I'm still having no luck getting a serial port going on this thing. I thought it might be because I was using a MAX 232 chip, instead of a MAX 3232 ("...and an extra 3 cubits for Linus, whose kernel this is...").
I also took the time to try to make a more permanent assembly by doing it up on a bit of perfboard -- so now I've got yellow wires (distinguishable connectors are for the weak!) poking out from perfboard instead of from breadboard. And still, nothing...not a goddamned peep, excep for a weird y-plus-umlaut character that pops up every now and then in Minicom and I'm blaming on either noise or acid flashbacks.
I'm at a loss here. As far as I can tell the connections are good (my three bits of electronics equipment are a soldering iron, a plastic box with many subdivisions, and a multimeter), and the circuit looks more or less like the circuit listed at the HRI site. That leaves connecting at the wrong place on the board, or maybe grounding. Not sure.
But hey! I got an offer to collaborate from pck; his electronic skills would be nice. And I'm going to shoot off an email to the guy who got it running in the first place to see if, a year later, he can help out.