Do you think its still possible to interface eg. the displays and touchscreens of these devices?
It should be possible, but unless you have access to the schematics for these devices it will likely require quite a bit of detective work/reverse engineering to identify the specific parts of the circuitry that need to be interfaced with. With luck, most of the used ICs would be commercially available and would have datasheets to simplify this process. However if these devices rely heavily custom ICs, like
ASICs, driving their displays and touch sensors it won't be impossible, but will likely require so much experimentation that it would be impractical.
Before you start, try Googling the words "tear down" along with "PocketPC" or the specific model numbers you have. If someone has gone through the process of taking apart and thoroughly examining one or more of these PockPCs it will help you determine if this project is feasible enough to pursue further.
