Okay, I'm going to let my ignorance show, and ask if anyone knows of a motion control system/board/card that will operate in conjunction with Mach 4? Recently purchased a 4 x 8 CNC Router with 3 independent spindles, and the system installed is NcStudio V8. This control system is old, yet widely used and will only operate in 32 bit on an ancient Windows XP Pro desktop.
I cannot get the thing to respond to MY Vectric project file although it will allow me to upload the .nc file.
I'm confident there's something amiss in the software however I'd REALLY rather convert the machine & controll system over to something compatible with Mach 4.
I guess my question is: What do I need to operate a 3-spindle 4x8 machine in conjunction with Mach 4?
Do I need to change out the motion control card & software... or can Mach 4 run the machine independently?
Any insight or info appreciated! Thank you in advance!

Mach4 requires a motion controller to work.  Once you choose a motion controller, you add the plugin to Mach4 to allow it to work with the motion controller you selected.
A cost effective solution is the Smootherstepper (ethernet).  it requires breakout board since there is no screw terminals on the smoothstepper itself, but we have used it in the past.
Currently we use the HiCON from Vital Systems.  More expensive, but it uses 24V logic in stead of 5V, so for us it is more stable, more reliable, and easier to use with the built in screw terminals, relays for spindle control, and analog output for spindle control. 

Thank you Chad... looking into your suggestion... trying to noodle out if/how it will function with this 3 spindle machine I've acquired... this is turning into a career move! lol ...

Does each spindle run independently?

Yes Sir... 3 independent spindles... apparently NcStudio runs them well... when it's working correctly.
I'm just at the point I don't feel good about investing more time, $$$, and effort into a dinosaur of a product, which isn't at ALL user friendly, and doesn't have the capability to switch over to Imperial if desired.
The idea of investing in another NcStudios breakout board, control card, new Windows XP Pro desktop... and God knows what else, in an effort to get this thing running isn't in the cards!

But I really appreciate your interest in trying to help!
Thank you immensely!

I’m curious to know what type of machine you have. Mach4 is incredibly capable.

I saw a machine like that last night while perusing youtube.  Each Spindle moves into cutting position via air cylinder from what I was watching; is that the case here?
This would be easy enough to implement with Mach4.  Might have to get creative on how you want to control each spindle.  If you have a spindle drive with each spindle, you could still run each spindle with separate relays and use the same 0-10v from the motion controller for each spindle. 
Then each tool would have it's own offset in X, Y, and Z; but that can be changed with the Tool Selection to update the offset. 

I was FINALLY able to figure out how to attach a pic... as you might see, it's a somewhat "vintage" Chinese machine with NO brand or markings. I guess I'm having difficulty conveying the basis of my issue with many... haha
I finally have the power hookups worked out... now the issue is getting it to operate my Vectric downloaded .tap file, (which Vectric associated with the NcStudio Post Processor)... the program loads, however doesn't show up on the "trace screen" as a work in progress.
Also can't get the spindles to activate (2 are on pneumatic cylinders) or turn on.
I'm going to venture down the "rabbit hole" and see if anyone at Weihong in China can offer any info (God help me! haha)
They are the people who produce this controller system... tried last week with no success, but I'm running out of options for a prompt fix.
I'll definitely be considering alternatives going forward, however most of what I'm seeing will become a "rocket science" project in installation & rewiring, which normally wouldn't present a problem, except I'm not sure I want to open an entirely NEW can-o-worms at this point! 

lol Good luck then! 
If you decide to go with Mach4; this forum is a gold mine of information and everyone is very helpful on here!