[1]http://threestepsoverjapan.blogspot.com/2011/12/gakken-kit-3...
I suppose its irrelevant these days; I could just wire up my own new Denshi blocks with ease, and it'd be a good reason to polish up my Japanese .. there is a thriving Denshi culture, but it seems to have withdrawn into Japan.
For some reason Denshi blocks never caught on out in the West; but I think - as we see with this new-school effort - there are still tinkerers out there who yearn for such modularity. In the case of Denshi in the 70's, I think it was more that kids just lost the blocks too easily. Magnets help, I guess!
EDIT: Exploring the subject a little more, I realize that in fact Denshi blocks are thriving in Japan .. in fact look at this great picture:
http://otonanokagaku.net/feature/vol27/0ku8jv00000006xr-img/...
I now have a reason for a 3d printer. :) (Another one, anyway)
http://en.wikipedia.org/wiki/Denshi_block
Still one of the most amazing toys I've ever seen - nothing can prepare you for the pleasures of assembling, lego-style, a circuit - and then it works!
I loved it so much I've now sort of become a bit of an EBay junky, trying to find Denshi blocks for my kids to play with .. all I've found so far is the cheap clone ripoff, but I hope to one day have a full collection of the real thing soon enough. I'd love to have the Denshi block system that came with a small synthesizer chip, for example .. this would be a fabulous toy for my 6 year old and 3 year old to play with together.
The more I think about it, the more I feel like we've sort of lost something that toys like this didn't persist in the marketplace and are just now being "re-invented" by new generations. It'd be great if Denshi blocks came back on the market .. maybe an open source version makes more sense now, though.