I have a very capable but old card, I use an eprom that is designed to respond to drip fed commands form a pc, but limited buffer. Commands can be 10 - 15 asci chars plus checksum and the card can take up to 50ms to respond or though its often less when I measured it. For smooth servo move it needs continuous commands and the RS232 just don't do that. The card will interpolate 3d straight moves and circles / arcs in any two axis but not complex moves, spirals etc. So, to sum up, complex moves must be short 3D interpolated. At the moment in my optimisation home brew, the host pc software works out the time the machine needs to complete a move ahead of the move. If it's less than 50ms it does a suitable ramp up and ramp down as the card will do a controled stop (out of my hands!) if it cant maintain constant velocity. This makes it very slow on complex multiple short fast xyz moves.

I am probably making a very naive statement but presumably this chipset is a simple swap from pwm to a voltage signal which my free but massivley good MAX250 amplifiers need? Very interested in your developments especially if it could do arcs, spirals on board, even if that just means a decent move buffer like next 40 or 50 moves or high speed comms. Don't like the pulse and direction type controllers for servos, sort of defeats the object and demands Mach3, might as well have steppers..

Basically, very very interested!

Tom