I've forgotten to mention my PocketBook also has a microSD card slot. It came with just 1 GB of internal memory, ⅓ of which is occupied with the OS (Linux) so I

I've forgotten to mention my PocketBook also has a microSD card slot. It came with just 1 GB of internal memory, ⅓ of which is occupied with the OS (Linux) so I've just bought an additional 16 GB microSD card to extend it recently. Now I just plug the card into my laptop SD slot (using a microSD-SD converter that came with the card) and don't even need to use a cable (which never worked well, it often happened that the device would charge but won't establish a connection).