Murphy's law is in full effect...

From: Daniel A. Seagraves <DSEAGRAV_at_toad.xkl.com>
Date: Mon Aug 16 08:20:42 1999

Well, plugging the Unibus end of the DW11 into the Q-bus didn't kill it,
but plugging it into a Unibus slot BACKWARDS did.
(What is it with me and absolutely stupid mistakes? Geez...)

At least I think it did. On applying power, I got smoke, but no pop.
The chip I crisped isn't marked with a U number, but, on the M8217 end,
it's in the bottom row (Just above the bus pins), 4th from the left edge
of the card (I'm holding the card with the component side facing me.)

The chip has a bad smell and is slightly discolored.
All the others look OK. The chip was also very hot when I cut the power and
yanked the card out. I was too busy trying to keep the cat from climbing
inside the box to pay attention to the card. Next time I shut the door.

Assuming there IS a next time. If I can't revive this card, or find a
Unibus RL02 controller in 4 days, this project dies. (I can't have the
large toys here after Friday. I can only have what fits under my bed,
which is the 83 and it's RL02.

So anyway, the chip is marked as follows:

915
DS8641N

There is no vendor ID, just a little mark like 2 lightning bolts in paralell
(Like a jagged = sign). So, the questions now are...

1. What's this chip, and what does it do?
2. Can I replace it, or am I just screwed?
3. Is there a way that with only a voltmeter (I don't have and can't
        afford a scope) to verify that the chip's dead? (I'm overly
        optimistic too...)
4. What stupid mistake am I gonna make next?
        My bets are that the tape drive will be dead for some reason
        and I stomp on the RSTS tape, or get halfway thru the restore,
        hit a bad block on the tape, and end up with an unusable drive.
        Failing that, I'll either crash the RL02 (I only have one pack)
        or find a way to nuke the 83 and the 34A at the same time.

(For refrence, I went and got a PDP-11/34A to use as the UNIBUS end of this.)

And yes, I know I misspelled parallel, I'm just too lazy to fix it.
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Received on Mon Aug 16 1999 - 08:20:42 BST