Posts: 883
Threads: 17
Joined: Feb 2006
Yes, they are 41 compatible, up to a point. The issue is really which 41 thing you are trying to mate to.
The difference is the B has a solid plug, the D has a cutout area between the contacts. Most 41 devices can use either. One of the spoilers is the 82120A battery for the calculator itself. There where two different versions of the same model number, the original had three pins which requires the D version, the later version with two pins can accept either 82059 plug style.
If that doesn't answer you question, repost with specifics.