On Thursday 31 October 2013 00:11:32 Jon Elson did opine:
> Gene Heskett wrote:
> > Yeah, but we're still stuck with DIPS in .1" widths. But then we
> > invented them 50 years ago. :)
>
> Except for a quick wire-wrap converter for something, I haven't used
> DIPs in years. SOIC is .050" (half DIP lead pitch) and there is stuff
> at .635mm (.025" or quarter DIP pitch) but all of electronics is moving
> toward hard metric dimensions.
But 75% of mine is one offs, for me, so I tend to use what is available at
the shack since I am 100 to 200 miles from a real electronics supply house.
Old habits die hard. The other 25% is probably a concept board for a 30 yo
legacy computer & the board designer isn't normally me, but somebody
sending me a set of eagle files from the free version with a "can you make
2 or 3 of these?" request.
Footprint changers because the older one time proms are now gone into the
sands of time and are now 5x faster eproms with 4 to 10 more pins, that
sort of stuff. If its simple, the new chip sits not more than .2" from the
old one, but a socket and 600 mil dip chip taller. I am sure some of this
could be done in tsop's but the footprint translations would use more real
estate, no net savings except maybe in power, and 99.9% of this is 5 volt
logic anyway.
> I just left my pick and place machine in metric, and do everything for
> it in mm units. Fortunately, my electronic CAD system will make data
> for either units easily. Funny, though, my PC board house wants data
> in inch units, but the boards are made in China! No doubt they convert
> everything to mm before sending data to the Chinese fab.
Chuckle. ok as long as they don't do a mars lander on the inch stuffs. ;-)
> Jon
Cheers Jon, Gene
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
However, never daunted, I will cope with adversity in my traditional
manner ... sulking and nausea.
-- Tom K. Ryan
A pen in the hand of this president is far more
dangerous than 200 million guns in the hands of
law-abiding citizens.
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