Hello JohnnySlumber,

You are not restricted to Windows 98 or even XP. I run my AXYZ Millennium from Windows 8 using Toolpath and NC files generated from RhinoCAM, with no issues at all but you cannot use the original Opto-Isolated USB/RS485 device or driver. AXYZ told me its not supported any more. Hopefully, you have sorted it by now but if you haven't, all you need is a new converter and the correct driver. You will need to connect the differential data lines correctly but other than that, it's straightforward. Let me know which converter you bought, you should be able to use that. The one I use can be bought in the UK from Farnells or (I think) Newark in the USA. It's not opto-isolated but I haven't had any issues in over 4 years use.

Regards,
Alan