hi,
   I would be using mach4 for my desktop cnc machine with
   
  Stepper controlled  Cnc controller  for 3 /4 axis :(Interfacing with the PC)
   
  1 No. of parallel and serial ports required?
   
  2. Analog output for spindle inteface.
   
  3. Encoder interface for spindle.
   
  4.Extra I/Os available eg. for turret,robot,logic related to this.(ladder)
   
  5.limit switches, reference switch details.
   
  6.Can we use external switches like emergency stop,feed hold, start,reset etc.
  ?
   
  7.Touch screen ver. is availabe?
   
  8.Is it working with windows XP?
   
  9.Cam package is availabe with you?
   
  regards,
   
   
  Vrushali A.