"Richard Clark" wrote in message
...
On Wed, 5 Jan 2005 12:03:37 -0800, "Joel Kolstad"
wrote:

"Ed Price" wrote in message
news:gAdBd.6143$yW5.2@fed1read02...
We spend a lot of time now arguing about how well the computer model
replicates reality, and whether the math has enough variables accounted
for. Working models seem so old fashioned.

That's because they're so expensive to build. You'd probably never finish
designing something like a modern RF IC if all you could do was design it
on
paper, build it, probe around a little to figure out what it 'really'
does,
and repeat.

Likewise, few companies can afford to design the autopilot for a jet
without
a great deal of simulation first. :-)


Hi Guys,

Back when I designed the UFDR for the 757/767, they were the first
airplanes designed entirely in software (conventional drafting went
the way of the Dodo). Today's 7E7 was entirely modeled in software if
I'm not mistaken.

73's
Richard Clark, KB7QHC


There's nothing wrong with doing a lot of modeling. OTOH, Boeing didn't go
from the computer model directly to production. Computer models don't do
very well in predicting the unexpected; things like digital designers
discovering the concept of parasitics ("There's nothing in my design that
generates 832 MHz!") or mechanical designers exploring the wonders of RF
stray coupling paths ("The RF gets from this compartment to that compartment
through a BOLT?!"

My initial point was that wondrous and amazing things can be proven through
software being pushed to the outer edges of its parameters. Before you
invest in several years of modeling, someone needs to take a whack at a
brassboard model to calibrate the sanity of the software.

Ed
wb6wsn