On Thu, Jun 26, 2014 at 2:14 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
  Be carefu lwith wrtie gate timing. I _think_ the drive
hardware prevents
 you from overwriting the servo bursts, but you get a fatal error if you
 try. Best nto to risk it though.
 
I second that!  You *really* don't want to risk overwriting a servo burst,
as there's no way for mere mortals to fix that.  It's not even clear
whether *anyone* has the ability to fix that any more; even back in the day
the "solution" was generally to throw the pack away and buy a new one.  So
even if the drive electronics has some protection against that, I'd
recommend ensuring that your design has protection against it as well.