7.1 Headless mode

--headless runs the emulator with no window and no audio device, as fast as the host allows:

$ jnext --headless --machine next --load myprog.nex \
      --delayed-screenshot shot.png \
      --delayed-screenshot-frames 150 \
      --delayed-automatic-exit-frames 200

That is the whole shape of an automated run: load something, capture at a known point, exit at a known point.