[OT] Power and NIC questions

I'll certainly second the statement about the Tantalum cap's. I once had a fire in my AMPRO system because of a shorted Tantalum, and, having seen the smoke emanating from the rear of the PSU (I hd used a PC-style case) immediately assumed the fault was in the often considered flaky power supply (this was in the mid-80's). In the process of prying the grommet with all the various power leads out of the supply case, I stuck a 1/2"-wide screwdriver I was using as a prybar, about 1" into my hand. (think about where you can stick a screwdriver 1" into your hand and not go out the other side ... ) Half a day and over $1k in medical expenses later, I looked at the Little Board and saw the burned spot where the cap had been. If Only I'd looked before I lept . . . <sigh>

About a year ago I once again was powering up an old Ampro Little Board, and, sure enough! ... the -12 was pulled down by a shorted tantalum bead. Apparently they do not age well. BTW, AUI uses -12 and +12 from the supply on most cards that support it. The coax gets an isolated negative voltage generated locally on the NIC, generally with a little switcher module. These are handy to hang onto when you're faced with a broken NIC. They generally make a nice -9-volt source for boxes that have no other negative supply, and that's satisfactory for RS-232.