Some Altair questions, if I may..

On Sun, Aug 24, 2014 at 2:02 PM, Brent Hilpert <hilpert at cs.ubc.ca> wrote: Heh, I wasn't requesting help with it, Brent.. ;-) I was just supplying a little narrative to keep those who are reading on the same page... you really think I'd expect anyone to supply useful comment on "something got hot and I'm not really sure where or why"? Really? That's just general electrical stuff, which I tend to have a good handle on - again, it's the world of digital electronics that's mostly very new to me. Anyway, it was getting very late, and I'd been at it for over eight hours. I'd accidentally swapped the +18 & -18 lines, and that was causing the excessive current & heat. When you're dealing with juggling a +lot+ of new info it's easy (at least for me) to slip-up and confuse yourself, draw unfounded conclusions, etc. My accuracy will improve dramatically once I have a handle on this stuff. SO THEN.. After finding & fixing a couple other issues (bad connections) and adjusting the brightness of the new LEDs to match the old ones (wow, showing some signs of life! I have the CPU board plugged in, but no RAM board, as all I have is a 64K dynamic card. Here's what I'm seeing: MEMR, STACK and WO are lit. D0-D7 remain lit. A15-A0 are another matter.. A15 is flashing about 2Hz, A14 at about 4Hz, A13 at about 8Hz and after that on down the line to A0 I assume all others are flashing as well, but persistence of vision makes them appear to be steadily lit. Oh, on power-up the A LEDs were off, but hitting RESET puts them in the flashing modes I described. So is this how it's supposed to act with no memory installed? I'm at the point where I pretty much must have a SRAM board for it.. I may have to resort to eBay, and hope I get one that's actually working. I really need a known-good part for this stage.