Regarding patents they last between 10 to 50 years (depending on the type of patent - intelectual property, ingeneering, design...), and you can renew them once.
HOWEVER if you can prove that the original owner of the patent has stopped using his patent (I think the legal delay is 3 or 5 years) or if you come with serious improvement on the original patent you have the right to distribute and sell your new product.
In our case you would have to prove that the actual owner of the Neo Geo design and specs is not using them anymore.
In any case it is always better to have the agreement from the original patent owner or be prepared to have a real good defense to prove your claim that the patent was left unsused, or come with a serious improvement in design.
Be aware that patent law is also different depending on which country it was first deposited. Countries like China have easier rules than teh US or Europe for example.
I believe a company like SNK has deposited the patent in most countries and therefore own the right to Neo Geo design in them. If you live in a remote country (let's say Azerbaidjan just for fun) the patent might not be deposited and it could be easier, but you can only distribute your new Neo in countries where the original patent was not deposited. After that comes the pb of games which are still published as of today and might be an asset to the owner of Neo Geo to prove that it still uses its original patent.
<small>[ August 06, 2003, 11:11 PM: Message edited by: Howdoin ]</small>
