Tiscali Broadband and Mac OSX

nospam writes:

>
> Ok, this is what I am trying to find out. I believe a modem is to
> modulate the digital output from a computer's stream of bits into an
> audio signal which can be sent over analogue connection (POTS).

No. It is the carrier signal is modulated to encode the digital
information.

> So I am
> either wrong or modems have nothing to do with transferring data over an
> asynchronous _digital_ subscriber line.

You are wrong. What goes from your telephone to the central office is
not digital; it is an analog signal encoding the digital information.

--
Bill Mitchell
Dept of Mathematics, The University of Florida
PO Box 118105, Gainesville, FL 32611--8105
mitchell.RemoveThis@math.ufl.edu (352) 392-0281 x284

> In article , nospam wrote:
>
>> Ok, this is what I am trying to find out. I believe a modem is to
>> modulate the digital output from a computer's stream of bits into an
>> audio signal which can be sent over analogue connection (POTS). So I
^^^^^^^^^^^^
>> am either wrong or modems have nothing to do with transferring data
>> over an asynchronous _digital_ subscriber line.

Why exactly must the modulation be done in the *audio* frequencies? Why
must it be sent over a POTS line? I suspect that there were usages of the
term "modem" outside of those restrictions by data telecom folks back
in the day.

Besides, my understanding is that if you plug a phone into a jack that
shares a line with a "DSL modem", you _hear_ things, and that while the
modulation involved is not to a single carrier frequency like "true"
modems of yore (which ended at 1200 baud, I think) I don't think that
a single bit over DSL is transferred as a single off-on-off pulse down
the wire. So there is some element of "modulation" involved.

Not that anyone with half a brain thinks that a reasonable definition
of "modem" is "device that modulates and demodulates" anyway...

Your arguments strike me as those of someone arguing in 1920 that you
can't use the term "accelerator pedal" for a gasoline powered automobile,
because the term was first used to refer to the steam valve in a
steam-powered vehicle.

The meaning of words is not "owned" by the techie's who coined them, which
is often (but not always) a good thing. At this point, a "modem" is "a
device for communication to a remote system via a wire." The etymology
of the word, and its technical basis, has little to do with the
definition of "modem" as a common English word today.