Maybe you can understand if you think of an OR gate that is made with two switches in parallel in series with a light bulb and battery. The state of each switch are the inputs. The output is the state of the lamp. For the inputs we will say that when the switch is closed it is a "1" state. When the switch is open it is a "0" state. For the output if the lamp is lit it is a "1" state. If it is not lit it is a "0" state. If either or both switches are closed (A "1" state.) the lamp will be lit. (A "1" state). If both switches are open (A "0" state) then there is no path for the current so the lamp will not be lit. (A "0" state.) If you wired the switches in series instead of parallel then you would have an AND gate. Both switches would have to be closed for there to be a path for the current so the lamp would light. If you actually build the gates this way and play with them it will get rid of this strange concept of "smashing outputs"


Les.

thank you .. do you know what was confusing me? and already appreciated WBahn about his answer ..

lets say I did of what you're saying on OR gate, lets say I was having 1,0 (respectively ordered !) then light is on, now changed to 0,1 (be careful about its order) then the output is "1" means that the bulb is lightened, but my question which already WBahn answered me, the light isn't go off for nano seconds because of getting new '1'(I conversed the inputs) and then come back light on, why? because simply if it was 1 then it stays 1.. and if what WBahn is demonstrating is wrong then my bulb would be go OFF for nano seconds and then on, but he answered me correctly and I appreciate you and him about his cooperative !

 

The TS is struggling with BASIC memory concepts; I saw no reason -- and specifically chose to avoid -- talking about vestigial traces of prior data due to the physical mechanisms to implement memory storage that require Herculean efforts and big bucks to exploit.

I don't know how to tag you .. just mentioned you in my last comment to be aware of

 

I don't know what it is that you do not understand.

I walk into a room and I look at the light switch (or maybe the light).
If I want it on, I turn it on.
If I want it off, I turn it off.
If the switch is already in the state that I want it to be, I leave it alone.

What is confusing about this?

 

How about a blackboard? You’ve written your name on it, Ryan, and you leave the room. I come in, erase your name, and write my name on it, dj. I might leave the room, but you come in and say, “What happened to my name?”

 

How about hard disks? It's been my impression since forever, that there is some sort of "ghost" of previous data sometimes accessible if you know how to access it. Popular "secure" hard drive wiping methods involve overwriting the HDD several times to ensure that this data is sufficiently corrupt that it can't be recovered.

I will answer this even though it is off topic.

Data on disks are written, not in bits nor bytes, but in blocks at a time called sectors. One sector might contain 256 or 512 bytes, or how many the disk controller has been programmed to use.

When a file is deleted, the data in the sector is not erased. What is updated is a sector table that says which sector is currently being used by a file and which sectors are up for grabs. Hence it is possible to "undelete" a file even after it has been deleted so long as the deleted sector has not been subsequently allocated to another file.

 

I don't know what it is that you do not understand.

I walk into a room and I look at the light switch (or maybe the light).
If I want it on, I turn it on.
If I want it off, I turn it off.
If the switch is already in the state that I want it to be, I leave it alone.

What is confusing about this?

the confusing is if it was off why would you turn it off?! is the PC much stupid to turn it twice on or off?
I'm just wondering if this really like that PC works or not, not saying you're not correct!

 

I will answer this even though it is off topic.

Data on disks are written, not in bits nor bytes, but in blocks at a time called sectors. One sector might contain 256 or 512 bytes, or how many the disk controller has been programmed to use.

When a file is deleted, the data in the sector is not erased. What is updated is a sector table that says which sector is currently being used by a file and which sectors are up for grabs. Hence it is possible to "undelete" a file even after it has been deleted so long as the deleted sector has not been subsequently allocated to another file.

thank you, my question to you is , what's the suitable " term " to say about the change from "OFF" to "ON" or conversely .. meaning what's the suitable term in electrical field to describe the phenomenon of changing between 0 and 1 i.e what's called the occurring "phenomenon" that describes the change between there's light and there's no light .....

 

Did you read this sentence?

If the switch is already in the state that I want it to be, I leave it alone.

Off Topic
Yes, there are situations where the PC will read off and put it back. I will not elaborate on this to avoid confusing you more.

 

thank you, my question to you is , what's the suitable " term " to say about the change from "OFF" to "ON"

The term we use is "change" or "transition".

or conversely .. meaning what's the suitable term in electrical field to describe the phenomenon of changing between 0 and 1 i.e what's called the occurring "phenomenon" that describes the change between there's light and there's no light .....

We say change or transition from 0 to 1, or logic LOW to logic HIGH.

In programming circles, we say change or transition from FALSE to TRUE.

We definitely do not use the word "smash".

 

Did you read this sentence?


Off Topic
Yes, there are situations where the PC will read off and put it back. I will not elaborate on this to avoid confusing you more.

So I can visualize that PC like ME (human) if I entered the room that was lightened and wanted to light it then keep it and get off directly. like that PC operate? wow it's good approach !

Yeah please don't tell me how because I dont want to be more confused and it's not the time to be known of ! just wanted to see how does it operate and got the answer !


thanks !

 

Hello,

In PC memory made of DRAM, the data is "refreshed" periodicaly, to avoid memory loss.
Read this wiki about the DRAM:
https://en.wikipedia.org/wiki/Dynamic_random-access_memory

Bertus

 

Imagine a keyboard with two keys - an ON key and an OFF key.
If you want whatever it is that the keys control be be ON, you push the ON key. You don't know whether the controlled thing was already on and you don't care if it was already on - you just want to be sure it is on when you have done your job pushing the ON button.
If you want whatever it is that the keys control to be OFF, you push the OFF key. You don't know whether the controlled thing was already OFF and you don't care if it was already off - you just want to be sure it is off when you have done your job of pushing the OFF button.
It isn't your job as the pusher of buttons to know what something else will do according to whether the device is on or off, your job is to push the buttons appropriately to make sure it is on or off.

This is exactly how data is written to memory in a computer.

 

OFF TOPIC ON THE DISK DATA ISSUE:

It has to do with magnetic remnance. Suppose you compose your note and write RANSOM to the disk. To try to cover that up after the note has been printed you write 000000 over top of RANSOM. What you are actually doing you can view as laying down 99% of each 0 and leaving 1% of each of the original characters - not quite perfect overwriting because the head may not be in precisely the same position, the force from the head might not be quite enough to change all the magnetic domains, etc. (99% and 1% totally pulled from thin air for illustration; I have no idea what the actual case might be). As far as the normal read head is concerned, all that is there is zeros. It simply has no hope of being able to detect the "shadow" and you wouldn't want it to be able to - it's like hysteresis where you want to ignore the noise. With the right equipment, the tiny differences between the shadow and 000000 may be detectable. It would be clear you wrote 000000 so the net result of 1% of RANSOM and 99% of 000000 would, if you could remove the 99% effect, reveal RANSOM. If you write 000000 again, you would, more or less, have only 1% of 1% of the original RANSOM left, making it much harder to detect. If you wrote 6 random characters each time, you can do a better job because the "filter" for the first over-write is much harder to discern. If you wind up in court with the prosecution claiming they found RANSOM, grill them at great length to prove they didn't find RANDOM. They went in there with the expectation of finding RANSOM, so there is confirmation bias on their part.

 

Imagine a keyboard with two keys - an ON key and an OFF key.
If you want whatever it is that the keys control be be ON, you push the ON key. You don't know whether the controlled thing was already on and you don't care if it was already on - you just want to be sure it is on when you have done your job pushing the ON button.
If you want whatever it is that the keys control to be OFF, you push the OFF key. You don't know whether the controlled thing was already OFF and you don't care if it was already off - you just want to be sure it is off when you have done your job of pushing the OFF button.
It isn't your job as the pusher of buttons to know what something else will do according to whether the device is on or off, your job is to push the buttons appropriately to make sure it is on or off.

This is exactly how data is written to memory in a computer.

But the pushed data where it gone?
You are confusing me more ..not accepting ur analogy at all sorry ?

I mean the pushed key where did it gone? Here ur analogy falls.

 

I'm sorry, I can see no way of getting through to you. I can think of other analogies, but you seem to have some strange fixation that is blocking your comprehension.

 

But the pushed data where it gone?
You are confusing me more ..not accepting ur analogy at all sorry ?

I mean the pushed key where did it gone? Here ur analogy falls

At this point it is clear that you are completely, hopelessly lost, and have somehow managed to get yourself thoroughly confused by trying to understand computers in terms of analogies that are loose, partial and imperfect.

This stuff is really, REALLY simple and easy to understand if you just discipline your mind a little bit to avoid using analogies as a crutch.

My advice: get yourself a good book on computers and their major components and how they operate, and study it. Learn the basic concepts involved using the standard, commonly accepted terms used in industry. And stop getting waylaid by analogies into drawing elaborate, convoluted and erroneous conclusions from them through "newbie logic."

 

At this point it is clear that you are completely, hopelessly lost, and have somehow managed to get yourself thoroughly confused by trying to understand computers in terms of analogies that are loose, partial and imperfect.

This stuff is really, REALLY simple and easy to understand if you just discipline your mind a little bit to avoid using analogies as a crutch.

My advice: get yourself a good book on computers and their major components and how they operate, and study it. Learn the basic concepts involved using the standard, commonly accepted terms used in industry. And stop getting waylaid by analogies into drawing elaborate, convoluted and erroneous conclusions from them through "newbie logic."

You mean in other words that I'm stupid and dumb for asking like these question? if so then I wouldn't open a thread for that, secondly if you are trying to say "it's like this just because it's this" then you're wrong because we must understood how actually PC works not saying ..well it's working like that ..next !

thanks

 

OFF TOPIC ON THE DISK DATA ISSUE:

Yes, it's off topic. Please take it to a separate thread where you can talk about it to your heart's content. I will probably join you there. Here is not the place to discuss it.

 

the confusing is if it was off why would you turn it off?! is the PC much stupid to turn it twice on or off?
I'm just wondering if this really like that PC works or not, not saying you're not correct!

At the end of the day, computers are completely and total stupid -- they have no intelligence whatsoever. None. They are electronic circuits that take inputs and produce outputs based on how the circuit is wired to behave.

Perhaps a better analogy is a light in a center room that has two switches than can each turn it on by pressing it and holding it. But the two switches are located in two separate room and the person in that room that is going to press it has no idea whether the light is on or off or whether the person in the other room is pressing their switch or not.

So if Person A wants to turn on the light, they press the button in Room A. Similarly, if Person B wants to turn on the light, they press the button in Room B. If Person A is holding the button down and Person B isn't, the light (in Room C) is ON. If Person B no presses the button, the light stays on continuously. Someone in Room C sees no change, not even for a microsecond. If Person A now releases their button, the light continues to shine, without interruption. The light only goes off when BOTH buttons are not being pushed, and it is ON when either Button A OR Button B is pressed -- this includes the case when both buttons are being pressed, making it what is known as an "inclusive-OR", meaning that the output is HI (ON, True, 1, whatever it makes sense to call it) when one input, the other input, or both inputs are HI.

 

At the end of the day, computers are completely and total stupid -- they have no intelligence whatsoever. None. They are electronic circuits that take inputs and produce outputs based on how the circuit is wired to behave.

Perhaps a better analogy is a light in a center room that has two switches than can each turn it on by pressing it and holding it. But the two switches are located in two separate room and the person in that room that is going to press it has no idea whether the light is on or off or whether the person in the other room is pressing their switch or not.

So if Person A wants to turn on the light, they press the button in Room A. Similarly, if Person B wants to turn on the light, they press the button in Room B. If Person A is holding the button down and Person B isn't, the light (in Room C) is ON. If Person B no presses the button, the light stays on continuously. Someone in Room C sees no change, not even for a microsecond. If Person A now releases their button, the light continues to shine, without interruption. The light only goes off when BOTH buttons are not being pushed, and it is ON when either Button A OR Button B is pressed -- this includes the case when both buttons are being pressed, making it what is known as an "inclusive-OR", meaning that the output is HI (ON, True, 1, whatever it makes sense to call it) when one input, the other input, or both inputs are HI.

Alright ! to sum up that the binary numbers "0/1" we can say its something can't be elaborated something itself says what's going on presently ..meaning recording what's happening right now and only just present ! , so in one word the interface of using 1/0 is in a sense of itself elaborated itself like 1+1=2 why? because simple 2 .. and there's no need to complex it ! all about "how" pc operates and its languages are just describing what's going on in present and only in present irrelevant to previous/future!

at the end there's facts of actually how PC operates that it based on them and subjected to them, so we must followed them comprehensively and believe in them in a sense ..

that's what I have concluded of whole our discussion.