alt Hacker NewsI love learning about pre-internet ways of transferring data on the back of other things. Another cool example is that the UK is only shutting down its longwave AM radio service this month (as opposed to decades ago) because the carrier is phase-modulated with data telling older electric meters to switch over. For years this was the only reason such an antiquated radio system stayed alive.
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In Munich (Germany), a lot of the displays at bus and tram stations get their data via a side leg on the FM radio broadcast of local station B5 aktuell [1]. More details are here [2], apparently it's called "Axentia iBus FM/DARC".
[1] https://www.mikrocontroller.net/topic/232846
[2] https://apollo.open-resource.org/mission:log:2014:08:08:darc...
I love learning about pre-internet ways of transferring data on the back of other things.
I once worked for a radio station that made 90% of its revenue from carrying data feeds on subcarriers, and not from main music programs.
Because of the geographic location and size of the signal, it was a vital link between two major cities before planting fiber optic lines became cheap.
> I love learning about pre-internet ways of transferring data on the back of other things
See Minitel from France and Telidon from Canada as other examples of data systems riding on analogue TV and/or POTS telephone systems.