----- Original Message -----
Sent: Saturday, January 04, 2003 8:30
AM
Subject: [USMA:24349] Re: iVDR "inch"
drives?
2003-01-03
I think the person who responded to you needs to be
informed that there is a big difference between something having an inch name
and something actually being measured in inches. Floppy disks, computer
monitors, plumbing, and maybe even tires all have inch names, but the inch
names don't even come close to their true dimensions. And most, if
not all, of these products are made in metric anyway.
A pfund (pound) may be 500 g in Germany, but it is only
454 g in the US. A sea mile is different from a land mile (1852 m vs.
1609 m). The similarities between units is their names and nothing
else. Just because an old name lingers on and things are called by that
old name, does not mean the unit has survived.
You may still call 500 g a pfund, but the scale to
measure it still says 500 g. You may use a zollstock, but the units
inscribed on them are millimetres. You can call a floppy disk 3.5 in,
but that doesn't make it so. The disk is still 90 x 94 x 3.3 mm^3.
You can call margarine butter, but it is still margarine. The name used
does not mean that the name accurately describes the product. Using
a wrong name can in fact lead to confusion as when a 3.5 inch is mistakenly
referred to as 8,89 cm.
Speaking of zoll, the zoll is/was not equal to an
inch:
zoll
the traditional German inch, equal to
1/12 fuss.
Originally the zoll was equal to 1.037 inches (about 2.634 centimetres). In
Switzerland, it is now considered a metric unit equal to exactly 3 centimetres
(1.1811 inches). There's no change in the plural.
In zoll, the floppy disk description can be: 3.42 zoll
(90 mm), or 3.38 (3.5 inch), or 3.00 (90 mm based on 30 mm/zoll), or even
2.96 (3.5 inch based on 30 mm/zoll). Take your choice! But, it
really doesn't matter what you call it because the dimensions will always be
90 x 94 x 3.3 mm^3.
Now a days it is almost impossible to convert an FFU
number to SI. That is because the chances are good that when the
original numbers were converted to FFU, they were modified to rational FFU
numbers without a change in the product. Thus, when changing back you
don't get the original and correct metric value.
Example: 20 mm = 0.787 inch which is
rationalised to 0.75 inch. And if back converted to SI, 0.75
inch becomes only 19 mm, a whole millimetre off from the original
value.
So, what is really gained by keeping FFU alive? It
seems nothing but error and confusion.
John
----- Original Message -----
Sent: Friday, 2003-01-03 06:34
Subject: [USMA:24335] iVDR "inch"
drives?
Discussion on the Ziff-Davis "ExtremeTech" forum.
Feel free to dive in.
http://discuss.extremetech.com/n/main.asp?webtag=extremetech&nav=messages&msg=24566.12
Initial
post:
A consortium called iVDR is said to be readying tiny 1.8" and
2.5" hard drives, with removable cartridges, for introduction at the 2003
Consumer Electronics Show in Las Vegas. While the disks look like a cool
idea, it appears that they may be ...
My response:
What in
God's name is this 1.8 "inch" and 2.5 "inch" garbage? These are all metric
companies in metric countries. Without doubt these new devices are in hard
metric sizes. So why are they using antique units to describe their size? Is
this another case of dumbing things down for Americans? The time has long
past to ditch the entire archaic and obsolete inch-pound measurement system
-- and any retrograde reference to it.
A response to that:
I
don't think they're dumbing anything down for Americans, it's just that some
things are still traditionally measured in inches. In Europe we still have
inch sizes for car, motorcycle and bicycle wheels. In Germany at least,
plumbing pipes and fittings are still done in inches, and we use 3,5" and
not 8,89cm floppies. A ruler here is still called a Zollstock (an "inch
stick"),one half kilo a Pfund (pound) and the international standard for
sea-going vessels is sea miles, so the metric system hasn't completely taken
over everything.
My further response:
The "3.5 inch" diskette
is a myth. The Japanese designed it in the 1980's as exactly 90 mm. Calling
it "8.89 cm" is a clumsy back-conversion from the inch description. IBM, one
of the first users of this device, dumbed down the size description for the
US audience, much as my local grocery chain dumbs down a 2 liter soda bottle
to "67.6 ounces".
Now, the old 5.5 inch diskette that really WAS a
floppy (bendable, not stiff) -- that WAS 5.5 inches. We know where that
format has gone. With one of the removable disks given an inch size, IBM
felt compelled to give the other the same thing, even when it didn't
apply.
The antique system still used by some in the USA should have
been tossed in the dustbin of history long ago.
Carleton
MacDonald
