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I do understand why 1 and 0 are used and why we have to make two states for data transfer storage and the rest. And why those two symbols and not off and on or some other means. It was most efficient and simple.

My quarrel is that 0 does not represent 0 volts but represents a range of lowest voltages or a range of falling voltages as it has a clear verticle component no matter what system is used to show it. the point is it is a range of values and not 0. If we use positive/negative phase or half of a phase or any other system makes no difference. I have never seen 0 volts in any graphs to represent 0. 0 volts one way or another has a verticle component. If 0 really is 0 volts, it would be the time axis itself because that is where we represent 0 volts and our instruments are on our side as the evidence.

In actuality 1 also represents a range of highest voltages (plural) no matter what system we use. They both 0 and 1 have a verticle line ( a leaning one implying gradual) But my main quarrel is with 0 because it means off. By consensus off means, nothing equivalent to transmission lines being down, the instrument is off.

It is interesting to notice that verticle lines have leans but horizontal lines are flat. sure, it makes sense. It is easier to maintain set voltage than the sudden value of some voltage value or no voltage value which is understandable. I have yet to see where we would achieve a duration of 0 volts on the time axis with no verticle component to mean that will indeed mean off (0 volts). If that be the case now and I somehow have not paid attention to please enlighten me. Thank you very kindly.

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    \$\begingroup\$ It is not clear what your question is. Could you please clearly ask a question that can be answered? \$\endgroup\$ – TimWescott Feb 22 at 3:36
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    \$\begingroup\$ Nothing says 0 has to be a low voltage and 1 a high voltage. It usually is, though. \$\endgroup\$ – Hearth Feb 22 at 3:38
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    \$\begingroup\$ The key is that there are two states sufficiently different to usually be able to tell them apart. What those states are, their source properties and their receiver decision threshold are implementation detail. \$\endgroup\$ – Chris Stratton Feb 22 at 3:43
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    \$\begingroup\$ All the answers are on the web, you must learn to understand the basics and learn how to learn. \$\endgroup\$ – Tony Stewart EE75 Feb 22 at 3:59
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    \$\begingroup\$ Ali - Welcome :-) I have "rolled back" (i.e. reversed) your edit, as it turned the question into a story (this site is not an appropriate place for life stories). Thanks. \$\endgroup\$ – SamGibson Feb 23 at 11:53
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In computer science, 1 is 1 and 0 is 0. What voltage or range of voltage levels represent those binary values is irrelevant.

In electronics, there is always a range of voltages associated with each value. This range depends on the particular technology. For example, in 3.3 V CMOS logic, voltages above 2.0 V are '1', and voltages below 0.8 V are '0'. In ECL logic, voltages above about -1 V are '1', and voltages below about -1.7 V are '0'.

But computer science is all about abstraction. The binary logic studied by computer science doesn't depend on the physical circuit used to implement it or the specific voltages used to represent the different values that the binary value can take.

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0 and 1 are simply the numbers allowed in binary. You can represent them any way you choose. A 0 may be represented by a frequency and a 1 by another frequency. Whether you are talking about the binary language of moisture evaporators, or data transmission via RS232, binary only has two states and those two states are represented by 0 and 1.

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It sounds as if you are personally offended that the (((symbol))) "0" is not rigidly limited to the (((physical value))) 0.00000000000 V.

0 and 1 are symbols, not physical constructs. Each symbol represents an agreed-upon set of physical conditions. In a super market, 1 represents a quantity of apples. In RS232, 1 represents a voltage range between approx. 3 V and 12 V. That literally is the world we live in.

NOTE that while in most traditional logic systems these sets of conditions are mutually exclusive, they are by no means unique. TTL, ECL, PECL, CMOS, LVDS, RS232, RS422, and on and on and on. There are dozens of different logic and data systems, many with overlapping physical descriptions (HCT and ACT CMOS devices follow TTL voltage regions) but many more with unique characteristics.

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    \$\begingroup\$ Technical quibble: in RS232, a 1 is represented by -3V to -15V while a 0 is represented by +3V to +15V. \$\endgroup\$ – brhans Feb 22 at 4:04
  • \$\begingroup\$ Yet RS232 has exactly the same threshold as TTL... 1.3V but RTS/CTS = true when high \$\endgroup\$ – Tony Stewart EE75 Feb 22 at 4:05
  • \$\begingroup\$ brhans - a tickle in the back of my brain said to check that. Been too long ... \$\endgroup\$ – AnalogKid Feb 22 at 6:06
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The easiest way to see zero volts is to not look too closely.

Most logic gates treat voltages close to zero as a zero and voltages distant from zero in a positive directions as a one.

Where they draw the line between 0 and 1 differs.

The datasheet for a part will tell you what range of voltages is acceptable as 1s and what range is acceptable as 0s

There will be a gap between the two ranges and actual boundary between 0 and 1 will be in that gap somewhere. but so long as your signal hits the allowed ranges it will be interpreted correctly.

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I do understand why 1 and 0 are used and why we have to make two states for data transfer storage and the rest. And why those two symbols and not off and on or some other means. It was most efficient and simple.

I already answered this in a previous question of yours. We use one and zero because we do math with it. You can call the states something else like A and B but it is difficult to do math like that. We try not to use things like HI/LO and ON/OFF because it fixes the logical interpretations to a physical representation which might change from system to system. Some systems might interpret ON/OFF as ONE/ZERO but others might interpret OFF/ON as ZERO/ONE.

My quarrel is that 0 does not represent 0 volts but represents a range of lowest voltages or a range of falling voltages as it has a clear verticle component no matter what system is used to show it. the point is it is a range of values and not 0. If we use positive/negative phase or half of a phase or any other system makes no difference. I have never seen 0 volts in any graphs to represent 0. 0 volts one way or another has a verticle component. If 0 really is 0 volts, it would be the time axis itself because that is where we represent 0 volts and our instruments are on our side as the evidence.

I also answered this in a previous questions of yours. Logic zero does not have to a low voltage range. It can be whatever the system designer wants it to be. Furthermore, logic zero cannot be made to work in reality if you define it as 0V because that means you are defining it as exactly 0V.

We use a range of voltages is because nothing in real life is ever exact. If I tell you to send me a 0V signal when you are ready, I am going to be waiting forever as while you hopelessly and repeatedly send voltages just below 0V and just above 0V over and over again without ever sending one that is exactly 0V.

In actuality 1 also represents a range of highest voltages (plural) no matter what system we use. They both 0 and 1 have a verticle line ( a leaning one implying gradual) But my main quarrel is with 0 because it means off. By consensus off means, nothing equivalent to transmission lines being down, the instrument is off.

Again, 1 does not have to represent the highest voltage range we are using. The system designer can make any voltage range map to logic 1.

You seem to have trouble believing that it is impossible to communicate when one of your communication symbols shares the same state as when the system is off, but you do it every day.

Think about this: When someone is speaking to you on the phone, the person has silences between each word. Do you think they hung up every time there is a silence? Of course not. Why not? Because it falls into the expectations of communication protocol you are using. The language you are using sets rules and expectations for what has meaning. If the silence lasts too long to have any meaning in the language then you might determine that the connection was lost. This is the same as a timeout in an electronic system.

If the other person starts making garbled noises that do not follow the rules or have any meaning in the language, you know the line is disrupted and you ignore what was said and might try to ask them to repeat what they said. This is the similar to a retry acknowledgement in an communication system.

Electronic systems also have languages (communication protocols). There are fixed ways to begin and end messages, messages have fixed lengths, and if they don't then the length of the entire message is sent somewhere near the beginning of the message so the system know what to expect.

You could make it so your signal states are unique from the system's off state, but this requires more hardware. Sometimes this is done, but often times it is not because you simply don't need it because the communication protocol and rules sets expectations for what a valid communication is.

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Hi / Lo are often equated to True//False and 1/0 in binary, while voltages are analog, with a valid range for each and margin in between.

I would say your quarrel ought to be a quandary, because there are so many reasons for this binary math. 1/0 or T/F are just symbols that represent Aristotlean logic and computer logic which are fields in math, logic and Philosophy. ( and ESC)

  1. There are actually 3 states or tri-states where the 3rd is high impedance at any floating voltage. (because the output was disabled )

  2. You will also see negative logic , which just means active low =0=ON such as in TTL Set/Reset and IRQ! in CMOS.

  3. Assume all electronic logic is based on analog voltages but we decide for each supply voltage a threshold with tolerances so there is room for noise and thermal drift. Thus the specs in datasheets will indicate max Vil (input-low) and min Vih (input high).

  4. Again analog with CMOS which has a switch resistance that varies with supply voltage and CMOS family , you get an impedance from the output voltages at standard currents. Vol (min) @ Iol implies Vol/Iol=Rol which limits current and capacitance limits risetime ( the slope) dV/dt=Ic/C or Vdd/Rol*C where C is CMOS input capacitance and trace capacitance combined.

But for binary CMOS specs are typically designed for a threshold at Vdd/2 with at least 25% tolerance over production variances and temp adds more variation.

But Binary leads to Hex which is used for convenient address words and Bytes of memory.

There's are only 10 (binary two) types of people at birth, one is Female, and the other is Male. But we don't need to count these in binary so we use decimal. Roman's never thought they need a zero. ;)

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