
This would explain why the accordian sound effect in the beginning of the game clips in the no-intro/GoodSet "normal" dump, but plays in the the (a1) dump.

The 7th EPROM includes data for most of the sound. 5 Megabytes, which was most likely assumed to be overdump data, was actually a 7th EPROM that was needed by the game to work. However, there exists a 3.5 Megabyte dump marked as (a1) that was released that will allow the game to function more properly. It was assumed when reassessing the ROM for inclusion in both no-intro and GoodSet that the "good" dump was meant to be 3 Megabytes in size like the final game.
