Thanks for these good suggestions! Yep a pocket computer on a rock may be simpler and easier than struggling with a more sophisticated solution but my MFDB requires a laptop that runs osx 10.10 and accepts firewire input, so the options are not that many. Plus I am wondering if a pocket computer will be powerful enough to do the job. As far as I can see the smallest Macbook Air is 11" but it doesn't have firewire input. An alternative option could be a Hackintosh laptop, which used to be heresy but can now be found for sale on ebay and amazon, so I try to find out what is the smallest possible laptop that can run osx 10.10 with either a card reader or some other way of connecting to a firewire cable. It would be great to find a tablet on steroids that could do this but I doubt that exists.