LinuxCNC Hal EDM. Linuxcnc poses the tool and workpiece. Hal limits the travel. Custom M codes set limits, sparkout times, on/off times and current. Cut is 7 amperes at 98uS on 498 uS off. Gap is maintained by a window comparator telling Hal ( thru an offset comp) to Advance or Retract. Video translation from phone .3gp to .ogv sped up for some reason, and audio is lost. This experiment is just to show its possible. It "sparks out" at bottom limit and when voltage is hi enuf for long enuf you can see an led on pyvcp panel light up. Some later version would 'press' the 'reduce offset' button which retracts the tool to where Linuxcnc expects it to be, and then... Linuxcnc could move to another pose ( or change the tool or ... many possibilities. The cut is a bit crazy becasue its only got a film of oil, but was strong, really smoky in the basement now :) The Uo is 100Vdc, the generator is 64 amps peak ( tho my single phase 230 from electric dryer would sorta limit that :/ noisy sideways version at http://videopasteus.s3.amazonaws.com/videos/af20499425e94721bf909369d5c2920c.html