Talk about blunt! I'm aware I can't just shove a usb cable into it, as theres still a small amount of data being read for batt/stat chrg/stat etc its slimly possible to tap into this and read it via a pc. A schematic of the main board would be grand as would a cartridge one.
Don't worry about...
Thats what I was eventually getting at. Used to make all sorts of USB cables for the likes of NSGold, Griffin and CruzerFlash, if anyone should happen to stagger across the scematics for a cartridge, I'm more than game to have a dabble.
Totally recommend R4onlinestore owned by William Murphy of Ireland. Very quick postage and replies personally if you need any help. Very reasonable priced R4, R4i, Gold etc
The 3DS aren't that much bigger, 512mb and 1024mb seems to be the normal size in the collection so a decent 32gb micro sd, Samsungs Class 10 32gb is £22.00 on amazon.co.uk will hold between 30 and 40 games. Just leave a gig or so for saves etc.
As a company I would be inclined to update existing products, reason being is existing customers will be liable to stay. But as its been many times repeated, it could be any time.