On ISIS info, from A33Zab
Thank you, A33Zab, for that detailed info on the ISIS. My reservations are disarmed, with just one small niggle: one wonders why yet another generation of standby instruments don't maintain an internal backup power source, good for 10, but ideally 15-20 mins of self sufficiency.
But as the question relates to AF447, this little device should have been more than adequate to coarsely validate any suspicions or doubts concerning the primary displays.
Thanks again.