That state of metric conversion in the US

[rickman]

It's the constant thickness of the flutes that distinguishes pozidrive.

Have any old Tektronix gear around? As in 5K or 7K series lab scopes, or
400 series portable scopes, or TM500 test gear? _LOADS_ of pozidrive
screws in them. As whit3rd said, using a phillips on these is a bad idea.

Actually, it was a Tek sig gen that had the screws the stuck on my
philips driver. I'll take another look at them to see the hash marks.

 

[rickman]

The Brat routes on a 1 mil grid. That can hit most anything.

We don't autoroute. It generally makes a mess of things.

https://dl.dropbox.com/u/53724080/PCBs/ESM_rev_B.jpg

https://dl.dropbox.com/u/53724080/PCBs/V470_board.JPG

https://dl.dropbox.com/u/53724080/PCBs/TEM2_FPGA.jpg


Show us your boards!

I don't get it. What are you showing the boards for...?

 

[josephkk]

Shades of the ancient CBS system.

You'd think if they can make an LCD do color, they'd have just used it
directly. Was this back in the days of passive panels and twisted nematic
formulations, when color LCDs sucked?

Tim

Well, considering that they were new over 25 years ago, it must have been
an interesting cost-performance tradeoff at the time. Getting that kind
of resolution (especially convergence) out of a shadow mask type tube
would have been rather challenging.

?-)

 

[Syd Rumpo]

On 26/02/2013 02:56, rickman wrote:

PS A friend is giving lectures on cold water safety and often says "mil"
to mean mm. Not that anyone in the audience will get confused, but it
hits a nerve in me.

What gets me is people saying 'mil' for 0.001"when they mean 'thou'.
And MBOPD for a thousand barrels of oil per day but MMBOPD for a million.

Cheers

 

[josephkk]

Oddly enough, when I read black text on white background of just the
right pitch on my laptop, it tinges in red. I really shouldn't have
tried to scrimp on the computer and bought one with an LCD screen
instead of a CRT! lol But really, I get red tinging sometimes on
smaller fonts.

Doggonit. You pulled too hard, my leg popped off, hand it back if you
will.

?-)

 

[josephkk]

I don't understand why nobody makes a LCD with sequential RGB LED
backlighting. You'd get three times as many pixels for free, and
energy efficiency would be many times better. I thought there were
some fast LCD chemistries around.

Interesting, i see a lot of ads for monitors with 4 ms or so response
times, way faster then vertical refresh rates. But you just blew your
Internet patent rights.

?-)

 

[josephkk]

Tell that to the spreadsheet people! I recently found that you can make
engineering notation work in spreadsheets, both Excel and Open Office.
But it is not built in and it quite a trick getting it to work.

I have tried a few, they are pretty ugly macros and not reliable.

?-/

 

[Martin Brown]

Although in principle there is no reason the driver which knows the
screen is rotated to portrait format cannot compensate in the same way.

I don't understand why nobody makes a LCD with sequential RGB LED
backlighting. You'd get three times as many pixels for free, and
energy efficiency would be many times better. I thought there were
some fast LCD chemistries around.

A couple of reasons - you don't need anything like as much chroma
resolution as intensity resolution to fool the eye. I suspect there may
be other practical barriers too like getting uniform illumination with
all three colours as well. Most screens struggle to do this now!

And perhaps more importantly there would be inter channel cross talk
between sequentially displayed R,B,G images which would be very hard to
eliminate. They already have to interleave hard black drive or overdrive
tricks between each successive video frame to get maximum quality images
without trailing smears on fast moving objects. Gamers tend to obsess
about dynamic response times for fast moving images. e.g.

http://www.tftcentral.co.uk/advanced.htm#odc

It doesn't really affect most other uses of LCD displays.

 

[JW]

Well, considering that they were new over 25 years ago, it must have been
an interesting cost-performance tradeoff at the time. Getting that kind
of resolution (especially convergence) out of a shadow mask type tube
would have been rather challenging.

Well, 20 years, anyway. At least for Tek.
http://www.electronicproducts.com/T...lloscope_makers_ride_the_color_bandwagon.aspx

 

[Martin Brown]

100E7 is 10E8 and is always numerically 1E9 and completely unambiguous.

There may be some innumerate humans that can't read numbers in
exponential notation but that is an entirely different matter.

Tell that to the spreadsheet people! I recently found that you can make
engineering notation work in spreadsheets, both Excel and Open Office.
But it is not built in and it quite a trick getting it to work.

Actually it *is* built in as a part of custom formatting of numbers in
cells although the format syntax is cryptic so you might not guess it.

Sample data in engineering notation

1 1.0E+0
12 12.0E+0
123 123.0E+0
1234 1.2E+3
12345 12.3E+3
123456 123.5E+3
1234567 1.2E+6
12345678 12.3E+6
123456789 123.5E+6
1234567890 1.2E+9

The required default setting is Format Cells Custom "##0.0E+0"
But the variable number of significant digits is not ideal!

Closest to being useful for engineers is "##0.0##E+0"

Alter the .0E bit to have at least enough digits. MS developers have no
sense of engineers wanting a fixed number of mantissa digits displayed.

Business users don't care about accuracy and precision.

That is in Excel 2010 - exact syntactic sugar may vary with version no.

 

[Uwe Hercksen]

Yeah, sorry, I meant pascals. Why on earth did they pick 1e5? And any
hints yet when they'll change the unit for pressure again or are they
done changing now?

Hello,

they simply used the base unit Meter of length and the base unit Newton
of force to get a unit for pressure called Pascal. 1 bar was choosen to
be 1e5 pascals to get a pressure unit to measure the atmospheric
pressure as aproximately 1 bar.
The units meter and newton very already defined and the natural air
pressure at sea level is a fact. Nobody had to pick 1e5, this factor is
the result of the definitions for the meter, the second and the
kilogramm. Newton is defined from kilogramm, meter and second.

Bye

 

[Martin Brown]

They did briefly try converting mmHg (ie torr) to pascals on hospital
patient charts but it was quickly discontinued after nonsensical data
was found with most patients blood pressure wrong by factors of 760/1E5.

Sometimes it makes sense to record critical data in the familiar
traditional measure to avoid risk of corruption bad unit conversions.

A lot of hard vacuum kit is still calibrated in torr or rather small
fractions thereof and I don't see it changing any time soon.

Yeah, sorry, I meant pascals. Why on earth did they pick 1e5? And any
hints yet when they'll change the unit for pressure again or are they
done changing now?

They didn't *pick* it any more than they picked 14.7lb/sq.in.

It just is what it is and in SI metric units by pure chance on Earth
today it comes out at very close to 10^5.

Had they chosen some other metal as the kilogram reference material then
a standard atmosphere would be a completely different number.

I fully expect torr and milliBar to coexist with the approved SI unit
essentially forever. The former are far too convenient to get dropped.

The inch is 10% more than an atto Parsec by pure chance too.

IUPAC have the same problem with chemistry. They spend time teaching
systematic names for chemicals to school children and the first thing
they learn at university is that ethanoic acid is still called acetic
and propan-2-ol is isopropanol if you want to be understood.

 

[SoothSayer]

Well, considering that they were new over 25 years ago, it must have been
an interesting cost-performance tradeoff at the time. Getting that kind
of resolution (especially convergence) out of a shadow mask type tube
would have been rather challenging.

?-)

Idiot!

LCDs are NOT raster scanned and do NOT have a slot mask OR electron
beam to 'converge'.

Learn about pixel level addressing, and progressive scan frame posting.

Sheesh.

 

[SoothSayer]

I have tried a few, they are pretty ugly macros and not reliable.

?-/

You retards are so Office 2003!

sheesh! 2k7, 2k10, 2k13... ALL have advanced functions.

Losers like you do not.

Joseph = not reliable. For anything other than obsoleted
"information" and convoluted, personally biased cracks.

 

[CellShocked]

The required default setting is Format Cells Custom "##0.0E+0"
But the variable number of significant digits is not ideal!

Closest to being useful for engineers is "##0.0##E+0"

Alter the .0E bit to have at least enough digits. MS developers have no
sense of engineers wanting a fixed number of mantissa digits displayed.

then use the CUSTOM cell format selection, NOT the "scientific".

You can make a cell utilize such notation in a couple ways.

 

[Jeroen Belleman]

You retards are so Office 2003!

sheesh! 2k7, 2k10, 2k13... ALL have advanced functions.

Please do tell! I'd love to see Excel use SI multiplier prefixes.
It doesn't, it can't, as far as I can tell.

(I suppose the 2k7 etc. refer to Excel versions? Shouldn't
that be 2k007, 2k01 and 2k013 then? The 'k' is redundant, too.)

Jeroen Belleman

 

[Martin Brown]

Please do tell! I'd love to see Excel use SI multiplier prefixes.
It doesn't, it can't, as far as I can tell.

It can and does but the syntax for enabling it as a custom number format
is rather perverse and you probably would not guess what it does from
just looking at it unless you are an Excel wizard.

See my adjacent post - but in summary:

The required default setting is Format Cells Custom "##0.0E+0"
But the variable number of significant digits is not ideal!

Closest to being useful for engineers is "##0.0##E+0"

And "#0.0#E+0" will do even powers of ten only.

This functionality has been available since at least Excel 2k. I don't
have any older versions still running here (or rather the machine they
run on no longer boots at present and is not a priority to fix).

(I suppose the 2k7 etc. refer to Excel versions? Shouldn't
that be 2k007, 2k01 and 2k013 then? The 'k' is redundant, too.)

Jeroen Belleman

Maybe he has a time machine and a version from 2700?

 

[[email protected]]

I much prefer metric. Decimal inches isn't bad. Fractional inches is
the pits. Converting between the three crashes space probes, and
wrecks the occasional part on my lathe.

I can think in 16s and 32s as well as 10s. The problems start when
you mix them, so don't do that.

 

[[email protected]]

On 26/02/2013 02:56, rickman wrote:



What gets me is people saying 'mil' for 0.001"when they mean 'thou'.
And MBOPD for a thousand barrels of oil per day but MMBOPD for a million.

It *is* correct.

 

[[email protected]]

I see those, usually swirley circles. Watch out for big arcs: that
could be detatchment.

You're speaking of auras here? I get them occasionally (both types,
but usually circles or amoeba). PITA.