Date   : Mon, 27 Jul 2009 22:38:41 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: Units of memory, Was: Master Ethernet upgrade

Pete Turnbull wrote:
> >> Jonathan Graham Harston wrote:
> >>>  1K is 1024 bytes. > >>
> >>    ^--------+ > >> I would imag|ine
> >> thus 1KB = 1024 bytes? > >
|  ^-----------------------+ No, 'cos that-+ is using 'K' as
> > a unit, but that-+ is using 'K' as a multiplier. 1KB is
> > 1*1000*B and B is 1 byte. But K isn't a unit, even in
> > computer science, unless of course you're
 
Technical terminology embedded in computing science for over 60
years. Are you going to go back in time and reprogram the BBC to
ensure it starts up saying "32.768KB" ?
 
One "1K" as a unit of memory size - as opposed to "1KB" - always
was, always is, and always will be 2 ^ 10, and 2 ^ 10 always was,
always is, and always will be 1024.
 
As long as you define your terminology before you use it, you can
use furlong-firkin-fortnight[1] if you really want to.
 
[1] Standard use in sheddie circles. Be back in a millifortnight.
 
Pete Turnbull wrote:
> On 25/07/2009 16:40, Jonathan Graham Harston wrote:
> > No, 'cos you can only have one multiplier prefix. It should have
> > had a ;) as memory units never take prefixes, you use a different
> > unit.
> 
> That's not true either.  Using several multipliers is quite common in
> electronics and physics, and perfectly acceptable in the SI system.
 
Are you sure? Why would you use mmA when there's a perfectly usable
uA?
 
Digging out my Tennent's, p37 says: "To obtain multiples and
submultiples of units, //a// standard prefix is used, as shown
below" (my emphasis)
 
and
 
"Quantities should be expressed as a value between 1 and 1000 with
an appropriate multiplier". eg, 47000W should be expressed as 47kW,
0.0000022s should be expressed as 2.2us.
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
BBC BASIC for Windows and Internationalisation
  See http://mdfs.net/Software/BBCBasic/Windows/ProgTips