Few people know that there are literally thousands of Pokey Chips stored in a limestone cave somewhere in Kansas City. A liquidation company bought truckloads of mint unopened ATARI carts, and among these is the ATARI 7800 version of Ballblazer.
While I didn't feel like ripping apart a perfectly good mint unopened box, I nevertheless scourged through my cartridge collection and opened mine for fun. The third photo shows the desoldered Pokey chip, under the one I got NOS from a dealer (note the manufacturing dates - 5 years apart).
Next I placed the salvaged '87 pokey on my protoboard and played it the Ballblazer title track through it. Love those fat basses.
NOTE1, The ATARI 400/800 (home computer) has a native pokey chip, and the Ballblazer title sounds exactly (to my ears) as it does on the 7800 Cart, its logical to assume that the LucarFilm Games authors didn't want to alter their composition by only using 7800's native TIA chip... but did it justify adding a chip to the cart which would boost production costs a lot? if someone has some info on this i would be curious to know.
NOTE2, the other 7800 Game cart that contained a Pokey chip is Commando, but its not available in the cave.