[onedoug]

Those backups look analogue to me. Am I wrong?

[Tzfat]

That altimeter is an old version standby altimeter. It is not the primary altimeter. Most carriers have replaced the round standby instruments with a single digital one that uses a separate power source, takes less room, and is easier to maintain.

[Kenny Bunk]

Doug baby, just because it's got a dial, doesn't mean it's an "analog" instrument like Lucky used on the flight to gay Paris.

The input can be strictly digital. The read-out, needle and dial, rather than a screen read-out. Think auto tachometer. The needle and dial you read in a modern car is driven off a sensor, not a spinning cable.