Another problem with these old controls is even when code is sent over serial, they are slow. Think like less than 9600 baud.

They also don't have the computing power to do adaptive or other modern tool paths.

Is 9600 baud a real problem realistically? That’s still at least 10 gcode commands per second, right?

If your CAM software is smart enough to use arc commands instead of using line segments, I don’t really see a tool path where you would need more than that.