@selfisekai @jasonkoebler yup.
Here's the full technical talk that goes into all the details:
https://media.ccc.de/v/37c3-12142-breaking_drm_in_polish_trains
And fun fact the ED78-010 train that was celebrating the Broken Compressor Day since December 21st, returned to work on January 1st, as expected:
https://www.rynek-kolejowy.pl/wiadomosci/noworoczny-cud-zepsuty-impuls-sam-sie-naprawil-1-stycznia-116803.html
@rysiek @selfisekai I've corrected the piece, this was my mistake. I dumbly assumed that 'emergency stop' signal corresponded to emergency brakes. Thanks for pointing out