Re: FAA To Finally Ditch Floppy Disks & Win-95

On 6/14/25 12:34 PM, Rich wrote:

c186282 <c186282@nnada.net> wrote:

On 6/13/25 11:35 PM, rbowman wrote:

On Fri, 13 Jun 2025 22:38:38 -0400, c186282 wrote:
>
>

     In any case it's become very clear that a major update is needed for
     the US airport/routing system. Knowing the govt process, the stuff
     will already be obsolete by the time it's installed, but not nearly
     SO obsolete.

>
In the early '70s we had a contract to build the controllers for the ALS
system. The heart of the controller was an Eagle Signal electromechanical
stepping switch which was pretty much obsolete. The harnesses had to be
laced since the FAA wasn't sure about those new-fangled nylon cable ties.

>
   Ooooh ! Nylon ! EVIL !!!   :-)

 Not so much that as: Ooooh!, we don't know how well this new "tie"
method will withstand extremes of cold, hot and vibration, and the
current regs.  specify "laced" and we *do* know how lacing withstands
extremes of cold, hot and vibration.

   Nylon has been around in quantity since the 40s.
   Somehow I doubt it's qualities were 'unknown'
   in the 50s and beyond  :-)
   MORE likely some senator was vested in a biz that
   made the older materials.
   There ARE circumstances where 'natural fibers' CAN
   outperform plastics - esp at very low temperatures
   where the plastics become more brittle. However
   those circumstances are few. 'Natural fibers' also
   tend to hold MOISTURE - which is bad for HV electricity
   apps and can lead to mold/fungi problems.

   But yes, it's VERY typical for govt projects to be
   WAY behind the tech curve. The specs are writ, but
   then there's a HUGE delay in the implementation.

 

   The lunar-lander computer still used "rope memory"
   because of that - even though PROMS and erasable
   PROMS were widely available by the late 60s.

 Also because (esp.  for EPROMS) the rope memory was much more radiation
hardened than EPROMS of the day were.  Also, for 'long duration'
projects such as that, often each component is designed and built, then
in the end the various parts are pieced together to produce the "flying
candle" you see on launch.  But the "computer" might have been designed
and built five years before that launch, and minus five years from
today might have meant no PROM or EPROMS were even available at the
time.

   I'd argue about UV-erasable PROMS and space radiation ...
   the damned things weren't THAT damned sensitive.
   Had a foil-lined box with a UVC tube lamp in it for the
   purpose, but you'd better let 'em soak for like ten or
   fifteen minutes to be sure. Used that a lot with the
   pre-flash PICs. Big whiff of ozone and NOx when you'd
   open the box  :-)
   There were also 'fuse PROMS' back then - literal made
   or broken wire connections. You CAN still buy them,
   checked recently. So long as they're socketed the
   firmware can be replaced pretty quick and easy. Low
   cap by today's standards, but in 1968 or so ...

   Took a tour of an attack sub in the late 80s - a bud
   of mine was crew so I got the better tour. Ever put
   your hand on a torpedo ? The sonar 'room' was highest
   tech ... but that tech involved a cubic-meter CPU box
   with a few of the old removable-stack hard drives ...
   early 70s/late-60s tech. Same reasons as mentioned -
   the vast delay between conception and realization.

 Yep, the entire sub likely took 10+ years to design and build.  By the
time the submariners get to launch their "new" sub, most of the tech on
board would look dated (by the standards of the commercial world)
because it was designed minus ten or minus fifteen years ago, with
posssiby cutting edge tech then, but no longer cutting edge "today".

   I figure that most of the specs for the Apollo/LEM were
   largely drawn even before Glenn splashed down. Amazed they
   didn't use tube-based computers ... probably would have
   except for the power requirements. However there ARE cold
   cathode tubes/valves which would be adequate for computing
   needs, low amperage, and you CAN make 'em pretty small.
   Fortunately by 1960 transistors had been around for awhile
   and the tech was crude enough to be radiation-resistant.

Few commercial products see more than a couple years of total sales
before they get a "redesign", none of them have been undergoing design
and build for fifteen years when they hit the market.

   That's an unfortunate truth. CONSUMERS get cutting-edge,
   but govt projects/contracts - no.

   The sonar guy seemed well versed in making best USE
   of that equipment, but STILL !!!
>
   Some of this is why I'd like people like Musk in the
   loop - chop years, maybe a decade, out of that awful
   process. It's NOT good to be too far behind the curve.

 Musk isn't the savior here.  His method (fire everyone then oops..
hire back some we really needed) won't work for projects that do really
need years to design and build (because they are largely "one-offs" --
i.e., Navy might have built 10 or 20 subs, Apple builds a million plus
iphones a week).  For something like a sub, you simply won't build one
in six months to a year like for a phone (well, not unless you want it
to implode at depth like that carbon fiber one did a couple years ago).

   Took a good tour of the Kennedy Space Center when I was
   maybe nine or ten. Again had an 'in' person. The tech
   in the launch control area looked to be a LOT of "one
   off" stuff - never made before, or again, very very
   task-specific. Ya know those old removable-stack hard
   drives mentioned ? Most consumer models all the heads
   moved in unison - just one actuator - but at NASA they
   had some where each head in the stack could move
   independently. This would have been a huge boon for
   multi-user systems, much quicker.

     There are few radiation-hardened chips coming out these days. We're
     still talking 80s tech. Slow - but robust. Big enough transistors so
     cosmic rays and such won't compromise things.

>
One project I worked on used TI's TMS9900 microprocessor of TI-99/4 fame.
Or notoriety, take your pick. Its claim to fame was TI produced rad-hard
parts. TI had ties to the defense industry that made them a natural.

 For electronics that have to go into space, radiation hardened is a
must.  Send your phone into space and in very short order all kinds of
weirdness and corruption will occur.

   Yep ... your expensive iPhone will be TRASH
   really quick.
   Rad-hard is difficult. Fast protons blast in and switch
   states, or literally erode the silicon. It's why most
   deep-space probes are still using 80s processors. However
   some alts to the conventional design/materials have since
   been found which allow denser circuits AND resist those
   nasty protons. It's maybe worth a little research, just
   for interest.
   It's the hyper-reliable/redundant PROGRAMMING they put
   into those chips which puts me in greatest awe. They
   can STILL fix the Voyager probes even beyond the rim
   of the solar system because of that. LOTS of ways to
   re-route, LOTS of stuff that survives if some bits
   don't. Blow ONE 5 nm transistor in your laptop
   and it's probably DONE - no work-arounds.
   How do you build hardware and software ASSUMING that
   random bits are going to be corrupted/broken ? It's
   almost black art ......