Hi Patrick,

A bit of digging about on the Internet confirmed my suspicion:
Meade hasn't changed their protocol to handle the RCX-400. It
essentially has the same control scheme as an LX-200 GPS scope. So
Guide 8 can control it (and every Meade scope of which I am aware)
without difficulty, as if it were an LX-200 or Autostar scope.

-- Bill