It might have been that Tengen did NOT license Nintendo coding libraries, instead they used their own. They probably reverse engineered an NES somewhat (the original version). So, when Nintendo changed their NES hardware, tengens code might not have full compatibilty with the new chipset.


> remember, Tengen didn't get the ok for any of their games, they'd just produce
> crap title after crap title. Who could forget Gauntlet how it would give you
> fake passwords. But anyways, its cause Tengen wasn't a licensed Nintendo
> developer, that would explain those ugly assed black carts they had. I imagine
> anything by Color Dreams and other non-licensed games to have the same affect.
>
> I came to kick ass and chew bubblegum, and I'm all out of bubble gum.
>