Is it still possible to buy this anywhere? If not, is anyone interested in selling theirs?
Unless someone is selling theirs, they're all sold out with no plans at the moment to make any more. The schematics are available though to make your own.
http://www.retrode.org/plug-in-adapters/
I was wondering though, would it be possible to update it to a 7800 adapter so you could dump 7800 carts and 2600 carts? I would think there would be a bigger market for that.
Yeah, I saw the schematics, but as had been established in the recent NES adapter thread, I'm a buyer, not a builder (just think of it as doing my part to turn around the economy). :-)
On the 7800, idea though... you think there's a big market for a 7800 dumper? I don't know... I actually don't know a single person that's ever owned a 7800. 5200 either, for that matter. I wouldn't there there'd be a whole lot of demand for that, but who knows. I'm sure if you're one of the people that do own a 7800, it'd be a nice option to have. :-)
I was thinking that it would be more along the lines of the GBx plugin where it could dump 7800 carts and 2600 carts. I haven't looked too much into it if it'll work or not, but I would think that the ability to dump carts for both systems would be more attractive to customers then being able to dump only one.