OK, this probably isn't the best mood to be going into Record Day with, which is why I've made a conscious decision to get this off my chest before it starts… I'm p***ed off.
You may recall my power supply that
blew up a few weeks ago. Well, I replaced it with a shiny new one, but then afterwards found my serial port no longer worked (more precisely: it could receive, but not transmit). I convinced myself that the SuperIO had been damaged (by getting an oscilloscope and seeing how dead the Tx pin on the serial header was), so a couple of weeks ago I finally went and ordered a PCI-serial adapter.
The card arrived today (thanks UPS for the delays

) and when I plugged it in I got exactly the same result: receive, no transmit.

It turns out (and I had suspected this, but convinced myself otherwise with the oscilloscope :facepalm) that the REAL problem was the lack of a –12 V supply on the new power supply. It seems that PSU manufacturers now no longer bother to include a –12-V pin, even though there's nothing stopping users from hooking them up to hardware that requires it (just like I did, in fact).
At this point, my best bet is probably to stack four coin cells, connect the positive end to one of the GND lines, and the negative end to the –12-V pin on the motherboard power connector (maybe using a wire salvaged from the old PSU). I'm just really annoyed that I allowed myself to waste my time and money on a serial card when in the back of my mind I suspected the –12-V rail. I'm also quite annoyed in general that the –12-V supply has been done away with so quietly, and in a way that can cause such weird problems. I mean, yes, not many people use a serial port anymore, but surely that's all the more reason to warn people who do that there might be problems like this.
OK, my annoyance is probably disproportionate, and people are probably wondering why the hell I care so much, and I'll probably have calmed down in a few hours – but again, I just wanted to get this off my chest so it wouldn't be gnawing at me going into Record Day!
