Parallel data recording, et al
Salute!
PJ has some great points about digital recording on a serial bus.
Working with flight test recorders in my previous life, we had several "channels" of data streams, all synched with time stamps. Even the analog data. The biggest difference between test profile recording and day-to-day maintenance and such recording for the big jets is the update rate. If we sample at 100hz or faster, we can build very accurate relationships between all the inputs. But then we need a huge storage capacity.
Looks to me that the stuff we see from the "maintenance" recorders and transmissions from the AF jet was only "blips" of all the data that still resides in the flight data recorders.
There are several independent "channels" on the flight recorders, and just look at some of the traces for various accidents/mishaps. We can see all kindsa things that happened at the same time.
and now back to the experts and regular program.