What is a digital system? Is it only binary or decimal, octal as well?

[radiolistener]

You contradict yourself, repeatedly.

If "internal implementation doesn't matters here" (which is sensible), then you cannot also use a different internal implementation (a 74hc107) to attempt to counter many people's points.

Well, in reality you can, but I'll leave others to assess your intentions.

There is no contradiction. If some element has digital interface, you can use it in digital circuit, and it don't matter how that element is implemented inside. It can use quantum properties of nature under the hood or whatever you want, but since it has digital interface you can use it as digital element.

[TimFox]

That makes it unambiguous that you are trolling.

The only troll here is people who posting mechanical calculator and talking that this is an example of digital system. 

The question asks about "a digital system".  There are many examples of digital systems using either mechanical or electromechanical hardware, often decimal.
You are the one who keeps trying to limit the discussion to binary hardware, on your own authority.

[xrunner]

I gotta find my college textbook for digital systems. Maybe he needs the authority of the printed word - I mean printed on paper. He might be old school and not trust the internets. I'll take a few pics of a relevant page or two that ought to straighten him out.

Now where did I put that book, I know it's here somewhere    *** starts digging around ***

[eplpwr]

I guess many people uses SSD:s for storage. Consumer SSD:s uses MLC, see:
https://en.wikipedia.org/wiki/Multi-level_cell

IMHO an SSD disk is a digital device, even though what is stored in each cell corresponds to an octal digit (TLC) or a hex digit (QLC).

Also, there is some rumors (sp?) floating around that the russian military uses trinary computers, though it's difficult to verify that.

Edit: spelling

[Tation]

From Mano, M., & Ciletti, M. D. (2012). Digital Design. Pearson.

One characteristic of digital systems is their ability to represent and manipulate discrete elements of information. Any set that is restricted to a finite number of elements contains discrete information. Examples of discrete sets are the 10 decimal digits, the 26 letters of the alphabet, the 52 playing cards, and the 64 squares of a chessboard. Early digital computers were used for numeric computations. In this case, the discrete elements were the digits. From this application, the term digital computer emerged. Discrete elements of information are represented in a digital system by physical quantities called signals. Electrical signals such as voltages and currents are the most common. Electronic devices called transistors predominate in the circuitry that implements these signals. The signals in most present day electronic digital systems use just two discrete values and are therefore said to be binary.

[tggzzz]

I guess many people uses SSD:s for storage. Consumer SSD:s uses MLC, see:
https://en.wikipedia.org/wiki/Multi-level_cell

IMHO an SSD disk is a digital device, even though what is stored in each cell corresponds to an octal digit (TLC) or a hex digit (QLC).

Not just your opinion!

Anybody that understands the fundamental distinctions between a digital system and an analogue system will come to that conclusion too.

[Zero999]

@tooki, if you're think that there is exists digital circuit and computers which working with signals that has 10 or 16 discrete level (or any other more than 2), there is no needs to propose to read books. Just provide example of such circuit.

Can you give me example of such digital logic elements? For example AND element which supports non binary input? Please provide example with datasheet...

If you don't have such example, then there is no sense to talking that it is exists... isn't it?

It’s frustrating that you’re either unable or unwilling to read properly: in the reply you’re responding to, I clearly said that “except for memory and telecommunications”, I am unaware of any non-binary digital logic.

You’re not even alone in considering QAM and the like to be analog, according to the wiki article about modulation. With that said, I strongly suspect that’s a minority opinion.

As for your accusation that we’ve been manipulating the Wikipedia articles to support our claims: you know that you can view the entire history of any Wikipedia article, so you can easily check what the article looked like before this thread ever began.

I don't understand why people are continuing to argue.

It appears as though this is a classic case of someone getting defensive and no longer thinking logically because they feel as though they're being bullied. There's no point in bothering to argue. It won't make any difference. The best case is he knows he's wrong on some level and will realise eventually, even if his ego prevents him from admitting it.

[wasedadoc]

I don't understand why people are continuing to argue.

It appears as though this is a classic case of someone getting defensive and no longer thinking logically because they feel as though they're being bullied. There's no point in bothering to argue. It won't make any difference. The best case is he knows he's wrong on some level and will realise eventually, even if his ego prevents him from admitting it.

There was a forerunner to this "only binary is digital" nonsense six months ago. See reply #34 and following at https://www.eevblog.com/forum/beginners/ethernet-bit-rate/msg4821791/#msg4821791

[Zero999]

You contradict yourself, repeatedly.

If "internal implementation doesn't matters here" (which is sensible), then you cannot also use a different internal implementation (a 74hc107) to attempt to counter many people's points.

Well, in reality you can, but I'll leave others to assess your intentions.

There is no contradiction. If some element has digital interface, you can use it in digital circuit, and it don't matter how that element is implemented inside. It can use quantum properties of nature under the hood or whatever you want, but since it has digital interface you can use it as digital element.

I strongly recommend you take a step back and ask yourself why most people here disagree with you? This is not bullying. The strongly worded posts are due to frustration, rather than personal attacks. It's very easy for one to allow their ego to get in the way of learning. Heck I've done it in the past!

[tooki]

You’re not even alone in considering QAM and the like to be analog, according to the wiki article about modulation. With that said, I strongly suspect that’s a minority opinion.

No, this is not opinion, this is just a knowledge of QAM signal and their properties...

It absolutely is an opinion. You’re shining proof of this.

Only people who don't know what is the signal modulation and how to properly implement it, can say that it can be "digital". The people who knows it very well cannot say that.

LMAO. I guess the ITU, semiconductor companies, and telecom device engineers who design that stuff don’t know what they’re talking about, and some random doofus on a forum knows better than them… (Yes, I checked.)

If some signal carries digital data, it don't means that this signal is digital, it just means that it carries digital data and nothing more.

That’s literally the point: we have told you repeatedly that being a digital signal is a matter of how the signal is interpreted, because ALL signals are “analog” in their physical reality. This includes bilevel (binary) signals like TTL, PCIe, or RS-232, just to name a few randomly chosen examples.

A signal is considered analog if its interpreted values are continuous (can take any value): an analog signal is valid for any value, regardless of precision, within its extrema. If the interpreted signal cannot take any arbitrary value of any precision, then it’s not analog, and is by definition digital!

Think of it like this: ignoring for the sake of theory the existence of noise, an analog signal is like infinite-resolution floating point. Digital is like integers: EVERY value MUST be interpreted as one of a limited set of possible values.

[golden_labels]

Actually, there is Look at the far right column of your unread replies list.

I do. I do not see any option like this. Even if I run the app.

[tggzzz]

I don't understand why people are continuing to argue.

It appears as though this is a classic case of someone getting defensive and no longer thinking logically because they feel as though they're being bullied. There's no point in bothering to argue. It won't make any difference. The best case is he knows he's wrong on some level and will realise eventually, even if his ego prevents him from admitting it.

There was a forerunner to this "only binary is digital" nonsense six months ago. See reply #34 and following at https://www.eevblog.com/forum/beginners/ethernet-bit-rate/msg4821791/#msg4821791

Ah. OK. I didn't realise this was a re-run.

That makes it seem less likely that he is a troll, and more likely that he is someone that is incapable.of understanding his error.

I taught my daughter that stupidity cannot be cured but ignorance can be cured. This is one of those cases where that isn't possible.

[tooki]

Actually, there is Look at the far right column of your unread replies list.

I do. I do not see any option like this. Even if I run the app.

Go to your Profile in the toolbar. Then in “Modify profile”, select “Look and feel”.

At the bottom of the list, find the item “Show quick-moderation as:” and change it from “don’t show” to “checkboxes”.

[tggzzz]

Actually, there is Look at the far right column of your unread replies list.

I do. I do not see any option like this. Even if I run the app.

Oh.

No idea about the app, on principle.

Mine looks like this.



Might be a profile setting or another of those pale blue arrows on a slightly less pale blue backgrounds (with acknowledgement to Doug Adams and the control pane of the Haggunenon Admiral's ship/Disaster Area stunt ship)

[Manul]

This might upset some purists, but for me the intuitive way of thinking what is digital and what is not digital is simply determinism. Digital system is such a system which maintains the deterministic result while subjected to inherent or external noise (within it's design limits). So in essense, given same input, it has a property of converging into indentical result. Not a very similar result, but identical. In contrast, for an analog system any amount of added noise will produce a different end result. Given that some amount of random noise is always present, for the analog system the result is by nature never deterministic. What, or how many states the digital system uses is not really important. It might also be not electrical states, could me mechanical or whatever.

[BeBuLamar]

I can't think of any device that uses Hex and is not digital.

[TimFox]

This might upset some purists, but for me the intuitive way of thinking what is digital and what is not digital is simply determinism. Digital system is such a system which maintains the deterministic result while subjected to inherent or external noise (within it's design limits). So in essense, given same input, it has a property of converging into indentical result. Not a very similar result, but identical. In contrast, for an analog system any amount of added noise will produce a different end result. Given that some amount of random noise is always present, for the analog system the result is by nature never deterministic. What, or how many states the digital system uses is not really important. It might also be not electrical states, could me mechanical or whatever.

In this context, deterministic would be synonymous with discrete.
However, another meaning of the word "determinism" is that the present state determines the next state.

[DimitriP]

I want to play too! So here I am #217

"digital system" sounds like an academic generalization and it's definition, applications or intented usage is best left as part of a multiple choice answer where the rest of the answers might be "more wrong".


(" Is it only binary or decimal, octal as well?") . 

Is an abacus a "digital system" ....sure.

The earliest digital computing device known is the Abacus. the Chinese Abacus is largely unchanged since early records reaching back to ~500 B.C. The notation is bi-quinary: an upper deck selecting the 0-5 or 6-10 range, and the lower deck representing (in unary notation) 0-5 or 6-10.
Courtesy of:   http://infolab.stanford.edu/pub/voy/museum/pictures/display/2-5-Mechanical.html


Can we be done now before we hit #300 ?

Thanks!

[DimitriP]

...and just to cover all the bases, and maybe help to hit# 400, one could argue that there are no absolutes when it comes to "systems". It's case of "mostly" or "primarily"  analog or digital.

You can take the most "digital  system" and the moment you add a temperature sensor, guess what you have. A not absolutely digital "system".

I'm going to go adjust the brightness of my "digital" monitor now.

[TimFox]

Yes, in the real world we have "mixed" or "mixed-signal" systems, often with an analog-to-digital converter in the middle of the system.

[DimitriP]

Yes, in the real world we have "mixed" or "mixed-signal" systems, often with an analog-to-digital converter in the middle of the system.

You nailed it @ #4, I just can't understand why we have 8 more pages after that

[golden_labels]

Go to your Profile in the toolbar. Then in “Modify profile”, select “Look and feel”. At the bottom of the list, find the item “Show quick-moderation as:” and change it from “don’t show” to “checkboxes”.

Ok, found, thanks. Ping: tggzzz.

You nailed it @ #4, I just can't understand why we have 8 more pages after that

Because a person busted into the thread with their ultimate truth, and it turned into xkcd 386 despite clear indicators it is a pointless effort.

Considering abacus a computing device in the context of this thread⁽¹⁾ is a bit overreaching, isn’t it? It’s like bringing up oil lamps while discussing incandescent lightbulbs.

⁽¹⁾ I’m aware of the etymology of this term. But this thread’s topic restricts the meaning.

[radiolistener]

The question asks about "a digital system".  There are many examples of digital systems using either mechanical or electromechanical hardware, often decimal.
You are the one who keeps trying to limit the discussion to binary hardware, on your own authority.

Yes, digital is limited to binary hardware, you can encode any kind of information with binary hardware, you can show binary, octal, decimal, hexadecimal numbers with digital circuit and even more, you can display alphabet letters and hierogylphs, but it still remains binary, because uses binary signals with two discrete values 0 and 1.

I understand your opinion that all components are digital because they using different kind of numbers and you can use it for yourself, you can name analog output of sound card DAC as digital signal as tggzzz proposed, you can use it for yourself usage. But this is not what term "digital" means in modern electronics.

So, if you want so other people can understand what you're talking about, you're needs to use word "digital" for components which has digital interface, that is, an interface using binary signals. Because term digital means binary digits. And as we discussed before there is no example of digital circuit that uses non binary signals. Even experimental ternary computers implemented with digital circuit which uses binary signals. So there is no sense to talk about existence of non existing things just to protect incorrect usage of word digital for analog signals.

Just because when you're talking about analog output of DAC as example of digital signal or talking about mechanical calculator as example of digital circuit, you will confuse other peoples... They will not understand what you're talking about.

Just to be clear. DAC is mixed signal component, because it uses two interfaces - digital and analog:
- Digital interface of DAC uses binary signals and is used to receive digital data from digital circuit (represented as binary bits, encoding doesn't matters)
- Analog interface of DAC uses analog signal and is used to output analog signal which is result of conversion from digital data (represented as binary bits).

You cannot name analog output of DAC as digital signal, because it is analog and is incompatible with digital interfaces. And from my opinion it is pretty clear for any engineer and don't requires explanations.


Regarding to SSD, it can use analog signals inside, and their circuit can be mixed signal, but since it expose only digital interface, you can consider it as pure digital component and use in digital system.

[radiolistener]

This might upset some purists, but for me the intuitive way of thinking what is digital and what is not digital is simply determinism.

No, term "digital" is not academic meaning, this is separate class of electronics which has it's own components, methods and algorithms which is different from analog electronics. So, you cannot name all what you want as "digital".

[Tation]

This might upset some purists, but for me the intuitive way of thinking what is digital and what is not digital is simply determinism. Digital system is such a system which maintains the deterministic result while subjected to inherent or external noise (within it's design limits). So in essense, given same input, it has a property of converging into indentical result.

But there do exist digital circuits ("pure" digital, built inside FPGAs) implementing non-deterministic true-random number generators. In some way they exploit "noise in time" to reach this goal.