
Come on, you've been doing this long enough not to fall for an eBay seller's hyperbole. Your cart definitely has a POKEY chip inside, because all Ballblazer carts have a POKEY chip.
POKEY allows the 7800 to not sound like utter garbage. It should have been in the console itself, so that the full library could use it, but Atari was cheap, so the 7800 shipped with the same lame TIA sound chip as the 2600. Developers could add POKEY to carts to make them sound better, but almost no one wanted to do that. Ballblazer and Commando are the only original titles with POKEYs.
These days some people pull the chips out of Ballblazer carts to make homebrew carts for games that utilize POKEY. That's kind of too bad though, because Ballblazer is a pretty good game. Someone has been working on producing a HOKEY chip which could be used for sound just like the POKEY and hopefully save all the remaining Ballblazer carts. It's also supposed to be in the eagerly awaited Concerto flash cart.
Games that use POKEY should also be supported by the XM add-on module, but that has been a disastrous project that is already 5 years past its original ship date and the less said about that, the better.
Anyway, yeah, Atari rules!
