What is a digital system? Is it only binary or decimal, octal as well? - Page 1
Forum section: electronics / beginners

author: oslon
author_rank: Newbie
timestamp: October 19, 2023, 01:31:03 am
content: https://www.uobabylon.edu.iq/eprints/publication_12_1733_6174.pdfI'm here.I'm wondering what is a digital system? Is it only binary? Or decimal, octal, hexa are also digital system?

author: xrunner
author_rank: Super Contributor
timestamp: October 19, 2023, 01:50:07 am
content: Digital fundamentally uses 0 and 1, that's binary. But if you want to group the ones and zeros as groups of three then you have octal like 777 (111 111 111) or 330 (011 011 000), etc, or groups of four for Hex like FFFF (1111 1111 1111 1111). Nevertheless it's still digital at the lowest level.

author: EPAIII
author_rank: Super Contributor
timestamp: October 19, 2023, 02:20:49 am
content: "Digital" is used as the opposite of "Analog". Both are ways of doing calculations or logical decisions in a machine. And both can use various technologies, such as electronic, electric, mechanical, pneumatic, hydraulic, and probably others.An analog type of system uses a physical representation of a value or state. And this representation can, in theory, have an unlimited level of resolution. So, using a mathematical device, an old fashioned slide rule can be set to any place along it's scale. There is no theoretical limit on where it can be set within it's range. However it's accuracy is limited by real world considerations in setting or reading these values.A digital system uses numbers to represent a value or state. These numbers can be of any base (10, 2/binary, 8/octal, 16/hexadecimal, etc.) There are ways to work around this, but in general, a digital system will be limited to a certain number of digits in the number system that it uses. So the accuracy of most digital systems is limited by the number of digits and the number of those digits used in the base that is selected.Although it may sound like digital would be more limited in accuracy, often it is the better of the two. Analog is usually limited by the ability to either set or read out an analog value while digital allows any number of digits to be easily entered or read out.But then, it should be remembered that most digital systems rely on conversions from and/or back to analog. Only the calculations or decision making is done in the digital realm.

author: themadhippy
author_rank: Super Contributor
timestamp: October 19, 2023, 03:06:27 am
content: I was taught that digital can only be 1 or 0 and has something to do with a=a2

author: TimFox
author_rank: Super Contributor
timestamp: October 19, 2023, 03:37:49 am
content: "Digital" comes from counting on one's digits: the steps are discrete."Binary" comes from having two choices: 1 or 0.A "digital voltmeter" normally reads out in base 10, i.e. decimal.There is more to "digital" than "binary".

author: golden_labels
author_rank: Super Contributor
timestamp: October 19, 2023, 03:39:19 am
content: More or less what EPAIII said. Digital systems work with discrete values. There is no limit to the number of states.Binary signals are most common, due to simplicity of implementation and highest resilence to noise. But this is not a hard limitation. Negabinary (e.g. UMC-1, UMC-10 computers) and ternary were seen in the past, balanced ternary is used now in experimental solutions due to its compatibility with light-based computing, your flash memory is likely using octal or hexadecimal, wireless commonly uses 256 digits, and there QAM can nowadays go up to 32768 states.

author: pdenisowski
author_rank: Super Contributor
timestamp: October 19, 2023, 11:06:35 am
content: Quote from: TimFox on October 19, 2023, 03:37:49 amOr, as Tom Lehrer put it, "Octal is decimal without the thumbs"

author: Siwastaja
author_rank: Super Contributor
timestamp: October 19, 2023, 12:07:34 pm
content: Quote from: oslon on October 19, 2023, 01:31:03 amYes, by very definition. Digital systems use discrete numbers, "digits". Underlying implementation is irrelevant, although it is often binary. Binary representations are subset of digital representations.

author: Dan123456
author_rank: Regular Contributor
timestamp: October 19, 2023, 12:50:39 pm
content: I always thought all digital systems are fundamentally binary as they are looking for an on or off.In my mind Hex, Oct, Decimal etc. are still looking for an on or off but just over a range.i.e. an IC says “do I have exactly 1V, 2V, 3v, etc.” Therefore it is still looking for a on or off aka a 1 or a 0.That said, maybe my understanding is flawed

author: xrunner
author_rank: Super Contributor
timestamp: October 19, 2023, 12:54:47 pm
content: Quote from: oslon on October 19, 2023, 01:31:03 amBack in the day you could fiddle with the the computer's physical binary switches right in front of you, and be a real man - program it directly 1's and 0's.

author: golden_labels
author_rank: Super Contributor
timestamp: October 19, 2023, 01:38:21 pm
content: Real men program it directly with 1s and 0s.Real programmers program it directly with cables.

author: tggzzz
author_rank: Super Contributor
timestamp: October 19, 2023, 03:17:16 pm
content: Quote from: Dan123456 on October 19, 2023, 12:50:39 pmNope. Digital systems arequantised.Some are ternary, e.g. +1,0,-1. Others have many more levels, e.g. QAM up to 8 bits per symbolhttps://en.wikipedia.org/wiki/Qam, or flash memory which can store 3 or more bits in each cellhttps://en.wikipedia.org/wiki/Triple-level_cell

author: khs
author_rank: Regular Contributor
timestamp: October 19, 2023, 04:33:44 pm
content: Quote from: tggzzz on October 19, 2023, 03:17:16 pmHmmmm: Maybe Mr. Heisenberg would say: All is quantised.

author: tggzzz
author_rank: Super Contributor
timestamp: October 19, 2023, 04:47:06 pm
content: Quote from: khs on October 19, 2023, 04:33:44 pmI like to point out that the outputs of digital circuits are analogue waveforms that areinterpretedas by an input as a digital signal. Your measuring device (e.g. a scope) might interpret the waveforms differently, especially if there is analogue "noise" around.The only digital waveforms people are likely to encounter are femtoamp and photon counting circuits

author: TimFox
author_rank: Super Contributor
timestamp: October 19, 2023, 04:48:29 pm
content: I have been reading several histories of mathematics, with discussions ranging back to prehistory.Base 5 and Base 10, using literal digits (fingers), are found in primitive societies, and Aristotle noticed the relationship between decimal notation and human hands.Before computational aids, such as tally boards, some societies added the gaps between knuckles and other anatomical features to count past 10 or 20 (adding toes).Sumerians may have been able to count in their Base 60 format (which still persists in time and angle measurement today) before writing numbers in cuneiform.A tribe in Papua New Guinea was documented in 1994 using lots of body parts, including the naughty bits, to reach 33, counting by anatomy.Late in the first millenium, the Venerable Bede calculated using finger flexing, reaching 0 to 9 with three fingers, and up to 9,999 with two hands.These early examples are all digital, counting only the "natural numbers" (mathematical term for the positive integers starting with 1).A recent popular survey of such systems is Chapter 1 of Keith Houston:Empire of the Sum: The rise and reign of the pocket calculatorW W Norton 2023.Binary means 0 or 1, Quinary means 1 to 5, Decimal means 1 to 10 or 0 to 9, etc."Vides ut primos discentes computos digitos tarda agitatione deflicant?" Firmicus Maternus(Do you see how awkwardly beginners in computation bend their fingers?)

author: TimFox
author_rank: Super Contributor
timestamp: October 19, 2023, 09:44:17 pm
content: Quote from: tggzzz on October 19, 2023, 04:47:06 pmThe analog waveforms present at the connector become digital after passing a threshold, like a camel passing through the eye of a needle.

author: JeremyC
author_rank: Regular Contributor
timestamp: October 19, 2023, 10:55:54 pm
content: Quote from: oslon on October 19, 2023, 01:31:03 amSince last few years it’s new, trendy terminology “system” the same as “analog system”...just ignore itPeople are being bored and starting to reinventing the wheel

author: alligatorblues
author_rank: Regular Contributor
timestamp: October 20, 2023, 03:01:44 am
content: Most electronic devices are analog and digiital. The parts of the device that interact with the physical world are analog. Meter and scope inputs, digital thermometers, cell phones, or anything that transforms a real-world reading to a digital readout. Analog components are susceptible to corruption due to various forms of interference and degradation. The beginning of the digital side is sampling. The analog component is sampled at various points. Each sample is assigned a number. In this process, the samples are reduced to binary, or base 2, for use in processing by mcu's, cpu's, and mask roms.The advantage to digital is error checking. The digital representation will never degrade. Each group of bits is put through a hashsum algorithm when it is transmitted, which appends some bits to the packet. Those bits are stripped off and stored at the receiving end. The original data is left, and it is hashsummed the same way. The bits stripped off are put back, and if the packets are identical, the receiving end instructs to send the next packet.Transmitting a digital signal requires about 1/10 the power of an analog signal, and the signal quality is vastly superior. And, if it wasn't for digital electronics, there would be no digital LCD readouts, only nixie tubes.Practically every electronic device interacts with the real world, so they use both analog and digital. Even computer moniitors process in digital, but convert the image to analog.

author: Mr.B
author_rank: Unknown
timestamp: October 20, 2023, 03:24:18 am
content: Quote from: TimFox on October 19, 2023, 04:48:29 pmAnd Women could count to 34...Sorry, I couldn't miss that opportunity.

author: TimFox
author_rank: Super Contributor
timestamp: October 20, 2023, 03:30:12 am
content: Quote from: alligatorblues on October 20, 2023, 03:01:44 amNixie tubesare used in digital systems. The digital representation of the discrete value is decoded to select one of 10 (or more) discrete electrodes in the Nixie tube for display.Segmented LED or LCD readouts decode the value into a selection of an appropriate pattern of segments.This is all done with digital logic circuits.Perhaps you are confusing Nixie tubes (gas-discharge glow devices) with cathode-ray tubes (that can display continuous waveforms)?

author: EPAIII
author_rank: Super Contributor
timestamp: October 20, 2023, 06:17:49 am
content: Perhaps Tim Fox put it well and succinctly: "'Digital' comes from counting on one's digits: the steps are discrete." Discrete steps are the essence of digital. And digital may have come from counting on one's fingers, but digital systems are not limited to ten digits. Hexadecimal, which adds six additional digits (usually A - F are used) to the ten decimal digits for a total of sixteen. Some cultures have used as many as 60 digits.And again he says that, "'Binary' comes from having two choices: 1 or 0." So binary is just one of many digital systems.Binary is so popular as a digital system because it is a lot easier to implement just two states in electronic systems. Things like mechanical adding machines and calculators were made using base ten, our common counting system which was derived from our ten fingers. They were true digital devices, but not binary based. there were ten buttons in each of the "place" columns. Eighty, ninety, or even a hundred or more keys was not unusual. A mechanical wheel with ten divisions on it was used to display each digit. But mechanical computational devices were both expensive and hard to keep running without routine maintenance or repairs. Electronic devices were more reliable with almost zero maintenance. But when things were to be made with electrical and electronic devices, it became a lot harder to have ten separate states. Yes, you could represent ten values with 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 Volts. But then, consider how expensive circuits that can distinguish those ten values would be. With electric and electronic devices it is a lot easier and less expensive to use only two values: ON and OFF, HI and LOW, Current and No Current, etc. Also logic circuits could be implemented with devices that have only two possible states because traditional logic has only two values: True and False. Thus binary was used when electronic devices were developed. And it is all due to economics that we now have the world where digital is almost synonymous with binary. Electronic circuits are a lot cheaper than mechanical devices and binary circuits are a lot cheaper than those that would use other numeric bases.So binary and digital are not the same. Binary is a sub-set of digital. Binary is digital. But digital is not always binary.And the person who said, "Follow the money." is oh so right.Quote from: Dan123456 on October 19, 2023, 12:50:39 pm

author: EPAIII
author_rank: Super Contributor
timestamp: October 20, 2023, 06:26:05 am
content: Been there! Done that!Yes, I actually wrote programs and input them that way.It isn't fun. Slow process so you have a very large incentive to minimize your code. But it did work. The machine in your photo is a lot nicer than the one I programmed. Mine had simple toggle switches and not near as many. That one looks like a dream by comparison.Oh, and I didn't get the tee shirt. Wish I had.Quote from: xrunner on October 19, 2023, 12:54:47 pm

author: tggzzz
author_rank: Super Contributor
timestamp: October 20, 2023, 08:15:14 am
content: A: Because it messes up the order in which people normally read text.Q: Why is top-posting such a bad thing?A: Top-posting.Q: What is the most annoying thing ine-mailposted responses?Quote from: EPAIII on October 20, 2023, 06:26:05 am

author: tggzzz
author_rank: Super Contributor
timestamp: October 20, 2023, 08:17:11 am
content: Quote from: tggzzz on October 19, 2023, 03:17:16 pmForgotthemost important 4-level digital system, where the symbols are C, A, G, T.

author: TimFox
author_rank: Super Contributor
timestamp: October 20, 2023, 02:07:47 pm
content: Quote from: EPAIII on October 20, 2023, 06:17:49 amWith respect to mechanical calculators and cash registers:Again, this is discussed in that book about pocket calculators.With non-decimal monetary systems, such as pounds-shillings-pence, the mechanical dials could be designed to count decimal (for pounds) and base 12 or 20 for the other two denominations.

author: golden_labels
author_rank: Super Contributor
timestamp: October 20, 2023, 02:25:55 pm
content: Quote from: tggzzz on October 20, 2023, 08:17:11 amDNA uses base-64, not quaternary. Each single symbol consists of three bases, giving 43=64 possible values.

author: tggzzz
author_rank: Super Contributor
timestamp: October 20, 2023, 07:55:38 pm
content: Quote from: TimFox on October 20, 2023, 02:07:47 pm... and halfpenny (pronounced ha'penny) and farthing 1/4d, so you also needed 0.25d. I remember, and still have halfpennies in circulation, but not farthings. Thrup'ny bits, tanners, bobs, florins, half-crowns and crowns (3d, 6d, 1s, 2s, 2/6d and 5s respectively) didn't require any special accomodationIt used to be fun to fun to find that your change contained pennies that had been in circulation for a century.It wasn't fun doing manual arithmetic in all the strange bases, but we were taught some tricks.

author: TimFox
author_rank: Super Contributor
timestamp: October 20, 2023, 08:47:18 pm
content: The origin of the old British system goes back to the Romans: among many variations, they had thelibra,solidus, anddenarius, whence pound (L), shilling (s), and pence (d).Etymologically, denarii live on in the Arabic dinars.At some point, the British decided they needed to add the "guinea" to confuse things, ending with 21 shillings after changes in gold prices.The American copper one-cent coin is often called a "penny", which it isn't, but the ten-cent coin is, legally, a "dime", as stamped on the reverse of the coin.The five-cent coin, called a "nickel", is actually 5 g of cupronickel (75 Ag, 25 Ni), and the raw material costs more than $0.05.

author: TimFox
author_rank: Super Contributor
timestamp: October 20, 2023, 08:50:05 pm
content: Quote from: Mr.B on October 20, 2023, 03:24:18 amActually, the Papuan system included both nipples, which males have as well as females.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: October 20, 2023, 09:42:07 pm
content: Any set that has a fixed universe of values. The null value may not fit in that set though. Probably not.

author: TimFox
author_rank: Super Contributor
timestamp: October 20, 2023, 09:44:05 pm
content: Genesis 15.5"Look now toward heaven, and tell the stars, if thou be able to number them"

author: radiolistener
author_rank: Super Contributor
timestamp: October 21, 2023, 02:51:49 am
content: Quote from: oslon on October 19, 2023, 01:31:03 amTerm "Digital" is used for a digital circuit where the signal must be one of two discrete levels. Each level is interpreted as one of two different states (for example, on/off, 0/1, true/false).If you combine 3 or 4 digital signals (with binary level) it still Digital, because uses digital signals.But if signal has more than 2 levels (is not binary) it is not "Digital". Technically you can name it as "Analog".For example, the signal which have 3 possible levels can be processed with ternary logic elements, but ternary logic is different from digital logic which uses binary signal representation. Ternary logic has different rules and different math, and such ternary logic is not common, so you can't name it as digital, because digital logic works with signals represented with binary levels.Also note that there is third type of circuit - Mixed Signal circuit. It used on boundary between Analog and Digital signals. For example ADC, DAC, etc.You can simulate ternary logic with digital logic, such circuit will have digital part which works with binary signal levels and usual digital logic elements, and mixed signal part that converts from ternary analog signal to binary digital signal and vice versa.This way was used for ternary computing experiments such as ternary computer "Сетунь" which was built in 1958 in the Soviet Union and was used to research ternary logic math.First Nixie tubes had 10 digits and each digit was controlled by separate signal which had two possible levels - on and off (1 and 0). In such way one binary signal was used to control one digit. This is why binary signals get name "Digital"...

author: EPAIII
author_rank: Super Contributor
timestamp: October 21, 2023, 04:08:28 am
content: Well, here I go, "top posting" again. You may not believe me, but I actually agree that it is annoying.Years ago I was first introduced to e-mail at the company where I worked. They used it extensively. And I had to use it to answer messages that were sent to me. So I LOGICALLY placed my answers BELOW the text of the message, keeping things inproper order.Well, they would have none of it. I was promptly scolded by multiple persons for being such an independent and logical thinker. I tried for a week or two, but when the e-mails had multiple levels of responses and the others were "top posted" it only confused things for me to add my response at the bottom.You can't fight the world and, for better or worse, the world "top posts".Or is there some rule on this board about this? I don't recall reading any.Quote from: tggzzz on October 20, 2023, 08:15:14 am

author: jonpaul
author_rank: Super Contributor
timestamp: October 21, 2023, 06:18:27 am
content: Hexeary logic:The Top secret 1942 SIGSALY speech scrambler digitized Vovcoder analog parameters into one of 6 logarithmic levels. These were added MOD 6 with a six level true random key, Vernam type code.https://media.defense.gov/2021/Jul/13/2002761542/-1/-1/0/SIGSALY.PDFMy 2019 IEEE Spectrum articleshttps://spectrum.ieee.org/rebuilding-a-piece-of-the-first-digital-voice-scramblerhttps://spectrum.ieee.org/sigsaly-analogtodigital-converter-construction-and-debuggingEnjoy!\ Jon

author: tggzzz
author_rank: Super Contributor
timestamp: October 21, 2023, 07:41:12 am
content: Top posts can work forfast single-pointresponses between two people. If there are interleaved conversations and/or multiple people, top-posting becomes a nightmare.Quote from: EPAIII on October 21, 2023, 04:08:28 amSo, you choose to do something annoying (your description). Why?QuoteWhy did you continue to work there? That would have been a red flag to me!QuoteThis forum is not the world, oddly enough. See next point.QuoteAs for a formal rule, no - and there shouldn't be. But that's unimportant. What's important is to observe the way people in the "society" interact, because that's an important part of why the societyworks.Or doesn't work, see edaboard and stackexchange which, while fine for boring "which button do I press to floggle the widget" questions, areuselessfor interesting subtleconversations.Quote

author: TimFox
author_rank: Super Contributor
timestamp: October 21, 2023, 02:25:53 pm
content: Back to the original question, here is a practical example of the distinction.Imagine a weighing scale, with a digital readout.It can be made using an analog sensor, such as a strain gauge, that requires an analog circuit to measure the strain (force) and convert it to a continuous voltage.That analog signal then goes into an ADC (analog-to-digital converter), which puts out a series of digital values (discrete multiple-binary-bit words).That digital signal train then goes into appropriate digital circuitry, including a digital processor, to compute desired values (in grams, ounces, taels, etc.) that go to the driver circuits to produce decimal patterns on Nixie tubes, LEDs, or a screen.Both signal types have their origins and uses.

author: BeBuLamar
author_rank: Super Contributor
timestamp: October 21, 2023, 02:51:26 pm
content: For the question in the tittle. They are all digital whether it's binary or decimal, hex, octal etc... The term digital doesn't mean binary.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 02:20:00 am
content: Quote from: BeBuLamar on October 21, 2023, 02:51:26 pmNo!This is typical mistake that non binary signal is digital, you can name it Discrete if it has discrete N levels, but if N is not 2, then you cannot name it as Digital. As said above term digital is used for circuit which works with signals that have binary state representing 0 or 1. Because Digital means that it works in binary system with binary math and binary logic. If signal is not binary, it cannot be processed with binary math and such signal is NOT digital.In theory you can create math and logic for any N-level discrete signals, but in practice such math will be complicated and needs research to understand it's properties. Binary logic and math is well known and analyzed, it already has a lot of components, so in practice only binary logic and math is used and such circuits are named Digital.Non digital but discrete signals are often used in modern communications, for example gigabit ethernet uses PAM-5 modulation, this is discrete signal, but not digital. In order to process it with digital processing circuit it needs to be converted from analog to digital form. It can be done with ADC and DAC. And when its converted to digital signals (represented with binary levels) PHY chip can do further processing in digital domain with usual circuit elements which working with digital signals.Quote from: BeBuLamar on October 21, 2023, 02:51:26 pmNO. The term digital means binary, this is synonym for binary and cannot be used for system which works with non binary signals.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 02:49:38 am
content: Just for your information:Merriam-Webster's Dictionary:QuoteOxford Learners Dictionaries:QuoteTech Terms Dictionary:Quote

author: TimFox
author_rank: Super Contributor
timestamp: October 22, 2023, 03:09:22 am
content: If digital be synonymous with binary, there is no need for both terms.Binary is a subset of digital.Normal arithmetic is done with 10 digits.A general definition from Wikipedia, which includes but is not limited to a single wire with a binary choice of states."A digital signal is a signal that represents data as a sequence of discrete values; at any given time it can only take on, at most, one of a finite number of values. This contrasts with an analog signal, which represents continuous values; at any given time it represents a real number within a continuous range of values."

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 22, 2023, 04:15:03 am
content: If digital is only binary, which is in turn a sequence of ones and zeros, then the output of a parallel out A-D converter is not digital because the output is not a sequence of ones and zeros. It can only bet interpreted as a group of simultaneous sequences.The interpretation I have just given is solely to illustrate the silliness of the how many angels can dance on the head of a pin argument going on here.If for some reason it is important for your application to make a distinction between a binary and octal system, then more words are necessary to explain why that distinction is important and what that difference is. Trying to load all of the possible minor differences that might require such a distinction is too much to load on a single word.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 04:40:51 am
content: Quote from: TimFox on October 22, 2023, 03:09:22 amActually Digital it is alias for Binary. Since many peoples are not familiar with term Binary, they don't know math and don't want to know about discrete math and other stuff, it's more easy for them to use term Digital. But if you're dealing with math, you can be happy with term binary.For example the math for binary logic and for ternary logic is different and have different properties and different laws. Binary logic is usual logic that we know with it's own math rules. But ternary logic is different thing, it has it's own rules, different math and laws that many peoples don't know at all and even don't know that it is exists. The term digital is applied to circuit that working with well known binary logic. Don't confuse it with logic and math for other numbering systems.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 05:00:18 am
content: Quote from: CatalinaWOW on October 22, 2023, 04:15:03 amAD converter is not digital, but not because it has group of digital lines, but because it works with both domains - Analog and Digital. Actually AD converter is Mixed Signal device.The parallel bus part of AD converter is of course Digital, because it uses digital signals represented with two levels 1 and 0.And analog input/output of AD converter is of course Analog, because it uses analog signal represented with more than two levels. For example if you use 2-bit DAC, it has analog output with 4 levels, 3-bit DAC has 8 levels, etc.For DAC this analog signal is Discrete, but NOT Digital, because represented with non binary state.Digital signal needs to be represented with binary state - 1 or 0.If it is represented with not binary state, then this is not digital signal.And all things known as Digital cannot be applied to such signal, because digital circuit works with binary state only.If you see some circuit that works with non binary state signals, then this is NOT Digital circuit.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 22, 2023, 05:51:03 am
content: Quote from: radiolistener on October 22, 2023, 05:00:18 amSo in your opinion circuitry that works on four discrete voltage levels (some memories did this) are not digital, and hence analog?

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 06:44:50 am
content: Quote from: CatalinaWOW on October 22, 2023, 05:51:03 amThis is not my opinion, this is official meaning of word digital.Yes, part of memory circuit which works with four discrete levels is not digital, but analog.Since memory chip also has digital controller which process that data, such memory chip is Mixed Signal circuit.And since all these analog things are encapsulated and there is no analog input/output with 4 levels from that memory chip, you can assume it as digital, just because all input/output signals of the chip are digital. But internally it is Mixed Signal circuit, because part of it's circuit works with analog discrete signal which has 4 levels.

author: kjpye
author_rank: Contributor
timestamp: October 22, 2023, 07:35:49 am
content: Quote from: radiolistener on October 22, 2023, 02:49:38 amNote that word before the part you emphasised. "Especially" most definitely does not mean "only".I suspect the other options you give are simplified for beginners.Given the origins of the word digital, if it is restricted to only a single number base, then that must be decimal.Calling all non-binary discrete systems analog makes the term analog useless,

author: golden_labels
author_rank: Super Contributor
timestamp: October 22, 2023, 07:39:52 am
content: radiolistener:This is complete bullshit, contrary to actual usage, supported by a comically failed attempt in appeal to authority. You could at least read the backlog, where people working in the industry for decades share their experience or give actual examples.This is an invalid argument, but since you considered it ok and it may be worth waking you up from your denial of reality, here is what your own sources say about word “analog”:Merriam-Webster,Oxford Learner’s Dictionaries,TechTerms, alsoWiktionary. Now look at what you claim to be “analog” and stop making fool of yourself.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 08:39:25 am
content: Quote from: golden_labels on October 22, 2023, 07:39:52 am"This is complete bullshit" - this is what you will hear when you try to provide some signal which has 4 levels on digital GPIO pin of some controller and ask firmware developer to handle all 4 levels because this is "digital" signal... And I will agree with him, because this is really complete bullshit.If you're talking that the signal is digital, it should have two possible state 1 or 0.And when you're talking that analog discrete signal with possible 4 levels is "digital", this is complete bullshit. Because there is no digital logic circuit that supports signal with 4 possible states.You can name digital signal as analog and analog as digital for yourself, but if you're want so other people can understand you, you should use term digital for signals with 2 possible levels 1 and 0. And use analog term for signals which can have more than 2 possible levels.Quote from: golden_labels on October 22, 2023, 07:39:52 amI don't needs to walk. Analog signal means that signal IS NOT DIGITAL. So, any signal which has more than 2 possible levels is analog. This is pretty easy...In order to process analog signal in digital domain you're needs to convert it from analog domain to digital domain. And in order to generate analog signal from digital domain you're needs to convert from digital domain to analog domain. There is no way to process analog signal in digital domain without converting. And you're needs to learn the difference between analog domain and digital domain to avoid confusing them.This is very simple:- Digital signal has two possible states: 1 and 0.- Analog signal has more than two possible states.Grouping of several signals don't change their type. If you have 8 lines and all are digital, then this is digital bus, not analog. The same if you use 8 lines and all are analog, then this is analog bus, not digital.

author: tggzzz
author_rank: Super Contributor
timestamp: October 22, 2023, 09:14:39 am
content: Radiolistener, I don't know about the meanings in Ukranian (as per your country flag).But in English and general engineering, you are wrong. Full stop.If you want to try arguing by "appeals to authority", consider this definition... "In digital electronics, a digital signal is a pulse train (a pulse amplitude modulated signal), i.e. a sequence of fixed-width square wave electrical pulses or light pulses, each occupying one of a discrete number of levels of amplitude. A special case is alogic signalor abinary signal, which varies between a low and a high signal level."https://en.wikipedia.org/wiki/Digital_signal#In_digital_electronicsThe other definitions on that page are also useful.Having pointed that out, it is also worth pointing out that digital values areimplementedas analogue waveforms where the receiverinterpretsthe analogue waveform as a digital value.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 09:26:50 am
content: Quote from: kjpye on October 22, 2023, 07:35:49 amOrigin of word digital is a binary signal which controls correspond digit on Nixie tube.For there is 10 signals, each can have state 0 or 1, so we have:0000000001 = decimal digit 00000000010 = decimal digit 10000000100 = decimal digit 20000001000 = decimal digit 3...1000000000 = decimal digit 9As you can see these signals controls decimal digits on Nixie tube, each signal = digit, so they called "digital".This is how it happened historically, so now you cannot name non binary signal as "digital", just because you want. It will leads to confusion.It just happened that term digital is used for binary signals in electronics and you're needs to accept it as is.Quote from: kjpye on October 22, 2023, 07:35:49 amThere is nothing useless, any non-binary discrete signal is analog, just because it is not digital.For example discrete signal with 16777216 possible levels is analog signal.The same discrete signal with 4 possible levels is also analog signal.But discrete signal with 2 possible levels is digital.Digital signals are used in digital domain. Digital domain uses digital components which work is based on Boolean logic and math.Analog signals are used in analog domain. Analog domain uses analog circuits, but can be processed in digital domain with conversion.All pretty clear and easy.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 09:45:25 am
content: Quote from: tggzzz on October 22, 2023, 09:14:39 amIt doesn't depends on language.If you're talking that input of your circuit is digital then anyone can understand that it accept only binary signals which can be 1 or 0, and it don't accept other levels.When you're talking that input of your circuit is analog then anyone can understand that it can accept more than two levels.People who knows usual electronics and discrete math expecting binary state for digital signals and Boolean logic for digital logic elements. If you use term digital for analog discrete signal with 4 levels it breaks existing terminology and it leads to confusion.Just for your information, if you use discrete signal with 3 and more possible levels then classic Boolean logic is no more applicable for such signal and it means that all existing digital electronics cannot be used to process your signal without conversion to digital domain.You're needs to use different math with different rules to process such signal directly without conversion to digital domain. It will be ternary domain with ternary logic and ternary math with it's own ternary laws and rules.This is why digital electronics is common, and you cannot find electronics with ternary logic and math. There are only two common domains in electronics - digital and analog. It is possible to research ternary math and maybe develop electronics based on ternary logic, but this is complicated and not common for a usual electronics. So there is no electronics which uses ternary math.

author: tooki
author_rank: Super Contributor
timestamp: October 22, 2023, 09:56:07 am
content: Quote from: radiolistener on October 22, 2023, 08:39:25 amYou are dead wrong, sorry.As others have said: binary is a subset of digital.Analog means that a continuous value changes in proportion to the information. For example, amplitude of a sound waveform: this modulates the amplitude of the carrier wave in AM radio, or the carrier frequency in FM.In contrast, in a digital system, the values are discrete (they can only take one of a fixed set of values), and those values need not correlate directly to the information being encoded. In digital audio, even if uncompressed, the individual digits do not correlate to a particular amplitude. In typical PCM encoding, the entire word needs to be a) identified, and b) interpreted, in order to derive an amplitude value.It’s true that in electronic signaling, most digital signals and circuits are binary. But not all are, and telecommunication signals frequently use non-binary representations of digital data. The fact that they encode informatikn using multiple levels (and in many, phase shifts) doesn’t make it analog, because the encoding doesn’t change in proportion to the information itself. Other than memory, I’m not aware of any digital logic that uses multilevel signaling, so in the context of practical digital circuit designother than telecommunications, yes, digital means binary. But not because they’re synonyms, but simply because “digital excluding telecom” is a set containing only one member in practice.All digital signals live in the analog domain, insofar as the physics of the real world are analog. So what we really mean when we say that a signal is digital (whether binary or otherwise) is that we are interpreting it in a digital way. This layer of abstraction is one thing that makes digital so useful, because noise can be ignored to an extent, since the physical signal is not an analog of the information.And let’s not forget that there are quasi-analog signals that take only two states, like pulse width modulation and pulse density modulation. And indeed, with simple analog filtering, true analog signals can be extracted from them. (You can’t take a PCM bitstream and analog filter it to get audio.)

author: tooki
author_rank: Super Contributor
timestamp: October 22, 2023, 10:02:25 am
content: Quote from: radiolistener on October 22, 2023, 09:45:25 amBoolean logic is indeed binary.But a system that takes 256 bits (bit = binary digit) and encodes them to a single symbol (like the combination of phase and amplitude in QAM) is still digital, because the signal is not an analog of the information being transmitted. Neither the amplitude nor the phase correlate to any aspect of the information. For example, if you were using it to transmit audio, neither amplitude nor phase of the QAM signal correlates to the amplitude value of the audio. And it’s also not analog by definition, insofar as it’s noncontinuous — there are discrete symbols being sent, not a continuously-variable (= stepless) signal.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 10:06:13 am
content: Quote from: tooki on October 22, 2023, 09:56:07 amThis is wrong claim. Digital electronics works with binary signals and uses Boolean logic.It seems that you're just confusing term Numerical with Digital, because things that you're talking about "digital" looks like usual Numerical term.Quote from: tooki on October 22, 2023, 09:56:07 amIt seems that you're confusing terms Digital/Analog with Discrete/Continuous...Signal or circuit can be digital (binary) or analog (non binary).And signal can be discrete or continuous.Please don't confuse term digital with term discrete. These are different thing with different meaning.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 10:13:50 am
content: Quote from: tooki on October 22, 2023, 10:02:25 amThis is incorrect understanding. QAM modulated signal is analog signal which is used to transmit digital data.The system which generate QAM signal can use digital computation in digital domain (with using binary signals and boolean logic) to calculate analog signal in digital representation and then convert it with DAC to analog domain. But it don't means that QAM modulated signal is digital.You can generate QAM with analog circuit, but it will be much more complicated and expensive than doing it in digital domain due to analog circuit limitations.If analog signal carrying digital data it don't means that this signal is digital. In order to be assumed as digital, the signal must be binary.

author: alm
author_rank: Super Contributor
timestamp: October 22, 2023, 10:14:46 am
content: Radiolistener vs the world claiming that digital = binary,deja vu

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 10:21:34 am
content: Quote from: alm on October 22, 2023, 10:14:46 amIt is very reckless to call several forum users who confusing terminology as the "world"...Yes, we already discussed that subject in the past.

author: tggzzz
author_rank: Super Contributor
timestamp: October 22, 2023, 10:25:30 am
content: Quote from: radiolistener on October 22, 2023, 09:26:50 amWrong (again).First nixie displays in 1955:https://en.wikipedia.org/wiki/Nixie_tubeFirst use of digital: "Mathematician George Stibitz of Bell Telephone Laboratories used the word digital in reference to the fast electric pulses emitted by a device designed to aim and fire anti-aircraft guns in 1942."https://en.wikipedia.org/wiki/Digital_signal_(electronics)

author: tggzzz
author_rank: Super Contributor
timestamp: October 22, 2023, 10:36:12 am
content: Quote from: radiolistener on October 22, 2023, 10:13:50 amA QAM waveform is indeed analogue, just asall waveforms are analogue. That concept is a pre-requisite for understanding the importance of signal integrity in digital electronic systems.Those analogue waveforms arequantised into discrete levelsrepresenting digitalsignals.Summary: tooki has understood it correctly, but you haven't.

author: tggzzz
author_rank: Super Contributor
timestamp: October 22, 2023, 10:42:50 am
content: Quote from: radiolistener on October 22, 2023, 10:21:34 amMany people use terms incorrectly, e.g. specifying time in nS (not ns), or specifying battery capacity in MW (not MWh), or scope bandwidth in mHz.In this case you are using terms incorrectly.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 10:45:46 am
content: Quote from: tggzzz on October 22, 2023, 10:25:30 amIt doesn't matter, modern term digital means that system works with binary signals and Boolean logic.Regarding to QAM. To be clear. Digital data in this context is the message signal carried over analog signal. Don't confuse message signal with analog signal which carries that message.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 10:53:36 am
content: Quote from: tggzzz on October 22, 2023, 10:42:50 amWhat I'm using incorrectly?I don't confuse terms "Digital" and "Discrete" like you. For me digital and discrete are different things.Digital means system works with binary signals and uses Boolean logic (in opposite to analog).Discrete means that system works uses discrete signal representation (in opposite to continuous).

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 11:00:24 am
content: Quote from: tggzzz on October 22, 2023, 10:36:12 amIt seems that you're confusing terms "modulated signal" and "message signal".QAM is modulated signal and it is analog.Message signal can be analog or digital.Modulated signal carries message signal, but if you use digital message signal it don't turns modulated signal into digital, it still remains analog.For example CW modulation expects digital message signal (binary 1 and 0), but modulated CW signal is analog signal and cannot be assumed as digital despite the fact that it carries digital signal.

author: wasedadoc
author_rank: Super Contributor
timestamp: October 22, 2023, 11:01:44 am
content: Quote from: radiolistener on October 22, 2023, 09:26:50 amOrigin of the word "digital" is the Latin word "digitus" meaning "finger" or "toe".

author: tggzzz
author_rank: Super Contributor
timestamp: October 22, 2023, 11:29:07 am
content: Quote from: radiolistener on October 22, 2023, 10:45:46 amIt is revealing that youchoseto omit the context in order to make your point. The context invalidates your response.You made the explicit incorrect statementhighlightedbelow...Quote from: tggzzz on October 22, 2023, 10:25:30 amGeneral principle: when you are in a hole, stop digging.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 11:35:31 am
content: Quote from: tooki on October 22, 2023, 09:56:07 amI will open you some secret, in digital electronics all signals are binary, that is why it digitalQuote from: tooki on October 22, 2023, 09:56:07 amIn telecommunications analog signals are used to carry digital message signals, but it don't turns analog signals into digital. As said above, for example CW modulated signal carries digital signal, but CW modulated signal cannot be assumed as digital just because consists of sine with varying amplitude which cannot be represented with digital signal (with binary levels 1 and 0).Quote from: tooki on October 22, 2023, 09:56:07 amFor modulated signal doesn't matters what you're using as modulation message signal - digital or analog. If modulated signal is analog it will remains analog. And you cannot name analog signal with varying phase and amplitude as digital just because it cannot be represented with binary 1 and 0.

author: tggzzz
author_rank: Super Contributor
timestamp: October 22, 2023, 11:37:02 am
content: Quote from: radiolistener on October 22, 2023, 10:53:36 amI suggest youslowlyread and understand the technical references several people have given to you.Start withhttps://en.wikipedia.org/wiki/Digital_signal#In_digital_electronicsand pay particular attention to the sections "In digital electronics", "In signal processing", and "Modulation".

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 12:14:14 pm
content: Quote from: tggzzz on October 22, 2023, 11:37:02 amWikipedia is often written by people who don't know the subject very well. I don't want to read long texts and guess what did you mean when proposed to read that link....Just give me answer on the question - where I'm wrong?If you're think that I'm complete noob and don't know what I'm talking about, just for your information, I have college and university degree in digital electronics and software development and worked for many years as software development engineer, I know digital signal processing and have experience in designing my own DSP chains for short wave receivers. I implemented CW,SSB,AM,FM demodulators in digital domain using different approaches and tested how they works with real air signals. I done it in FPGA as digital circuit and in software as a program. I'm licensed ham amateur and know technical details about antennas, radio waves, spectrum, modulation, how all these things works in analog domain and from physics point of view. So, don't hesitate to point me where I'm wrong exactly...As any people I can be wrong, but if you want to say that I'm wrong, then please provide me with logically correct and clean reason. Not abstract "you're wrong go and read RTFM".Currently I see that you're confusing terminology (terms Digital, Discrete, Numerical) and cannot provide clean and logical point of view. In addition I see that you don't understand well theory about signal modulation and confusing modulated signal with modulation message signal. For some reason you're don't want to accept classic meaning of term Digital and want to name analog signals and circuits as digital just because it can be used to carry digital data. Sorry, but I cannot accept so confusing arguments.

author: BeBuLamar
author_rank: Super Contributor
timestamp: October 22, 2023, 12:26:46 pm
content: So if Hex or Decimal is not digital then they are analog?The French doesn't call it digital but they call it Numerique vs Analogue.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 12:33:01 pm
content: Quote from: BeBuLamar on October 22, 2023, 12:26:46 pmHex and Decimal are numbering systems. It is not about analog/digital, but about different systems for number representation.If you want to use hex or decimal digit to represent signal, it requires to process signal with 10 or 16 levels. There is no logic and math developed for such signals, so - yes, such signals are analog, because they are not digital and other kind of signal just don't exists in modern electronics. In theory it is possible to develop, but it requires a lot of work starting from math development and research for such systems.As far as I know, such work is not being carried out. There was some attempts to research ternary logic, but it seems that it is not widespread. I think this because it is complicated and don't provide you with some benefit in comparison with digital electronics.So, there are only two common domains in electronics - digital and analog.

author: tggzzz
author_rank: Super Contributor
timestamp: October 22, 2023, 01:11:23 pm
content: Quote from: radiolistener on October 22, 2023, 12:14:14 pmWikipedia is often written by people whodoknow the subject very well. The wackypedia article is one such article.If you aren't prepared to listen to answers and think about the responses, then there is no point in others trying to help you.QuoteSee the previous responses from myselfand many other people.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 01:17:28 pm
content: Quote from: tggzzz on October 22, 2023, 01:11:23 pmSorry, but if you don't have answer, it's better to be quiet instead of engaging in chatter to dodging the answer.I still don’t see what exactly you disagree with... And I didn't asked help about this topic.

author: BeBuLamar
author_rank: Super Contributor
timestamp: October 22, 2023, 01:23:28 pm
content: Quote from: radiolistener on October 22, 2023, 12:33:01 pmA hex digit is only 2 levels but 4 bits in parallel. All things involving hex, octal are also binary in nature. When you use Hex or Octal you're talking about a digital system.

author: tggzzz
author_rank: Super Contributor
timestamp: October 22, 2023, 01:24:21 pm
content: Quote from: radiolistener on October 22, 2023, 01:17:28 pmI refer you to the last line of my previous response which - again - you have chosen to omit. Not impressive.Here it is again: "See the previous responses from myselfand many other people".

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 01:32:23 pm
content: Quote from: BeBuLamar on October 22, 2023, 01:23:28 pmif you want to represent hex digit with single signal it requires 16 levels. Such signal is analog.Grouping binary signals don't changes signal type it still binary.So if you're using many binary signals, it doesn't means how much, it still will be digital system.

author: tggzzz
author_rank: Super Contributor
timestamp: October 22, 2023, 01:36:53 pm
content: Quote from: radiolistener on October 22, 2023, 01:32:23 pmYour last line contradicts your first line. Think about that.

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 01:40:11 pm
content: Quote from: tggzzz on October 22, 2023, 01:24:21 pmI don't have goal to make impression on you...I just asked you what you're disagree with exactly?If you don't have clean answer on my question, then there is nothing to discuss...

author: radiolistener
author_rank: Super Contributor
timestamp: October 22, 2023, 01:44:37 pm
content: Quote from: tggzzz on October 22, 2023, 01:36:53 pmI don't see any contradiction here. All is pretty clear.Signal with 16 levels is analog signal.Several digital signals is digital system.

author: TimFox
author_rank: Super Contributor
timestamp: October 22, 2023, 02:17:54 pm
content: Absolutely not. A system with only 16 levels, and no (legitimate) levels in between them, is digital.An analog signal moves continuously over its range.Of course, as young engineers learn when something goes wrong, any voltage on a given wire is an analog signal: it becomes digital when quantized, but quantizers can be confused by ringing, etc.

author: radiogeek381
author_rank: Regular Contributor
timestamp: October 22, 2023, 02:37:35 pm
content: QuoteAs many many people have said, digital is not synonymous with “binary”. There are, in fact, ternary discrete value logics in use today in modern computer design. The primary modern example is in logic validation, automatic test pattern generation, and reset simulations. In these cases the third value is “U” or “undefined/unknown,” which may result from a flip-flop or other storage element that hasn’t been reset. There are a number of formal algebras for ternary logic. Here are two that I’ve seen used:T and T => TT and F => FT and U => UF and U => F (conservative F and U => U)T or T => TT or F => TT or U => T. (conservative T or U => U)F or U => Unot T => Fnot F => Tnot U => U============There are of course, other ternary logics where “U” does not mean unknown.There are programming systems where logical return values (discrete values) take on True, False, and NULL. The latter meaning that no result could be produced.In all cases “Digital,” among skilled and experienced practitioners of the art, has come to mean “discrete valued” logic. There is nothing magic about binary or boolean logics other than the fact that they are comparatively easy to implement with active devices acting as simple switches or two-level storage elements.======Ternary logic is handy for computing devices built from hydraulic components.At the end of the 1950’s the Soviets builthttps://en.wikipedia.org/wiki/Setunan example of a ternary design that was likely motivated by the expense of active devices.The extension from ternary logic to other logics with multiple symbols is possible, of course.======As for qualifications. I did my first digital design for money in 1979. Since then I’ve worked in almost every part of digital design including logic design, modules, system packaging and cooling, signal integrity, electrical design rule checks, validation, performance measurement/evaluation/simulation/modeling, architecture, compilers, modeling and simulation languages, CAD tools, applications programming, computing history, teaching, sales support, project management, and finance. I’ve built widgets in SSI CMOS, TTL, ECL, NMOS, and VLSI CMOS. I’ve taught both logic design and architecture. (For 19 years I worked for a company called “Digital Equipment Corporation.”) For most of the last 20 years I have been an architect.So I know what I’m talking about.

author: tggzzz
author_rank: Super Contributor
timestamp: October 22, 2023, 03:17:52 pm
content: Quote from: radiogeek381 on October 22, 2023, 02:37:35 pmAs I'm sureyourealise, the IEEE Standard Logic Type has 9 values:type STD_ULOGIC is (‘U’, -- uninitialized‘X’, -- strong 0 or 1 (= unknown)‘0’, -- strong 0‘1’, -- strong 1‘Z’, -- high impedance‘W’, -- weak 0 or 1 (= unknown)‘L’, -- weak 0‘H’, -- weak 1‘-’, -- don’t care);and those are necessary when simulating simple gates and buffers.Where two outputs are connected together, the resolution function isTYPE stdlogic_table IS ARRAY(std_ulogic, std_ulogic) OF std_ulogic;CONSTANT resolution_table : stdlogic_table :=(-- U X 0 1 Z W L H - -------- -------------------------------------------(‘U’,‘U’,‘U’,‘U’,‘U’,‘U’,‘U’,‘U’,‘U’), -- U(‘U’,‘X’,‘X’,‘X’,‘X’,‘X’,‘X’,‘X’,‘X’), -- X(‘U’,‘X’,‘0’,‘X’,‘0’,‘0’,‘0’,‘0’,‘X’), -- 0(‘U’,‘X’,‘X’,‘1’,‘1’,‘1’,‘1’,‘1’,‘X’), -- 1(‘U’,‘X’,‘0’,‘1’,‘Z’,‘W’,‘L’,‘H’,‘X’), -- Z(‘U’,‘X’,‘0’,‘1’,‘W’,‘W’,‘W’,‘W’,‘X’), -- W(‘U’,‘X’,‘0’,‘1’,‘L’,‘W’,‘L’,‘W’,‘X’), -- L(‘U’,‘X’,‘0’,‘1’,‘H’,‘W’,‘W’,‘H’,‘X’), -- H(‘U’,‘X’,‘X’,‘X’,‘X’,‘X’,‘X’,‘X’,‘X’) -- -);https://www.vhdl-online.de/courses/system_design/vhdl_language_and_syntax/extended_data_types/standard_logic_typeRadiolistener appears to be under the misapprehension that "Type bit is (‘0’, ‘1’);" is the necessary and sufficient definition of a digital signal.

author: TimFox
author_rank: Super Contributor
timestamp: October 22, 2023, 04:18:19 pm
content: Also, "waveform" and "signal" are not synonymous.Typical digital signals are assembled from binary bits, but a single binary bit is sufficient for only simple results, such as turning on the ceiling light.A sweet analogy: cookies are assembled from chocolate chips.A signal made from four binary bits, with 16 discrete states or values, can represent numbers in hexadecimal, Gray code, and several variations of binary-coded decimal (only 10 states used).The four bits can be sent serially on a single wire, or in parallel on four wires, for a digital system to process.A 16-bit signal can give a huge set of still-discrete states: Unicode is now up to more than 150,000 discrete characters, encoding into 21 bits (heading to 32).With a signal made from an analog waveform, the value is continuous (in principle), with resolution limited by noise and bandwidth.

author: TimFox
author_rank: Super Contributor
timestamp: October 22, 2023, 05:39:09 pm
content: An interesting example of a digital system's readout:Some early -hp- digital frequency counters such as the 524B, using vacuum tubes, pre-Nixie, used vertical rows of discrete neon bulbs for the most-significant decimal digits, and two moving-needle meters to indicate the two least-significant digits.Each meter had marks for the 10 states of those two digits: values of meter current between those marks were not valid.http://madrona.ca/e/edte/HP524B/viewL.jpg

author: Nominal Animal
author_rank: Super Contributor
timestamp: October 22, 2023, 06:46:22 pm
content: Quote from: tggzzz on October 22, 2023, 03:17:52 pmInteresting!For those of us who don't think in VHDL, converted to plain text: Connecting two outputs together yields the actual results shown in the following table:│ U X 0 1 Z W L H -──┼───────────────────────────U │ U U U U U U U U U U =UninitializedX │ U X X X X X X X X X =Strong 0 or 1 (unknown)0 │ U X 0 X 0 0 0 0 X 0 =Strong 01 │ U X X 1 1 1 1 1 X 1 =Strong 1Z │ U X 0 1 Z W L H X Z =High impedanceW │ U X 0 1 W W W W X W =Weak 0 or 1 (unknown)L │ U X 0 1 L W L W X L =Weak 0H │ U X 0 1 H W W H X H =Weak 1- │ U X X X X X X X X - =Don't careper tggzzz's VHDL. It's very logical, too. (Pun not intended.)

author: Nominal Animal
author_rank: Super Contributor
timestamp: October 22, 2023, 08:00:48 pm
content: One useful definition of 'digital system' I like, is 'a system whose inputs, outputs, and internals have a finite number of valid discrete states'.The corresponding definition for 'analog system' is then 'a system whose inputs, outputs, and internals have continuous ranges of valid states'.A 'mixed system' is obviously one that includes both.By 'internals', I am referring to any internal point or feature that is relevant externally, and not just an internal detail like an implementation detail.By 'discrete', I mean separate, distinct, non-continuous.By 'valid', I mean that transitions between functionally meaningful states are not considered, and that only states where the system works as intended are considered, and that design errors and unintended states are not considered.The 'finite' is more a consequence of having discrete states and a limited operational ranges, but it is useful to remember: for any specific digital system, the number of valid discrete states can be determined in a very straightforward manner; it is neverinfinite.A 'digital system' does not require that all its components are themselves 'digital systems'. For example, in many binary logic digital circuits an N-channel MOSFET or NPN BJT can be used to invert the logic signal, even though its internal operation is analog: continuous, not discrete.Similarly, a purely 'analog system' can contain components that internally are digital: for example, a toggle switch.What matters is whether at each meaningful point –– so excluding internals of its components! –– the valid states are discrete, or continuous.As with all human languages, this is not a perfect definition. Consider an old-style tungsten filament light fixture controlled by a triac dimmer. It has one discrete state, completely off and unlit, as well as a continuous range of intensities from some lower limit up to maximum. Thus, it has one discrete state and one continuous range of states. Instead of having a term to describe this, we just ignore that one discrete state (it being "off" and thus not very interesting, as the same effect can be obtained by removing the entire system), and call it 'analog'. Plus, because this definition relies on terms used in physics, it can be misunderstood if the terms used in it are not understood.This leads to the first degree crude approximation of "digital ≃ discrete", "analog ≃ continuous".As to discrete systems, fundamentally binary ones are the most common, because two is the smallest number of discrete states one can have and still have the ability to change. Ternary systems exist, but are nowadays very rare. Most other discrete systems use binary at the lowest level, but combining a number of binary units into larger words, leading to 8-bit bytes and 16-, 32-, and 64-bit words. Again, those are just the most common ones, others also exist. Not all discrete systems use binary at their lowest level either: for example, multi-level flash memory cells as used in typical solid state storage nowadays, have a number of different valid states, depending on the amount of charge in that cell, so that each cell specifies the value for more than one bit.(Physically, any charge is alwaysquantized, because electical charge is discrete, depending on the number of charged particles, with the unit charge having the same magnitude as the charge of an electron or proton have, 1.602176634×10⁻¹⁹ Coulombs. This is such a small amount of charge that forpracticalpurposes, the amount of charge in a multi-level flash memory cell is considered continuous. Once again, we must consider the level of complexity at which we are observing things.)

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 22, 2023, 09:08:29 pm
content: I might ask radiolistener: If digital and binary are identically equal, what is the point of having two words?Radiolistener correctly asserts that the vast majority of implemented digital systems are binary. And admits that non-Boolean logic systems are possible. But then incorrectly asserts that the have not been formally defined and implemented. As Nominal has expanded ternary is fairly well developed, and as radiolistener has expounded on his curriculum vitae, he should be familiar with "fuzzy logic" which was something of a fad a couple of decades ago.In my personal opinion, developed with a somewhat longer and deeper curriculum vitae, ibinary or Boolean is a subset of digital. It is by far the most common subset in current practice, and given an engineering approach where small difference can be ignored used as a useful approximation of the whole set. This rounding approach is widely useful. But those small differences are where many new ideas are found, and often fertile ground for breakthrough ideas

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 01:33:38 am
content: Quote from: TimFox on October 22, 2023, 02:17:54 pmNo. The signal is Analog when it is not Digital. And you cannot categorize signal as Digital if it have more than 2 discrete levels.The main mistake in your claim is that you're assume that non binary but discrete level signal as Digital, this is incorrect.Such signal with discrete 16 levels is Discrete, but NOT Digital, because it cannot be represented with binary digit.And since there is no special domain for N-level discrete signal, where N != 2, such signal falls into the Analog category.If you develop math and laws for ternary logic, you can involve new domain, for example you can name it "Ternary Domain". You can develop math, logic, laws for that domain, develop algorithms and electronic blocks for such domain, develop and manufacture integrated circuit for such domain. And then you can categorize signal with 3 possible levels to Ternary Domain.The same for signal with discrete 16 levels, you're needs to develop math, laws and rules, develop electronic blocks for logic operations which working with signal that have 16 levels and then you can categorize such signal with 16 levels to a new invented domain.But since there is still no Ternary Domain and other type domains in modern electronics, you're have just 2 options: Digital Domain )for signals with 2 discrete levels and Analog Domain for all the rest signals. And this is why you're have only Analog choice for signal with 3 discrete levels. And the same only Analog choice for signal with 16 discrete levels.Digital Domain is already used for signals with 2 discrete levels and Boolean logic where signal is represented with binary digit. You cannot use digital electronic blocks (such as basic AND, OR, XOR, NOT elements) which are designed to work with 2 discrete levels according to Boolean logic to process signals with 3 or 16 discrete levels.Such signals are incompatible with Digital Domain.

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 02:02:43 am
content: Quote from: CatalinaWOW on October 22, 2023, 09:08:29 pmThey are not identically equals, they have different meaning.Binary means numbering system with base 2, the same as Decimal means numbering system with base 10 and Hexadecimal is a numbering system with base 16, etcDigital means digital domain, which covers all math, laws and electronic circuit which are designed to works with basic signals that have only 2 discrete levels and uses Boolean algebra, algorithms and approaches and all others things.Any thing that works with signals which has more than 2 discrete levels is not covered by Digital Domain and falls to Analog Domain. You cannot apply math and rules or logic elements used in Digital Domain for such signals. Since there is just Digital and Analog domain, all things which cannot be categorized as Digital are falls to Analog category.For me, this is pretty clear and easy, I don't understand why so clear things leads to an irresistible desire to pull an owl on a globe, that is, to call a non-binary signal as digital...It should be pretty obvious that the signal with 16 discrete levels is not compatible with digital circuits and should be treated as analog signal and needs to use ADC / DAC to convert it to digital domain and process within digital domain or use analog circuit to process it in analog domain, there is no other choice....

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 02:29:31 am
content: Quote from: tggzzz on October 22, 2023, 03:17:52 pmNo, I know about special cases, but they are not represent valid state of the signal. I deliberately avoid to talk about it to avoid more confusion for those who don't familiar with digital electronics. They are describe special cases when signal is missing at all or is undefined, or stay in metastable state, which happens in real digital system because it is build with analog circuit and there is no way to build ideal digital system with binary signals.When I talked that digital signal has binary value, I mean valid signal value, when signal is present, is defined and stable. There is just two values 0 and 1 for valid signal. But real life is a little bit complicated and we needs to deal with all these special cases with missing or undefined signal or metastability issues which happens not because it is digital, but due to analog limitations of our world, where it is impossible do develop ideal digital system and any basic digital logic element is built with analog components and utilize analog nature of our world...

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 02:59:18 am
content: Quote from: TimFox on October 22, 2023, 04:18:19 pmYes, analog signal is continuous and not limited to some fixed discrete values, but it don't means that analog signal which specification has 16 discrete levels is not analog. It is still analog.Discrete/Continuous and Digital/Analog are different properties.For example digital signal can be Discrete in time or Continuous in time. In both cases the signal is Digital.The same thing with signal level, analog signal can be Discrete in amplitude or Continuous in amplitude. In both cases the signal is Analog.So, the Discrete/Continuous property of signal cannot be used to categorize it as Anaglog or Digital.

author: Electro Fan
author_rank: Super Contributor
timestamp: October 23, 2023, 04:42:47 am
content: Perilous as it might be…Analog is continuously variable.Digital is binary, 2 states, “on” or “off”, roughly the absence or presence of electricity (as defined by some agreed upon threshold) and as represented by bits (binary digits), 1s and 0s. Depending on the convention used the 1s and 0s might use 7 bit ASCII, 8 bit EBCDIC, HEX, etc. or various other encoding schemes to represent information in a format meaningful to machines or humans (including data, text, audio, images, and video). Many conventions can be evolved from the basics (8 bit Bytes, 16 bit Bytes, 32 bit Bytes, 64 bit Bytes, etc) and many A2D and D2A techniques can be employed. As a result digital can approximate analog and analog can be represented by digital.

author: Tomorokoshi
author_rank: Super Contributor
timestamp: October 23, 2023, 05:00:47 am
content: Let's say the context here is that of a computing system in the most general terms.Paraphrasing Mr. Blaauw's model of Architecture, Realization, and Implementation, let's be very careful and precise about exactly which aspect of the system is being discussed.*1. The set of all states described in the Architecture of the system.2. The methodology by which the set of all states described in the Architecture is Realized in the design.3. The componentry in the Implementation that allows for the function of the methods from the Realization.Therefore, when having a discussion like this, it is important that both are talking about the same view into the system. Is one person thinking from the Architecture point of view, while another is thinking from the Implementation point of view, while a third is thinking from the Realization point of view?Part of the confusion with "digital" and "binary" is understanding where precisely these are considered in the design. I will discuss two computer systems.The Motorola MC68000 ProcessorAny other modern processor could just as well have been chosen. I selected this because:1. I am familiar with it.2. I suspect many of you are also familiar with it.3. It is an elegant design.4. It is well documented in case someone needs to look something up.5. None of that analog peripheral nonsense is built-in to confuse things.In a system the 68000 addresses memory and peripherals through a 23-bit address bus. The upper and lower 8-bit bytes of a 16-bit word are selected using two additional control lines. The 16-bit data bus can return either or both of the 8-bit high and low bytes based on the control lines.Each of the individual address and data bus signals is specified as either a "High" of nominally 5V or a "Low" of nominally 0V. The input and output drive circuits can reliably transfer using these voltage representations of states. Therefore, while a range is acceptable for the two logic levels, that does not matter in the context of this system.While the programmer's view of the register set can perform binary operations, the register architecture is grouped into 8-bit bytes, 16-bit words, and 32-bit "longs". Operations are at the byte, word, and long level.MC68000 Observation 1: To the programmer the digital data is processed in groupings of 8 binary digits known as "bytes".MC68000 Observation 2: The address and data lines use digital signals in a binary format.MC68000 Observation 3: The digital signals can be measured as generally discrete values.All of this is implemented on an integrated circuit.The IBM 650 ComputerThis goes back to the 1950's. Why study the IBM 650? Why study any computer technology? What makes it interesting is the contrast it provides to "modern" systems, not the direct applicability of the system.Part of the discussion here is that "digital" and "binary" are considered somewhat synonymous. What would it mean for a system to be digital, but not binary?The IBM 650 is a decimal computer. To the programmer, the architecture is strictly that of a decimal system. For instance, the programmer is not working with base-2 registers that are somehow interpreted to look like base-10 in the fashion of the MC68000 BCD manipulation instructions.The implementation of a decimal digit is done with 4 binary digits, interconnected to produce a unit that counts from 0 through 9. Is this HEX? No, it isn't: the operations are decimal. 0.1 can be represented exactly.Homework: Using fixed-point variable representation on a binary computer, work out the value for "0.1".Just like the MC68000, signal levels in the IBM 650 generally take on two ranges. However, the grouping and controls of the 4 binary digits works out to a decimal digit.IBM 650 Observation 1: To the programmer the digital data is processed in groups of decimal digits.IBM 650 Observation 2: The address and data lines use digital signals in the decimal format.IBM 650 Observation 3: The digital signals can be measured as generally discrete values.All of this is implemented with vacuum tubes.ConclusionHere we have an example with the IBM 650 computer that is digital, but not binary, at the Architecture level. To the programmer, the Implementation and Realization are not important.Note that we can have discrete circuits multi-level that are not analog. For instance, a monostable multivibrator realized using two triodes could be made to have 10 quasi-stable states. It is not an analog circuit from the point of view of being able to process a continuous time-varying signal such as an audio signal. It would be used as a divide-by-ten circuit.* Gerrit Blaauw developed the architecture of the IBM 360 computer, and decided on the 8-bit byte.

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 05:01:04 am
content: Quote from: Electro Fan on October 23, 2023, 04:42:47 amTo be more precise, analog signal can handle both - continuous and discrete amplitude.Analog signal can be discrete or continuous in time and can be discrete or continuous in amplitude.It depends on your requirements for signal but not on Analog/Digital type.The same digital signal can be continuous and can be discrete in time.But for amplitude digital signal is always discrete, because uses binary level which is discrete.Quote from: Tomorokoshi on October 23, 2023, 05:00:47 amNo, this is wrong example. It says about decimal representation of digital data on display for human, but that digital data is still binary and requires conversion from binary to decimal in order to show it to the user.Just open schematic of IBM machine and check, I bet that it uses binary signals, because it is digital

author: Tomorokoshi
author_rank: Super Contributor
timestamp: October 23, 2023, 05:22:39 am
content: Quote from: radiolistener on October 23, 2023, 05:01:04 am1. What is the circuit for a binary digit?2. How many transistors does it use?3. If it uses more than one transistor, is it still binary?4. At which level are you discussing the question: Architecture, Implementation, or Realization?For Blaau's paper on Computer Architecture:https://www.infra-repository.org/oiar-2013/images/3/3b/Blaauw_Architectuur.pdf

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 23, 2023, 05:29:09 am
content: Quote from: radiolistener on October 23, 2023, 02:59:18 amBy your definition a digital signal cannot be continuous in time. There is a discontinuity (the left derivative and the right derivative are not equal) at every state change.But I am sure you have a reason that this is not applicable, because you have some alternate definition of continuity.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 23, 2023, 05:42:56 am
content: Quote from: Tomorokoshi on October 23, 2023, 05:00:47 amI think you are on the trail of the problem here. Radiolistener has stated that programmers always think in binary terms. This may be true of microcontroller programmers, but I can tell you from personal experience that a large class of programmers do not think about the machine representation of signals at all. This becomes obvious when you get the blank stare look from a programmer who is used to high level languages when asked whether he assumed that the output of the A-D converter was offset binary or twos-complement. There are many other examples which can be given.In the world view of radiolistener the classification he defines for analog and digital is complete and sufficient. It totally works for all use cases he has encountered. Others here see the world differently.Problems like these are common in the world, and characterized well the the Jaines parable of 10 blind men and an elephant. Each blind man correctly describes the elephant as he has encountered it. But is has trouble reconciling his own observations with those of the others.

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 05:55:25 am
content: Quote from: CatalinaWOW on October 23, 2023, 05:29:09 amYes ideal digital circuit is not possible in our analog world. Because ideal digital signal needs to switch from 0 to 1 in zero time interval. This is impossible and this is why digital circuit has bandwidth limitations. That discontinuity happens on time intervals which is outside of working bandwidth. You can ignore it for working bandwidth.For example, digital AND element has input and output signals which are continuous in time. And these continuous signals are digital.

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 06:03:48 am
content: Quote from: CatalinaWOW on October 23, 2023, 05:42:56 amThis is false claim.I stated that digital circuit always use binary signals. You can't find digital logic element that can accept signal with 10 or 16 discrete levels. It always uses binary. As user you can see decimal values, hexadecimal values, but this is result of conversion from internal binary form to selected numbering system. The digital system always works with digital data stored and transferred in binary form which is represented with 1 and 0.If circuit uses signal with more than 2 discrete level, this is NOT Digital circuit but Analog or Mixed signal one and pure digital circuit cannot handle such signal...

author: tooki
author_rank: Super Contributor
timestamp: October 23, 2023, 07:07:09 am
content: radiolistener, you really, really need to find some books on information theory and read them. You are basing your beliefs on the domains you know well, and then incorrectly extrapolating that what’s true in your domain is true of all domains.

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 08:26:10 am
content: @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 seems that some people are sure that digital system can use non binary signals just because their computers can show decimal and hexadecimal digit, this is just misunderstanding. Any digital circuit works with binary signals and binary data, this is obvious. If it shows you decimal value or provide analog output, this is just result of conversion from digital to analog. But original data in digital circuit is stored and processed in binary form.There is also another misunderstanding from previous topic, where some users tried to convince me that radio link uses digital signal just because it transfers digital data or because their transmitter DAC has discrete voltage levels (more than two) or discrete in time and has some sample rate. This is also wrong. Such radio link is analog, it just carries digital data, but it uses analog signal to carry that data.

author: tggzzz
author_rank: Super Contributor
timestamp: October 23, 2023, 08:59:16 am
content: I think it is clear that radiolistener is using the word "digital" in the same manner that Humpty Dumpty famously used the word "glory".I doubt he has read the children's classic book that written >185(!) years ago, and which has many concepts that have entered several countries culture. Here's the relevant quote:“I don't know what you mean by 'glory,' " Alice said.Humpty Dumpty smiled contemptuously. "Of course you don't—till I tell you. I meant 'there's a nice knock-down argument for you!' ""But 'glory' doesn't mean 'a nice knock-down argument'," Alice objected."When I use a word," Humpty Dumpty said, in rather a scornful tone, "it means just what I choose it to mean—neither more nor less.""The question is," said Alice, "whether you can make words mean so many different things.""The question is," said Humpty Dumpty, "which is to be master—that's all.”https://www.goodreads.com/quotes/tag/humpty-dumpty

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 09:30:31 am
content: Quote from: Nominal Animal on October 22, 2023, 08:00:48 pmAccording to such definition, sound card output is digital, just because it has finite number of valid discrete states (for example 16777216 discrete amplitude states and 48000 states per second clock states)...Quote from: Nominal Animal on October 22, 2023, 08:00:48 pmLet's take for example a simple logic gate AND. It has input and output which is continuous in time.So, using such "crude approximation" it leads to analog category for digital logic gate...And another example with analog switch connected to some clock to enable its output at discrete points of time.Since it's discrete in time, using such "crude approximation" it leads to digital category for signal which is pure analog...

author: AndyBeez
author_rank: Frequent Contributor
timestamp: October 23, 2023, 09:39:10 am
content: To the OP:Digital means 'digitizing' the world into numbers.Binary is a numeric system used in 'digitization'. Silicon based computers use Binary because they can only safely switch between the zero and the one state.Binary is just another name for the base two number system. Hence, all number bases can be represented in any other number base. Octal is base 8, hexadecimal is base 16.So a 'digital computer' could be a human with a pencil or an abacus. The only major difference is their calculations use a different number base. Often 10, 12, and 16.Beware, the term Binary should not be confused with the term Boolean. To operate, both Boolean mathematics and logic require all values to be in base two, which is also binary.

author: tggzzz
author_rank: Super Contributor
timestamp: October 23, 2023, 11:17:46 am
content: Quote from: radiolistener on October 23, 2023, 09:30:31 amThe output of a sound card is indeed digital. The input is analogue. That's why the sound card is an "analogue to digital converter".According to your peculiarmisunderstanding, there are no such things as ADCs, only AACs.QuoteThe inputs and outputs of logic gates are indeed analogue.The device that recieves the outputsinterpretsthe analogue voltages (or currents) as digital signals.If you doubt that, explain how a CMOS logic gate can be used as an amplifier, and have a look at how ECL/PECL logic gates work (in particular the voltages). e.g. a CD4007UB CMOS dual complementary pair plus inverter, with listed applications being extremely high-input impedance amplifiers, shapers, inverters, threshold detector, linear amplifiers, crystal oscillatorshttps://www.ti.com/product/CD4007UBQuoteOh, how naive and simplistic. Have a look at N-path filters, a.k.a. commutating capacitor filters

author: TimFox
author_rank: Super Contributor
timestamp: October 23, 2023, 01:56:14 pm
content: Two electrical mechanisms that are truly digital, in decimal not binary:The Strowger switch, used in telephone exchanges:https://en.wikipedia.org/wiki/Strowger_switchThe Dekatron counter, using gas-discharge, counting directly and displaying the result:https://en.wikipedia.org/wiki/Dekatron

author: Nominal Animal
author_rank: Super Contributor
timestamp: October 23, 2023, 02:38:51 pm
content: Quote from: radiolistener on October 23, 2023, 09:30:31 amThe output of a DAC is still digital, but add a capacitor or alow-passband-pass filter (often DC is blocked!), and you have an analog output, because it is continuous and no discrete states can be observed a priori in the output.Quote from: radiolistener on October 23, 2023, 09:30:31 amNo, it doesn't. While the input and output are voltage levels, in normal use one range of voltages is considered "low", another "high", and the rest are indeterminate. Thelogicis discrete, while the voltage levels used to convey that logic is continuous.This is why it is so important to consider the system at the correct complexity level. Any definition is useless if you only use its "holes" or weaknesses, instead of its strengths. Definitions are tools, not some kind of absolute revelation of fundamental facts.As tggzz explained, many logic gates can be used as an analogue component, too. Thus, "discrete" or "continuous" also depends on the design, the intent, of the component and system.Quote from: radiolistener on October 23, 2023, 09:30:31 amNo, like I wrote: there are mixed systems, but we lack exact terminology for them. I thought I made this clear with the triac mains dimmer with a switch: the states consist of both discrete (off) and a continuous range of states (duty cycle). The clocked part is digital, because it has a finite number of states; but because of its construction, it can also be used with analog signals. Thus, a mixed system.The reason I prefer this definition over others is that it isuseful. Using that definition, it is very easy to branch into mathematics (discrete side to mathematical logic and various theories, continuous side to functions, calculus, transforms), physics (discrete vs. continuous systems, mechanics), electronics (especially the theoretical side), and even history of computing/calculation and esoteric systems like fluidics. You can find "grasping points" in each using the terms in the definition.Sure, if you stop nitpicking and use the definitions as I described, you can poke valid holes into it. That does not make this definition any less valid in the above sense,because it is useful. We haven't discarded Newton's Laws of Motion just because we discovered that they're not exactly correct in all situations; they're still a valid model within their known limitations.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: October 23, 2023, 04:29:06 pm
content: In the context of digitising analog series, has any definition included the uncertainty introduced by decimation and interpolation? A digital system observes at discrete intervals, but it cannot 'see' into the gaps inbetween.Could a future computer technology operate in pure and infinite Fourier Transforms, rather than in bistate binary? But would it still be a 'digital' computer?

author: tggzzz
author_rank: Super Contributor
timestamp: October 23, 2023, 04:55:42 pm
content: Quote from: TimFox on October 23, 2023, 01:56:14 pmThe world's oldest working computer is based on dekatrons and P.O. type 300 relays. It is the Harwell Dekatron, a.k.a. WITCH. While manyearly computersrepresented numbers decimally, they used various encoding schemes to represent the ten digits using binary logic (e.g. BCD, bi-quinary and two-out-of-five codes).AFAIK the WITCH is the only computer that useddecimallogic elements to implement arithmetic operations.Presumably radiolistener will try to claim WITCH is analogue. Hopefully this clear real-world example that digital != binary won't cause him too much distressGo to The National Museum of Computing and see it; well worth while.https://www.tnmoc.org/witchAnd a video showing it working, reading instructions from paper tape and outputting results on a teletype:https://youtu.be/SYpPPIsxq64?t=660https://youtu.be/SYpPPIsxq64?t=821 I have both: the dekatrons in a geiger counter, and the relays from when I was a kid.

author: TimFox
author_rank: Super Contributor
timestamp: October 23, 2023, 05:02:15 pm
content: The first computer I encountered was one sold by IBM for college use, their 1620.https://www.ibm.com/ibm/history/exhibits/mainframe/mainframe_PP1620.htmlThe internal representation of numbers was BCD, using discrete-transistor logic.(The keypunches installed next to the computer used 25L6GT tubes to drive the solenoids.)I have also used electronic counters with Dekatrons in particle-counting lab exercises during the same era.

author: TimFox
author_rank: Super Contributor
timestamp: October 23, 2023, 05:09:37 pm
content: Quote from: AndyBeez on October 23, 2023, 04:29:06 pmTrue analog computation used to be a thing: it worked well on "integro-differential" problemshttps://en.wikipedia.org/wiki/Integro-differential_equationThe continuous output of the computed answer could be seen on a CRT, or traced with an analog pen plotter.When visiting a Boeing facility, I saw their house newsletter, which had lots of Boeing history (including photos of aircraft).One issue showed a Boeing engineer, ca. 1950, operating an analog computer, properly dressed in white shirt and tie.To his left was a tall rack cabinet, holding the electronics. To his right was a blackboard, identifying the knobs on the computer with the terms of his equations.The caption, written by a younger person, stated that the computer generated so much heat that 400 vacuum tubes were required to cool it.In the next issue, there were letters from retired Boeing employees about that comment.

author: wasedadoc
author_rank: Super Contributor
timestamp: October 23, 2023, 06:00:41 pm
content: Quote from: AndyBeez on October 23, 2023, 04:29:06 pmThat's what Nyquist is all about. If the signal is bandlimited limited with none above half the sampling frequency, the signal is truly and completely characterised by the samples. The original signal, including all the portions between the samples can in theory be recovered with 100% accuracy.If you decimate the samples that is just equivalent to reducing the original sample rate by the corresponding ratio.Note that all of the above is applicable to the analogue samples. Quantising by for example an A to D converter introduces additional considerations.

author: TimFox
author_rank: Super Contributor
timestamp: October 23, 2023, 06:33:21 pm
content: Yes, "Nyquist" is about discrete-time sampling. "Quantization error" is about discrete-level quantizing. Normal analog-to-digital conversion systems involve both types of error.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 23, 2023, 07:21:32 pm
content: Quote from: TimFox on October 23, 2023, 05:02:15 pmYes. And the 1620 did multiplication and division, not by multiplying those BCD numbers "digitally", but using a look up table identical in principal to the times table used to teach children arithmetic. Certainly digital, but not boolean.

author: TimFox
author_rank: Super Contributor
timestamp: October 23, 2023, 07:40:21 pm
content: Back in the 1970s,Electronic Designmagazine ran a series of articles about how to do digital arithmetic with BCD-represented values.

author: tggzzz
author_rank: Super Contributor
timestamp: October 23, 2023, 07:46:16 pm
content: Quote from: TimFox on October 23, 2023, 05:02:15 pmI used an Elliott 803, also working at the TNMoC.Distinguishing features: bit serial, 39-bit words, binary, magneticfilmwith sprocket holes - and a seminal Algol-60 compiler by CAR (Tony) Hoare. He also created Quicksort, CSP, and the null pointer (his self-acknowledged billion dollar mistake!), etc, etc,

author: RJSV
author_rank: Super Contributor
timestamp: October 23, 2023, 08:03:34 pm
content: Firstly, I think it's a falacy to bring 'binary' zeros and ones into the definition, where those two symbols are specific examples; I.E. 'A digital system will often use zero and one.'Digital means that your (analog) value is resolved, to discrete digits, and that analog level test often uses a slight bit of hysteresis. The key is understanding the term 'discrete', as being a confident / assured single result. It maybe sounds silly, but in a number result like '345' each digit, like a '3', can be interpreted as 'not 2 and not 4', and as discrete from those surrounding numbers.Thus, a system could be, for example; in base 7, using a multiple state chemical compound. The various chemical 'states' are discrete from one another, (in whatever sensing method used). It's the testing against some level or state that gives it 'digital' quality.Um,...kinda underperformed, on that answer!

author: BeBuLamar
author_rank: Super Contributor
timestamp: October 23, 2023, 09:23:14 pm
content: Quote from: RJSV on October 23, 2023, 08:03:34 pmThat is why the Frechn calls it numerique.

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 10:17:05 pm
content: Quote from: tggzzz on October 23, 2023, 11:17:46 amCan you please explain why any soundcard uses DAC (Digital to Analog Converter) on it's output?In short, you're claiming that analog output of DAC is digital. If output is digital, then please explain what is the reason for DAC here?Maybe it will help you to understand your mistake...

author: wasedadoc
author_rank: Super Contributor
timestamp: October 23, 2023, 10:30:43 pm
content: Quote from: radiolistener on October 23, 2023, 10:17:05 pmCrossed wires! (that is a figure of speech, not a literal statement.)A soundcard can be digital in converted to analogue out or analogue in converted to digital out or can do both of those conversions. radiolistener is thinking of the first of those three whereas tggzzz's sentence is about the second.

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 10:32:51 pm
content: Quote from: Nominal Animal on October 23, 2023, 02:38:51 pmNo, it is not digital and cannot be processed with digital input of some circuit. Just because it uses non binary signal levels.If you want to refute this, then please provide example of digital input which can handle analog signal from DAC (with no using ADC for converting from analog to digital and no using hacks like using digital circuit to perform analog to digital conversion, like using time-to-digital conversion with some RC, etc)Regarding to filter requirement, even without filter it is not digital, because has more than 2 signal levels. The filter is required for different purpose. It is required just to remove aliases which appears during digital-to-analog conversion. And this is why this filter is named "antialiasing filter".

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 10:47:36 pm
content: Quote from: wasedadoc on October 23, 2023, 10:30:43 pmJust to simplify things for better understanding and avoid confusion. I'm talking about output of sound card which don't have input, only output.This output is analog, and this is why there is digital to analog converter on sound card output.It needs to convert digital signals (binary data) to analog signal on soundcard output.

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 10:56:18 pm
content: Quote from: TimFox on October 23, 2023, 07:40:21 pmYes, such arithmetic is digital, because it deals with digital data which is binary.As you probably know BCD meansBinaryCoded Decimal

author: gf
author_rank: Super Contributor
timestamp: October 23, 2023, 11:07:39 pm
content: Quote from: radiolistener on October 23, 2023, 10:32:51 pmWikipedia's definition ofDigital SignalisQuoteA "digital PAM signal with five levels" is also given as an example and plotted in adiagram.If this PAM signal is considered "digital", then the usual quantized staircase output of a DAC can be considered "digital", too.

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 11:29:39 pm
content: Quote from: Nominal Animal on October 23, 2023, 02:38:51 pmI talked about time continuity, not level.Regarding to the level, yes digital logic is discrete, because it works with digital signals which is binary. And binary is discrete.If you want to talk about digital logic which is not binary, then provide example of such circuit, but this circuit should be digital. You can't find it, because digital circuit requires digital signals which is binary...And if some circuit works with non binary signals you will find that it uses analog-to-digital converter to convert analog signal to digital, process it in digital circuit and then convert back to analog with digital-to-analog converter.There is no way to process non binary signals with digital circuit without ADC and DAC, just because digital circuit works with binary signals only. Andnon binary signals are not compatible with digital circuit, so you're needs to convert it from analog to digital, then process in digital circuit and then convert it back from digital to analog.In simple words, non binary signal always require analog component to convert it from analog to digital code which is binary and from digital code to analog.Because non binary signals are not digital, they are analog.Even if signal is discrete in amplitude and discrete in time, but their amplitude is not binary, it still analog and requires ADC and DAC in order to process it with digital circuit.

author: TimFox
author_rank: Super Contributor
timestamp: October 23, 2023, 11:35:21 pm
content: An ancient non-binary, often decimal, digital system is the abacus or soroban.

author: radiolistener
author_rank: Super Contributor
timestamp: October 23, 2023, 11:44:47 pm
content: Quote from: gf on October 23, 2023, 11:07:39 pmI wouldn’t be surprised if the text on Wikipedia was written by one of the users here who attempt to prove here that the analog signal is digital, but still cannot provide example of digital circuit which can handle non binary signal...Quote from: gf on October 23, 2023, 11:07:39 pmPAM signal is analog signal and cannot be processed with digital circuit. PHY controller uses analog-to-digital converter to convert analog PAM signal to digital signals and process it in digital circuit. The same PHY controller uses digital-to-analog converter to convert digital signals from digital circuit to analog PAM output.And PAM signal is not just simple 5 levels. Usually PHY controllers also use programmable gain amplifiers for tuning PAM signal amplitude. Also signal amplitude has attenuation which depends on cable length and it also needs to be taken into account. So, there is much more possible levels.And in addition, gigabit PHY uses the same pair for transmit and receive simultaneously, it requires analog operations on signal to extract receive signal from the pair.All this cannot be done with digital circuit and requires analog signal processing.

author: wasedadoc
author_rank: Super Contributor
timestamp: October 24, 2023, 12:06:45 am
content: Quote from: radiolistener on October 23, 2023, 11:29:39 pmAll real signals flowing between integrated circuits using binary logic are analogue. The inputs of those ICs have circuitry which decides if the input is to be considered a binary 0 or 1. That is a 1-bit ADC, the simplest case of an n-bit flash ADC.Similarly at the output of an binary IC there is a 1-bit DAC.That binary ICs contain what are essentially ADCs and DACs is even more evident when considering binary ICs that for example operate with 3.3 Volt logic levels at input and ouput but internally use circa 1 Volt levels.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 12:26:12 am
content: Quote from: wasedadoc on October 24, 2023, 12:06:45 amYes, all signals can be considered as analogue. But not all of them can be considered as digital.The signal can be considered as digital if it uses 2 discrete levels.Otherwise it needs to be considered as analogue and converted to digital with ADC before processing it on digital circuit.Also note that there are different voltage standards for digital signal and if signal uses 2 discrete levels, this is not enough to claim that it is compatible with some digital circuit. It may require level shifter to adjust amplitude for compatibility.This is why digital signal is a signal that uses binary signal levels. And analog signal is a signal that is not digital...As you can see it well corresponds with meaning for the words "digital" and "analog" in dictionaries. Which said that:Quote from:https://www.merriam-webster.com/dictionary/digitalQuote from:https://www.merriam-webster.com/dictionary/analog

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 12:28:45 am
content: Quote from: radiolistener on October 23, 2023, 10:17:05 pmCan you explain why it is called adigitalto analogue converter? According to your repeated statements digital==binary and 0x1234 is analogue, so it ought to be called an analogue to analogue converter.Or are you just trolling?I'll be interested to hear you explain how arithmetic was (and is) done in the Harwell Dekatron (WITCH) computer, which is based on decimal logic elements, not binary logical elements.

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2023, 12:33:23 am
content: Starting in ancient Greece (Pythagoras, Euclid, etc.), there was a distinction between arithmetic and geometry in mathematics.For a while, due to disbelief in incommensurate numbers (what we now call irrational numbers), geometry took precedence, since quantities could be represented geometrically without using numbers.Later, arithmetic progressed with positional notation (as we use now) and the invention of zero.Both systems are useful. Sound familiar?Why is a Dekatron not digital, even though it contains no binary representation?In tggzzz' example, the Dekatron was actually in the heart of the computer, not merely a display such as a Nixie tube.It certainly is not analog, like a sliderule.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 12:49:01 am
content: Quote from: tggzzz on October 24, 2023, 12:28:45 amIt is called digital-to-analog converter because it converts digital signals to analog signal.That is why it called digital-to-analog converter...Pretty simple to understand, isn't it?Quote from: tggzzz on October 24, 2023, 12:28:45 amPreviously I already stated for you that Digital != Binary. These words have different meaning.Binary is used to identify numbering system with base 2.Digital is used to identify digital circuit/system which uses signals with binary level, Boolean algebra, binary arithmetic and all other stuff known as "digital electronics" which is not analog and cannot handle analog signals.Quote from: tggzzz on October 24, 2023, 12:28:45 amI don't know what you're talking about and I never said what you're talking.0x1234 is just a number represented in hexadecimal representation and cannot be categorized neither as analog or neither as digital.Quote from: tggzzz on October 24, 2023, 12:28:45 amI don't know what is Harwell Dekatron, according to internet, this is usual digital computer which uses binary arithmetic as any other computer. So, I don't know what did you wanted to say with thatAt a glance you're just confusing information stored as digital data with digital data itself. You can store decimal or hexadecimal numbers in binary form, but it will be still information in binary format which stores some information about decimal number or something other.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 12:54:31 am
content: Quote from: radiolistener on October 23, 2023, 11:29:39 pmDekatrons. They are the decimal logic elements used to implement arithmetic in the Harwell Dekatron (WITCH) computer - the oldest operating computer in the world.See the references that I provided earlier, which show them performing arithmetic operations before printing results on a teletype.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 01:01:45 am
content: Quote from: radiolistener on October 24, 2023, 12:49:01 amFalse. It is implemented using decimal logic elements, not binary logic elements.See this earlier post, which you seem to have conveniently ignored...https://www.eevblog.com/forum/beginners/what-is-a-digital-system-is-it-only-binary-or-decimal-octal-as-well/msg5129826/#msg5129826Now you have no excuse for lack of knowledge.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 01:08:02 am
content: Quote from: tggzzz on October 24, 2023, 12:54:31 amok, just read about it, if I understand correctly it uses non binary signals for computation, is it right?If this is correct, then this Harwell Dekatron computer cannot be categorized as Digital. Technically you can name it as Decimal circuit, but such name is not common, so you can classify it as Analog circuit. But this is definitely not Digital circuit.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 01:19:16 am
content: Quote from: radiolistener on October 24, 2023, 01:08:02 amEverybody else knows the WITCH is a digital computer. You are the only person who has even thought of calling it an analogue computer.You are clearly channelling Humpty Dumpty, as per a previous post.

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2023, 01:24:06 am
content: Absolute nonsense:The Dekatron isnotan analog circuit.It is an electronic equivalent to counting on ones fingers, hence the term "digital"."Digit" comes from the Latin for finger.The normal Dekatron has 10 possible states, corresponding to 0,1,2,3,4,5,6,7,8, and 9, and can increment or decrement the state: hence its usefulness for computing.It has no valid states besides these 10, nor intermediate states along a continuum.Have you ever seen the two words "decimal" and "digit" adjacent to each other in mathematical discussion?

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 01:31:34 am
content: Quote from: TimFox on October 24, 2023, 01:24:06 amjust asked chat-gpt about this computer, and this is what he said:QuoteSo, this Harwell Dekatron (WITCH) is Digital circuit, because it uses binary signals.As I understand it uses BCD encoding to store numbers in his memory due to dekatron tube specific, but it doesn't affect Digital calssification, because it still uses binary signals and digital logic...You can store numbers in any kind of encoding in digital circuit. It doesn't matters if you store number "15" in memory as "00001111" or as "00010101". The main thing here is that you're using binary data which can be handled with digital circuit. So this kind of circuit is categorized as digital because it uses binary signals.The same thing for ternary computer "Сетунь". It was usual digital circuit with binary signals but it was used to emulate ternary logic.As I remember, "Сетунь" was used 2 binary signals for one ternary digit with the following encoding:00 = 001 = 110 = 211 = not used (not allowed state)

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2023, 03:36:06 am
content: You can't find anything better than chat-gpt fiction?The Dekatron is a state machine with 10 discrete states, associated with the digits 0 to 9.It isnota binary-coded decimal device.If you want a reasonable history of the development of digital systems, look way back in this thread to the recently-published book I cited about the development of pocket calculators.After discussions of ancient arithmetic, there are chapters about mechanical computation devices and later electro-mechanical devices, and even later electrical devices, many of which worked in base 10, or sometimes in other bases needed for computations in situations such as the old English monetary system of pounds, shillings, and pence.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 04:06:47 am
content: Quote from: TimFox on October 24, 2023, 03:36:06 amI don't know about Harwell Dekatron (WITCH) internals. And google don't help to reveal how it was build under the hood. So, I asked chat-gpt as big knowledge data base.If it provided wrong answer, then explain what is wrong?Quote from: TimFox on October 24, 2023, 03:36:06 amYou can encode any type of state machine with digital circuit which works with binary signals.You can store decimal values in a plain binary form, in BCD form, as temperature code, or whatever you want.You can even implement unstable state and noise with digital circuit.It all will be digital circuit which use binary signals.But we're talking about not digital circuit which uses non-binary signals.For example if signal can get 3 discrete values, you can implement it in different way:- emulate on digital circuit with using two binary signals to represent one ternary signal- use analog circuit which works directly with analog signal that represent one ternary signalBoth methos works, but first method uses digital circuit with binary signals and second method uses analog circuit with analog signals.The same you can emulate digital signal with analog one and emulate analog signal with digital one.The things you're talking about is just a choice of used encoding.You cannot determine category of circuit by meaning of variable in the program that running on that circuit.If you categorize circuit as digital just because it works with numbers, you will realize soon that such categorization is broken, because you can process number on both domains. Numbers can be processed on digital domain and on analog domain.For example, you can implement analog calcualtor which will perform sum calculation for numbers, but such analog calculator cannot be categorized as digital supposedly because it works with numbers or because it can display numbers in decimal or hexadecimal format.In order to categorize circuit as Analog or Digital, you're needs to see on signals type used by that circuit. If it uses binary signals you can categorize it as digital. If it uses non binary signals, then this is analog circuit.Quote from: TimFox on October 24, 2023, 03:36:06 amThe meaning of data processed by circuit doesn't matters for Analog/Digital circuit category. The data can be binary numbers, octal numbers, decimal numbers, hexadecimal numbers, alphabet letters, hieroglyphs, or other kind of symbols or color or whatever you want, it doesn't matter for Analog/Digital category, both category can process all these things.The device which works with numbers in base 10 can be implemented with digital circuit using binary signals.And the same, the device which works with numbers in base 10 can be implemented with analog circuit.The information that device works with numbers in base 10 saying nothing about Analog/Digital category of circuit which is used in this device. It can be analog or digital. The same thing for numbers with base 2, base 8, base 16, base 100500 or whatever you want base...This is just information processed by device and you cannot make conclusion how this information is processed inside device from type of that information...For example, you can emulate analog signals on PC and it will works with analog signals. But it doesn't means that PC is analog circuit...

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 04:46:01 am
content: Quote from: TimFox on October 24, 2023, 03:36:06 amit doesn't matters how many discrete states it have and which digits are associated with these states, or what kind of information are associated to these states.But as I can see on that picture:it is controlled with binary signals. Isn't it?And since it works with binary signals it can be categorized as digital...

author: Tation
author_rank: Regular Contributor
timestamp: October 24, 2023, 07:12:05 am
content: What I learned long time ago: digital = discrete-time AND quantized.Thus, digital signal = countable sequence of symbols from some countable alphabetBase 2 or any other base is irrelevant. Interestingly, the output of an ideal DAC, prior to the reconstruction-filter, is digital. Maybe it is because of this that such filter is called a reconstruction one, and not an smothing one.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 07:20:33 am
content: Quote from: radiolistener on October 24, 2023, 01:31:34 amYou seem not to be aware of the the LLM phenomenon of "hallucination"?

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 07:37:35 am
content: Quote from: Tation on October 24, 2023, 07:12:05 amQuantisation is the important point, since the "forbidden zone" between the individual symbols allows the digital signal to be losslessly regenerated by a receiver.It doesn't have to be discrete-time; asynchronous logic doesn't have a clock.Most digital circuits are clocked, since analysing larger asynchronous circuits rapidly becomes intractable. You have to consider all state-space transitions that might occur when more than one input changes at the same time.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 08:04:04 am
content: Quote from: tggzzz on October 24, 2023, 07:20:33 amI know, but I don't see any indication that what it said is false.I added picture above from wiki with example of dekatron cyclogram and it shows that it is controlled with binary signals. Isn't it?Correct me if I'm wrong, but dekatron can be replaced with74HC4017. Isn't it?So there is no any magic and no non binary signals, dekatron is classic digital counter with binary signals...

author: Nusa
author_rank: Super Contributor
timestamp: October 24, 2023, 08:15:20 am
content: While I've a large professional background in software and a lengthy amateur hobby in electronics, I'll skip all that and go for a simple proof.Analog clock = round thing with hands most of us are familiar with.Digital clock = Box with a decimal digit display of some type that most of us are also familiar with.Binary clock = Box with a bit-based display of some type that is more of a novelty item for professionals, but does exist.Note that the words "binary" and "digital" clearly are not the same here.One example is sufficient to disprove the claim that binary and digital are aways synonyms.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 08:21:06 am
content: Quote from: radiolistener on October 24, 2023, 08:04:04 amYour lack of understanding won't surprise any of the other contributors to this thread.Not being able to recognise when an LLM is hallucinating is becoming a serious problem for society; one lawyer in the US is in trouble because he tried to argue his client's case based on case law that turned out to have been invented by a hallucinating LLM.Apart from that, it is quite amusing to review your posts in this thread. Theevolutionof your statements about digital/analogue/binary/hex/analogue/etc reminds me never to forget that "there is no such thing as a true Scotsman".

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 08:30:49 am
content: Quote from: tggzzz on October 24, 2023, 08:21:06 amListen, I know about chat-gpt issues very well and I don't blind believe to all what he said. On the contrary I think that chat-gpt is very stupid, but it has good database and often provides good finding.And in this case what he said looks pretty precise. Isn't it?I read more about dekatron and it seems that this is just a tube version of classic digital counter which works with binary signals.And it seems that you can replace dekatron tubes with some small modern circuit like74HC4017and a couple of LED's. Isn't it?So, I don't see that chat-gpt was wrong when he said that Harwell Dekatron (WITCH) works with binary signals with discrete 1 and 0.And I don't see here any usage for signal with 10 discrete levels. Dekatron don't use it. It uses classic binary signals. This is classic digital circuit.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 08:42:46 am
content: Quote from: tggzzz on October 24, 2023, 08:21:06 amWhat kind of evolution do you mean? My statement is always was that digital is circuit that uses binary signals and analog is all signals which is not digital. This is pretty simple and there is no change in my statement. Just explanation of this simple thing with a lot of examples and details.Explanation for binary/hex format was provided for you. Just because you're confuse information about something (number or something else) encoded in digital data with digital data itself.this is yours statement has constantly evolution, you're trying to find different examples to name non binary signal as digital, but I show you examples again and again that your classification is broken and don't works. Isn't it?For example you said that dekatron uses decimal signals and is named as digital, but it appears that this is false claim and dekatron is classic digital counter with binary signals...What will be your next example?Seriously, it's funny to see how you're trying to refute simple and clear things.Here was a funny example of your attempt to classify number as analog or digital thing...Quote from: tggzzz on October 24, 2023, 12:28:45 amIt also clearly shows that you are trying to manipulate by attributing to me statements that I have never made.Just for your information, number is a number, you cannot classify number as digital or analog.And it don't depends in which format you wrote that number bin/dec/hex or something else. Category digital or analog can be applied to implementation of storage which stores or transfers information about that number, but not to a number itself.Signal or circuit can be digital or analog.Number cannot be digital or analog.

author: golden_labels
author_rank: Super Contributor
timestamp: October 24, 2023, 09:09:32 am
content: My cup of popcorn is almost empty. Perhaps it’s time to stop? Any attempt to discuss the topic only gives them an excuse to post more sophisms and increase the volume of incorrect information in the thread. A random reader is more likely to find their post instead of anything of value posted earlier and it gets even worse with each response.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 09:32:43 am
content: Quote from: golden_labels on October 24, 2023, 09:09:32 amI quite agree.I thought of posting a list of some of radiolistener's more entertaining statements, but decided life is too short and it would serve no useful purpose (Humpty Dumpty, Scotsman).I hope and expect that if anybody blunders into this thread in the future, they will see the balance between radiolistener and other posters.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 09:42:03 am
content: Quote from: radiolistener on October 24, 2023, 08:30:49 amA digital signal does not have to be encoded in discrete levels. Obvious alternative encodings are frequency (FSK), phase (PSK).In the case of dekatrons, angle is used. Uniquely for an electronic device you canliterally seeeach of the ten states encoded as a different discrete/quantised angle.Here are my dekatrons showing the number 13 encoded in angles...And here's another angle encoding (of the number 28), in an electromechanical device mounted next to those dekatrons...And here's an example of a "digitally controlled" mechanical device that encodes digital numbers as angles...

author: wasedadoc
author_rank: Super Contributor
timestamp: October 24, 2023, 10:11:59 am
content: Quote from: radiolistener on October 24, 2023, 08:04:04 amYou are wrong because you totally missed the point. You can emulate the function of the dekatron with a 4 stage binary counter plus some gates to make it loop every 10 cycles but the internal workings are completely different. The operation of the dekatron is more like the mechanical odometer in a car. Each wheel, with the markings 0 to 9 on it rim, rotating one position when nudged by the wheel to its right moving from 9 to 0. No binary/boolean anything involved.Claiming that the dekatron based computer was binary becasue you can replace the dekatron by a 74HC107 is the equivalent of saying that since you can replace the internal combustion engine in a car by electric motor(s), then the internal combustion engine is an electrical engine.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 10:19:52 am
content: Quote from: golden_labels on October 24, 2023, 09:09:32 amyes, tggzzz often posting a lot of sophisms and constantly uses dishonest methods of discussion, such as turning the discussion to personalities and trying to attribute to me something that I did not say and even rejected. But I just ignore it. I am interested in the reasons for his delusions. Moreover, as it turned out, such misconceptions are not only found among him.As you can see topic starter also have the same misconceptions he confuse digital/analog system category with base of number system. Which is different things. And as you can see even more serious users here have confusion in this question. From my point of view these things are pretty clear, so I even don't understand why such misconceptions happens at all. And this is interesting to find the reasons for these misconceptions.I suppose that the main point of misconception is that many peoples are confusing signals in electronic circuit with information which is carried by this signal. So, when they hear that signal carries information about decimal number, they are think that this signal has 10 discrete levels. This is incorrect.In digital circuit information about numbers is encoded as a set of binary signals. The encoding method can be different, for example usual binary form, or BCD, orthermometer code, or something else.It's important to note here that number system base (binary, decimal, hexadecimal) don't matters here. It will have sense when you want to display that number to the user. In order to display it, you're needs to format it according to a number system base expected by user. But this is separate task for displaying and it don't affect the way how this number is stored and transferred in the system.For example, the number is stored and transferred in the system in binary form, but when it needs to be displayed for a user it can be formatted in binary or decimal or hexadecimal format depends on user preference.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 10:36:59 am
content: Quote from: wasedadoc on October 24, 2023, 10:11:59 amNicely put, and an valid analogy that ought to be enlightening.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 24, 2023, 10:38:04 am
content: i love to see threads derailing loll

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 10:39:51 am
content: Quote from: wasedadoc on October 24, 2023, 10:11:59 amyes, this is exactly the same what you get if you replace dekatron with 74HC4017 and a ten LED's placed in a circle loop.And this is what I mean when asked if this is correct that you can replace dekatron with digital counter like 74HC4017.So, I don't understand why you're talking that I was "wrong and totally missed the point"Quote from: wasedadoc on October 24, 2023, 10:11:59 amControl signals for dekatron and dekatron outputs are binary signals (signals that has two discrete level 1 or 0). The same as for 74HC4017, isn't it?Quote from: wasedadoc on October 24, 2023, 10:11:59 amI talked about 74HC4017, not about 74HC107.I claimed that dekatron based computer is digital, because it uses binary signals (signal which has two discrete level 1 and 0). And as I see this it thuth isn't it?I don't understand your analogy with combustion/electric motor. It don't have sense here and looks like non relevant at all.Dekatron based computer uses the same digital signals as 74HC4017, difference is just voltage level (which can be fixed with level shifter if you want to replace dekatron with 74HC4017), but both using the same signals with two discrete value 1 and 0. Isn't it?As you can see, original claim of tggzzz, that dekatron computer uses decimal signals (signals with 10 discrete levels) is completely invalid.Dekatron computer uses binary signals and this is the reason why it can be classified as digital circuit.So, dekatron computer cannot be example of digital circuit which works with decimal signals (signal with 10 discrete levels) as it was mentioned by tggzzz, because this is digital circuit which works with binary signalsI’ll just remind you that the dispute about dekatron computer flared up when tggzzz mentioned it as example of digital circuit which works with non binary signals (signal which has more than 2 discrete level).

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 10:52:35 am
content: Quote from: radiolistener on October 24, 2023, 10:39:51 amNo, the dekatron is decimal, with discrete values encoded as around roughly 0degrees, 36degrees, 72degrees, 108degrees etc.The rest of your response is merely wryly amusing.

author: wasedadoc
author_rank: Super Contributor
timestamp: October 24, 2023, 10:59:39 am
content: Quote from: radiolistener on October 24, 2023, 10:39:51 amAgain you totally missed the point.The dekatron based computer does its calculations and stores the numbers using one of the 10 possible positions of the discharge in a dekatron. No binary counters. Decimal and digital.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 11:01:06 am
content: Quote from: tggzzz on October 24, 2023, 10:52:35 amomg74HC4017 with ten LED's placed in circle also "is decimal, with discrete values rencoded as around roughly 0degrees, 36degrees, 72degrees, 108degrees etc."Decimal here is just a conditional meaning of information displayed by LED's, but circuit works with binary signals and classified as digital.

author: wasedadoc
author_rank: Super Contributor
timestamp: October 24, 2023, 11:05:33 am
content: Mother watching the passing out parade at the military academy turns to the woman beside her and says "They are all marching out of step except my son".

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 11:07:22 am
content: Quote from: radiolistener on October 24, 2023, 10:39:51 amWrong attribution, control signals do not define whether or not a device is digital or analogue, and angle is used to encode the data (not a level).

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 11:08:41 am
content: Quote from: wasedadoc on October 24, 2023, 11:05:33 amTouché, againI've taken the liberty of emphasising your point.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 11:12:26 am
content: Quote from: radiolistener on October 24, 2023, 11:01:06 amA 4017 is not a dekatron, oddly enough. Neither is an electric motor an internal combustion engine.We realise that you cannot understand wasedadoc's analogy and its relevance.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 11:16:11 am
content: Quote from: wasedadoc on October 24, 2023, 10:59:39 amThe same thing can be done with classic digital decimal counter or with binary counter and circuit with reset the counter when it count from 9 to 10.But you're missed the main point. The point here is that it uses binary signals, that is, a signal that has two discrete levels 0 and 1. This is classic digital circuit which uses binary signals.It don't use "decimal signal" with 10 discrete levels: 0,1,2,3,4,5,6,7,8,9.But tggzzz mentioned dekatron as an example of digital device which uses such decimal signal with 10 discrete levels: 0,1,2,3,4,5,6,7,8,9. Which is incorrect.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 11:32:34 am
content: Quote from: tggzzz on October 24, 2023, 11:07:22 amThe angle is just a conditional format for displaying a number and don't affect system categorization. You can display data in any format it doesn't matter. For example you can show angle on digital display or on analog voltmeter. The format of data displayed to the user doesn't matters. The main point here is how data is stored and transferred in the system.The number itself is stored as 10 binary signals here, each signal can have two possible value: on and off (1 and 0). And it is controlled with binary signals. All signals are binary (digital signal, logic signal to be clear). And this is why such system can be categorized as digital.This is what I'm talking about from beginning. The digital circuit uses binary signals, if circuit uses non binary signal (signal that has more than 2 discrete levels), then this is not digital system, but analog one.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 11:54:57 am
content: Quote from: wasedadoc on October 24, 2023, 11:05:33 amIf several people have a common misconception, this does not make their opinion correct.If you want to get correct opinion you're needs to analyze facts and don't count the number of peoples with some opinion.The crowd is always stupid and always making wrong decision. This has been confirmed by many centuries of history.It can be easily be proven, since smart peoples are rare and stupid people are frequent. So the crowd in average is stupid...And such knowledge can be utilized, if your opinion is the same as crowds opinion, there is a sense to check your opinion more precisely, because this is a strong indication that your opinion is possible incorrect...

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 12:26:42 pm
content: Quote from: tggzzz on October 24, 2023, 11:12:26 amif your mind is unable to detect similarity between dekatron and digital counter, then I understand why you're think that wasedadoc's analogy is relevant.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 12:47:21 pm
content: Regarding to the question if signal is digital or not, there is a simple and easy sanity check.If you're thinking that some signal is digital, just check if you can process it with some digital GPIO input with no loss. If this is not possible, then signal is not digital but analog.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 01:10:45 pm
content: Quote from: radiolistener on October 24, 2023, 12:26:42 pmThe dekatronisa digital counter.If you are unable to detect the difference between a dekatron and a binary counter, then...

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2023, 02:01:13 pm
content: The Dekatron is not merely a display device (such as the Nixie tube), but each of the ten digital discrete states has an electrical output.

author: madires
author_rank: Super Contributor
timestamp: October 24, 2023, 02:53:53 pm
content: Quote from: oslon on October 19, 2023, 01:31:03 amIn this case it's a math related question, not electronics. What the author of the PDF means by 'digital system' is the representation of numbers in the form of a row of digits (numerals). The number system doesn't matter at all. It's only about the way of writing (and reading) a number.In electronics the term 'digital system' means something completely different, i.e. a circuit/device which uses non-continuous signal levels. Many associate that with binary states (0 and 1, or low and high), but it can also involve more states/levels, e.g. tri-state (low, high and HiZ).

author: wasedadoc
author_rank: Super Contributor
timestamp: October 24, 2023, 03:16:01 pm
content: It is easy to demonstrate that a dekatron is not a binary device and does not use binary counting.In the 74HC4017 there are circuit elements which are in one state when the count is 0 or 2 or 4 or 6 or 8 and in a different state when the count is 1 or 3 or 5 or 7 or 9.There are other circuit elements which are in one state when the count is 0 or 1 or 4 or 5 or 8 or 9 and in a different state when the count is 2 or 3 or 6 or 7.There are other circuit elements which are in one state when the count is 0 or 1 or 2 or 3 or 8 or 9 and in a different state when the count is 4 or 5 or 6 or 7.There are other circuit elements which are in one state when the count is 0 or 1 or 2 or 3 or 4 or 5 or 6 or 7 and in a different state when the count is 8 or 9.But in the dekatron there are 10 circuit elements. Each one of them is in one state for 9 of the 10 counts. Each one of them is only in its other state for 1 of the 10 counts. For example one part of the dekatron is in one state (not glowing) when the count is 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 and in another state (glowing) when the count is 0. Another part is one state when the count is 0 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 and in another state when the count is 1. Etc.The dekatron counts by moving the glow from one to the next. Similar to the odometer turning a wheel by 36 degrees. The dekatron is not just an indicating device. It does not indicate the state of 4 groups of circuit elements. There are no 4 groups in it or in its support circuitry.

author: khs
author_rank: Regular Contributor
timestamp: October 24, 2023, 03:42:55 pm
content: Quote from: radiolistener on October 24, 2023, 12:47:21 pmOK, let's make a simple test.I use a GPIO pin from an Adruino and connect it to an input of a MC660LMC660L is a MHTL device with 15 V logic. Max low voltage of a MC660L is 6.5 V.Hi level from the Adruino (5V) will not work. So the GPIO output of the Adruino is not a digital signal.If I connect the output of the MC660L to the Adruino, the Adruino is no longer a digital device.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 04:16:02 pm
content: Quote from: tggzzz on October 24, 2023, 01:10:45 pmCan you please show me, where I said that dekatron is binary counter?I said that dekatron works with binary signals.Do you understand difference between binary signal and binary counter?

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2023, 04:17:23 pm
content: For readers interested in the history of calculators and computing, including mechanical, electromechanical, and electronic, once again I recommend a recent book:K Houston,Empire of the Sum: The rise and reign of the pocket calculator, Norton 2023.Especially, see chapters 4-6 about digital mechanical devices, which typically were decimal rather than binary in construction and interface.Later chapters concentrate on electronic devices, including an important British product, the Amita, which used a combination of a Dekatron, thyratrons, and Nixie tubes in a package reminiscent of the electromechanical comptometers that preceded it.The book does not cover mainframes, etc., but concentrates on calculators.For the history of digital representation of numbers, the standard reference is U C Merzbach and C B Boyer,A History of Mathematics, 3rd ed, Wiley 2011.Both books are free of claptrap.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 04:27:23 pm
content: Quote from: TimFox on October 24, 2023, 02:01:13 pmyes, this is what I'm talking about, and all of these outputs are binary signals they output unitary code representing decimal value.The same as 74HC4017...I don't see here decimal signal with 10 discrete levels. All signals are binary.

author: radiolistener
author_rank: Super Contributor
timestamp: October 24, 2023, 04:32:47 pm
content: Quote from: khs on October 24, 2023, 03:42:55 pmNo. If you read careful what I wrote before, digital signals have different logic level standard. If you want to connect digital signal from one circuit to another, you're needs to make sure that they have the same logic level standard. If they have different standard (as in your case) you're needs to use level shifter to convert from one standard to another. But if it uses 2 discrete levels, it is digital.For analog signal you cannot convert level standard, because it uses more than 2 discrete levels and incompatible with digital signals.

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2023, 04:40:20 pm
content: More recent history: Japan has a long tradition of using the "soroban" abacus for arithmetic.The usual format has one bead above the bar and four below it to represent the decimal digits (a phrase that seems to annoy some people) 0 to 9.When I first visited Japan in 1982, it was common when paying at a small vendor's shop to see him add up the tab (very quickly) on a (decimal) soroban mounted above the electrical cash register (another decimal computation object), then enter the soroban's result into the cash register to keep the daily tally.There was a famous competition in 1946, sponsored byStars and Stripesduring the American occupation, between a virtuoso soroban user from the Japanese Post Office and an expert from MacArthur's accounting department on an electrical calculator.Addition, subtraction, and division were won by the Japanese competitor, while the American won multiplication.Since 1980 or so, Japanese education in soroban use has diminished.One of my Japanese colleagues remembered that he was taught how to extract a square root on a soroban in elementary school, but admitted that he had forgotten the algorithm since then.The National Cash Register Co. (Now, NCR inc) patented the wheel-inside-a-wheel method of non-binary decimal digital computation before 1900, and kept that as their logo for years.https://americanhistory.si.edu/collections/search/object/nmah_694235

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 04:54:05 pm
content: Quote from: TimFox on October 24, 2023, 04:40:20 pmHere's a video showing how to calculate square roots on a western digital decimal calculator. The section on square roots starts at 20:00 and is a little, shall we say, tedious.

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2023, 04:57:24 pm
content: I once used a motor-driven high-end electromechanical calculator for the same purpose: it was fun to watch.In 1970, there was a room next to my undergraduate physics labs with calculators for student use: it contained fully electronic units from Wang, along with electromechanical devices from Friden.It was updated shortly thereafter.Life is more interesting when one removes ones blinders.

author: xrunner
author_rank: Super Contributor
timestamp: October 24, 2023, 05:07:28 pm
content: The OP hasn't chimed in, looks like they're long gone. Probably gave up and went to ChatGPT for the answer.

author: IanB
author_rank: Super Contributor
timestamp: October 24, 2023, 05:14:55 pm
content: Quote from: radiolistener on October 24, 2023, 11:32:34 amNonsense! In early computers, people experimented with tri-state logic, and these were still digital computers.The word "digital" comes by analogy with fingers, which are digits. When you count on your fingers you have distinct, integer values (1, 2, 3, etc.).I think a lot of confusion arises because the title of the thread contains a misunderstanding.The two domains are discrete and continuous. The continuous domain is synonymous with the analog domain.The discrete domain is characterized by values having fixed values with intervals between them. The design calculations involve Boolean or integer mathematics, or branches thereof, such as Z-transforms. An electronic digital computer is a special case of a discrete logic system.The continuous domain is characterized by values being continuously variable, with no fixed values. The design calculations involve the reals and related branches of mathematics such as Fourier transforms.

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 05:16:07 pm
content: Quote from: TimFox on October 24, 2023, 04:57:24 pmMy father used one in the 60s, later upgrading it to a something the size and weight of 2 bricks with 7-segment panaplex displays, followed by an HP85. He tended to dislike computers, because he saw too many people number crunching without having a feel for the physics. But in theearly80s he did assess how a PWR might react after a catastrophic failure, by comparing it to how water flows out of a bathtub.I started on slide rule, then Sinclair Scientific, then an HP35 bolted to a desk in the university library. I still have the slide rule and (working) Sinclair Scientific, and have acquired a (working) HP35 and two (gulp) slide rules with 50ft long scales. The latter were in production for 94 years, and unsurprisingly continue to work.QuotePrecisely. Hence my .sig

author: tggzzz
author_rank: Super Contributor
timestamp: October 24, 2023, 05:19:25 pm
content: Quote from: IanB on October 24, 2023, 05:14:55 pmPrepare to flatten your forehead

author: Tation
author_rank: Regular Contributor
timestamp: October 24, 2023, 05:21:21 pm
content: Ternary digital computer:https://link.springer.com/content/pdf/10.1007/978-3-642-22816-2_10.pdf(yes, they call it a «ternary digital computer»)Donald Knuth also discusses the ternary system on vol. 2 of The Art of Computer Programming (in my 3rd ed., it is on pages 207-208).

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2023, 05:23:18 pm
content: Quote from: IanB on October 24, 2023, 05:14:55 pmIn early mathematics (e.g., Pythagoras and Euclid), these two domains were treated as geometry (continuous domain) and arithmetic (discrete domain).Advances were made in Egypt, Mesopotamia, Greece, India, China, and Arabia before Europe took up mathematics seriously.

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2023, 05:25:38 pm
content: Quote from: Tation on October 24, 2023, 05:21:21 pmFrom the Tation link:"The common binary code used in modern computers has the digit set {0, 1}.Binary code does not contain arithmetical full value, as it is impossible to representthe negative numbers in it. However, a ternary code with a digit set {–1, 0, 1}provides optimal arithmetical values for numbers formation. Therefore, we not onlyan artificial and imperfect complement code of numbers, but we also obtainconsiderable arithmetical advantages. These include a uniform number code, avariable length of operands, a singular shift operation, a tri-value of a function’s “signof a number”, an optimal rounding by simply cutting off lower digits, and acompensation of errors rounding in the process of calculating."Note the discussion of two different digit sets (binary and ternary) in a digital system.

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2023, 06:37:28 pm
content: Quote from: radiolistener on October 24, 2023, 04:27:23 pmThe Dekatron has ten discrete digital states, transitions between them do not involve binary representations in the internal function.With the 74LS4017 and its kin, the internal function does depend on binary representations.Equivalent results do not imply identical internal function.Consider a stepper motor driving a gear set to a pointer that shows discrete steps (not continuous), as in a modern quartz watch: no binary bits are involved in the incrementing of the pointer as it jerks along.There are more objects in heaven and earth than are dreamt of in your binary arithmetic.

author: tooki
author_rank: Super Contributor
timestamp: October 25, 2023, 06:49:30 am
content: Quote from: radiolistener on October 23, 2023, 08:26:10 amIt’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 digitallogic.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.

author: golden_labels
author_rank: Super Contributor
timestamp: October 25, 2023, 07:24:58 am
content: Quote from: coromonadalix on October 24, 2023, 10:38:04 amThe worst part is that now this garbage spams my “new replies” list. And there is no way to “unsubscribe”, other than bothering moderators to remove my own posts from the thread. :/

author: tggzzz
author_rank: Super Contributor
timestamp: October 25, 2023, 08:01:45 am
content: Quote from: golden_labels on October 25, 2023, 07:24:58 amActually, there isLook at the far right column of your unread replies list. To un-ignore, your profile -> modify profile -> ignore topics options.IMHO it would be more useful to have an "ignore any topic started by user X", e.g. the user that has had three profiles here and whose name begins with f

author: Tation
author_rank: Regular Contributor
timestamp: October 25, 2023, 09:13:05 am
content: Examples of ternary logics (comparison against Boolean logic is left as an exercise to the student):Kleene's logic:https://www.logic.at/multlog/kleene.pdfPriest's logic:https://www.logic.at/multlog/paradox.pdfAn a many-valued (also infinite-valued) logic, the Łukasiewicz-Tarski logic:https://en.m.wikipedia.org/wiki/%C5%81ukasiewicz_logicSorry, not easy reads...

author: radiolistener
author_rank: Super Contributor
timestamp: October 25, 2023, 09:42:26 am
content: Quote from: tggzzz on October 24, 2023, 04:54:05 pmit is not digital. You're confusing decimal with digital...

author: radiolistener
author_rank: Super Contributor
timestamp: October 25, 2023, 09:49:34 am
content: Quote from: TimFox on October 24, 2023, 06:37:28 pmsince it don't expose it on public interface, internal implementation doesn't matters here, the main point here is that both using the same binary signals for output decimal digit in one-hot encoding. And both have 10 states.

author: radiolistener
author_rank: Super Contributor
timestamp: October 25, 2023, 10:03:12 am
content: Quote from: IanB on October 24, 2023, 05:14:55 pmtri-state is usual binary signal which has third state which means that signal is missing or undefined. But third state don't have third voltage level, it still uses 2 discrete level 0 and 1, but it also can be switched to third state where signal output is disabled.Probably you wanted to say "experimented withternarylogic, and these were still digital computers."Yes, this is true, there was experimental computers with ternary logic. And yes, these ternary computers were digital.But they were digital not because ternary signals are digital, but because they actually was implemented as usual digital circuit with usual binary signals.They emulated ternary logic on digital circuit by using two binary signals to emulate one ternary signal. It was done with the following encoding:digital binary signals = ternary signal00 = 001 = 110 = 211 = not used state (not allowed).

author: radiolistener
author_rank: Super Contributor
timestamp: October 25, 2023, 10:21:14 am
content: Quote from: tooki on October 25, 2023, 06:49:30 amNo, this is not opinion, this is just a knowledge of QAM signal and their properties...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.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.

author: tggzzz
author_rank: Super Contributor
timestamp: October 25, 2023, 10:29:20 am
content: Quote from: radiolistener on October 25, 2023, 09:42:26 amThat makes it unambiguous that you are trolling.

author: radiolistener
author_rank: Super Contributor
timestamp: October 25, 2023, 10:35:02 am
content: Quote from: tggzzz on October 25, 2023, 10:29:20 amThe only troll here is people who posting mechanical calculator and talking that this is an example of digital system.

author: tggzzz
author_rank: Super Contributor
timestamp: October 25, 2023, 10:41:27 am
content: Quote from: radiolistener on October 25, 2023, 09:49:34 amYou 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.Quote from: radiolistener on October 24, 2023, 08:04:04 amQuote from: radiolistener on October 24, 2023, 11:01:06 am

author: tggzzz
author_rank: Super Contributor
timestamp: October 25, 2023, 10:42:53 am
content: Quote from: radiolistener on October 25, 2023, 10:35:02 amSome mechanical calculators are analogue. The example in the video is clearly digital, not analogue.

author: radiolistener
author_rank: Super Contributor
timestamp: October 25, 2023, 10:50:16 am
content: Quote from: tggzzz on October 25, 2023, 10:41:27 amThere 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.

author: TimFox
author_rank: Super Contributor
timestamp: October 25, 2023, 01:36:50 pm
content: Quote from: radiolistener on October 25, 2023, 10:35:02 amThe 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.

author: xrunner
author_rank: Super Contributor
timestamp: October 25, 2023, 02:14:54 pm
content: I gotta find my college textbook for digital systems. Maybe he needs the authority of the printed word - I mean printed onpaper. 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 ***

author: eplpwr
author_rank: Regular Contributor
timestamp: October 25, 2023, 02:47:44 pm
content: I guess many people uses SSD:s for storage. Consumer SSD:s uses MLC, see:https://en.wikipedia.org/wiki/Multi-level_cellIMHO an SSD disk is adigitaldevice, 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

author: Tation
author_rank: Regular Contributor
timestamp: October 25, 2023, 03:07:29 pm
content: From Mano, M., & Ciletti, M. D. (2012). Digital Design. Pearson.Quote

author: tggzzz
author_rank: Super Contributor
timestamp: October 25, 2023, 06:01:20 pm
content: Quote from: eplpwr on October 25, 2023, 02:47:44 pmNot just your opinion!Anybody that understands the fundamental distinctions between a digital system and an analogue system will come to that conclusion too.

author: Zero999
author_rank: Super Contributor
timestamp: October 25, 2023, 07:23:31 pm
content: Quote from: tooki on October 25, 2023, 06:49:30 amI 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.

author: wasedadoc
author_rank: Super Contributor
timestamp: October 25, 2023, 07:33:12 pm
content: Quote from: Zero999 on October 25, 2023, 07:23:31 pmThere was a forerunner to this "only binary is digital" nonsense six months ago. See reply #34 and following athttps://www.eevblog.com/forum/beginners/ethernet-bit-rate/msg4821791/#msg4821791

author: Zero999
author_rank: Super Contributor
timestamp: October 25, 2023, 07:36:32 pm
content: Quote from: radiolistener on October 25, 2023, 10:50:16 amI 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!

author: tooki
author_rank: Super Contributor
timestamp: October 25, 2023, 07:45:53 pm
content: Quote from: radiolistener on October 25, 2023, 10:21:14 amIt absolutely is an opinion. You’re shining proof of this.Quote from: radiolistener on October 25, 2023, 10:21:14 amLMAO. 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.)Quote from: radiolistener on October 25, 2023, 10:21:14 amThat’s literally the point: we have told you repeatedly that being a digitalsignalis a matter of how the signal isinterpreted, 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 itsinterpretedvalues 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.

author: golden_labels
author_rank: Super Contributor
timestamp: October 25, 2023, 07:55:59 pm
content: Quote from: tggzzz on October 25, 2023, 08:01:45 amI do. I do not see any option like this. Even if I run the app.

author: tggzzz
author_rank: Super Contributor
timestamp: October 25, 2023, 08:03:24 pm
content: Quote from: wasedadoc on October 25, 2023, 07:33:12 pmAh. 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.

author: tooki
author_rank: Super Contributor
timestamp: October 25, 2023, 08:16:17 pm
content: Quote from: golden_labels on October 25, 2023, 07:55:59 pmGo 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”.

author: tggzzz
author_rank: Super Contributor
timestamp: October 25, 2023, 08:19:30 pm
content: Quote from: golden_labels on October 25, 2023, 07:55:59 pmOh.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)

author: Manul
author_rank: Super Contributor
timestamp: October 25, 2023, 08:30:32 pm
content: 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.

author: BeBuLamar
author_rank: Super Contributor
timestamp: October 25, 2023, 09:22:37 pm
content: I can't think of any device that uses Hex and is not digital.

author: TimFox
author_rank: Super Contributor
timestamp: October 25, 2023, 10:04:42 pm
content: Quote from: Manul on October 25, 2023, 08:30:32 pmIn this context, deterministic would be synonymous with discrete.However, another meaning of the word "determinism" is that the present state determines the next state.

author: DimitriP
author_rank: Super Contributor
timestamp: October 25, 2023, 10:33:02 pm
content: 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 itonly binaryor 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.htmlCan we be done now before we hit #300 ?Thanks!

author: DimitriP
author_rank: Super Contributor
timestamp: October 25, 2023, 10:46:27 pm
content: ...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.

author: TimFox
author_rank: Super Contributor
timestamp: October 25, 2023, 10:47:48 pm
content: 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.

author: DimitriP
author_rank: Super Contributor
timestamp: October 25, 2023, 10:54:05 pm
content: Quote from: TimFox on October 25, 2023, 10:47:48 pmYou nailed it @ #4, I just can't understand why we have 8 more pages after that

author: golden_labels
author_rank: Super Contributor
timestamp: October 26, 2023, 12:34:08 am
content: Quote from: tooki on October 25, 2023, 08:16:17 pmOk, found, thanks. Ping: tggzzz.Quote from: DimitriP on October 25, 2023, 10:54:05 pmBecause a person busted into the thread with their ultimate truth, and it turned intoxkcd 386despite clear indicators it is a pointless effort.Considering abacus a computing devicein 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 theetymology of this term. But this thread’s topic restricts the meaning.

author: radiolistener
author_rank: Super Contributor
timestamp: October 26, 2023, 02:55:04 am
content: Quote from: TimFox on October 25, 2023, 01:36:50 pmYes, 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.

author: radiolistener
author_rank: Super Contributor
timestamp: October 26, 2023, 03:53:19 am
content: Quote from: Manul on October 25, 2023, 08:30:32 pmNo, 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".

author: Tation
author_rank: Regular Contributor
timestamp: October 26, 2023, 05:58:48 am
content: Quote from: Manul on October 25, 2023, 08:30:32 pmBut 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.

author: Manul
author_rank: Super Contributor
timestamp: October 26, 2023, 09:57:24 am
content: Quote from: Tation on October 26, 2023, 05:58:48 amYou are correct, it can be done. That is an interesting category where a digital circuit is intentionally pushed into analog domain. Instead of being insensitive to noise and having converging properties, it is made in such a way that noise is amplified and circuit diverges into uncertain state, a random bit. These random bits usually are not very random, they might correlate strongly with power supply ripple for example. But if these random bits have at least some true randomness in them, then multiple bits can be combined to produce random bits of higher quality. It's like "breeding" where "gene of randomness" is getting stronger every next generation until you get almost fully undeterministic pure random bits, aka true-random. I think bits are usually combined by XORing them. Some extra post processing might be present too. So yeah, the core circuit producing random bits can be seen as analog circuit combined with 1bit ADC and down the stream it's then all digital.

author: tggzzz
author_rank: Super Contributor
timestamp: October 26, 2023, 10:56:15 am
content: Quote from: Manul on October 26, 2023, 09:57:24 amDo not conflate "unpredictable" "or "statistical" with "analogue".Consider a radioactive atom decaying. The decay is a digital event (discrete time, discrete state), and the time at which it occurs is unpredictable. That does not mean it is "pushed into the analogue domain". Similar points can be made about a single photon arriving at a photodetector.Do not conflate "emergent behaviour" with "analogue".Consider a digital computer. It will exhibit apparently "random" and "irreversible" behaviour simply because it contains so many states that the output cannot be fully predictedunlessyou have a "magic"oracle. That does not somehow mean the digital computer has become an "analogue" computer.

author: radiolistener
author_rank: Super Contributor
timestamp: October 26, 2023, 02:59:15 pm
content: Quote from: tggzzz on October 26, 2023, 10:56:15 am

author: tooki
author_rank: Super Contributor
timestamp: October 26, 2023, 04:47:44 pm
content: Quote from: tggzzz on October 26, 2023, 10:56:15 amOK now that really is a stretch. Yes, it’s discrete, but it’s not information or logic, so it’s irrelevant to the discussion.

author: TimFox
author_rank: Super Contributor
timestamp: October 26, 2023, 04:52:33 pm
content: For binary digital systems, there can be errors due to the thermal noise in the system at finite temperature, which becomes important at high speeds and small voltage levels.For a non-handwaving discussion of this phenomenon, seehttps://core.ac.uk/download/pdf/56632959.pdfBasically, for a binary system sitting at a voltage level consistent with either state 0 or state 1, thermal noise could give an unwanted excursion to the other level, depending on how much time that excursion must last to give an error.

author: tggzzz
author_rank: Super Contributor
timestamp: October 26, 2023, 06:15:29 pm
content: Quote from: tooki on October 26, 2023, 04:47:44 pmThe radioactive decay is indeed a stretch in this thread.A single photon arriving at a detector is digital and does carry information. Example: photon counting OTDRs, which I first looked at >40 years ago when they were a laboratory curiosity. I would have tried to build one myself, but Peltier devices couldn't practically reach the necessary temperatures in field equipment.The emergent behaviour of a computer is obviously relevant in the context of the point made by Manul.

author: Zero999
author_rank: Super Contributor
timestamp: October 26, 2023, 06:40:18 pm
content: Well one could argue that all electronics are digital, since current is quantised as electron flow. . .Radioactive decay isn't really digital and neither is current flow, because the photons can be emitted at any point in time, which is in not discrete steps i.e. digital.Is PWM generated by an analogue circuit, such as a 555 timer digital? No, it's not, even though the output can either be high or low, the duty cycle is infinitely variable.

author: tggzzz
author_rank: Super Contributor
timestamp: October 26, 2023, 08:01:13 pm
content: Quote from: Zero999 on October 26, 2023, 06:40:18 pmFor femtoamp circuits that is accurate. For higher currents, it becomes continuous with a statistical component. Much like individual air molecules and air masses.One of the reasons that transistors can't shrink too much more is that the number of electrons and dopant atoms would become too few.QuoteDiscrete time is not a required characteristic of digital circuits: consider asynchronous logic. Large circuits are clocked because it is impractical to analyse and design the explosion of transient states in an asynchronous circuit.The sole required characteristic is that the relevant variable (voltage, current, phase, frequency, etc) has a finite set of discrete values. Practically there fill be forbidden gaps between the discrete states, but that is not strictly necessary.QuoteThe key point is how the analogue values are interpreted. Consider ASK, FSK and pulse density encoding. Summary: yes, repeat no.Besides, 555s contain a flip flop that drives the outputs.

author: TimFox
author_rank: Super Contributor
timestamp: October 26, 2023, 08:04:28 pm
content: Normal-size current through a metal conductor is a slight tendency of a multitude of electrons to move in one direction: shot noise is not important.Electron flow through a vacuum diode (or Zener diode) is one at a time hitting the anode, so "shot noise" statistical fluctuations are important.

author: Zero999
author_rank: Super Contributor
timestamp: October 26, 2023, 08:17:56 pm
content: Quote from: tggzzz on October 26, 2023, 08:01:13 pmThe current is only one variable. Time is another. Measuring a small current, over a small timescale might seemingly result in a digital output, but it's not really digital, but based on probability. The same is true of air molecules.QuoteAh yes, that's true of course, it doesn't need a clock.QuoteThe 555 has two comparators and uses an analogue circuit for the timing, so is very much analogue, even though the output is either high or low.

author: tggzzz
author_rank: Super Contributor
timestamp: October 26, 2023, 08:40:47 pm
content: Quote from: Zero999 on October 26, 2023, 08:17:56 pmBy one definition a 555 is analogue.By another definition it is mixed signal: analogue inputs and digital outputs.By another it is digital - in the same way that a 7414 is digital: an analogue input is interpreted by a Schmitt trigger or comparator, and defined to be either high or low. If you want to think in terms of a 7404, then that too has analogue inputs, and the decision is based on whether the analogue inputs are saturated. (Or ECL where there is no saturation, but it is based on whether one input(s) is higher than the other(s) ).Philosophy is fun, and it does (or ought to) lead to a deeper understanding of the significant differences and similarities.

author: radiolistener
author_rank: Super Contributor
timestamp: October 27, 2023, 01:39:26 pm
content: Quote from: tooki on October 25, 2023, 07:45:53 pmSorry, but your "by definition digital" signal is incompatible with digital electronics, because digital electronics uses classic digital signals which is binary only and is incompatible with your "by definition digital".So, your unique invention to use any analog signal which has some N discrete levels, where N>2, as digital is broken by definition...This is not what digital electronics expect for digital signal, it expects binary signals only.You can invent new reasons and come up with examples, but the fact remains a fact that pure digital electronics expects binary signals only.So, all your inventions and reasons to name analog signal with discrete levels as digital will be broken by design.You can cry, laugh, be angry, but you can't change this...

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2023, 01:54:45 pm
content: In logic, a proposition is equivalent to its contrapositive, but not its converse."If a system is binary, then it is digital" is equivalent to "If a system is not digital, then it is not binary."It is not equivalent to its converse: "If a system is digital, then it is binary."We are speaking here of definitions in technical English.Binary logic is the most common way to do things now with digital systems, but that does not imply that other digital non-binary systems do not exist.This is getting tiresome.[edit: corrected typo on second line for contrapositive statement]

author: radiolistener
author_rank: Super Contributor
timestamp: October 27, 2023, 02:17:15 pm
content: Quote from: TimFox on October 27, 2023, 01:54:45 pmWell, you can believe in a mythical digital system which uses non binary signals, but in reality such digital system doesn't exists.And you're needs to accept the fact that all non binary but discrete signals are treated as analog signals and converted through ADC/DAC in order to process it in digital circuit... That is how it doing in reality

author: madires
author_rank: Super Contributor
timestamp: October 27, 2023, 02:49:03 pm
content: So the tri-state ICs I have don't exist?

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2023, 03:53:25 pm
content: Quote from: radiolistener on October 27, 2023, 02:17:15 pmAs I write this, my left wrist has a standard quartz-type wristwatch, powered from an electrochemical cell.It contains a 32,768 Hz crystal oscillator, a binary count-down chain to produce a 1 Hz pulse train, and a digital electromechanical system with a stepper motor driving a gear chain.The result of the gear chain is a system without any binary content whatsoever, displayed using the ancient Mesopotamian sexagesimal system (withpars minuta primaandpars minuta secundaon separate mechanical dials).The discrete behavior is clearly visible: typical of a quartz watch, the second hand jumps in 1 second increments; my mechanical watch shows 1/4 second jumps.Please take off your blinders: binary is an important subset of digital, and there is no need for two such words if they were synonymous.You have ignored not only standard textbook definitions presented here, but practical examples of hardware that are digital but not binary, preaching the heresy that only binary counts.

author: IanB
author_rank: Super Contributor
timestamp: October 27, 2023, 04:06:50 pm
content: Quote from: TimFox on October 27, 2023, 01:54:45 pmYou have a mistake in your wording here. The correct statement would be this:"If a system is binary, then it is digital" is equivalent to "If a system is not digital, then it is not binary."

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2023, 04:11:11 pm
content: Oops--I have corrected that typo on my reply above, entered before coffee.

author: radiolistener
author_rank: Super Contributor
timestamp: October 27, 2023, 04:58:01 pm
content: Quote from: madires on October 27, 2023, 02:49:03 pmtri-state signal is binary signal, so this is classic digital.Third state is not signal value, it just means missing signal (disabled output). It is useful to combine several devices on the same digital bus, so you can select which device put it's output on the bus. But the signal still has two discrete levels 0 and 1.

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2023, 05:10:15 pm
content: Yes, tri-state is a hardware feature used in binary systems.However, "ternary" is a non-binary digital system using three distinct states.An early thesis (1967) describing ternary digital systems: Google "Hu Sung ternary thesis"(The redactions are signatures on the submitted thesis form.)The author makes use of PNP and NPN BJTs in some of his circuits, using a ternary system with -V, 0, and +V on each line.[edit: sorry, I can't make a citeable link for the Hu Sung thesis.]From the introduction to the thesis:"The ternary digital system is one possible form of digital system. Although binary switching theory hasbeen used in almost every digital system developed so far, this is mainly due to the fact that basic switchingelements in common use are two-state devices and that design techniques for the binary system arewell-developed. However, it is useful to broaden the study of two-leveled logical systems to that of three-leveledsystems."

author: madires
author_rank: Super Contributor
timestamp: October 27, 2023, 05:49:26 pm
content: Quote from: radiolistener on October 27, 2023, 04:58:01 pmSome of those ICs have a tri-state input and all three states are equally important.

author: radiolistener
author_rank: Super Contributor
timestamp: October 27, 2023, 06:05:37 pm
content: Quote from: madires on October 27, 2023, 05:49:26 pmbut input has just two discrete level 0 and 1. Third state just disables output to allow other components to use the same singal. Pull up or pull down modes are used to setup default value when signal is missing. But signal is still binary and can be 0 or 1.

author: madires
author_rank: Super Contributor
timestamp: October 27, 2023, 06:39:28 pm
content: Again, the inputs are tri-state, not binary. There's no 'enable/disable output' pin. And the third state (HiZ) doesn't disable any output.

author: tooki
author_rank: Super Contributor
timestamp: October 27, 2023, 08:25:06 pm
content: Quote from: radiolistener on October 27, 2023, 01:39:26 pmIt’s only incompatible with YOUR excessively rigid definition. It’s not incompatible with theactualdefinition.We’ve given you numerous examples of non-binary digital signals, systems, and real-world products that employ them.You’re just either too stubborn or too stupid to recognize why digital ≠ binary.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: October 27, 2023, 09:26:25 pm
content: To me Tri-state either means true, false and don't care, or, there are two stable states ofsomethingplus a transitioning metastable state inbetween. Think heads, tails and the edge of the coin. The high Z state on buses is really just a parking brake applied to a GPIO line to keep the noise floor from making up its own states.However, when you enter the world ofquantum qubits, alltri statesbecome a stable state* Although qubits might just be worked as zeros and ones

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2023, 09:40:34 pm
content: You can make a truth table for a logic gate that works with tri-state gates, but you have to have three outcomes, just as a normal binary gate has two outcomes.

author: Zero999
author_rank: Super Contributor
timestamp: October 27, 2023, 10:04:39 pm
content: Tri-state output can be used to get three logic levels. The programmable instrumentation amplifiers, ISL28533, ISL28534, ISL28535, ISL28633, ISL28634 and ISL28635, use two pins to select between 9 different gains, with a microcontroller with tri-state outputs.https://www.renesas.com/eu/en/document/dst/isl28533-isl28534-isl28535-isl28633-isl28634-isl28635-datasheet?r=493621

author: Electro Fan
author_rank: Super Contributor
timestamp: October 27, 2023, 10:30:57 pm
content: Not sure what the debate is really about any more in this thread.While digital could mean various things depending on the context, it generally refers to a technique for coding and processing information which at the foundation is binary (ie, a 1 or 0, the presence or absence of electricity) subject to some agreed upon thresholds and conventions.Of course, digital might refer to digits as in human fingers and toes, or it might refer to a digital readout such as the output of a clock, and it could probably mean a lot of things to a lot of people but the vast majority of the Information Technology humans use to create Information Systems that are used to manage information (including in the form of data, text, audio, image, and video) gets foundationally managed as bits (binary digits), ie, 1s and 0s. The 1s and 0s can be coded according to popular standards such as ASCII, or Hex, etc, or using proprietary, or special purpose, or obscure techniques, but digital at it's foundation is more often than not (there are exceptions for nearly everything) binary, ie 1s and 0s.Sometimes when trying to determine if something is on or off we might come up with can't discern/don't know or maybe even don't care. No doubt we can point to three states or conditions, or potentially n number of states and conditions. In fact we can do a lot of things a lot of different ways, but while we could do a lot of things it turns out that with just 1s and 0s we can do a huge number of things, and the simplicity, consistency, and elegance of binary has made the concept of binary the foundation of the biggest revolution in human history - so maybe instead of obscuring the reality with what are interesting if not edge cases at best, we ought to acknowledge that digital is fundamentally, at it's core, binary. I think we might be blurring bits with states and logic and codes. The distinctions are meaningful but we might be losing sight of the forest while examining the trees.Using 1s and 0s we can represent virtually anything but given that our systems generally need to provide some practical utility the 1s and 0s get truncated into Bytes or other finite sets of bits which then in some cases come up short of analog's "continuously variable". And of course, humans are becoming very clever at developing "mixed-use" techniques which use A2D and D2A. We live in an analog and physical world that we are learning to increasingly impact through the application of digital technology - which generally, at it's foundation, is binary, ie, 1s and 0s.Net, net: I think we can give it to radiolistener that for most people most of the time "binary" and "digital" are highly and very commonly related even if the two terms are not completely synonymous and not fully interchangeable.

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2023, 10:38:17 pm
content: I will not give to Radiolistener his emphatic statement that all digital systems are binary, just because most of them are, and that inherently decimal digital systems do not exist, by his idiosyncratic definition.

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2023, 10:41:54 pm
content: Quote from: Zero999 on October 27, 2023, 10:04:39 pmThat use of tri-state hardware would then be a ternary digital system, where each pin has three possible levels.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 07:04:17 am
content: Quote from: Zero999 on October 27, 2023, 10:04:39 pmyou can use N digital signals to get 2^N discrete levels, this is how digital-to-analog converter works, but digital signals on input of DAC is still digital and uses 2 discrete levels.It just means that circuit which converts digital binary signal with third state to analog discrete signal with 3 levels is digital-to-analog converter.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 08:06:32 am
content: Quote from: tooki on October 27, 2023, 08:25:06 pmit is incompatible not with my "excessively rigid definition", it is incompatible with all existing digital electronics. You can't connect your analog N-level discrete signal, where N>2 to a digital electronics component, because all of them expecting signals with only 2 discrete level.You can fantasize and invent mythical digital circuits that support discrete analog signals, but in reality they don't exists and you will have to use analog-to-digital conversion if you want to use such a discrete signal in a digital circuit. There is no other way.I'm sorry to ruin your myths, but this is the reality,all existing digital electronics works with binary signals and uses math, logic and algorithms which expecting binary signals onlyIf you want to use N-level discrete signal where N>2 in digital electronics, you're needs to convert that signal from analog to digital with ADC.If you want to generate N-level discrete signal where N>2 in digital electronics, you're needs to convert digital binary signals to analog with DAC.Sorry, but there is no way to process N-level discrete signals where N>2 directly in digital circuit.Yes, in theory you can invent ternary signals, develop math and logic for it and implement components that works with ternary signals directly without classic digital electronics that uses binary signals.But such ternary signals and components will be incompatible with all existing digital electronics, so you cannot name it as digital and cannot use digital methodology and digital algorithms for such ternary signals, you're needs to invent some new name, otherwise it will leads to confusion.But there is no such ternary components, this is dead branch of electronics, and any ternary signals (or other discrete signals with N>2)are treated as analogand processed with classic digital electronics (using binary signals) with help of DAC and ADC converters, so there is no sense to even talking about it...

author: tggzzz
author_rank: Super Contributor
timestamp: October 28, 2023, 09:26:06 am
content: Quote from: Electro Fan on October 27, 2023, 10:30:57 pmThresholds are a necessary characteristic, often with a forbidden zone.Binary is a sufficient characteristic, but not a necessary characteristic.There are technically and commercially important non-binary digital circuits and systems. See previous posts for examples.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 10:15:05 am
content: Quote from: tggzzz on October 28, 2023, 09:26:06 amnon binary but digital circuit doesn't exists and cannot exists, because digital circuit needs to use binary signals by convention. If it doesn't use binary signals, then it is not digital and needs to be treated as analog signals.The circuit can use both kind of signals analog and digital (binary), this kind of circuit is named as mixed signal. It has two interfaces - digital and analog.Some people may mistakenly name such mixed signal circuit as digital, because it has digital interface. But to be clear it is not digital, but mixed signal circuit because has both digital and analog interfaces.The example of such mixed signal circuit is programmable gain amplifiers, they have analog input and output and digital (binary) signals to control the gain.Another example of mixed signal component is DAC (Digital to Analog Converter). It has digital (binary) signals on the input and analog signal on the output.By convention digital (binary) signals are marked as Dxx, where xx is the meaning of signal. And analog signals are marked as Axx, where xx is the meaning of signal.For example DAC inputs are digital (binary) signals and marked as D0...D15.DAC output is analog signal and marked as AVOUT.DAC reference input is analog signal and marked as AREF.Analog ground is usually marked as AGND and digital ground is marked as GND or DGND.

author: tooki
author_rank: Super Contributor
timestamp: October 28, 2023, 12:22:39 pm
content: That’s not a definition, it’s a circular argument: “binary means digital because digital means binary”. We’ve given you multiple proven definitions of digital that your “definition” violates.You still aren’t getting it, but it’s obvious you’re not evenattemptingto understand what people have explained to you multiple times.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 12:29:43 pm
content: Quote from: tooki on October 28, 2023, 12:22:39 pmI understand it very well you're name all circuits as digital, just because you want.I'm name digital things that is a part of digital electronics and is compatible with digital interfaces.That's the difference

author: tooki
author_rank: Super Contributor
timestamp: October 28, 2023, 01:17:16 pm
content: It’s not because “I want” it, but because that’s the formal definition.Everyone has acknowledged that non-binary digitallogicisn’t used. But multilevel signaling does get used (we provided examples) to interface with the outside world. And because digital vs. analog deals with how the signal isinterpreted(not how it’s generated, and not how the interpretation is physically implemented, and not how the signal is further used once inside), those signals are still digital, because they’re encoding digitalinformation. (Multiple bits encoded into a single symbol are still digital.)

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 01:22:22 pm
content: Quote from: tooki on October 28, 2023, 01:17:16 pmyes, it is used but with help of analog-to-digital and digital-to-analog converters.Multilevel signals first converted form analog to digital then processed in digital circuit as binary signals and then converted back to analog signal.Digital signals don't needs to be converted from analog to digital...

author: tooki
author_rank: Super Contributor
timestamp: October 28, 2023, 01:31:09 pm
content: Quote from: radiolistener on October 28, 2023, 01:22:22 pmYes, they do. As we’ve told you already:everysignal is “analog” at the physical level. The bilevel digital inputs of a typical logic devicedoconvert voltages to logic states. As someone already said: you could consider such inputs to be 1-bit ADCs. Sure, it’s a spectacularly simple circuit. But it does convert the dirty analogness of the physical signal to digital. It is the very fact that the circuitinterpretsthe voltage levels as ones and zeros that makes it digital; the same signal going into, for example, an op-amp could be interpreted differently by an analog circuit.

author: ebastler
author_rank: Super Contributor
timestamp: October 28, 2023, 01:34:07 pm
content: Quote from: radiolistener on October 28, 2023, 10:15:05 amYou are really arguing yourself into a corner here. Nobody, over these many pages of discussion, has tought of mixed-signal systems when they argued that "digital" is not the same as "binary". Rather, everyone except you seems to be thinking of systems which use a small, discrete number of states to represent mathematical digits (!) and perform operations on them.Historically, digital computers using the base-10 system have existed -- using both, mechanical and electronic implementations. The mechanical implementations make it most obvious that there is no underlying binary representation: The gear and counter wheels can indeed take 10 different positions. Nevertheless, they have always been considered "digital" computers, and still are.A bit more recently, ternary logic has been used in computers -- not very commonly, sure. But there's no doubt that it uses digital, non-binary logic.https://en.wikipedia.org/wiki/Ternary_computerI happily agree that pretty much all "digital logic" ICs you can buy todayarebinary. But that does not mean that "digital" is the same as "binary".

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 02:33:12 pm
content: Logic again:To disprove the statement "all digital systems are binary", it is only necessary to showonedigital system that is not binary (e.g., ternary or decimal or sexagesimal).That has been done many times in this thread.The statement "almost all digital systems now in use are inherently binary" is different.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 02:46:16 pm
content: Quote from: ebastler on October 28, 2023, 01:34:07 pmAs explained before, these computers with base-10 was used binary signals to represent base-10 digits. 10 binary signals represent decimal value in one-hot encoding or 4 binary signals represent decimal value in BCD encoding. But they all used binary signals.This encoding:00000000001 = 000000000010 = 100000000100 = 200000001000 = 3...still uses binary signalsThe same with ternary computer, it uses two binary signals to represent 1 ternary value.They all used classic digital signals (binary), this is why it was digital.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 02:50:53 pm
content: Quote from: radiolistener on October 28, 2023, 02:46:16 pmWrong: a true ternary computer system uses three possible levels on one wire to represent one ternary value, typically -V, 0, and +V, where V is a discrete voltage value.Just because they are not common does not mean they don't exist or have never existed.A decimal computation device (most of which are mechanical or electromechanical) has ten states on a dial (or similar) to represent one decimal digit, with no binary component whatsoever!You are defying common technical English definitions of terms to fight a useless battle to impose your narrow view of digital systems by excluding those you don't like.Have you ever used an electromechanical calculator?

author: ebastler
author_rank: Super Contributor
timestamp: October 28, 2023, 02:51:01 pm
content: Quote from: radiolistener on October 28, 2023, 02:46:16 pmI had specifically mentioned the mechanical base-10 digital computers/calculators as an obvious counter-example.QuoteWhy would you think so??

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 02:55:49 pm
content: Quote from: TimFox on October 28, 2023, 02:50:53 pmNo, they all used binary signals. Ternary logic was emulated on digital circuit which uses classic digital signals (binary). They don't use 3 discrete levels for physical signal representation.For example ternary computer Сетунь (Setun) was used the following encoding for ternary values:binary signals = ternary value00 = 001 = 110 = 211 = not used stateIn such way ternary logic was implemented with classic digital logic elements AND/OR/XOR/NOT which working with binary signals and Boolean algebra.And some of them was emulated on a usual computer as software implementation.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 03:05:45 pm
content: Quote from: ebastler on October 28, 2023, 02:51:01 pmMechanical computers with base 10 aredecimal computers, not digital. It doesn't have any relation to digital electronics at all.Quote from: ebastler on October 28, 2023, 02:51:01 pmSome time ago I was talked with people who worked on ternary computer Сетунь and he explained how it was implemented.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 03:22:00 pm
content: Quote from: TimFox on October 28, 2023, 02:50:53 pmAs already mentioned here. According to English dictionary, digital means:QuoteAs you can see, this is you are defying common technical English definitions of terms...

author: ebastler
author_rank: Super Contributor
timestamp: October 28, 2023, 03:24:01 pm
content: Quote from: radiolistener on October 28, 2023, 03:05:45 pmI'm reluctant to even call that circularreasoning, because there is no rhyme or reason to it. "Decimal" and "binary" are both special cases of "digital". And why you suddenly want to limit the discussion to "electronics" is beyond me; please see the thread title.I waited for a long time before I joined this discussion. I'll be much quicker to leave it again. Cheers!

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 03:30:35 pm
content: Quote from: ebastler on October 28, 2023, 03:24:01 pmNo. Decimal and binary are names of numbering system with different base.Digital electronics works with binary signals only, but can store information about decimal (or any other) values as a set of binary signals.Quote from: ebastler on October 28, 2023, 03:24:01 pmBecause thread title is about "digital system" and term "digital system" is used as category of electronic system which is implemented with digital electronics.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 03:42:54 pm
content: Quote from: ebastler on October 28, 2023, 02:51:01 pmQuoteQuote

author: ebastler
author_rank: Super Contributor
timestamp: October 28, 2023, 03:49:29 pm
content: Can't help myself...What would you call this, then?https://louis-dr.github.io/index-ternary.htmlhttps://louis-dr.github.io/ternalu3.html

author: madires
author_rank: Super Contributor
timestamp: October 28, 2023, 03:52:40 pm
content: Quote from: radiolistener on October 28, 2023, 03:30:35 pmThe OP's question was mathematics related, just saying.

author: MK14
author_rank: Super Contributor
timestamp: October 28, 2023, 03:59:02 pm
content: QuoteSource:https://www.monolithicpower.com/en/analog-vs-digital-signalSo, according to the supplied source (there seem to be other sources, saying basically the same thing). It can be binary or any other counting system (i.e. NOT binary), as long as it has a discrete number of states (i.e. is NOT analogue, as in an almost infinite number of states).This is a very long thread, for something which might have been started either by a 2 post spambot or fly-by user, who just wanted to advertise their link/paper or something like that.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 03:59:54 pm
content: Quote from: ebastler on October 28, 2023, 03:49:29 pmThis is an example of what is NOT digital system

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 04:06:40 pm
content: ebastler, it seems that you don't understand what is the digital logic, digital circuit, digital system.You can read this article, it will show you what term digital means:https://learn.sparkfun.com/tutorials/digital-logic/allBy the way, just opened your second link and it shows usual digital circuit which emulates ternary logic. This is what I was talking about... There is no signals with 3 disrete levels, it uses binary signals to emulate ternary logic.So, the answer on your question: this is classic digital circuit with binary signals which emulates ternary logic.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 04:24:44 pm
content: https://www.techopedia.com/definition/27425/digital-logicQuoteI just have no idea where you get misunderstanding that digital circuit may work with non binary signals... Because every dictionary explains that "digital" means binary data, binary signal, boolean logic....

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 04:31:08 pm
content: Quote from: MK14 on October 28, 2023, 03:59:02 pmNo.It can be any numbering, any counting, but digital systemMUST represent any data with binary signals. This is mandatory requirement for digital system. You can encode any number with binary data. But digital system works with digital signals only which is binary...You can use any encoding: binary, BCD, one-hot, themperature code, you can invent your own numbering system and invent your own encoding for numbers, etc, but all data must be represented with binary signals.

author: MK14
author_rank: Super Contributor
timestamp: October 28, 2023, 04:39:16 pm
content: Quote from: radiolistener on October 28, 2023, 04:31:08 pmSo are you saying, that modern high capacity SSD's, are NOT digital devices, because they (typically, for the latest modern ones), use multiple/many states (more than 2), per memory cell element.https://en.wikipedia.org/wiki/Multi-level_cell

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 04:42:06 pm
content: Quote from: MK14 on October 28, 2023, 04:39:16 pmYes, internally they are not pure digital, they are mixed signal circuit, because they working with analog signal inside. But they expose only digital interface and you don't have access to their internal analog signal. So, you can assume it as digital element, because it's public digital interface works the same as for pure digital device. Analog part is private and not available outside chip, so you can ignore that.

author: MK14
author_rank: Super Contributor
timestamp: October 28, 2023, 04:53:51 pm
content: Quote from: radiolistener on October 28, 2023, 04:42:06 pmYes, that sounds right. But there have been, and perhaps still are, computer systems, calculators and so on, which use systems, that are not binary.https://en.wikipedia.org/wiki/Ternary_computerWhich describes, various devices, such as computers, which use three different states, in order to work.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 05:00:50 pm
content: Quote from: MK14 on October 28, 2023, 04:53:51 pmAs I know, all ternary computers were implemented on classic digital circuits (with binary signals). It just emulate ternary values with two binary signals and implements ternary logic with usual digital logic elements. This is how ternary computer Setun was implemented.Some of ternary computers were implemented as software program for usual digital computer. But if there is exists ternary computer which works with 3 level signals, then it will be example of non digital computer, because it don't use digital logic, don't use digital signals and don't use all what is named as digital electronics, but I don't know about such examples.

author: Tation
author_rank: Regular Contributor
timestamp: October 28, 2023, 05:06:32 pm
content: Quote from: radiolistener on October 28, 2023, 02:46:16 pmDo you have any reference supporting such claim?

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 05:13:41 pm
content: "digital system MUST represent any data with binary signals. This is mandatory requirement for digital system"So you keep saying, despite centuries of digital systems using non-binary components and representations, that predate binary systems.You may have a limited universe of discourse, but there are many examples in the larger picture, brought to your attention by multiple posters, after which you put your fingers in your ears and recite your mantra.George Boole introduced his system in 1854, following work by Leibnitz.In the 1930s, Shannon applied binary Boolean algebra to switching circuits, after which "Boolean" came to mean binary.Boolean algebra is used for symbolic logic that recognizes only "true" or "false" as valid outcomes; other forms of logic can have further answers in their set of valid outcomes.Binary arithmetic differs from Boolean algebra, but also uses binary variables.Modern mathematics recognizes a multiplicity of "Boolean algebras", but that is higher mathematics.In this forum, there are manyopinionslegitimately held by individuals that disagree with each other, such as personal preferences for Windows, Linux, Mac, or other operating system.Different people find different choices better suited to their experience, application, or familiarity.One of my strongly held opinions is in favor of RPN over "algebraic" notation on pocket calculators.However, the standarddefinitionof digital (antonym of analog) is that it uses discrete states and representation, instead of continuous.If someone claims that "there must have been a year zero" in discussing the civil calendar in use in Western countries, that opinion of theirs is wrong, since the civil calendar is otherwise defined to go from 1 BC to AD 1 without a year in between, and a different definition would change the historical date of Caesar's assassination.(Astronomers do use a different calendar definition, where the year before AD 1 is zero, and years before that are shifted by one from the legal civil calendar, but we don't rewrite the history books.)

author: MK14
author_rank: Super Contributor
timestamp: October 28, 2023, 05:17:02 pm
content: Quote from: radiolistener on October 28, 2023, 05:00:50 pmQuoteSo, non-binary signal levels (i.e. more than 2 states), are fine, and still digital (signals), even if rarely used.Source:https://en.wikipedia.org/wiki/Digital_signal

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 05:23:58 pm
content: Quote from: Tation on October 28, 2023, 05:06:32 pmAs I remember, there was shared document with implementation details, it don't covers all details of Setun, but explains some aspects and ternary logic details, it was shared on some forum, but I don't remember where it was exactly. It was many years ago. Probably it was on zx-pk.ru

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 05:33:01 pm
content: I had to edit my reply 244 several pages ago about the 1967 thesis by Sung Chiao Hu at Oregon State University, since there was no http reference copyable.Looking again at his thesis, he shows practicable ternary logic gates, with -2 V, 0, and +2 V levels on each single line, using NPN and PNP transistors.He also defines the Boolean-style algebra for ternary variables.That would have a nuisance with tubes; he also discusses tunnel diodes as a possible hardware solution.Google: "Hu Sung ternary thesis" to download the thesis (pdf of typescript).

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 05:42:08 pm
content: Quote from: TimFox on October 28, 2023, 05:13:41 pmyes, I keep saying that digital circuit works with binary signals only. And there is no digital system which using non-binary components. All examples which was mentioned in this thread are digital and using binary signals (such as ternary computer and dekatron computer).Mechanical calculator are analogue systems because it using gears which are continuous devices and is not compatible with digital logic which uses discrete binary values.Quote from: TimFox on October 28, 2023, 05:13:41 pmThere is no such "standard definition" that it uses discrete states instead of continuous.The standard definition is that digital uses binary digits and digital logic which also known as Boolean logic which is invented for binary signals only.From that point yes, you can say that digital signal is discrete, because binary is discrete. But you can't say that any discrete signal is digital, this will be incorrect, because it includes non binary signals which are not compatible with digital logic.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 05:45:52 pm
content: Nonsense: that isyourstandard definition.The actual standard definitions state that binary is an important specific case of "digital".If you use a Geneva mechanism in the mechanical gear train, the results are as discrete as the output of a TTL logic gate, which does take a finite time to change from one state to another.https://en.wikipedia.org/wiki/Geneva_driveMy quartz watch shows the second hand jumping discretely in one-second increments, from a gear train driven by a stepper motor.My old-fashioned 60 Hz synchronous-motor analog wall clock shows the second hand moving continuously.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 05:49:50 pm
content: Quote from: TimFox on October 28, 2023, 05:33:01 pmYes, you can implement ternary elements, but will not be digital. Because digital electronics uses digital logic which is designed for binary signals. It won't work for ternary signals. The same digital electronics uses different methods and algorithms designed for binary signals, so it won't work for ternary signals. So your ternary signals will be completely incompatible with digital electronics.In order to connect your ternary signal to digital circuit you will needs to use analog to digital converter to convert ternary signal from analog to digital.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 05:52:17 pm
content: No, if the ternary system is used consistently within the mechanism, it will compute without any binary representation.At the end of the ternary computation, it is straightforward to convert the result to binary to connect with your conventional system, but that's a conversion from one digital system to another, which does not require ADCs.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 05:57:19 pm
content: Quote from: TimFox on October 28, 2023, 05:45:52 pmI can agree here, if you implement mechanical gears that will work with two discrete state and implement boolean logic on such gears, then may be you can name it as digitalUsually digital system means electronic system, not mechanical. But technically yes, you can implement digital logic with mechanical or pneumatic devices which will work on the same digital principles, but will not use electricity.

author: MK14
author_rank: Super Contributor
timestamp: October 28, 2023, 05:59:32 pm
content: Quote from: radiolistener on October 28, 2023, 05:42:08 pmNot really.E.g. A relay, is a sort of very simple, mechanical (or electromechanical device) 'calculator', which can process two digital states, on and off.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 06:15:57 pm
content: Quote from: TimFox on October 28, 2023, 05:52:17 pmyes, exactly. But this will be ternary mechanism, not digital mechanism.Quote from: TimFox on October 28, 2023, 05:52:17 pmNo. There is no way to convert analog signal (ternary) to digital without analog to digital conversion. For digital system ternary signal is analog signal.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 06:22:37 pm
content: Quote from: radiolistener on October 28, 2023, 05:57:19 pmOne feature of mechanical and electromechanical digital systems is that they are not limited to binary, and usually workeddirectlyin decimal (or pounds-shillings-pence) digits.One of the first was built by Blaise Pascal in the 17th century, and was in limited commercial production for about 10 years, for use in bookkeeping computations.During the same period, analog computation by devices equivalent to modern sliderules was developed, after the invention of logarithms in mathematics.The decimal digits appearing on a 20th-century electromechanical calculator jump from one decimal state to another.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 06:27:11 pm
content: Quote from: radiolistener on October 28, 2023, 06:15:57 pmYou are totally wrong. Using ternary logic gates with only three states, it is a straightforward digital design problem to produce the discrete binary equivalent of a discrete ternary value.Of course, a ternary value cannot be connected directly to a binary gate, since that would result in an incorrect result where the binary gate could not discriminate between, say, -2 V and 0 V.In principle, that is no harder than designing a circuit using only binary logic gates to directly (no recursion or successive steps) convert a hexadecimal binary word to the same value in BCD or grey code.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 06:27:56 pm
content: Quote from: TimFox on October 28, 2023, 06:22:37 pmif it works with decimal values directly (without binary signals), then it cannot use digital logic and so, cannot be named as digital.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 06:30:47 pm
content: Once again, you argue that a digital system must be binary, because only binary systems are digital, ignoring the fact that binary is but one of a countably-infinite types of digital representations.Your opinion that "digital" and "binary" are synonymous is contrary to technical definition, and confuses two related but separate concepts.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 28, 2023, 06:36:25 pm
content: Quote from: radiolistener on October 28, 2023, 06:15:57 pmMinor logical correction. Connection of a ternary system to a binary system requires a ternary to binary converter. You will not agree with this correction because the subtle point here is at the heart of your view of the world.I am not trying to correct your view of the world. You find this view both useful and sufficient. I am curious why you feel so strongly about trying to change others views, views which those others find useful? I agree with you that Boolean logic only works in binary systems. Just as Euclidean geometry only works in Euclidean spaces. But I don't deny the existence of non Boolean logics any more than I reject the existence of non Euclidean geometries.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 06:38:46 pm
content: Quote from: TimFox on October 28, 2023, 06:30:47 pmNo. Digital and binary are not synonymous. And digital system must be binary not because only binary systems are digital.The reason why digital system must be binary is because entire digital domain is designed for binary signals only. Digital logic works with binary signals only, digital methods and algorithms are designed for binary signals only. That's the reason why digital circuit must use binary signals.If you want to use non binary signal in digital circuit, you're needs to treat it as analog and use ADC.

author: radiolistener
author_rank: Super Contributor
timestamp: October 28, 2023, 06:57:43 pm
content: Quote from: CatalinaWOW on October 28, 2023, 06:36:25 pmYes, it requires ternary to binary converter. But for digital domain ternary to binary converter is nothing else as analog to digital converter.Quote from: CatalinaWOW on October 28, 2023, 06:36:25 pmI also don't deny existence of non Boolean logic, on the contrary I already said that you can develop non digital system and it will include logic, math and algorithms.But you can't name Minkowski space as Euclidean space. The same you can't name a system designed for ternary signals as digital system, just because digital system is designed for binary signals.

author: ebastler
author_rank: Super Contributor
timestamp: October 28, 2023, 07:27:22 pm
content: Gentlemen, I think it is time to conclude that radiolistener is trolling you. If you enjoy the exchange, feel free to keep going of course. But don't expect any breakthroughs...

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 07:37:12 pm
content: The ternary to binary converter can stay in the realm of discrete states, for example using relays, and never venture into the realm of analog signals.You need to look up "petitio principii", the logical fallacy ("begging the question") when an argument's premises assume the truth of the conclusion, roughly synonymous with circular reasoning.

author: wasedadoc
author_rank: Super Contributor
timestamp: October 28, 2023, 07:56:35 pm
content: Quote from: radiolistener on October 28, 2023, 06:15:57 pmLet's say I have a ternary system and it transmits the "messages" 0, 1 or 2 using the three levels -V, 0 and +V. At the receiver I convert the messages to binary. I have a 2-bit ADC with quantising levels at -V/2, 0 and +V/2. I use a truth table to convert the 2-bit output to binary.Later I realise I could substitute the 2-bit ADC with two 1-bit ADCs. One with threshold at -V/2 and another 1-bit ADC with threshold at +V/2. Again I use a truth table slightly modified from the above one, to convert the two 1-bit outputs to binary. Input below -V/2, input above -V/2 and below +V/2, input above V/2. I'm converting ternary to binary using two ADCs. According to radiolistener this system is not digital.Later I consider not to use ternary, but binary using levels 0 andV/2+V. I would remove the first ADC, keep the second one and remove the truth table. According to radiolistener this would now a digtal system because it is purely binary. Yet radiolistener also contends that digital system does not have ADC but this one does. The contradiction is evident.Edited to correct "V/2" to "+V" in the first sentence of the third paragraph. The concept is not affected.

author: tggzzz
author_rank: Super Contributor
timestamp: October 28, 2023, 08:15:06 pm
content: Quote from: tooki on October 28, 2023, 12:22:39 pmHas anybody else made the observation that radiolistenerin an inappropriate moniker?

author: MK14
author_rank: Super Contributor
timestamp: October 28, 2023, 08:19:11 pm
content: Quote from: tggzzz on October 28, 2023, 08:15:06 pmI noticed, and was tempted to mention it.

author: IanB
author_rank: Super Contributor
timestamp: October 28, 2023, 08:23:05 pm
content: Quote from: tggzzz on October 28, 2023, 08:15:06 pmI guess it is because nobody has accepted his premise that modern digital electronics works in binary. Which is true, but it is too limiting. The title asks "What is a digitalsystem?" It doesn't limit the discussion toelectronic digital logic circuits, which are, conventionally, binary in operation.

author: tggzzz
author_rank: Super Contributor
timestamp: October 28, 2023, 09:00:50 pm
content: Quote from: IanB on October 28, 2023, 08:23:05 pmThe problem is that radiolistener doesn't listen to all the other people.There are numerous commercially important electronic digital logic circuits that aren't binary. I have some in my pocket: a USB flash disc.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2023, 09:08:51 pm
content: Here is a simple digital logic circuit that converts one line of a ternary digital state to two lines of binary digital state, using the conversion table in the figure.The circuit is purely "combinational", not "sequential" logic.Normal DC-coil relays are used since they are agnostic about the polarity of the coil current.This example of diode-relay logic is no more an ADC than is a 7404 TTL inverter gate section.For completeness, the drawing defines the conversion table between the three input states that I have named "N", "Z", and "P" and the two-bit binary code at the output.The logic levels are also defined, although obviously the discrete input levels are not precisely defined as shown, just as TTL levels are not precise but given as ranges.The ternary source will deliver only three possible states, each of which is near the voltage shown, but does not vary continuously between states, but jump between the three states in the same manner as binary TTL hardware jumps between two states.

author: Electro Fan
author_rank: Super Contributor
timestamp: October 28, 2023, 11:43:49 pm
content: Ok, so it seems that "ternary" is "exhibit A" and the poster child example of why digital is not the same as binary.The claim is that +5V, 0V, and -5V are discreet levels, ie they are digital and not continuously variable; however it is noted in this example that these 3 levels are not really exact discreet levels but ranges. ("The logic levels are also defined, although obviously the discrete input levels are not precisely defined as shown, just as TTL levels are not precise but given as ranges.").Presumably in this argument we don't want to call the ranges "analog" because they are not "continuously variable"’; rather they are values within "ranges." Seems like skating on some random ambiguity as many analog signals are not infinitely variable but rather fall within "ranges." Nonetheless, we will proceed on the premise that these 3 ranges are not "analog" but rather they are "digital" values. Fair?Next, after all of that ^, we proceed to show how these three values (each representing some range) are designated as 1s and 0s (binary digits): 00, 01, and 10. So in the end, we have taken some value that we insist is not "analog" but digital and we represent the value with binary digits.It seems that in terms of the output, ie the representation of non-binary digital values in this digital system, the example shows the output to be binary. So, if this is our poster child example, we can't argue with the fact that the output of a digital system is binary because this example shows that the output is binary.All that is left then is to make the case that the input of this digital system is not binary - which is based on the premise that this digital system has 3 possible states (some range in the vicinity of +5V, some range in the vicinity of 0V, and some range in the vicinity of -5V). This then, is the basis for the argument that digital systems are not necessarily binary.If this is a fair restatement of the discussion, then we can say that the input of a digital system might be something other than binary (ie, something with more than 2 states), but the output (at least in this poster child example) is still binary.Now, before going too far into the rabbit hole, someone might say "but the output isn't really binary either, it isn’t two states because the values (as shown) are 00, 01, and 00. So according to this logic there are three states. Personally, I would say "tilt" on such an argument because as has been said over and over throughout this thread, the notion of binary is that two states (0 and 1) can be used to code many other values subject only to the number of bits within a "Byte". So, I think we have to agree that the output of a digital system is binary (unless it gets converted to something else, such as analog).So unless someone wants to argue otherwise (and I’m guessing someone will), it seems that the “ternary” example is consistent with a digital system in which the output is “binary.”This leaves us with whether the input of a digital system is binary, or if in fact the input of a digital system can have more than 2 states. Again, in our poster child example the input has 3 states, and even though the poster child example clarifies that these 3 states are not limited to 3 discreet values but are in fact values that fall within 3 ranges, we choose to refer to these 3 ranges as "ternary." Whether "ternary" means exactly 3 values (which it doesn't in the poster child example) or whether it means roughly 3 values (which it does in the poster child example), we can all agree that the input has more than 2 values. However, if we accept that these three values are not discreet, but are in fact ranges, then we have to acknowledge that the values could be many values more than 3. For example, approximately +5V could be 5.000000V or 5.0000001V or 4.999999V or pretty much any number of values if we are willing to move the decimal point. Nonetheless, in this poster child example we say it's "ternary" and we use the ternary example to defeat the idea of digital as meaning binary and we insist that because there are (at least) 3 values in the input, it is therefore an example of a "digital" system and therefore "digital" cannot be synonymous with "binary". Or so the argument goes.If it ended this discussion on a consensus, I'd be inclined to say "ok, if we can accept that the output of a digital system is binary, ie 1s and 0s, ie, binary digits then sure, good enough for discussion sake if not an exact definition." But I have a hunch this thread might have a bunch more posts to go, so what the heck, let's keep going.So, next, beyond the output side of a digital system being binary, let's revisit the idea that "ternary" is a special case that has 3 states. As we've seen above, the 3 states are not discreet, they are ranges, and the ranges could represent a huge number of actual values depending on where the decimal point resides. But let's give the poster child example the benefit of the doubt; let's call it 3 states and say "ah ha, it is 3 values and 3 is greater than (and definitely different than) the 2 states of binary – so therefore digital can’t mean just binary.” This then raises the question of "who cares"? Because darn near everything we input to a digital system (all the alphas, all the numerics, all the special characters, all the pixels, and pretty much all the everything) has more than 2 states. But you know what? When we get done coding all the darn near everything (including in the poster child ternary example that we insist is "not binary") what the digital system does is it converts the 3 states (or n states), or ranges (with an infinite number of possible values) to 1s and 0s, ie to 2 states we call "binary." Again, how many 1s and 0s we use to encode something else is just a function of how many values we want to represent with binary digits as we string the bits together into Bytes according to various coding conventions.If we zoom out and look at the huge amount of information inputted, processed, and outputted with computers and embedded devices and all the information collected and distributed with networks the vast vast vast majority of it gets reduced to 1s and 0s. The argument that digital and binary are not synonymous might be more academically interesting than useful.(edit for typos and clarification)

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 29, 2023, 12:21:43 am
content: Read the Wikipedia article on ternary logic. The discussion there has nothing to do with electrical circuits. After reading that I realized that my comment about a ternary to binary converter was naive and wrong. There is no way to directly convert a three state system to two states. It is possible to emulate a ternary system using two bits to hold the three symbols. And it is possible to create circuits which implement the (complex) logic tables of ternary logic. But I find it very strained to call such circuitry analog. In a sense it is analog, but it is analog in exactly the same sense as binary circuitry which uses voltage levels to represent the states.

author: radiolistener
author_rank: Super Contributor
timestamp: October 29, 2023, 04:30:56 am
content: Quote from: TimFox on October 28, 2023, 07:37:12 pmAny ADC staying in the realm of discrete states, but this is device which get analog signal on the input and produce digital signals on the output. But ADC input is still analog input, it is not digital.

author: radiolistener
author_rank: Super Contributor
timestamp: October 29, 2023, 04:39:12 am
content: Quote from: wasedadoc on October 28, 2023, 07:56:35 pmNo. You cannot put 3 level signal on two digital input with different level standard, because it will leads to metastability issues. If you want to do what you want, you're needs to use two analog comparators for signal which has 3 discrete levels. Each comparator should be tuned for different analog threshold, then it will works and you can convert your 3-level signal to a digital domain.You're needs to understand, that digital signal doesn't allows valid level between 0 and 1. This is why digital signals are not compatible with analog one. If you put such analog signal with 3 discrete level on digital input it will leads to metastability issues and your digital circuit won't works as expected.Analog comparator is analog component and if you're using it, your circuit is not pure digital. It is mixed signal, because it works with both kind of signals - analog and digital.You can create analog circuit using digital and analog components. This is how ADC and DAC are implemented. But it don't means that you can assume discrete 3 level signal as digital and process it on digital logic such as AND/OR/XOR/NOT elements.It just means that when you build some circuit which works with analog and digital signals, such circuit is not pure digital. It is mixed signal circuit. It means that is uses both domains - digital and analog.There are only two domain: digital and analog. And any circuit which is not digital (based on non binary signals) is fall to analog category. It can be discrete, but still fall to analog category, because incompatible with digital.There is no ternary domain, so if you invent ternary signal and ternary logic elements, your circuit automatically falls into analog catergory. Because it is not compatible with digital logic.

author: JeremyC
author_rank: Regular Contributor
timestamp: October 29, 2023, 04:49:01 am
content: Quote from: oslon on October 19, 2023, 01:31:03 am@oslon, you just opened a can of worms

author: radiolistener
author_rank: Super Contributor
timestamp: October 29, 2023, 05:08:24 am
content: Quote from: TimFox on October 28, 2023, 09:08:51 pmYour circuit uses non digital domain with bipolar voltage source and open voltage threshold of diodes and triggering voltage of relay. These things are not digital, they are analog. So your circuit is mixed signal circuit which uses analog domain and digital domain.In short, this is simplified ADC which converts analog signal to digital. This is not pure digital circuit.It will be more easy to understand why this circuit is not pure digital if you add voltage shift +2.5V.In such way your circuit will works with:N = +5 VZ = +2.5 VP = 0 VGND = +2.5 VSo, your circuit has digital output from relay. But it has analog circuit which controls relay state.In order to improve stability of such circuit it will be better to use analog comparators to control relays. So, in such way you will will reduce effect of relay hysteresis and no needs to play with GND offset. But also relays become useless and you can use analog comparators output as digital output directly. And if you overview what happened with circuit, you will notice that it is turned into classic ADC.

author: radiolistener
author_rank: Super Contributor
timestamp: October 29, 2023, 06:20:35 am
content: Quote from: tggzzz on October 28, 2023, 09:00:50 pmI cannot listen to all peoples, this is just impossible, because there is more than 8 billion peoples on the EarthBut I listen to peoples in this thread, which of course cannot represent all peoples.And I am not obliged to accept someone else's opinion with which I do not agree, even if it is shared by several people.As we already discussed before, most part of peoples are stupid, smart peoples are rare.So accepting opinion just because it is shared by many peoples is a stupid idea.You're needs to have your own head and not rely on mass opinion.Quote from: tggzzz on October 28, 2023, 09:00:50 pmThis is your mistake. There is no electronic digital logic circuits that aren't binary. This is technically impossible and even sounds absurdly.Quote from: tggzzz on October 28, 2023, 09:00:50 pmUSB flash drive is mixed signal device, it includes analogue voltage regulators and other analogue stuff inside. For example it can store data as analog signals, etc.But it has digital interface and don't expose it's analog signals outside. So you can categorize it as digital, just because nothing will be changed if you replace it with pure digital device - it will have the same digital interface and will works the same.So you shouldn't care if there are analog signals inside the device if you don't have access to those analog signals. Since you have only digital interface, you can assume that device is digital.

author: radiolistener
author_rank: Super Contributor
timestamp: October 29, 2023, 07:20:02 am
content: When someone talking about digital circuit, it is pretty clear that he is talking about circuit that works with binary signals and uses digital logic elements such as AND/XOR/OR/NOT.And it will be crazy to think that he is talking about analog amplifier on sound DAC output which has 16777216 discrete voltage levels...

author: tooki
author_rank: Super Contributor
timestamp: October 29, 2023, 12:16:37 pm
content: Quote from: IanB on October 28, 2023, 08:23:05 pmWhat do you mean? Multiple people, including myself, have agreed that practically all digital electronics, save for some types of memory and many types of communications, are strictly binary. But he’s too stubborn or too stupid to even recognizethat.

author: Zero999
author_rank: Super Contributor
timestamp: October 29, 2023, 01:15:08 pm
content: Quote from: radiolistener on October 29, 2023, 07:20:02 amNot necessarily.A quote from the programmable gain amplifier IC, I mentioned earlier.Quotehttps://docs.rs-online.com/81e5/0900766b814ecfcf.pdf

author: wasedadoc
author_rank: Super Contributor
timestamp: October 29, 2023, 02:16:34 pm
content: Quote from: radiolistener on October 29, 2023, 04:39:12 am1. You are quoting where I describe a pure binary system. Nothing 3-level in it. But then you write nonsense about 3-level on 2 digital input and metastability issues.2. Yes you can "put 3 level signal on two digital inputs with different level standard" without issues.

author: tggzzz
author_rank: Super Contributor
timestamp: October 29, 2023, 02:30:52 pm
content: Quote from: wasedadoc on October 29, 2023, 02:16:34 pmYou can.I can.All but one person contributing to this thread can.Some people remain convinced of things that aren't even wrong. The question is why they continue in such beliefs. And then whether it is worth paying any attention to them on thatand othersubjects.

author: TimFox
author_rank: Super Contributor
timestamp: October 29, 2023, 02:31:11 pm
content: Quote from: radiolistener on October 29, 2023, 05:08:24 amThe circuit controlling the relays is no more an analog circuit than is a 7404 TTL binary inverter run from a split power supply of +/- 2.5 V.(In real systems, I have run 4000-series CMOS binary logic from split supplies of +/- 6 V for special purposes.)The voltage into the 7404 can be varied continuously, but there are only two valid states of the input that give valid states of the output, and the designer must make the transition rapidly to minimize time in the invalid states.I posted a simple circuit: obviously, it could be improved.The ternary levels I quoted are consistent with those suggested in the 1967 thesis for a true ternary system.Digital systems include those that are not inherently binary, despite your continued baseless claim.

author: IanB
author_rank: Super Contributor
timestamp: October 29, 2023, 04:24:56 pm
content: Converting from ternary to binary is of course a digital computation using arithmetic logic. It does not require going through the analog domain. For example:Suppose we have 1002 in base 3 (a ternary digital value), and we wish to convert it to binary. We can proceed as follows:Code:Ternary logic Binary digits1002 - 121 = 111 => 1111 - 22 = 12 => 112 - 11 = 1 => 11 - 2 fails => 01 - 1 = 0 => 1As a result, 10023= 111012This is a computation that can be performed by any kind of ternary computing device that supports integer arithmetic.

author: TimFox
author_rank: Super Contributor
timestamp: October 29, 2023, 04:27:56 pm
content: That is a good example of a sequential calculation, reminiscent of long division in decimal digital systems.

author: tooki
author_rank: Super Contributor
timestamp: October 30, 2023, 07:32:37 am
content: Quote from: radiolistener on October 29, 2023, 07:20:02 amNot by the time the conversion is done. Then you have a fully analog signal. (Once the bandwidth limit is applied to the output, the steps are gone.)But of course you’re missing the real point: it’s about how you interpret the signal on the input.

author: MK14
author_rank: Super Contributor
timestamp: October 30, 2023, 11:46:12 am
content: Bold added by me.Quote from: tooki on October 30, 2023, 07:32:37 amThe following example, is NOT how I think things should be interpreted. But some other(s), but I won't mention names, **might** think that way.Example:A 5 volt (output is precisely 0 volts for logic '0' and precisely 5 volts for logic '1'), all digital logic series, which treats input (threshold) voltages below 2.5 volts as logic '0', and equal to or above 2.5 volts as logic '1'. Hysteresis, noise thresholds and other practical real life phenomenon, are being disregarded, for this example.Therefore, it is a 100% analogue device, a non-inverting buffer, is actually a 1 bit, A to D converter. Which is equivalent (internal circuitry wise) to the inverting input being connected to exactly 2.5 volts, and the non-inverting input, being used as the input.Much like acomparator, sorry, I mean op-amp, as this is 100% analogue.In other words. Yes, a non-binary input/output digital system, **could** be interpreted as being equivalent to an A to D (and DAC, depending on if input or output, etc) converter. But would still be a 'Digital System', just with more than 2 states, but still a fixed number of defined output (voltage, current, etc) levels.In the same way a simple wire (or bunch of them, possibly screened or similar), can be used for many different purposes, which would tend to change its name. E.g. Wire, Cable, Accelerator-Cable, Tie-Wrap, USB lead, Meter Leads, Lighting Cable, Breadboard Leads, Ethernet Patch Cable, etc.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 30, 2023, 01:29:30 pm
content: I've been thinking about this over the length of the thread, and think that for me the meaning of a digital system is closely tied to reversibility. Given the outputs can you unambiguously reconstruct the inputs? Obviously this isn't a formal definition. You can't reconstruct the input of an or gate from the output, but you do know at least the values that could have been there. A to D converters illustrate another ambiguity of this definition. You can certainly reconstruct the inputs from a theoretical D to A, and for a good 8 bit real D to A, but I know of no 32 bit D to A converters that are monotonic and linear enough to allow recovery of the inputs. In spite of these weaknesses I find this a useful definition.Edited to correct my bonehead reversal of D to A into A to D, and a spelling error. Thinking of D to A makes the point I was attempting to make more clear and avoids all the need to discuss thermal noise and the like. And if someone comes up with a good enough 32 bit converter make it 48 bit. The points that my definition is not a complete formal definition. There are counter examples, but it works as an organizing tool for me. There is no one correct way to sort things. Others have their preferred bins.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: October 30, 2023, 06:36:14 pm
content: Quote from: CatalinaWOW on October 30, 2023, 01:29:30 pmTotally agreed. A digital system should also be method and timeagnostic. That is, apuredigital system will not care how values are derived, stored, transmitted, duplicated or reproduced. Furthermore, it will not care when or even if these events occur. A digital system can comprise of a gate that switches from zero to one in a pico second, yet the bit that is set can stay retained in a data store that is not accessed for another human millennia - in a digital system that has yet to be invented.

author: IanB
author_rank: Super Contributor
timestamp: October 30, 2023, 06:41:35 pm
content: Quote from: AndyBeez on October 30, 2023, 06:36:14 pmI don't think this is a differentiator for a digital system though. Analog systems can have the same property.For example, a vinyl record. The information it contains can be retrieved by a mechanical stylus, or optically, or by other methods. It is also durable, and probably able to last for millennia if stored carefully.

author: radiolistener
author_rank: Super Contributor
timestamp: October 30, 2023, 07:12:12 pm
content: Quote from: IanB on October 30, 2023, 06:41:35 pmI just wonder... The vinyl record is recorded on material which is discrete and consists of finite number of atoms... The sound waves also quantized with phonons, so it also can be classified as discrete. And according to your classification the number of discrete levels doesn't matter, if it is finite, then it is digital, isn't it? But why did you classify it as analogue?

author: MK14
author_rank: Super Contributor
timestamp: October 30, 2023, 07:19:43 pm
content: Quote from: radiolistener on October 30, 2023, 07:12:12 pmThat does seem to be a valid point!BUT, there are some counter examples.Let's say, we had tenidenticalrecords. I.e. They were all pressed (manufactured), from the same master record disc, at the record factory.In practice, there will be tiny, but significant (minute/tiny) variations, from the master they were pressed from. When those ten records are, microscopically or using other techniques, compared to each other.I.e. Noise (variations) between those ten example recordings.BUT, if they had been genuinely digital (E.g. CDs). They would each (assuming no destructive data errors), after any error correction things used in that digital format. Be identical (digitally speaking).I.e. A digital diff of the ten digital versions of those disks (if they had been recorded digitally, rather than as analogue records), would all agree with each other (assuming no bad data blocks or damage, etc).

author: radiolistener
author_rank: Super Contributor
timestamp: October 30, 2023, 07:27:08 pm
content: Quote from: MK14 on October 30, 2023, 07:19:43 pmeach copy of CD disk has it's own errors and it consists a lot of errors, but since records on CD also consists redundant information for recovery purposes, it is recovered on MCU in CD player.

author: MK14
author_rank: Super Contributor
timestamp: October 30, 2023, 07:30:56 pm
content: Quote from: radiolistener on October 30, 2023, 07:27:08 pmI agree. They would (tend to be) different, between the copies of the same CD, if the raw unprocessed (corrected) data, is available. But, after all error corrections have been implemented (and assuming no actual uncorrectable data errors or damage), the CDs would have the same digital data on them (which could be music).

author: TimFox
author_rank: Super Contributor
timestamp: October 30, 2023, 07:36:39 pm
content: Yes, error-correction is vital to audio CDs: In the compact disc system, cross-interleaved Reed–Solomon code (CIRC) provides error detection and error correction. CIRC adds to every three data bytes one redundant parity byte. Phonons are quantized vibrations of solid lattices, not directly relevant to the encoding surface of the vinyl groove in a phonograph record.Of course, the surface itself will become discontinuous at the atomic level, which will vary from disc to disc.The full-scale "wiggle" on an LP is roughly 25 um, and atoms are roughly 10-4um in size, so the noise due to atoms is maybe -108 dB from full-scale, well below the electronic noise level.The only objects that are truly identical are atoms, molecules, elementary particles, and other quantum objects.Classical physics, when colliding billiard balls, could distinguish them by their color.

author: radiolistener
author_rank: Super Contributor
timestamp: October 30, 2023, 07:53:48 pm
content: Quote from: TimFox on October 30, 2023, 07:36:39 pmBut record is made with a needle which is made from solid body and sound waves energy is transferred through needle and is quantized...We can walk more deep and remember that mechanical and sound pressure is transferred with electromagnetic interaction between particles (molecules and atoms). And electromagnetic interaction between particles is quantized with discrete energy portions which also known as photons...So, every thing in our world is discrete. Then there is a question, why you don't classify all things as digital because they all have finite discrete levels?Quote from: TimFox on October 30, 2023, 07:36:39 pmYes, there is noise floor which limits number of pressure levels which can be stable detected, but since number of atoms is finite, there is finite number of configuration for them and finite number of pressure levels which can be recorded on surface. It is very large, but finiteFor example, if wee see on the output of modern 32-bit audio DAC's, the weight of its least significant bit is well bellow thermal noise floor, so you cannot detect it even with using high end measurement equipment. The same, as vinyl record... But someone here classified it as digital, just because it has finite number of discrete levels...

author: TimFox
author_rank: Super Contributor
timestamp: October 30, 2023, 08:10:31 pm
content: A small but macroscopic surface area of the needle is in mechanical contact with a similar small area of the vinyl, and the mechanism responds to either the amplitude or velocity of the needle's displacement (piezo or magnetic, respectively) after passing it through a mechanical system (mass, compliance, etc.).Phonons are waves propagating through a crystal lattice, which have quantum properties.(My favorite is "Umklapp", which is like aliasing in sampled time systems, but in three dimensions.)Phonons in the diamond needle are not relevant to the system response, and are usually up in the GHz range.

author: radiolistener
author_rank: Super Contributor
timestamp: October 30, 2023, 08:26:03 pm
content: there is electromagnetic interaction between particles which transfers sound wave as pressure wave from one particle to another.And the energy of electromagnetic interaction between particles is discrete and quantized with photons. Yes quantum of energy is very small and simple sine sound involves incredible amount of photons to transfer sound wave through vinyl player needle, but energy transfer is discrete, NOT continuous...So, is vinyl record digital?

author: TimFox
author_rank: Super Contributor
timestamp: October 30, 2023, 08:42:00 pm
content: Is it binary?All voltage waveforms can be called analog, even at the input of a binary logic gate, but real systems can interpret the waveform as either a discrete (digital) or continuous (analog) code of the important variable (e.g., musical sound).If the discrete levels that are encoded are closer together than the system noise, then the analog interpretation is normally more relevant.

author: radiolistener
author_rank: Super Contributor
timestamp: October 30, 2023, 08:55:49 pm
content: Quote from: TimFox on October 30, 2023, 08:42:00 pmNo it is not binary and therefore not digital but analogue.But I wonder to know why it is analog from those who thinks that digital means discrete and it don't matter how many discrete levels it has...

author: Zero999
author_rank: Super Contributor
timestamp: October 30, 2023, 08:59:08 pm
content: Quote from: TimFox on October 30, 2023, 08:42:00 pmI remember making that point to an audiophool analogue zealot. I tried all sorts of analogies such as a screen consisting of discrete pixels, views through mist, representing noise, but the concept just didn't sink into his thick head.

author: radiolistener
author_rank: Super Contributor
timestamp: October 30, 2023, 09:00:48 pm
content: Quote from: TimFox on October 30, 2023, 08:42:00 pmNoise floor depends on temperature and bandwidth, does it means that classification digital/analog depends on circuit temperature and signal bandwidth?

author: TimFox
author_rank: Super Contributor
timestamp: October 30, 2023, 09:01:54 pm
content: Quote from: radiolistener on October 30, 2023, 08:55:49 pmValid logic: it is not digital, therefore it is analog.Also: it is not digital, therefore it is not binary.The converse of the second is specious.

author: TimFox
author_rank: Super Contributor
timestamp: October 30, 2023, 09:02:55 pm
content: Quote from: radiolistener on October 30, 2023, 09:00:48 pmTemperature and bandwidth are valid system parameters.Other parameters of the system are also needed to estimate the noise floor, such as operating conditions of the amplifiers.Usually, my statement above can be evaluated without an exact value for the noise floor, in practical situations.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: October 30, 2023, 09:03:24 pm
content: Quote from: IanB on October 30, 2023, 06:41:35 pmI did think about a vinyl record which is effectively a linear sound wave. However, even the vinyl record passes the agnostic test in the sense the mastering, whether in analog or digital, cares nothing about the sound reproduction process. The difference is, a digital system can copywithout generational lossfrom the information store. Ad infinitum. Analog systems inherently inject noise into the duplication process. I remember that very well from the early days of editing VHS video tapes. To duplicate vinyl requires a pressing master which, degrades over usage.So maybe our definition of what IS a digital system needs to state that generation noise is zero. Or the S/N ratio is infinite?

author: IanB
author_rank: Super Contributor
timestamp: October 30, 2023, 09:10:42 pm
content: Quote from: AndyBeez on October 30, 2023, 09:03:24 pmThat seems like a good definition, if we qualify it by saying "in the ideal case" or "in principle". Because in practice, there can be unrecoverable errors during transmission or storage, resulting in information loss. An ideal digital system can store or transmit information such that it can be recovered exactly, without loss.

author: TimFox
author_rank: Super Contributor
timestamp: October 30, 2023, 09:18:41 pm
content: As integrated circuit technology advances, voltage differences between binary states get smaller and the bandwidth gets larger.An article I cited many replies ago goes into practical considerations about when thermal noise will cause excessive error rates in binary hardware, swinging the voltage level outside of the noise margin for enough time to register.

author: radiolistener
author_rank: Super Contributor
timestamp: October 30, 2023, 09:18:59 pm
content: Quote from: AndyBeez on October 30, 2023, 09:03:24 pmI would not refer it to a property of digital system. It don't inject new noise, just because it works with math information about wave instead of wave itself. But noise is still injected when you reconstruct wave on digital to analog converter or when you capture wave with analog to digital converter

author: Electro Fan
author_rank: Super Contributor
timestamp: October 30, 2023, 09:20:17 pm
content: Quote from: AndyBeez on October 30, 2023, 09:03:24 pma copy of a copy

author: RJSV
author_rank: Super Contributor
timestamp: October 30, 2023, 10:18:12 pm
content: O.K. now, you can fault me for having obsessions, lots of them. But observing:Started searching through these pages;....OP only here ONCE, starts this thread. Obsessed would have checked the whole thread, but I gave up at page 7, now assuming OP is maybe, gone now.Seeing some bikering,...(have fun, folks).One argument to be made, is an arithmetic process, say multiplication, where you can just use a PROM, somehow addressed by your two operands. Then, you simply place each answer, when you make (burn) the PROM tables for multiplying. That particular ALU type fragment does not need binary - Boolean to do a calculation, as it's all a look-up table. Now, whether or not the PROM being used is binary based, with internal binary and Boolean functionality, is subject to further argument....(Gosh, I'm my own worst critique, sadly).But if you can set up some functional approach, say, with UNITARY numbers, then no binary (needed). I've done that; the system signals turn out to be 'base 1' or 'un-coded'.With a mechanical, chemical, system type you CAN deal with simple, un-coded signals, in the classic sense, where the 'encoding' is maintained by physical channel or line position, and the time encoding is done by the presence of 'signal'. That is to say; no explicit separate CLOCK signal. Works with a falling 'pinball' or other moving mechanical signal.No Boolean operations, you can address and read your PROM storage device, and get the ALU style multiplication result, again in the non-binary 'base 1' format.Now....Let's argue, about my name/handle....(lol).

author: tooki
author_rank: Super Contributor
timestamp: October 30, 2023, 11:06:49 pm
content: Quote from: radiolistener on October 30, 2023, 07:27:08 pmRecovered/corrected: yes. In an MCU: absolutely not. It’s done in dedicated CD decoder chips. They deliver a finished digital audio stream (typically I2S) either directly to a DAC, or first to a DSP for effects. (And often a separate S/PDIF stream to external digital outputs, either coaxial or TOSLINK optical.)

author: RJSV
author_rank: Super Contributor
timestamp: October 30, 2023, 11:09:47 pm
content: In case you are wondering, the particulars of operating a mechanical or chemical PROM, it goes something like this:(I didn't want to interrupt or distract from established thread, here.)Let's say you've pieced together a decimal system, but using UNITARY or un-coded signalling:To access your PROM in a row/column fashion, say you have a BUS SWITCH that will direct your BUS. You need ten variations, of zero thru 9. Let's say it's a '7', which will enter and operate (position) your multi-pole BUS SWITCH. If you can get your signal,...I.E. a seven, to reset all ten BUS switches, except the one for ROW7, and have it (the unitary '7' signal) have it also SET the ROW7 switch, then that half of procedure is done.Next, you can send the second operand on down the BUS, from the top (gravity fed system), then that is a full decode, to the desired (Row, Column) memory cell. Example that might be a 'two', if you've set up to multiply '7 X 2'.Each of the ten signals does this, including 'zero'. That symbol 'zero' has equal weight as the others, being a symbol, not a numeric value, or at least not directly explicitly.As a second example, suppose you are multiplying '5 X 3'. In that example, the incoming '5' is another custom signal, that turns off the switches (0, 1, 2, 3, 4, 6, 7, 8, and 9). Meanwhile also sets the Row5 BUS switch. This way the mechanical signal PROM points to the correct ROW. It's this customized approach, slightly bulky, that gets you the function you want; BUS selection, as per each individual signal. This all fits in a single X,Y (row, column) access scheme.Each such BUS switch has two pivot positions, so you could argue that...

author: tooki
author_rank: Super Contributor
timestamp: October 30, 2023, 11:13:52 pm
content: Quote from: radiolistener on October 30, 2023, 07:53:48 pmThat “somebody” wasyouif I’m not sorely mistaken.As I and others have said: part of a DAC is output filtering, and that completely removes the stair steps and restores the original signal.I’m not aware of any 32-bit ADCs and DACs. You can sorta get 32 bits by oversampling. My understanding is that 32-bit audio formats basically begin as 24-bit sampled audio, and the extra bits are to maintain fidelity during subsequent audio production. Output occurs through whatever DAC the listener is using, after distribution as 16-bit (usually) or 24-bit (“high res”) compressed or uncompressed audio. .

author: radiolistener
author_rank: Super Contributor
timestamp: October 31, 2023, 07:26:02 am
content: Quote from: tooki on October 30, 2023, 11:13:52 pmI'm talking about 32-bit DAC's likeAK4493SEQorPCM1795or something like that, which is used in modern high-end audio.

author: tggzzz
author_rank: Super Contributor
timestamp: October 31, 2023, 08:32:54 am
content: Quote from: AndyBeez on October 30, 2023, 09:03:24 pmBetter to state the necessary and sufficient condition which enables that: discrete levels with a "forbidden zone" between levels.

author: tooki
author_rank: Super Contributor
timestamp: October 31, 2023, 08:38:56 am
content: Quote from: radiolistener on October 31, 2023, 07:26:02 amWithout intending to apply a “no true Scotsman” argument, they certainly do accept 32-bit formats, and looks like nice parts, but at a maximum 125dB and 126dB, respectively, SNR (and dynamic range) their true resolution is just under 21 bits. :/

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2023, 01:52:56 pm
content: Quote from: tggzzz on October 31, 2023, 08:32:54 amThe "forbidden zone" is a measure of "noise immunity", which is mandatory for binary and other digital systems to be discrete.Note that the "systems" are digital or analog, the voltage is whatever it is made to be, but the systems' valid states are discrete.

author: radiolistener
author_rank: Super Contributor
timestamp: October 31, 2023, 02:16:41 pm
content: Quote from: tooki on October 31, 2023, 08:38:56 amThey have true resolution 32 bit.SNR shows dynamic range between max amplitude 0 dBFS and noise floor. Ideal 32 bit DAC has quantization noise floor at -194.4 dBFS. But in reality there are a lot of other noise source, so the real noise floor is always worse than quantization noise of ideal DAC. This is why effective number of bits is always less than DAC resolution. For high resolution DAC's this difference is higher. But all 32 bits of these 32 bit DAC are real and used for conversion.ENOB < resolution bits is due to presence of unwanted noise sources and leakage. Not because they have less significant bits.It means that you can use all 32 bits, all of them will work and you will find with tests that they all are significant. But if you want to get full 194.4 dB dynamic range from that 32 bit DAC, you will get noise limitation at 123 dB. This is analog circuit limitations... Most of opamp have about 90-100 dB dynamic range or even worse, so 123 dB is very good result.

author: RJSV
author_rank: Super Contributor
timestamp: November 02, 2023, 09:36:09 pm
content: Hi there, OP !Doing some more thinking. Wanting to consider the meaning, when a 2-state device, like any typical pivot lever or sliding thingy gets involved, where the machine itself isn't considered to be in BINARY realm, (such as previous example running as a decimal device and decimal BUS for data transfers. I think the fuller description has to be something along the lines of 'Binary Coded' numbers. Otherwise, any device having an obvious physical set of two stable states of position could force folks to admit, perhaps incorrectly, that some system is binary based.But that's somewhat imperfect, when a single bit is (often) processed as, yes, 'BINARY'. So;...round and round we go.I'd suggest, maybe a more nuanced approach, to 'tiptoe past' the 2-position things as being (sole) proof. Otherwise every open/closed door, eyelash, birth twins, and other 'things of two's in a set, would trigger a legitimate 'binary System' label.Having said that, the OP's question included OCTAL, and DECIMAL based systems. In those two types, definitely binary, the OCTAL variation uses 3 bits, in binary code, using all eight states, (0 thru 7).The BCD types simply use just the first 10 states, usually ignoring the (10 thru 15) binary states available, to create a system that has decimal based behavior, and, on lowest function level, binary based hardware.Another system type is ASCII, for encoding a character set, using 7 of the available bits, (in a system byte), where I believe there are 96 distinct states used for characters, again ignoring states from 97 through 127. Those, of course, are useful when encoding various punctuation symbols.So, that language could refer to a 'base 96' system, incorrect language as the 'base' is still base 2, or binary based.Somewhat of a matter of language, but I tend to consider a binary coded decimal system as having BOTH types, in a hierarchy,...not definitely correct. Similarly, if you had a BCD system using two digits (BUS), then I like to refer to'Base 100', the most correct phrase is 'Modulo 100', as a programmer would think of the BUS and memory formats. It's more of being 'virtual base100' in those cases.Twisted language, but once you've used the 'virtual' term....gets dicey but survivable..