Just wanted to say hi.
Sega SC-3000s are my thing. The SC-3000 was my first computer when I was nine, and we've kept one in the family ever since. It was technically a very capable little home computer that just suffered from a lack of available software. The Basic language in particular was excellent, and it had a good local following in NZ and Australia. In fact, Australasia was about the only place outside Japan it had a sizable following, although it was also sold in small numbers through Europe.
I have about 4 or 5 SC-3000s, a couple of SF-7000s, and a Japanese SG-1000 II console. I'm not looking to sell any of that at the moment though, sorry.
A couple of years back I hooked up with the guys at SC-3000 Survivors (http://sc-3000.com) and did a bit of software restoration work on some old tape games.
That morphed into first a do-it-yourself multicart for the SC-3000 using DIP switches, then a full boot menu version of the cart which gives you instant loading of all the old tape games. That has consumed a lot of my spare time over the last year or so

http://sc3000-multicart.com
I've also been posting various technical comments on the SMS Power dev forums at
http://www.smspower.org/forums/viewtopic.php?t=13351
I have a pretty good handle on the SC-3000 architecture now, so I'm happy to answer any questions you may have about it.
I'd like to say thanks to Tezza for his vintage computer blog in particular. I've had to learn everything required to build the multicart and repair my SC-3000s and SF-7000s from scratch over the past couple of years, and there have been lots of excellent hints and tips hidden in there that I've found very useful, especially on the repair side.
Cheers