Hi,
I use an external motion controller, an Ethernet SmoothStepper (approx. $180USD) by Warp9TD. It has both a Mach3
and a Mach4 plugin.
There is to my knowledge no Chinese manufacturer that produces a Mach4 capable controller (that works anyway....
whatever they claim) and therefore suspect that your machine is likely to be able to run Mach3 only.
I use Mach4 and personally believe that its light years ahead of Mach3.
The funny thing is that Mach3 and Mach4 do almost exactly the same thing. Until just recently there was nothing
Mach4 could do that Mach3 could not and vice versa. Mach4 does certain things much better and very much more robustly.
The real strength of Mach4 is its ability to be customized. For example:
https://www.machsupport.com/forum/index.php?topic=40008.0This is a thread where a guy wanted something just a little different than Mach4 as standard. It too me a couple of hours
to make two new DRO's, a new toggle button and some code to populate tool length compensated Max and Min Extents
DRO's in work coordinates instead of the more usual machine coordinates. This is possible with Mach3 but very much
harder.
If you have a simple machine and don't require anything special then Mach3 will be fine, and you are familiar with it and
is $25 cheaper.
If you want to customize your machine or want to use some of the new functionality that Mach4 offers
then go that way, it will cost an extra $25 for the software and somewhere in the region of $120 to $250 for an economical
external motion controller, or $600 plus for a real top quality unit. As Byranna pointed out there is a parallel port option
for Mach4, called Darwin for which a $25 license fee applies. Darwin is not fully featured with things like lathe threading,
THC and backlash comp but otherwise works pretty well. It still requires a 32 bit OS, Windows7 or earlier just like Mach3's
parallel port. Darwin allows a cheap way to try out Mach4 although Mach4 was intended to be paired with an external
motion controller.
Craig