Bruce Layne wrote: > LinuxCNC was initially conceived to directly control machine motion in > realtime using a parallel port, No, not really true. The original EMC (1) was conceived to control a servo machine with a dumb motion interface board such as the Servo-to-Go. A board with encoder counters, velocity DACs and some digital I/O, but no processor. Steppers through the parallel port was later added. Then, after the change to EMC2 (which became LinuxCNC) many other interface devices and some outboard motion controllers were added. EMC2, mostly the addition of HAL between the interpreter and low-level motion hardware, was a way to make all this more flexible, but not to change any part of the existing functionality ar directly add new functionality. It was a way to make adding that functionality a lot easier, and that has certainly happened.
At least, that is my take on the history of it. > I love being able to pick up a cheap or free PC and use it as a machine > controller, but I think it'd also be great if there was a small, low > cost commercially available PC that is pretty much guaranteed to work as > a LinuxCNC controller. Well, the Intel D525MW was that for a while, and as soon as some of the other vendor's products get qualified, we should be able to recommend a quite reasonably priced unit that will be available for a few years. A complete D525 system with box, power supply SSD drive and memory can be had for about $150 - 200, depending on what you need. If the RT-Preempt kernel turns out to be suitable for LinuxCNC, then we may be able to move to the BeagleBone ($89) or RasberryPi (price and availabilty not so clear). I personally think the Pi is a bit too low-powered to be usable, but the Beagle looks promising, especially if the GUI is hosted on another CPU. Jon ------------------------------------------------------------------------------ Don't let slow site performance ruin your business. Deploy New Relic APM Deploy New Relic app performance management and know exactly what is happening inside your Ruby, Python, PHP, Java, and .NET app Try New Relic at no cost today and get our sweet Data Nerd shirt too! http://p.sf.net/sfu/newrelic-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
