Square waves or 1's and 0's?

I guess we all interpreted your question a little different.

My question was oversimplified and came out of ignorance. Your anwsers will give me all the reading I want tonight because I have to re-read. You guys are over my head but it's fun trying to understand it. You are a great source, better than anything else I've found on the net.

I was tired of reading the argument that the quality of cable doesn't matter because the signal is simply ones and zeros. I have two digital coax cables and it clearly does matter.

Thank you.

Lynne

that was a true statement Lynne simply because digital cable carries simple shape signal compared to an analogue music.

OK. An analogue wave form is continuous in terms of time and voltage and frequency. A digital wave form is a square wave, as it were, which means it is repetitively maybe not on-off but high-low, higher-not-so-high, low-lower in terms of time and voltage as it represents the encoded information. And the binary system is the only one that can work for this Pulse Code Modulation because the language is ones and zeros. The vehicle for this language is the square wave because it is not continuous but repetitive.

That's my homework.

Lynne, if you haven't already, take a look at the figures shown in the Wikipedia writeup I linked to earlier for Biphase Mark/Differential Manchester Encoding, Biphase Mark (shown in the second figure) being the encoding method used for S/PDIF. The paragraph above the figures helps to clarify them.

Think of all the waveforms shown in the figures as being graphs that depict voltage along their vertical axis, and time along their horizontal axis.

As you'll see, 1 and 0 data information is conveyed by virtue of whether one "transition" or two "transitions" occur within each "clock period" (defined below). A "transition" being defined as a CHANGE from either the higher voltage ("logic 1") state to the lower voltage ("logic 0") state, or vice versa.

The higher voltage (logic 1) state is the upper of the two possible voltage levels of each signal waveform that is shown, and the lower voltage (logic 0) state is the lower of those two levels.

A "clock period" is defined as the amount of time either between one positive-going (logic 0 to logic 1) transition of the clock waveform and the next positive-going transition of that waveform, or, equivalently, between one negative-going (logic 1 to logic 0) transition of the clock waveform and the next negative-going transition of that waveform.

That encoding method allows both clock and data to be conveyed in a single signal, as Steve and I indicated earlier.

Best,
-- Al