Thanks to everyone who has posted on this issue. I cant find my invoice for this item, however I recall when I purchased it last year, the seller was advertising the Artsoft logo, so I assumed that those folks had checked it out, or tested it and were supporting the product, but perhaps not. At any rate, one place where it is currently available is this place...
https://www.thanksbuyer.com/upgraded-nmotion-mach3-6-axis-usb-cnc-motion-card-interface-adapter-for-engraving-machine-servo-step-motor-45150 .... this guy also retails on ebay as well.
Doing an ebay search for 'nmotion mach3 cnc controller' yields several places in China for this unit. Be careful though as prices vary quite a bit. This controller will handle up to 6 axis machines, which is what I purchased for about $170 US last year. I see it now for $153 US plus shipping.
I purchased this as I am installing some closed loop stepper motors (with built in encoders) and the matching hybrid servo/stepper drivers. I initially started out with an 'NVUM' controller but couldnt get it to work properly as it kept killing my USB port, so I would have to reboot to get it going again. 10 minutes later it would die. I checked some blogs and found others that were having the same problem so I looked for something else and found this nMotion controller. I contacted them initially and they confirmed this controller would work properly with the hybrid motors so I bought one.
If this works it will be great as there is a full - error checking closed loop - between the motor and the driver, via the encoders, so supposedly there are not more missed steps. There are several suppliers for these motors in China, but if anyone is interested, then email me and I will give you my contacts. These motor/driver combos are approximately $120US per kit depending on the motor size etc. Make sure you order a matched set.
I am sequestered in Calgary, Alberta if anyone is from this area. Please feel free to PM me.
If/when I get this beast operational I will post back my results.
Thanks all.
Pete