desoldering (was Re: VAX 9440)

Jim Manley jim.manley at
Tue Nov 13 17:32:35 CST 2018

All this yammering about fancy desoldering gizmos harkens back memories of
a "desoldering station" consisting of a hot soldering iron ... made of a
hefty amount of copper (the kind you put in a pit of fire to heat up!) and
a long, skinny screwdriver, or two, used to _very_ gently pry up ICs from
each end while you ran the iron along the pins, loosening the IC a bit at a
time until it popped loose.  Clearing the pin holes of solder involved
blowing through them as you heated up the pads ... with your breath,
hopefully before the pads debonded from the PC board!  There's no skill
involved any more with the fancy-schmancy stuff ...

That also harkens back to my days in the Navy when I would go visit the
local Defense Reutilization and Marketing Office (DRMO), previously just
called "The Dump".  That's where all sorts of DoD-owned military and
commercial grade equipment was sent as soon as the new models came along
that the Air Force always got first (it helps when you don't have to drive
your runways full of aircraft and fuel all over the world, like we do in
the Navy!).  Most of the Navy stuff showed up when ships got decommissioned
... a typical ship can stay in service for four or five decades, soooo ...
anyone need any vacuum tubes, or a mechanical fire-control computer???  Do
you know why the Air Force always builds the Officers Club first, and the
runways last, on a new base?  Congress will _always_ approve more money to
finish a runway on a typically horribly-underbid DoD contract (that their
brothers-in-law always seem to be involved with)!

Anyway, as I was perusing the offerings, I wandered around a corner and
there was a guy sitting over what can only be described as a medieval
blacksmith's furnace.  He was recovering the gold and other precious metals
from boards and ICs by basically heating everything and collecting the
metals as they dribbled out of the cracking, charring non-metals!  He
appeared to be positioning the materials over time to achieve various
melting temperatures, which allowed him to pretty accurately collect each
metal in sequence as the materials heated up.  I can only wonder whether he
wound up with a medical retirement, as I don't recall him wearing any kind
of respirator, and it was being done in a large warehouse structure.  Come
to think of it, I'm surprised _I_ didn't wind up with a medical retirement,
given the amount of time I spent in those places finding all sorts of great

Speaking of inheriting Air Force hand-me-downs, a little-known factoid is
that Admiral Grace Hopper (co-author of COBOL and an operator of the
Harvard Mark IV) used to send her enlisted people around the Pentagon in
the evenings to snag things left in the halls by Air Force offices to be
carted off by the janitors.  That included all of the furniture in her
basement-level office and even the American Flag there (complete with heavy
stand and oak pole with an eagle atop it).  Few able-bodied military
men escorted by armed guards ever wandered around in the basement of the
Pentagon because of the dank, poorly lit (if at all) corridors, let alone a

However, Admiral Hopper wasn't just any woman, and there are rumors that
the ne'er-do-wells scattered like cockroaches when they heard her coming
(and that was easy to do, as she was always instructing someone about
something very useful in conversations).  I still have a Nanosecond piece
of ~11.2-inch insulated 22-gauge solid wire that she handed out at her
presentations - it's even signed, which means it has little marks that
correspond to where her signature crossed its horizontal midpoint!  She
originally used them to explain to MBA-degreed flag officers why there was
a noticeable delay between the then-new geosynchronous communications
satellites located about 22,300 miles in altitude over the Equator, and
satellite ground stations.

She would show them a Nanosecond wire (the distance it would take for an
electromagnetic wave to travel at the speed of light in one nanosecond) and
then move it along an imaginary line-of-sight from a ground station to a
satellite and start counting, "One nanosecond ... two nanoseconds ... three
nanoseconds ... " until the audience members all exhibited the "Ah-HA!"
moment on their faces.  Then, she would repeat it along another path
between the satellite and another ground station.

Ain't computing history great???

All the Best,

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