[EMAIL PROTECTED] wrote:
> Square waves taking more space. Just plain BS. The shape of a wave has no
> bearing whatsoever on how much "space" is required to store it.
>
> DDS-2 and DDS-3 (two of the DAT data standards) have nearly identically
> length tapes (120m vs. 125m), and have the same linear speed over the
> heads. DDS-3 has three times the storage capacity as DDS-2. Clearly,
> speed is not a contributing factor to data density.
Depending on the methode used to store a square wave, you'll need less or more
bits. It also depends on the sampling frequentie and the base-frequency of the
squarewave. A squarewave can be described as an addition of an infinitive number
of cosinus waves. Since all digital sampling devices store information on the
frequentie and the amplitude of the samples (this is the base of the discrete
digital systems like CD/DAT/MD/DCC), you'll see that you need a lot of space to
store a squarewave accuratly. So the statement is true and is absolutly no 'plain
BS' since the shape of a wave defines how much space is required to store it.
I'll here a lot of people now saying, hey, hold on, if I sample somthing it gives
me a presentation of numbers which represent just amplitudes in time and each
waveform produces the same number of samples..... So what is Ralph talking about?
And that's where most people go wrong when thing about digital signals. Therefore
a simple question: What does a single sample represent? Yes? Found it? Right,
nothing! Yes, you've read that right, a single sample represents nothing!
Another question: What does a series of samples represent? You'll possible think
that they represent a collection waves of a certain altitude and a certain
frequency that are described by a series of samples. But there you wrong. A
series of samples describes all the frequencies with their amplitude (which can
be zero).
So if you change the storage methode: samples -> frequencies/amplitudes, the
waveform actually makes a big difference in how much space is required!
Cheers,
Ralph <- who was still lurking.......
--
=======================================================================
Ralph Smeets Functional Verification Centre Of Competence - CMG
Voice: (+33) (0)4 76 58 44 46 STMicroelectronics
Fax: (+33) (0)4 76 58 40 11 5, chem de la Dhuy
Mobile: (+33) (0)6 82 66 62 70 38240 MEYLAN
E-Mail: [EMAIL PROTECTED] FRANCE
=======================================================================
"For millions of years, mankind lived just like the animals. Then
something happened which unleashed the powers of our imagination:
We learned to talk."
-- Stephen Hawking, later used by Pink Floyd --
=======================================================================
-----------------------------------------------------------------
To stop getting this list send a message containing just the word
"unsubscribe" to [EMAIL PROTECTED]
