Thanks, I've tried to play with card tricks. Interestingly, the autostartable sd cards lead to the printer not starting up fully - more or less only one led on the bottom was on. And unfrtunately none of the systems was able to create an image on the SD card.
Maybe I will grep through the forums to find some more information but if you can give me more hints, that'd be great.
From the dev perspective, a printer firmware is also an interesting playground. As soon as you have full control over a print system much better images than the ones created by the "fits for anyone" can be created. But unfortunately my ARM asm skills are very rusty and I first have to find out how the beast really works, i.e. what operating system.
Cheers