@Roman: thanks Roman i understand a bit better what's happening.
a bit OT:
Roman wrote:
Run 'crontab -e' to edit current user's crontab file. Then add a line like:
@reboot /usr/bin/vncserver :4 -name pure-data -geometry 1000x800 -dpi 80; sleep 5; DISPLAY=:4 /usr/bin/pd -open mypatch.pd
save it and reboot. At next boot, this will launch a vncserver on DISPLAY :4 and then start Pd with its GUI in said vnc session.
on my raspbian jessie this doesn't work. did you (Roman) install extra things?
rolf