Hi,
you can download Mach4 and if you use the Sim(ulator) plugin and run for as long as you like all for free.
The Sim plugin will not drive any motors. If you actually want to experiment on a live machine you will have to install a motion control plugin and
select that plugin as the active motion control device. There is a parallel port plugin for $25. It works but it will never be fully featured, lathe threading, THC
and that sort of thing. It was meant for people to have a cheap way into Mach4, if your serious you will need an external motion controller.
There are half a dozen manufacturers of external motion control devices which are Mach4 ready, ranging from about $120 to $650 or even more if you want a
Gallil controller. At this time there is only one Chinese manufacturer of Mach4 capable controllers and it doesn't work very well at all. If you see someone advertising
cheap Mach4 controllers be very suspicious.
With ANY active motion control plugin (other than Sim) Mach4 runs in Demo mode, that is to say it runs exactly as a licenced version for about six minutes before you need to restart
the program.
Thus to experiment with Mach4 you will need to spend some dollars, $25 as a min for the Darwin Parallel port plugin for which you require a PC with 32 bit OS Windows 7 or earlier.
Other than that you are up for say a UC100 or ESS as a min. The UC100 is $120. Don't be tempted by the cheap UC100s you see on Amazon or EBay, they are Chinese ripoffs.
Buy direct from the manufacturer or their nominated distributor. With an external motion controller you can use just about any PC you want to run Mach4, it will run on even
very small and low powered PCs for instance.
Craig