JPN Sega 16-bit collector here; the Teradrive was an interesting piece of kit, but I've always been floored by just how many variants of the core system there were: from the beautiful Wondermega RG-M1 to the Laseractive, to a Megadrive and MegaCD shoved into a boombox, etc. There's a reason that generation from Sega spawned multiple books about its history.
And then there was this, which is perhaps even more impossible to get ahold of: http://segaretro.org/Sega_Mega_Anser At least the Teradrive pops up on Japanese auction sites, some even in the original packaging; I've never actually seen a full Mega Anser out there, though a couple of the Ten Pad controllers show up every year or two.
In short, Sega attempted to provide the utility of the platform as a limited use-case computer, and then attempted to bring the functionality of the platform _to_ a computer.
This one is very approachable and thorough, and was the result of a Kickstarter last year. Really great book, and probably my favorite; these guys went over the top.
The other one I have stored away is in 100% Japanese and was more a canonical catalog of every released game. Released, I want to say, maybe a 6-8 years ago? Hard as heck to find.
A friend of mine owned one of the latter Amstrad MegaPC models, same sort of thing but based on the 80386SX processor. It was pretty cool - http://www.segaretro.org/Amstrad_Mega_PC
It's funny how, in this page, MHz has a deep ring. Probably remains of the emotions of a younger self. At that time all these console/* hybrids were amazing to me. Console/PC, Console/TapeRecorder, anything..
Even more fascinating when you realise that economically that era went down in history as ”Japan's lost decade” (which turned out to be rather optimistic, because we now need to number them).
And then there was this, which is perhaps even more impossible to get ahold of: http://segaretro.org/Sega_Mega_Anser At least the Teradrive pops up on Japanese auction sites, some even in the original packaging; I've never actually seen a full Mega Anser out there, though a couple of the Ten Pad controllers show up every year or two.
In short, Sega attempted to provide the utility of the platform as a limited use-case computer, and then attempted to bring the functionality of the platform _to_ a computer.