kByte, KByte, Kbyte, kbyte???
Stefan Schuett
when the hell do I use which variant???
We had a very emotional debate in our company about it and I
would appreciate every hint.
Stefan
John Nurick
"k" should be lower-case on analogy with kilometre, kg, kHz, u.s.w.
I think I see "byte" more often than "Byte".
--
Best wishes
John Nurick
e-mail: j.nu...@dial.pipex.com
v-mail: <+44|0> 191 281 1306
Markus Laker
> when the hell do I use which variant???
> We had a very emotional debate in our company about it and I
> would appreciate every hint.
It's common to use 'K' to mean 1024 and 'k' to mean 1000. Furthermore, some
people distinguish between 'B' as an abbreviation of 'byte' and 'b' as an
abbreviation for 'bit'. Where the context is clear, the 'B' or 'b' can be
omitted altogether. If you're going to spell out 'byte', however, I don't
think there's much need for a capital letter.
In short, if they're real kilobytes, I suggest 'KB' or 'Kbyte'.
[Posted and mailed.]
--
Markus Laker.
Steve MacGregor
| when the hell do I use which variant???
| We had a very emotional debate in our company about it and I
| would appreciate every hint.
Use Kbyte, and nothing else.
The metric symbol for 1000 is "k", but what we want here is the
computational prefix for "1024", which is a capital "K", just to be
different. There is no reason at all to capitalize "byte".
Well, if you want to abbreviate the "byte", too, you should probably
use a capital B for that. And I say this only because I see "KB" as an
abbreviation of "kilobyte", but never "Kb".
--
--------------------------------------------------
Help stamp out, eliminate, and abolish redundancy!
--------------------------------------------------
John Savage
Stefan Schuett <schuett...@ov.fr.bosch.de> writes:
>when the hell do I use which variant???
>We had a very emotional debate in our company about it and I
>would appreciate every hint.
The correct answer is probably "kilobytes".
kB is the abbreviation for kilobytes, and
kb " " " " kilobits.
I believe there is [supposed to be] a recognized distinction
between a capitalized and non-capitalized prefix in this case.
It goes something like this: kB means 10^3 (1000) bytes, but
KB (or maybe that's K B) means 2^10 (1024) bytes.
This convention cannot extend to the "mega-" prefix because both lower
case and upper case interpretations already apply to the letter M.
--
John Savage ko...@sydney.dialix.com.au
Carol C. Kankelborg
If I may jump in, without having seen the initial post, I'll offer
my two cents.
The 4 variants in the subject line all refer to kilobytes.
(1 byte = 8 bits or binary digits; also referred to as an octet
in Europe)
kilobytes is often abbreviated as KB or kB. I'm not aware of
any specific distinction. kilobits is Kb or kb. This convention
of 'B' = Bytes and 'b' = bits is generally used, but usage
can get sloppy if the meaning is obvious from context.
My initial reaction is that KB and Kb are more commonly used.
This applies to MB (Megabytes), GB (Gigabytes), etc.
In the computer design world, the kilo prefix refers to 2^10 (1024),
M = 2^20, and G = 2^30. However, once marketing got its hands on
the nomenclature, it realized that when you are measuring bytes
in chunks of 1000 instead of 1024, there are more chunks, so when
Hard drive sizes are advertized in MB, it is usually referring to
millions (10^6) of bytes, not (2^20) of bytes, so that the size
is a bigger number.
--
Carol C. Kankelborg
Amdahl Corp. cs...@eng.amdahl.com
The above opinions are uniquely mine.
Simon Slavin
In article <4m28li$69o$1...@sydney.DIALix.oz.au>,
John Savage <ko...@sydney.dialix.com.au> wrote:
> Stefan Schuett <schuett...@ov.fr.bosch.de> writes:
> >when the hell do I use which variant???
>
> The correct answer is probably "kilobytes".
>
> kB is the abbreviation for kilobytes, and
> kb " " " " kilobits.
I've never heard that, but then I never need to write about kilobits.
I don't think that the capitalisation of the 'b' is important. I've
seen both capital and lower-case 'b' used for 'bytes'.
> It goes something like this: kB means 10^3 (1000) bytes, but
> KB (or maybe that's K B) means 2^10 (1024) bytes.
Anyone who uses a lower-case 'k' doesn't know what they're typing about.
There's no unit represented by a lower-case 'k'. The committee who
standardised the abbreviations was very clear on the matter. An upper-
case 'K' was defined to mean 'one thousand', not 1024. The use of 'K'
for 1024 is 'slang'.
> This convention cannot extend to the "mega-" prefix because both lower
> case and upper case interpretations already apply to the letter M.
That's what I was talking about. Something with a lower-case 'k'
would be referring to some unit less than 1. I occasionally see
adverts for 500mb disk drives which was funny the first time.
Simon.
--
Simon Slavin -- Computing | "We are /all/ lying in the gutter, but /some/
Contractor Ordinaire | of us are looking at the stars." -- Oscar Wilde
Daan Sandee
In article <ADAD698D...@hearsay.demon.co.uk>, sla...@hearsay.demon.co.uk (Simon Slavin) writes:
|> In article <4m28li$69o$1...@sydney.DIALix.oz.au>,
|> John Savage <ko...@sydney.dialix.com.au> wrote:
|>
|> > Stefan Schuett <schuett...@ov.fr.bosch.de> writes:
|> > >when the hell do I use which variant???
|> >
|> > The correct answer is probably "kilobytes".
|> >
|> > kB is the abbreviation for kilobytes, and
|> > kb " " " " kilobits.
|>
|> I've never heard that, but then I never need to write about kilobits.
Well, people who do need have heard.
|> I don't think that the capitalisation of the 'b' is important. I've
|> seen both capital and lower-case 'b' used for 'bytes'.
By people who didn't know any better, I assume.
|> > It goes something like this: kB means 10^3 (1000) bytes, but
|> > KB (or maybe that's K B) means 2^10 (1024) bytes.
|>
|> Anyone who uses a lower-case 'k' doesn't know what they're typing about.
|> There's no unit represented by a lower-case 'k'. The committee who
|> standardised the abbreviations was very clear on the matter. An upper-
|> case 'K' was defined to mean 'one thousand', not 1024. The use of 'K'
|> for 1024 is 'slang'.
However, the vast majority of Earthlings, who grew up in a world where
the metric system was a fact of daily life, and not something you learned
about in physics class, know what the symbol (it is not an abbreviation)
is for, e.g., "kilogram". Nary a K in sight.
TNHD explains (p.293) how k is used for 1000 and K for 1024. This last is
unofficial computerspeak, of course, not SI. TNHD also consistently uses
B for bytes.
|> > This convention cannot extend to the "mega-" prefix because both lower
|> > case and upper case interpretations already apply to the letter M.
|>
|> That's what I was talking about. Something with a lower-case 'k'
|> would be referring to some unit less than 1. I occasionally see
Please go to the SI committee in Paris and tell them that you are right
and they are wrong. (Do you know which unit has the symbol hPa, where
it used, and why they spell it so funny?)
|> Simon Slavin -- Computing | "We are /all/ lying in the gutter, but /some/
|> Contractor Ordinaire | of us are looking at the stars." -- Oscar Wilde
A computing contractor ??? Gawd help us all.
Daan Sandee san...@think.com
Burlington, MA
Colin Mahoney
On 29 Apr 1996 21:20:18 +1000, John Savage
<ko...@sydney.dialix.com.au> wrote:
>>
>It goes something like this: kB means 10^3 (1000) bytes, but
>KB (or maybe that's K B) means 2^10 (1024) bytes.
>
>This convention cannot extend to the "mega-" prefix because both lower
>case and upper case interpretations already apply to the letter M.
Surely lower case 'm' should be saved for 'milli'?
>--
>John Savage ko...@sydney.dialix.com.au
---------------------------------------
Colin Mahoney ( cmah...@readysoft.es )
Sabadell, Spain
---------------------------------------
Tony Pritchard
In article <ADAD698D...@hearsay.demon.co.uk>,
Simon Slavin <sla...@hearsay.demon.co.uk> wrote:
> In article <4m28li$69o$1...@sydney.DIALix.oz.au>,
> John Savage <ko...@sydney.dialix.com.au> wrote:
>
> > Stefan Schuett <schuett...@ov.fr.bosch.de> writes:
> > >when the hell do I use which variant???
> >
> > The correct answer is probably "kilobytes".
> >
> > kB is the abbreviation for kilobytes, and
> > kb " " " " kilobits.
>
> I've never heard that, but then I never need to write about kilobits.
> seen both capital and lower-case 'b' used for 'bytes'.
>
> > KB (or maybe that's K B) means 2^10 (1024) bytes.
>
> There's no unit represented by a lower-case 'k'. The committee who
> standardised the abbreviations was very clear on the matter. An upper-
> case 'K' was defined to mean 'one thousand', not 1024.
What *are* you talking about.
**What** committee??
The SI prefix for kilo (=1000) is lower-case k, and always has been.
No SI unit symbol has an upper-case K for kilo, in any circumstances
whatsoever.
Am I to understand that there is some committee somewhere that is
promulgating an alternative measurement system to SI?
Tony Pritchard
Lower Hutt, New Zealand
Tom Heathcote
Carol C. Kankelborg (cs...@eng.amdahl.com) wrote:
: In the computer design world, the kilo prefix refers to 2^10 (1024),
: M = 2^20, and G = 2^30. However, once marketing got its hands on
: the nomenclature, it realized that when you are measuring bytes
: in chunks of 1000 instead of 1024, there are more chunks, so when
: Hard drive sizes are advertized in MB, it is usually referring to
: millions (10^6) of bytes, not (2^20) of bytes, so that the size
: is a bigger number.
AFAIK the megabytes used to describe hard drive sizes refer not to
millions of bytes, but to *thousands* of kilobytes (ie. 1MB = 1,024,000
bytes). This cartainly applies to 1.44 MB floppy disks, which hold
1440 KB or 1,474,560 bytes.
It can be confusing, especially when different pieces of software use
the two different definitions. It took me a while to work out why
Microsoft Diagnostics and the Norton Utilities couldn't agree on the
size of my hard drive - one said 406MB and the other 416MB.
It's interesting that when referring to memory size, only the 2^20
definition seems to be used. Maybe in a few years when machines
commonly have 128 or 256MB of RAM, some marketing manager will
decide to call them 131 and 262MB instead.
Maybe for the sake of clarity we should refer to the 1000KB unit as
a 'short megabyte' (by analogy with the 'short cwt' and 'short ton').
As hard drive sizes move into gigabytes and before long, terabytes,
the situation can only become more confusing. IMHO, what is needed
is a legally binding definition of what these prefixes mean in the
context of computing. Personally I would favour the power of 2
definitions.
Tom Heathcote.
Geoff Butler
In article <4m8d7t$2...@bone.think.com> san...@Think.COM "Daan Sandee" writes:
> [snipped an entirely justified rant]
> Please go to the SI committee in Paris and tell them that you are right
> and they are wrong. (Do you know which unit has the symbol hPa, where
> it used, and why they spell it so funny?)
Ok, I'll bite: Perhaps a hectoPascal (that which we used to know as
a millibar, which was presumably abandoned because "lower- and upper-
case M both mean Mega" so there's no abbreviation for it ;-), but why
do they spell it so funny?
Geoff Butler
Daan Sandee
The unit of pressure in the older cgs system was the bar, originally
defined as one dyne/cm2, but later redefined to 1,000,000 dynes/cm2
to make 1 bar approx 1 atmosphere (so atmospheric pressure was usually
around 1000 millibars.) The symbol for millibar was mb.
With the introduction of the mks system, later expanded to SI, the unit
of pressure became the pascal (note lower case), defined as one newton/m2.
They could have defined it 100,000 N/m2 to make it approx 1 atmosphere
but they didn't, so now 1 atmosphere is 100,000 pascal. By now,
meteorological instruments and programs were so accustomed to having
atmospheric pressure having a value of around 1000 [something] units,
that the unit that meteorologists use is the hectopascal. This is a
very recent innovation in meteorology, although the mks system must be
at least forty years old.
In SI, all names of units are lower case (newton, pascal, henry). and
they are commonly written using a symbol (not an abbreviation) which
may or may not be capitalized. Thus, the symbol for pascal is Pa and
the symbol for hectopascal is hPa.
Rainer Thonnes
> There's no unit represented by a lower-case 'k'. The committee who
> standardised the abbreviations was very clear on the matter. An upper-
> case 'K' was defined to mean 'one thousand', not 1024.
Evidence? When did this committee pronounce, last week?
km, kV, kHz are the standard symbols for kilometres, kiloVolts, and
kiloHertz. Km, KV, KHz are simply wrong.
Interestingly enough, 'k' seems to be the only exception to the rule you
alluded to, which uses capital letters for multipliers greater than one
and lower-case ones for those less than 1. There's another exception, of
course, namely that for millionths we even switch to a different language,
but at least it's a lower-case mew.
Paul L. Allen
In article <4md3tr$5...@bone.think.com>
san...@Think.COM (Daan Sandee) writes:
> With the introduction of the mks system, later expanded to SI, the unit
> of pressure became the pascal (note lower case),
That's Pascal (note upper case).
> defined as one newton/m2.
That's Newton/m2 (note upper case).
> In SI, all names of units are lower case (newton, pascal, henry).
That's Newton, Pascal and Henry (note upper case). Also Kelvin, Volt,
Coloumb, Amp (note upper case). But candela, metre, second (note lower
case).
> and they are commonly written using a symbol (not an abbreviation) which
> may or may not be capitalized.
Rubbish. The symbol is capitalized depending upon whether or not the
unit itself is capitalized.
Newton N
Pascal Pa
Amp A
Henry H
Farad F
Coloumb C
Tesla T
Kelvin T
Watt W
metre s
gram g
second s
> Thus, the symbol for pascal is Pa and the symbol for hectopascal is hPa.
That's Pascal and hectoPascal.
In case you hadn't deduced the rule for yourself, all SI units which are
named after people start with a capital letter (just like people's names).
Newton after Isaac Newton, Amp after Ampere, Farad after Faraday, Kelvin
after Lord Kelvin, etc. However, the metre, gram, second and candela
are not named after people (apologies to Messrs Metre, Gram, Second and
Candela, if there are any out there, but these units are not names after
your ancestors).
It's bad enough that this group is filled up with deluded gibberish and
bad linguistics, but now we have bad science too (and at such a basic
level)...
--Paul
kna...@iphcip1.physik.uni-mainz.de
This posting has the purpose to redirect the thread to *the* appropriate
newsgroup, which is comp.std.internat (International Standards) where this
topic has been extensively discussed before (including the moot definition
of `byte' itself -- there are good reasons to prefer the standardese term
`octet'.
--J"org Knappen.
In article <ADAD698D...@hearsay.demon.co.uk>, sla...@hearsay.demon.co.uk (Simon Slavin) writes:
:In article <4m28li$69o$1...@sydney.DIALix.oz.au>,
:John Savage <ko...@sydney.dialix.com.au> wrote:
:
:> Stefan Schuett <schuett...@ov.fr.bosch.de> writes:
:> >when the hell do I use which variant???
:>
:> The correct answer is probably "kilobytes".
:>
:> kB is the abbreviation for kilobytes, and
:> kb " " " " kilobits.
:
:I've never heard that, but then I never need to write about kilobits.
:I don't think that the capitalisation of the 'b' is important. I've
:seen both capital and lower-case 'b' used for 'bytes'.
:
:> It goes something like this: kB means 10^3 (1000) bytes, but
:> KB (or maybe that's K B) means 2^10 (1024) bytes.
:
:Anyone who uses a lower-case 'k' doesn't know what they're typing about.
:There's no unit represented by a lower-case 'k'. The committee who
:standardised the abbreviations was very clear on the matter. An upper-
:case 'K' was defined to mean 'one thousand', not 1024. The use of 'K'
:for 1024 is 'slang'.
:
:> This convention cannot extend to the "mega-" prefix because both lower
:> case and upper case interpretations already apply to the letter M.
:
:That's what I was talking about. Something with a lower-case 'k'
:would be referring to some unit less than 1. I occasionally see
:adverts for 500mb disk drives which was funny the first time.
:
:Simon.
:--
:Simon Slavin -- Computing | "We are /all/ lying in the gutter, but /some/
Simon Slavin
In article <4m8r5c$n...@atlantis.atlantis.actrix.gen.nz>,
to...@atlantis.actrix.gen.nz (Tony Pritchard) wrote:
> In article <ADAD698D...@hearsay.demon.co.uk>,
> Simon Slavin <sla...@hearsay.demon.co.uk> wrote:
> > Anyone who uses a lower-case 'k' doesn't know what they're typing about.
> > There's no unit represented by a lower-case 'k'. The committee who
> > standardised the abbreviations was very clear on the matter. An upper-
> > case 'K' was defined to mean 'one thousand', not 1024.
>
> What *are* you talking about.
>
> **What** committee??
>
> The SI prefix for kilo (=1000) is lower-case k,
Whoops. You're right. I'm wrong. It was a lower-case 'k'. Sorry.
Niklas Bonnemark
"Paul L. Allen" <p...@sktb.demon.co.uk> wrote:
> In case you hadn't deduced the rule for yourself, all SI units which are
> named after people start with a capital letter (just like people's names).
> Newton after Isaac Newton, Amp after Ampere, Farad after Faraday, Kelvin
> after Lord Kelvin, etc.
Allow me to doubt that. Say, do you write Amperage or amperage,
Voltage or voltage?
And do you write the basic elements that are named after people the
same way? That is, Curium and not curium, Berkelium and not berkelium,
Einsteinium and not einsteinium, Nobelium and not nobelium, etc. ?
__________________________________________________________
Niklas Bonnemark (Bönnemark)
Trelleborg, Sweden
niklas.b...@mailbox.swipnet.se
http://www.lookup.com/Homepages/49985/home.html
Markus Kuhn
Simon Slavin wrote:
:Anyone who uses a lower-case 'k' doesn't know what they're typing about.
:There's no unit represented by a lower-case 'k'. The committee who
:standardised the abbreviations was very clear on the matter. An upper-
:for 1024 is 'slang'.
The lowercase 'k' is without any doubt the abreviation for kilo
meaning 10^3 = 1000. I have ISO 31 and ISO 1000 which define the
International System of Units (SI) where kilo is specified here on my
desk and this international standard says exactly what my physics
teachers and professors told me.
To the best of my knowledge, there exists NO formal standard
whatsoever describing that 'K' means 1024. I know that it is to some
degree widely used, but is certainly not universally accepted or
standardized.
If you know, where the K = 1024 definition comes from, where it has
been used first or which committee has specified it in which standard,
I would would be VERY interested in the answer!
Markus
--
Markus Kuhn, Computer Science student -- University of Erlangen,
Internet Mail: <msk...@cip.informatik.uni-erlangen.de> - Germany
WWW Home: <http://wwwcip.informatik.uni-erlangen.de/user/mskuhn>
Markus Kuhn
Standardized Units for Use in Information Technology
----------------------------------------------------
or "What is a Megabyte ..."
Markus Kuhn -- 1996-05-04
A formal standard that defines units for information capacity and
related quantities does not exist and is urgently needed. This paper
presents a possible standard and critiques existing practice.
1 Introduction
In information technology, many units for memory capacity, data
transmission rate, etc. are used today without formal standardization.
The current application of units in information processing is
ill-defined, unsystematic, and inconsistent.
International Standard ISO 31 [1,2], based on the International System
of Units (SI), defines quantities and units for various fields of
science and technology. ISO 31 is well-accepted around the world, but
it currently excludes units for "information content", and no other
comprehensive formal standard specifying units for information
technology exists.
In order to eliminate the current uncertainty in engineering and trade
involved with the use of units for information capacity and related
quantities, I propose the extension of ISO 31 by a new part
"Information Technology" that defines a set of practical units for
this field. The next section gives an idea of how such a definition
might look like.
2 Proposal
The unit of information capacity shall be 1 bit. The name bit is
derived from 'binary digit' and shall not be abbreviated further. The
quantity information capacity is dimensionless, because it refers to a
number of binary symbols.
Unit: 1 bit
One bit is the information capacity equivalent to one binary digit. It
represents the knowledge about which one of two possible complementary
events has happened.
Unless explicitly noted, the information capacity described in the
unit bit or multiples of the unit bit shall never be measured or
calculated based on any low entropy assumptions of the information.
This means for the information capacity 1 bit that the a priori
probability of both binary values can be 0.5 and both values need not
be correlated in any way to any other available knowledge.
Note: This definition of the unit bit makes it clear that high entropy
random bit sequences must be used to measure the information capacity
of devices that use internal data compression.
The unit bit shall not be used in order to measure decision content of
symbols or entropy of sources in information theory or in order to
measure entropy in thermodynamics. (See also the unit shannon (Sh)
mentioned below).
The following widely used multiple of the unit bit is defined as an
alternative unit of information capacity based on the definition of
the unit bit:
Alternative unit: 1 byte = 1 by = 8 bit
Note: The abbreviation 'B' is already used for the unit 'bel' (usually
used as dB) defined in ISO 31-2. In addition, capital letter
abbreviations are used in the SI only for units named after a person,
therefore the 'B' is not available for 'byte'. The abbreviation 'b' is
already used for the unit 'barn' (1 b = 1e-28 m^2), which is used to
specify cross-sections in nuclear physics and which is mentioned in
ISO 31-10 and in various national laws about legal units of
measurement (e.g., [4]).
Note: Historically, the term 'byte' has been also used in the computer
industry to refer to the information capacity required to represent
one text character or to refer to the smallest fraction of a machine
word which can be addressed separately. However, today the meaning of
1 byte = 8 bit clearly dominates any other meaning, therefore
standardization on the modern widely known meaning of 'byte' is
adequate. Several international standards use the definition 1 byte =
8 bit (e.g., ISO 9660 and ISO 11544). In the French language, the term
'octet' is often used instead of 'byte', however the abbreviation
should in any case remain 'by', because 'o' can easily be confused
with the digit 0. (For this reason, SI avoids 'O' for the ohm and uses
the capital Greek letter omega).
Note: It has been suggested to define additional multiples of 1 bit as
alternative units for information capacity. Some suggestions have been
for instance
1 nibble = 1 ni = 4 bit
1 rune = 1 r = 16 bit
1 quad = 1 q = 32 bit
However these are today not widely used and therefore standardization
seems premature. The terms 'word', 'halfword' and 'doubleword' are
specified in an IBM standard, but they commonly also refer to
different machine word sizes and are consequently not good candidates
for international standardization.
The units defined here can be used together with other SI units and SI
prefixes. As in the SI, the prefixes denote powers of ten.
Examples:
1 kbit/s = 1 000 bit/second (data transmission rate)
1 kbyte/cm = 800 000 bit/meter (tape storage density)
1 Mbyte = 8 000 000 bit (file length)
Note: It is possible and recommended by this proposal to use the
unabbreviated unit name "byte" with abbreviated prefixes as shown
above. The abbreviation "by" for "byte" is mainly intended for
situations where a compact notation is desirable (e.g., in narrow
tables).
As powers of two play a significant role in digital information
technology, the following SI prefixes can also be used to denote the
next higher power of two instead of a power of ten. In this case, a
subscripted digit 2 shall be appended to the abbreviation of the SI
prefix and the syllable "di" is added before the prefix name. If
printing a lowered digit 2 in a smaller font is not possible (like in
this ISO 8859-1 file), also a normal digit 2 directly after the prefix
abbreviation is acceptable.
Binary prefixes:
dikilo = k2 = 2^10 = 1024
dimega = M2 = 2^20 = 1048576
digiga = G2 = 2^30 = 1073741824
ditera = T2 = 2^40 = 1099511627776
dipeta = P2 = 2^50 = 1125899906842624
diexa = E2 = 2^60 = 1152921504606846976
dizetta = Z2 = 2^70 = 1180591620717411303424
diyotta = Y2 = 2^80 = 1208925819614629174706176
Examples:
- Maximum application memory size of a historical PC operating system:
640 k2byte = 5 242 880 bit = 5 M2bit
- Formatted capacity of a 90 mm (3.5 in) high density PC floppy disk:
2 * 80 * 18 * 512 byte = 1440 k2by = 11 796 480 bit = 11.25 M2bit
Note: The Unicode and ISO 10646 character sets include a character
SUBSCRIPT TWO as code hexadecimal 2082, which allows correct display
of the binary prefix abbreviations on computers. Unfortunately, many
very widely used old character sets (especially ISO 8859 and IBM
CP437) contain no such character.
Note: In some situations, binary prefixes might also be useful when
applied to other units. For example, the common digital wrist watch
crystal frequency is 32 768 Hz = 32 k2Hz or the number of pixels on a
1024x768 raster graphics screen could be denoted 0.75 dimegapixels.
Negative powers of two can also sometimes be useful as prefixes. For
example, a timer with a frequency of 1024 Hz = 1 k2Hz has a timing
resolution of 1/1024 s = 0.97656... ms = 1 m2s = 1 dimillisecond.
Note: In spoken language, the "di" syllable can be omitted when it is
either clear or irrelevant from the context whether a power of two or
ten is described (like the "one megabit chip", which is obviously a
"one dimegabit chip"). In written texts however, the distinction shall
always be made clear by adding the (subscript) digit '2' to the
abbreviated prefix. The syllable "di" has been selected, because it is
short, easy to pronounce in many languages, and offers some
consistency with the chemical notation (e.g., carbon dioxide = CO2).
3 Existing practice
The 10^3 versus 2^10 notation problem has already been discussed early
in the computer science literature. Suggestions included using the
small Greek letter kappa or the symbol 'bK' and its powers for powers
of 1024 [5,6,7]. These proposals have never gained any significant
acceptance and are not aligned well with the SI and ISO 31 standards.
There seems to exist some consensus in the technical world, that the
prefix kilo used with the units bit and byte denotes a factor of 2^10
= 1024. Unfortunately, this is highly inconsistent with the official
meaning of kilo as specified in the SI standard, which is a factor of
10^3 = 1000 and which is widely used this way in all areas of science,
technology, and trade. An often mentioned proposal to solve this
contradiction is to use the capital letter K for 1024 and the normal
SI abbreviation for kilo which is the small letter k for 1000. This at
first glance elegant solution fails however already with mega which
has the capital letter M as the normal SI abbreviation and where the
small letter m denotes already milli = 10^-3 = 0.001.
However, the SI prefixes are not used consistently today as powers of
two in the context of byte. For example, a 90 mm floppy disk (yes, it
is really exactly 90 mm wide, not 3 1/2 inch!), which has a formatted
storage capacity of 18 * 2 * 80 * 512 byte = 1 474 560 byte = 1.44 *
1000 * 1024 byte, is commonly referred to as a "1.44 megabyte floppy
disk". Here, mega is commonly used as a prefix denoting a factor of
1024 000 instead of 2^20. In general, in the context of magnetic and
optical storage systems, both the definitions 1 megabyte = 1000 * 1000
byte and 1 megabyte = 1000 * 1024 byte seem to be much more popular
than 1 megabyte = 1024 * 1024 byte.
In the context of data transmission rates, the units kbit/s, Mbit/s,
and Gbit/s are today used consistently with the prefixes referring to
powers of ten.
It is sometimes suggested to abbreviate bit as b and byte as B.
Existing practice however seems to be to abbreviate byte both as b and
B. Also bit is sometimes abbreviated as both b even and B, but bit is
usually not abbreviated at all.
In [3], in addition to bit and byte, also the units baud (Bd) (for
modem data transmission symbol rate), and shannon (Sh) (for decision
content and entropy) have been defined. These and other quantities,
units and abbreviations for units should probably be included here,
too.
Theoretically, it might be possible to specify the unit bit in terms
of existing SI base units for thermodynamic entropy. However, this has
very little practical application in both thermodynamics and
information technology. A quantity measured in bit usually denotes
only a dimensionless number of binary symbols and therefore this
thermodynamic definition of the bit is not suggested here.
References:
[1] International Standard ISO 31-0, Quantities and units -- Part 0:
General principles, International Organization for Standardization,
Geneva, 1992.
[2] Quantities and units, ISO Standards Handbook, International
Organization for Standardization, third edition, 345 p., Geneva,
1993, ISBN 92-67-10185-4, 161 CHF.
This book contains the full text of ISO 31 and ISO 1000. Check
<http://www.iso.ch/> for ordering details.
[3] Terms and abbreviations for information quantities in
telecommunication, CCITT Recommendation B.14, CCITT Blue Book,
Fascicle I.3, International Telecommunication Union, Geneva, 1989.
[4] German law about legal units for measurement: Ausführungsverordnung
zum Gesetz über Einheiten im Meßwesen (Einheitenverordnung - EinhV),
published 1985-12-13 in BGBl. I S. 2272, last modification
1991-03-22 in BGBl. I S. 836.
[5] Donald R. Morrison, Abbreviations for Computer and Memory Sizes,
Communications of the ACM, Vol 11, No. 3, March 1968, p. 150.
[6] Wallace Givens, Proposed Abbreviation for 1024: bK, Communications
of the ACM, Vol. 11, No. 6, June 1968, p. 391.
[7] Bruce A. Martin, On Binary Notation, Communications of the ACM,
Vol 11, No. 10, October 1968, p. 658.
I wish to thank all people who have helped me to improve this
proposal, including
Lawrence Crowl <Lawrenc...@Eng.Sun.COM>
Rainer Seitel <uj...@rzstud1.rz.uni-karlsruhe.de>
Any further suggestions for improvement or other comments are very
welcome! Feel free to forward this document to anyone interested. The
latest version of this text is available from my Web homepage (see
last line).
I would also like to get in contact with people active in ISO TC12,
ISO JTC1, CGPM, or other standards organizations who would be
interested in working on a draft standard for information technology
units. ISO 31 will be reviewed in 1997, so now is the right time to
start discussion of such a specification.
Markus Kuhn
Schlehenweg 9
D-91080 Uttenreuth
GERMANY
phone/fax: +49 9131 52226
Steve MacGregor
Jene tajpis lastatempe Paul L. Allen:
> In case you hadn't deduced the rule for yourself, all SI units which are
> named after people start with a capital letter (just like people's names).
> Newton after Isaac Newton, Amp after Ampere, Farad after Faraday, Kelvin
> after Lord Kelvin, etc.
Not quite. Names of SI units all all lower-case (in English), but
their =abbreviations= are (or begin with) majascules:
W = watt after Watt
A = ampere after Ampere
V = volt after Volta
F = farad after Faraday
K = kelvin after Lord Kelvin
Nt = newton after Newton
Pa = pascal after Pascal
The rule would be different in German, in which all all nouns are
capitalized.
--
---------------------------------------------------------
Whom are you going to call? GRAMMAR BUSTERS!!!
---------------------------------------------------------
Tony Pritchard
In article <b6SBj...@sktb.demon.co.uk>,
> san...@Think.COM (Daan Sandee) writes:
> > Thus, the symbol for pascal is Pa and the symbol for hectopascal is hPa.
>
> That's Pascal and hectoPascal.
>
> In case you hadn't deduced the rule for yourself, all SI units which are
> named after people start with a capital letter (just like people's names).
> Newton after Isaac Newton, Amp after Ampere, Farad after Faraday, Kelvin
> after Lord Kelvin, etc. However, the metre, gram, second and candela
> are not named after people (apologies to Messrs Metre, Gram, Second and
> Candela, if there are any out there, but these units are not names after
> your ancestors).
The posting by Paul Allen is totally and utterly wrong.
In the SI system, where a unit is named after a person:
a) The unit name is not (repeat not) capitalised.
Thus hectopascal, newton.
b) The unit symbol *is* capitalised.
Thus hPa, N.
There is simply no option, no argument about this. It's just the way it
was specified by the SI committee.
Jukka Korpela
In article <4md3tr$5...@bone.think.com> san...@Think.COM (Daan Sandee) writes:
- - By now,
meteorological instruments and programs were so accustomed to having
atmospheric pressure having a value of around 1000 [something] units,
that the unit that meteorologists use is the hectopascal. - -
You are right, but they are not. They use a pseudo-SI unit. They
simply use the unit they've used before but call it "hectopascal"
instead of "millibar".
"Hectopascal" is a pseudo-SI unit, since old prefixes hecto- (h-),
deka- (D- or da-), deci- (d-), and centi- (c-) do not fit into the
SI framework. In the SI system, the prefixes represent multiplication
by such a power of ten where the absolute value of the exponent is
evenly divisible by three. Thus, kilo- (10**3) is SI conformant
whereas hecto- (10**2) is not.
From the pragmatic point of view, the hecto- prefix and other non-SI
prefixes mentioned above are redundant and confusing. It is better
to use a unified and regular system, even if it requires changing your
habits. For instance, 1050 mbar (or "hPa") is 105 kPa. Similarly,
when you ultimately abandon the mediaeval units and go metric,
the correct replacement for 1 inch is not 2.54 cm but 25.4 mm.
Yucca
John Nurick
jkor...@cc.hut.fi (Jukka Korpela) wrote:
<snip>
>"Hectopascal" is a pseudo-SI unit, since old prefixes hecto- (h-),
>deka- (D- or da-), deci- (d-), and centi- (c-) do not fit into the
>SI framework. In the SI system, the prefixes represent multiplication
>by such a power of ten where the absolute value of the exponent is
>evenly divisible by three. Thus, kilo- (10**3) is SI conformant
>whereas hecto- (10**2) is not.
>
>From the pragmatic point of view, the hecto- prefix and other non-SI
>prefixes mentioned above are redundant and confusing. It is better
>to use a unified and regular system, even if it requires changing your
>habits. For instance, 1050 mbar (or "hPa") is 105 kPa. Similarly,
>when you ultimately abandon the mediaeval units and go metric,
>the correct replacement for 1 inch is not 2.54 cm but 25.4 mm.
Yes - but SI is not consistent itself. The unit of mass is the kilogram,
not the gram, but no one talks about kilokilograms or microkilograms.
And no one uses "megagram (Mg)" instead of "tonne", or "megametre (Mm)
instead of "thousand kilometer".
Paul L. Allen
In article <318b7f52...@nntpserver.swip.net>
niklas.b...@mailbox.swipnet.se (Niklas Bonnemark) writes:
> "Paul L. Allen" <p...@sktb.demon.co.uk> wrote:
>
> > In case you hadn't deduced the rule for yourself, all SI units which are
> > named after people start with a capital letter (just like people's names).
> > Newton after Isaac Newton, Amp after Ampere, Farad after Faraday, Kelvin
> > after Lord Kelvin, etc.
>
> Allow me to doubt that. Say, do you write Amperage or amperage,
> Voltage or voltage?
Oh dear, oh dear. The correct technical terms are current and
electro-motive force (for sources like batteries) and potential difference
(for sinks like resistors). So you would write `a current of 1 Amp flowing
through a resistance of 1 Ohm results in a potential difference of 1 Volt
across it', not `an amperage of 1 Amp flowing through an Ohmmage of 1 Ohm
results in a voltage of 1 volt across it'.
Admittedly, the use of voltage is quite common in less formal writing,
replacing both EMF and PD but amperage is not. Even so, your question shows
that you cannot distinguish between a unit of measuremnt (the Volt) and a
descriptive term (voltage).
> And do you write the basic elements that are named after people the
> same way? That is, Curium and not curium, Berkelium and not berkelium,
> Einsteinium and not einsteinium, Nobelium and not nobelium, etc. ?
I know this isn't in the sci hierarchy, but I would have thought that
even those people on sci.lang and alt.usage.english could distinguish
between a unit of measurement and an element.
Whatever next? People rushing off to discover Hertz in them thar hills?
Somebody claiming to be able to transmute Newtons into litres using the
philosopher's stone? Somebody claiming that his thermometer reads 98
Nobelium? Maybe somebody else claiming his brain volume is 21 Curium.
Which reminds me of a line from a Zappa song about the commonest element
in the universe being stupidity...
--Paul
Mark Baker
In article <4mjfb3$7...@globe.indirect.com>,
stev...@indirect.com (Steve MacGregor) writes:
>Nt = newton after Newton
No, the abbreviation for newton is just N.
Niklas Bonnemark
"Paul L. Allen" <p...@sktb.demon.co.uk> wrote:
> Oh dear, oh dear. The correct technical terms are current and
> electro-motive force (for sources like batteries) and potential difference
> (for sinks like resistors). So you would write `a current of 1 Amp flowing
> through a resistance of 1 Ohm results in a potential difference of 1 Volt
> across it', not `an amperage of 1 Amp flowing through an Ohmmage of 1 Ohm
> results in a voltage of 1 volt across it'.
>
> Admittedly, the use of voltage is quite common in less formal writing,
> replacing both EMF and PD but amperage is not. Even so, your question shows
> that you cannot distinguish between a unit of measuremnt (the Volt) and a
> descriptive term (voltage).
Why? Did I say that it is the same thing?
Why do you choose to write the descriptive terms, amperage and
voltage, with small initial letters when you write the units, volt and
amp, with initial capitals?
> I know this isn't in the sci hierarchy, but I would have thought that
> even those people on sci.lang and alt.usage.english could distinguish
> between a unit of measurement and an element.
I certainly can. I just wanted to compare with other words which
derive from personal names. Let us avoid personal attacks and
concentrate on the points at issue.
Are we to understand by your statement
> all SI units which are named after people start with a capital letter
that this applies only to SI units and not, as I tried to exemplify,
to decriptive terms like voltage or to elements like einsteinium?
__________________________________________________________
Niklas Bonnemark (Bönnemark)
Trelleborg, Sweden
niklas.b...@mailbox.swipnet.se
Jukka Korpela
Yes - but SI is not consistent itself.
Admittedly. It still beats the Anglo-Saxon system(s) with no
difficulty.
The unit of mass is the kilogram,
not the gram, but no one talks about kilokilograms or microkilograms.
Quite right. And "kilokilogram" would not even be correct. Although the
basic unit of mass is "kilogram", the derived units are formed by
adding a prefix to "gram".
And no one uses "megagram (Mg)" instead of "tonne", or "megametre (Mm)
instead of "thousand kilometer".
Occasionally one does. Hopefully people will find out how convenient
it is to use "megametre" or eg "teragram" instead of the clumsy
"million tons".
Yucca
Colin Mahoney
On 6 May 1996 09:06:42 +1200, to...@atlantis.actrix.gen.nz (Tony
Pritchard) wrote:
>The posting by Paul Allen is totally and utterly wrong.
>
>In the SI system, where a unit is named after a person:
>
>a) The unit name is not (repeat not) capitalised.
> Thus hectopascal, newton.
>
>b) The unit symbol *is* capitalised.
> Thus hPa, N.
>
I think you just re-defined 'totally and utterly' to mean 'partially'.
Paul L. Allen
In article <4mj592$d...@atlantis.atlantis.actrix.gen.nz>
to...@atlantis.actrix.gen.nz (Tony Pritchard) writes:
> In article <b6SBj...@sktb.demon.co.uk>,
> Paul L. Allen <p...@sktb.demon.co.uk> wrote:
> > In article <4md3tr$5...@bone.think.com>
> > san...@Think.COM (Daan Sandee) writes:
>
> > > Thus, the symbol for pascal is Pa and the symbol for hectopascal is hPa.
> >
> > That's Pascal and hectoPascal.
> >
> > In case you hadn't deduced the rule for yourself, all SI units which are
> > named after people start with a capital letter (just like people's names).
> > Newton after Isaac Newton, Amp after Ampere, Farad after Faraday, Kelvin
> > after Lord Kelvin, etc. However, the metre, gram, second and candela
> > are not named after people (apologies to Messrs Metre, Gram, Second and
> > Candela, if there are any out there, but these units are not names after
> > your ancestors).
>
>
> The posting by Paul Allen is totally and utterly wrong.
Umm, steady on. A little wrong, perhaps.
> In the SI system, where a unit is named after a person:
>
> a) The unit name is not (repeat not) capitalised.
> Thus hectopascal, newton.
My apologies, you are indeed correct (and I should have checked first,
but I was so annoyed at the previous poster insisting that the symbols
were lower case...)
> b) The unit symbol *is* capitalised.
> Thus hPa, N.
Which is what I said, so I'm not *totally and utterly* wrong...
> There is simply no option, no argument about this. It's just the way it
> was specified by the SI committee.
There I will agree with you.
--Paul
Daan Sandee
In article <b8dwv...@sktb.demon.co.uk>, "Paul L. Allen" <p...@sktb.demon.co.uk> writes:
|> In article <4mj592$d...@atlantis.atlantis.actrix.gen.nz>
|> to...@atlantis.actrix.gen.nz (Tony Pritchard) writes:
|>
|> > In article <b6SBj...@sktb.demon.co.uk>,
|> > Paul L. Allen <p...@sktb.demon.co.uk> wrote:
|> > > In article <4md3tr$5...@bone.think.com>
|> > > san...@Think.COM (Daan Sandee) writes:
|> >
|> > > > Thus, the symbol for pascal is Pa and the symbol for hectopascal is hPa.
|> > >
|> > > That's Pascal and hectoPascal.
|> > >
|> > > In case you hadn't deduced the rule for yourself, all SI units which are
|> > > named after people start with a capital letter (just like people's names).
|> >
|>
|> Umm, steady on. A little wrong, perhaps.
|>
|> > In the SI system, where a unit is named after a person:
|> >
|> > a) The unit name is not (repeat not) capitalised.
|> > Thus hectopascal, newton.
|>
|> My apologies, you are indeed correct (and I should have checked first,
|> but I was so annoyed at the previous poster insisting that the symbols
|> were lower case...)
Uh, which previous poster insisted that which symbols were lower case ?
|> > b) The unit symbol *is* capitalised.
|> > Thus hPa, N.
|>
|> Which is what I said, so I'm not *totally and utterly* wrong...
The apparent purpose of your post was to disagree with me, and as it was
wrong at every point where you "corrected" me, and correct at every point
where you agreed with me, I think it is a fair statement that, with the
exception of the parts that were redundant, it was utterly wrong.
I think that you have to widen your horizons a little. You see, the vast
majority of the people on this earth have learned the metric system at
the age of seven (if they didn't know about it already), and have thereafter
used it in daily life. Really. Meters and kilograms (and their spelling,
abbreviation, etc.) are facts of life for most of us.
However, citizens of a few benighted countries where they base their
measurements on the width of the king's thumb, or something, have the
impression that the SI system is something you learn about in physics
class, and they are always ready to show off their knowledge, even
if they have the feeling that they may not be entirely correct, just
to prove that they didn't spend all their time in class sleeping.
To disagree with a European, or for that matter most of the world's
population (except that most of those don't read Usenet), about the
proper spelling of "kilowatt" or "km" is just as stupid as disagreeing
with them about the proper spelling of their native language. For us,
"kilowatt" and "km" *are* part of our native language.
About once a year, somewhere on Usenet, usually in an inappropriate
newsgroup, I get into a fight about the metric system, and it is
invariably someone from the US or the UK who holds strong but erroneous
opinions. It is true, of course, that that covers 90% of Usenet ; but
the point is that those people do not realize that most of the rest of
the world is two hundred years ahead of them, and that, even if they are
underrepresented on Usenet, their opinions might therefore be worth
listening to.
Bruce Hunter
In article <4mo75o$9...@bone.think.com>, san...@Think.COM says...
>
>I think that you have to widen your horizons a little. You see, the vast
>majority of the people on this earth have learned the metric system at
>the age of seven (if they didn't know about it already), and have thereafter
>used it in daily life.
At the age of seven. were the vast majority at the same school at which it
was also taught that there were five continents? (Does "five" in Imperial
units equal "seven" in metric units, perhaps? Forgive me if this question has
an obvious answer to the vast majority, but I am one of the implied minority
who were taught in Imperial units whilst at school, when there were still
seven continents.
> Really. Meters and kilograms (and their spelling,
>abbreviation, etc.) are facts of life for most of us.
>[Blah. blah]
Really? The "most of us" must reside on the North American continent,
according to your view. On the European continent, at least, "most of us"
regard "metres" as an actuality, rather than just a "fact of life", as indeed
does the SI Standard for the defintion of a "metre". A "meter" is a device
for recording the measurement of some quantity, at least in "English" as
opposed to USA'n.
The parochialism of some (no flame intended - definitely not "all") USAns
never ceases to amaze. But it would seem that there are some who really
appear to have mistakenly posted their messages to this forum, rather than to
"alt.usage.american", and who seem to take pleasure in parading the
limitations of their knowledge of the usage the English language to the world
at large.
A litle research before posting, Daan, may not go amiss, especially for such
a pedant. The rest of the verbiage from your last posting here
notwithstanding.
regards,
Bruce
Daan Sandee
In article <4morrn$3...@newsgate.dircon.co.uk>, br...@sgml.dircon.co.uk (Bruce Hunter) writes:
|> In article <4mo75o$9...@bone.think.com>, san...@Think.COM says...
I received this post by email. I replied to it by email (my mistake),
not realizing that the email was just because either the poster or the
brain-damaged newsreader thought it was a good idea to provide the
original poster with a so-called misnamed "courtesy copy". I'll be
damned if I type it in again ; let Bruce post it if he wants.
This atrocious habit of some newsreaders (and possibly some posters) has
been discussed here before. A short sojourn on news.admin.net-abuse.misc
taught me that the preferred solution is to include a Reply-To line in
your posting pointing to wherever you want junk mail to go. However, for
junk mail artists (that scan the newsspool for email addresses), you need
to forge a From line, which is a different issue. I am still investigating
how to teach my newsreader to do one or the other automagically. In the
meantime, anyone who really wants to send me email will find the address
in my .sig.
Matthew Rabuzzi
Markus Kuhn <msk...@unrza3.dialin.rrze.uni-erlangen.de> writes:
: Standardized Units for Use in Information Technology [a proposal]
:
: As powers of two play a significant role in digital information
: technology, the following SI prefixes can also be used to denote the
: next higher power of two instead of a power of ten. In this case, a
:
: Binary prefixes:
: dikilo = k2 = 2^10 = 1024
: dimega = M2 = 2^20 = 1048576
: digiga = G2 = 2^30 = 1073741824
: ditera = T2 = 2^40 = 1099511627776
: dipeta = P2 = 2^50 = 1125899906842624
: diexa = E2 = 2^60 = 1152921504606846976
: dizetta = Z2 = 2^70 = 1180591620717411303424
: diyotta = Y2 = 2^80 = 1208925819614629174706176
Well, with 64-bit-word architectures we also need a handy moniker
for 2^64. It may not be SI but I've seen it used: the bubbabyte.
: first glance elegant solution fails however already with mega which
: has the capital letter M as the normal SI abbreviation and where the
: small letter m denotes already milli = 10^-3 = 0.001.
Yes, but what would a millibyte be? Put three of them together and
you get a trilobyte?
.........................................................
Shave and a haircut
Matthew Rabuzzi
Eddie Wiles
On 8 May 1996, Bruce Hunter wrote:
> But it would seem that there are some who really
> appear to have mistakenly posted their messages to this forum, rather than to
> "alt.usage.american", and who seem to take pleasure in parading the
> limitations of their knowledge of the usage the English language to the world
> at large.
As a newcomer, I haven't followed this thread, but I have to disagree with
you here. The English language has, of course, developed in many countries
other than the one in which it originally grew. So there are several
different "usages" of English, arguably the most important (second to British
English) being American English. It's still English: American isn't a
language.
After all, and I'm speaking as a fellow Limey here, American English has
broadened our vocabulary, ironed out many inconsistencies and been, on the
whole, "a good thing". Let's thank America (and Australia, and so on) rather
than imply that she stole our language.
- Eddie Wiles
Mark Odegard
[posted to newsgroup & e-mailed]
On 8 May 1996 13:57:25 GMT, san...@Think.COM (Daan Sandee)
wrote:
As a direct response to Daan's justified complaint, I've
jiggled my Free Agent introductory string. I myself *like*
to receive automatic cc's to postings I've made. But I also
am frustrated when you don't know if it's been posted or
not, especially as e-mail seems to show up well-nigh
instantaneously while postings can be *days* behind before
showing up on your newsreader.
--
Mark Odegard. Shortly to be with something better than Netcom 1-800.
Rainer Thonnes
In article <b7TNM...@sktb.demon.co.uk>,
> niklas.b...@mailbox.swipnet.se (Niklas Bonnemark) writes:
> >
> > Allow me to doubt that. Say, do you write Amperage or amperage,
> > Voltage or voltage?
>
> electro-motive force (for sources like batteries) and potential difference
> (for sinks like resistors). So you would write `a current of 1 Amp flowing
> through a resistance of 1 Ohm results in a potential difference of 1 Volt
> across it', not `an amperage of 1 Amp flowing through an Ohmmage of 1 Ohm
> results in a voltage of 1 volt across it'.
>
> Admittedly, the use of voltage is quite common in less formal writing,
> replacing both EMF and PD but amperage is not. Even so, your question shows
> that you cannot distinguish between a unit of measuremnt (the Volt) and a
> descriptive term (voltage).
You're being unduly harsh. Although Niklas's use of "amperage" was
ill-advised (at least in English, it may be different in Sweden), his
main point was whether you write voltage with a capital V.
As you point out, voltage is a very widely used synonym for EMF, potential,
or tension. That does not mean the speaker does not know the difference
between the quantity being measured and the units in which this is done.
Voltage is relatively unique in this respect, but if you dislike amperage,
would you disapprove as unequivocally of mileage (cars) and footage (film)?
Claude D. Bilbo
In <b7TNM...@sktb.demon.co.uk>, "Paul L. Allen" wrote:
>Oh dear, oh dear. The correct technical terms are current and
>electro-motive force (for sources like batteries) and potential difference
>(for sinks like resistors). So you would write `a current of 1 Amp flowing
>through a resistance of 1 Ohm results in a potential difference of 1 Volt
>across it', not `an amperage of 1 Amp flowing through an Ohmmage of 1 Ohm
>results in a voltage of 1 volt across it'.
When I've seen EMF used, it was to describe voltages produced by inductive
coupling, but I don't know if that's standard or not. I see potential
used a lot. But in any case, just wanted to point out that it's not an
Amp, but rather an Ampere. Resistance is fine, but Impedance is more
general.
>Admittedly, the use of voltage is quite common in less formal writing,
>replacing both EMF and PD but amperage is not. Even so, your question shows
>that you cannot distinguish between a unit of measuremnt (the Volt) and a
>descriptive term (voltage).
FWIW, 'tension' is used to describe 'voltage' as well.
-----------------------------------------------------------------
| Claude D. Bilbo | |
| cbi...@mindspring.com | All of my opinions are |
| bilb...@eng.uab.edu | completely uncorrelated.|
| http://www.mindspring.com/~cbilbo/ | |
-----------------------------------------------------------------
John Nurick
No, a millibyte is like a centibyte only less poisonous and with
fewer legs.
John Coughlin
Chris (chr...@dircon.co.uk) writes:
>
> I hesitate to join this furious argument, but I was taught at school
> exactly the same rule - multipliers are capitalised, dividers are lower
> case, e.g. 'm' is 'milli', 'M' is Mega. And, BTW, pascal, newton, etc. are
> now accepted as words on the UK TV programme Countdown which does not
> allow capitalised words (based on the Shorter Oxford Dictionary). I trust
> neither source but offer them as ammunition in the battle.
>
I was taught that prefixes smaller than mega were lower case. This includes
the recently (or is it soon-to-be ?) defunct deka (symbol da) and hecto
(symbol h) and the long-abandoned myria (symbol my).
--
"Computers let you make more mistakes faster than anything except handguns
and tequila." -- Mitch Radcliffe
Markus Kuhn
rab...@patch.tandem.com (Matthew Rabuzzi) writes:
>Well, with 64-bit-word architectures we also need a handy moniker
>for 2^64. It may not be SI but I've seen it used: the bubbabyte.
If you can suggest nice prefix names for 2^8, 2^16, 2^24, 2^32, ...,
2^64 (bubba), I'd be glad to add them to my porposal. Please consider
that they should also be easy to pronounce in languages like French
and Japanese, which have a phonetic very different from the English
one.
>: first glance elegant solution fails however already with mega which
>: has the capital letter M as the normal SI abbreviation and where the
>: small letter m denotes already milli = 10^-3 = 0.001.
>Yes, but what would a millibyte be? Put three of them together and
>you get a trilobyte?
Check my Web home page for scanned text image compression software
(jbigkit) that stores images with around 50 millibit/pixel.
BTW: I have just uploaded a new revision of the proposal to
<ftp://ftp.informatik.uni-erlangen.de/pub/doc/ISO/information-units>.
The major change is that I use again 'b' as the abbreviation for
'byte', and not 'by'. I added the following text:
The abbreviation 'b' is also already used for the unit 'barn'
(where 1 b = 1e-28 m²), which is used to specify cross-sections in
nuclear physics. Although 'barn' is mentioned (not defined!) in an
informal remark in ISO 31-10 and listed in some national laws about
legal units of measurement (e.g., [6]), it is not an SI unit, and 1
barn = 1 b can also easily be written using the SI unit femtometer as
100 fm². It is unlikely that 'barn' and 'byte' will be used in the
same context frequently. However, whether the official abbreviation
for 'byte' shall be 'b' or 'by' is a matter that might need further
discussion.
Further suggestions are very welcome! I am especially interested in
references to earlier attempts of standardizing the meaning of
'kilobyte', etc. So far, all I have found in the literature is:
[7] Donald R. Morrison, Abbreviations for Computer and Memory Sizes,
Communications of the ACM, Vol 11, No. 3, March 1968, p. 150.
[8] Wallace Givens, Proposed Abbreviation for 1024: bK, Communications
of the ACM, Vol. 11, No. 6, June 1968, p. 391.
[9] Bruce A. Martin, On Binary Notation, Communications of the ACM,
Vol 11, No. 10, October 1968, p. 658.
Markus
Perrin
In article <4mo75o$9...@bone.think.com>, Daan Sandee <san...@Think.COM> wrote:
>About once a year, somewhere on Usenet, usually in an inappropriate
>newsgroup, I get into a fight about the metric system, and it is
>invariably someone from the US or the UK who holds strong but erroneous
>opinions.
And during every said discussion there is some snob who starts
relating the American system of measurement to alchemy or some such.
It is true, of course, that that covers 90% of Usenet ; but
>the point is that those people do not realize that most of the rest of
>the world is two hundred years ahead of them, and that, even if they are
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>underrepresented on Usenet, their opinions might therefore be worth
>listening to.
Yup kind of like this. Look, "foot", "inch", "gallon",
"mile", "quart", "Fahrenheit", "acre", and the like are all part of MY
language and part of the language of most Americans. I am a physicist
(or getting there, anyway), I use the metric system in my work, but I
think in terms of the "American system" (seems silly to call it the
English system anymore) and I find it much more convenient and poetic
for daily life than SI units. If you disagree, fine and good, but
while you are sick and tired of US/UKians telling you how to speak
your language, I am sick of everyone else making snide remarks about
mine.
*Soapbox mode off*
/
:@-) Scott
\
Eric Dunstan
In article <Dqu9Lx.BDw.0.sta...@dcs.ed.ac.uk>,
r...@dcs.ed.ac.uk says...
>
>In article <ADAD698D...@hearsay.demon.co.uk>,
>sla...@hearsay.demon.co.uk (Simon Slavin) writes:
>>
>> Anyone who uses a lower-case 'k' doesn't know what they're typing
about.
>> There's no unit represented by a lower-case 'k'. The committee who
>> standardised the abbreviations was very clear on the matter. An
upper-
>> case 'K' was defined to mean 'one thousand', not 1024.
>
>
>km, kV, kHz are the standard symbols for kilometres, kiloVolts, and
>kiloHertz. Km, KV, KHz are simply wrong.
quite so - K is specific for Kelvin - as in t(degrees)C = T K-273.15
and there are others. eg M = mega as opposed m = metre, G = giga/g= gram
etc.
eric dunstan (where, in my name, the capitals are not important and
quite un-necessary <g>)
>
>Interestingly enough, 'k' seems to be the only exception to the rule
you
>alluded to, which uses capital letters for multipliers greater than one
>and lower-case ones for those less than 1. There's another exception,
of
>course, namely that for millionths we even switch to a different
language,
>but at least it's a lower-case mew.
John Savage
msk...@unrza3.dialin.rrze.uni-erlangen.de (Markus Kuhn) writes:
>To the best of my knowledge, there exists NO formal standard
>whatsoever describing that 'K' means 1024. I know that it is to some
>degree widely used, but is certainly not universally accepted or
>standardized.
I believe that K = 1024 has been adopted as standard IEEE usage.
When the largest representative body of Electrical & Electronics
engineers sets its publication conventions these inevitably then
become de facto standards.
--
John Savage ko...@sydney.dialix.com.au
El Comandante del Presidio
On Tuesday, May 07, 1996, Jukka Korpela wrote...
> Occasionally one does. Hopefully people will find out how convenient
> it is to use "megametre" or eg "teragram" instead of the clumsy
> "million tons".
As Sam Goldwyn used to say, "If you want to send a teragram, use Western
Union."
Markus Kuhn
John Savage <ko...@sydney.dialix.com.au> writes:
>msk...@unrza3.dialin.rrze.uni-erlangen.de (Markus Kuhn) writes:
>>To the best of my knowledge, there exists NO formal standard
>>whatsoever describing that 'K' means 1024. I know that it is to some
>>degree widely used, but is certainly not universally accepted or
>>standardized.
>I believe that K = 1024 has been adopted as standard IEEE usage.
I find this a little bit hard to believe. Can you tell me in which
IEEE publication K = 1024 has been defined?
Rainer Thonnes
In article <chris-c-0905...@gw3-019.pool.dircon.co.uk>,
chr...@dircon.co.uk (Chris) writes:
> r...@dcs.ed.ac.uk (Rainer Thonnes) wrote:
>
> > Interestingly enough, 'k' seems to be the only exception to the rule you
> > alluded to, which uses capital letters for multipliers greater than one
> > and lower-case ones for those less than 1.
>
> exactly the same rule - multipliers are capitalised, dividers are lower
> case, e.g. 'm' is 'milli', 'M' is Mega.
I was convinced, but mistakenly so, that "hecto" became 'H', and that "hPa"
was therefore incorrect. Alas, it really is 'h', so now there are two
exceptions.
Perhaps the real rule is that whenever the *same* letter is used for both
positive and negative powers of ten, the positive one uses the capitalised
one. Hence m/M (milli/mega) and d/D (deci/deca).
Sadly, that rule isn't very useful, since it applies only to a universe of
two cases. It's strengthened a little, by the fact that most other
multipliers seem to fit in. Unfortunately, as soon as you start to widen
the scope of a rule, you have to admit exceptions.
The most important rule is that most rules have exceptions.
Another oddball is "da" as an alternative to 'D'.
afpnum(cd)/(Dh)kMGT - can anyone extend this?
Bob Devine
In article <4mr4ta$e...@gazette.loc3.tandem.com>,
Matthew Rabuzzi <rab...@patch.tandem.com> wrote:
>
>Markus Kuhn <msk...@unrza3.dialin.rrze.uni-erlangen.de> writes:
>: Standardized Units for Use in Information Technology [a proposal]
>
>for 2^64. It may not be SI but I've seen it used: the bubbabyte.
I always like the idea of calling a 64 bit word a "crayte". It follows
the style of "byte" and it reflects Seymour Cray's like of 64 bit CPUs.
Not that a standards committee would EVER support that name...
Bob Devine
Aneta Spisak
In article <Dr6wty.8sn.0.sta...@dcs.ed.ac.uk>
Sure.
Y yotta 24
Z zetta 21
E exa 18
P peta 15
T tera 12
G giga 9
M mega 6
my myria 4
k kilo 3
h hecto 2
da deka 1
d deci -1
c centi -2
m milli -3
µ (*) micro -6
n nano -9
p pico -12
f femto -15
a atto -18
z zepto -21
y yocto -24
(*) The Greek letter mu
The lower-case "u" is a way of writing mu in ASCII -- like
"@" for a schwa -- not an actual prefix; I'd also be very
skeptical about "D" rather than "da" for "deka-."
Hans Christophersen
The explanation found e.g. in "edb-forkortelser" (ISBN 87-12-02474-0) p394f (Dictionary of
Computer Abbreviations and Acronyms) Ref: http://www2.dk-online.dk/users/christ_h/aod.htm is:
b = bit
B = byte
k = kilo = 10^3 = 1000
K = Kilo = 2^10 = 1024
Lowercase k is used in connection with data transmission, modems etc. (and in the metric system).
Uppercase K is used in connection with memory size.