I remember Barry posting a explanation of in-house Sega studios and how AM1-12 are a mystery. Well they aren't, from the research I've done it was like this:
AM1 - WOW Entertainment
AM2
AM3 - Hitmaker
AM4 - Sega Mechatronics
AM5 - Theme park attraction like at Joypolis, like the Rail Chase one
AM6 - Smilebit
AM7 - Overworks
AM8 - Sonic Team
AM9 - United Game Artists
AM10 - Wave Master
AM11 - Amusement Vision
AM12 - Sega Rosso
I think that is pretty much clear to most around here, except Sega Mechatronics and AM5 with Theme park attractions
Sega Mechatronics is a valuable part of Sega - the arcade studios that are famous only do half the work really, doing just the videogame software. Another important part is the housing, technology of these arcade cabinets, which is what Mechatronics has done. Not only that they also make cabinets that lightly reliant on software such semi-gambling japanese games (medal games like Starhorse), crane games and other prize games as well as things like Japanese photobooths.
Then there is the AM5 - theme park development, and that itself transformed around kids arcade games in 2001, with the Mushiking cards game.
Today the mechatronics division is still valuable to Sega, however I think that got downsized due to recent structiring. The head of it since 1999 - Masao Yoshimoto - is now at the board of directors for the casino division - Sega Sammy Creation.
And then there N. Pro. R&D Department which has done the sandpit arcade game - that department is itself the evolution of the kids arcade game department which was previous AM5.
Either way, I guess I'm just pointing out that for arcade studios there aren't just the videogame studios.