems
to take advantage of EMC.
NIST set up a mailing list for people interested in EMC. As time went on,
others outside NIST became interested in improving EMC. Many people requested
or coded small improvements to the code. Ray Henry wanted to refine the user
interface. Since Ray was reluctant to try tampering with the C code in which
the user interface was written, a simpler method was sought. Fred Proctor of
NIST suggested a scripting language and wrote code to interface the Tcl/Tk
scripting language to the internal NML communications of EMC. With this tool
Ray went on to write a Tcl/Tk program that is the user interface in
predominate use with EMC today.
By this time interest in EMC as beginning to pick up substantially. As more
and more people began to attempt installation of EMC, the difficulty of
patching a Linux kernel with the real time extensions and of compiling the
EMC code became glaringly obvious. Many attempts to document the process and
write scripts were attempted, some with moderate success. The problem of
matching the correct version of the patches and compilers with the selected
version of Linux kept cropping up. Paul Corner came to the rescue with the
BDI (brain dead install) which was a CD from which a complete working system
(Linux, patches, and EMC) could be installed. Paul’s BDI has evolved into a
bootable CD that can be run on most PC style computers to 'test drive' EMC
without overwriting the existing system on the hard disk. Once the user
decides that they want a permanent EMC system, the same CD can install a
complete EMC/Linux environment. The BDI approach has opened the world of
EMC to a much larger potential user community. As this community became
larger, the EMC mailing list and code archives were moved to the SourceForge
and the LinuxCNC web site was established.
With a larger community of users participating, EMC became a major focus of
interest at the on-going CNC exhibits at NAMES and NAMES became the annual
meeting event for EMC. For the first couple of years, the meetings just
happened because the interested parties were at NAMES. In 2003 the EMC user
community had its first announced public meeting. It was held the Monday
after NAMES in the lobby of the arena where the NAMES show was held.
Organization was loose, but the idea of a hardware abstraction layer
(HAL) was born and the movement to restructure the code for ease of
development (EMC2) was proposed.
In the spring of 2011, the LinuxCNC Board of Directors was contacted by
a law firm representing EMC Corporation (www.emc.com) about the use of
"EMC" and "EMC2" to identify the software offered on linuxcnc.org. EMC
Corporation has registered various trademarks relating to EMC and EMC²
(EMC with superscripted numeral two).
After a number of conversations with the representative of EMC
Corporation, the final result is that, starting with the next major
release of the software, linuxcnc.org will stop identifying the software
using "emc" or "EMC", or those terms followed by digits. To the extent
that the LinuxCNC Board of Directors controls the names used to identify
the software offered on linuxcnc.org, the board has agreed to this.
As a result, it was necessary to choose a new name for the software. Of
the options the board considered, there was consensus that "LinuxCNC" is
the best option, as this has been our website's name for years.
In preparation for the new name, we have received a sub-license of the
LINUX® trademark from the Linux Foundation (www.linuxfoundation.org),
protecting our use of the LinuxCNC name. (LINUX® is the registered trademark
of Linus Torvalds in the U.S. and other countries.)
The rebranding effort will include the linuxcnc.org website, the IRC
channels, and versions of the software and documentation starting with
2.5.0. Rebranding will begin right away.
A paper written from NIST's perspective on the history of EMC and its
transition to open source is available
http://www.nist.gov/manuscript-publication-search.cfm?pub_id=821651[here].
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