I'm one of the developers at CNCdrive, I'm the one who the OP discussed this issue with in e-mail,
so I thought to quickly clarify a few things so others will also know this when reading.
The UC100 currently can't cut threads with Mach4, so it can't be used for most lathe works,
because we could not fit our code to the Mach4 thread cutting interface yet,
we just could not make that work as calling some lathe functions just freezing up Mach4 and we could not figure out why yet, so we put this part of the development apart at the moment, but will contact the Artsoft guys as soon as we will find the time, so hopefully we can then resolve this issue.
So, the important thing is that the UC100 will not work with Mach4lathe at the moment, it works only with the Mach4mill, so please do not buy a UC100 if you want to use Mach4lathe,
because it currently can't cut threads with Mach4, so it is yet useless with Mach4lathe.
Thank you.