As Gary says some controllers will & some won't, I would also agree with Gary that it isn't a great idea, what I have & a lot of other people do is have a dedicated computer for control of their CNC, you don't need a particulally high spec computer to run the control software, I actually have 2 computers for this, one in use & the other one set up ready to go as a back up, both machines were old machines that people were chucking out so didn't cost me anything Using a different computer for your design software means there are no problems what so ever en it comes to opening & working on files while the CNC is running
I will admit to doing exactly this with some level of frequency, but I also agree that overall, it's not necessarily the best idea. I don't do it when running something new or complicated, however, as that's exactly the time when paying attention to the machine is very important. Most of my design work is done in my office in my house on my Mac, but sometimes I find the need to tweak or make changes while I'm waiting for something to run...and leaving the shop is a worse choice than multitasking on the one machine in the shop.
Same here...I run an XP computer with nothing but the operating system and Mach3 control software...no internet program either, and I've had zero problems with my setup...but like Martin, I have a spare XP computer configured and ready just in case.