Reasons for hacking DSOs

[kcbrown]

Arguing what today's written laws say is pointless.

If something becomes widespread enough to affect a large company's business model then laws will appear. Bet on it.

I should note that this is an invalid argument.

It amounts to an argument that says "you shouldn't do X, because if you do X, then it will be made illegal and you won't be able to do X anymore".

But someone who is refraining from doing X because it might otherwise become illegal can't possibly be concerned about the legality of doing X, because at that point the legality of doing X makes absolutely no difference -- their behavior is already the same as it would be if X were illegal.

If you are concerned about some action becoming illegal, then you have to suggest something else other than refraining from the action as a means of preserving its legality.  Something that is legal but that nobody does for fear of it becoming illegal is something for which its legality is already irrelevant.

[kcbrown]

You have unusually limited requirements.

Yes, my requirement are limited. (I use my scope maybe 10 times a year, even.) But maybe not so unusually so. Even 10 MHz and 25MHz scopes were very popular 5 years ago. Or even in the 70's. I wonder why it's necessary to have a 100MHz scope to use logic chips? Back when I actually used them, I didn't even have a scope.

If you scoped a TTL logic circuit on a 50MHz scope, you would see nothing useful, then?

You would see some useful things, but miss important ones such as voltage overshoot, bad edges, and runt pulses. Collectively known as signal integrity.

Modern logic is faster, even jellybean components have >700MHz components.

The next logical question would then be: what would a 100 MHz scope allow you to see in that a 50 MHz one wouldn't, in the modern digital domain?  A related question might be: what's the minimum scope bandwidth necessary to see artifacts like ringing, overshoot, etc., with modern digital components, assuming that the base clock frequency you're using is well under 50 MHz (I realize that isn't really relevant to the artifacts themselves, but I mention it because a 50 MHz scope probably won't be useful for much if the base clock frequency exceeds that).


All of which is to say: under what circumstances with modern digital components would 100 MHz be useful where 50 MHz wouldn't be?

[tggzzz]

You have unusually limited requirements.

Yes, my requirement are limited. (I use my scope maybe 10 times a year, even.) But maybe not so unusually so. Even 10 MHz and 25MHz scopes were very popular 5 years ago. Or even in the 70's. I wonder why it's necessary to have a 100MHz scope to use logic chips? Back when I actually used them, I didn't even have a scope.

If you scoped a TTL logic circuit on a 50MHz scope, you would see nothing useful, then?

You would see some useful things, but miss important ones such as voltage overshoot, bad edges, and runt pulses. Collectively known as signal integrity.

Modern logic is faster, even jellybean components have >700MHz components.

The next logical question would then be: what would a 100 MHz scope allow you to see in that a 50 MHz one wouldn't, in the modern digital domain?  A related question might be: what's the minimum scope bandwidth necessary to see artifacts like ringing, overshoot, etc., with modern digital components, assuming that the base clock frequency you're using is well under 50 MHz (I realize that isn't really relevant to the artifacts themselves, but I mention it because a 50 MHz scope probably won't be useful for much if the base clock frequency exceeds that).


All of which is to say: under what circumstances with modern digital components would 100 MHz be useful where 50 MHz wouldn't be?

This is well documented;  Google is your friend. " Bogotin rule of thumb" is a good starting point.

Start from the rule of thumb that the transition time is 0.35/BW.

[kcbrown]

All of which is to say: under what circumstances with modern digital components would 100 MHz be useful where 50 MHz wouldn't be?

This is well documented;  Google is your friend. " Bogotin rule of thumb" is a good starting point.

Start from the rule of thumb that the transition time is 0.35/BW.

That ... is a gold mine!   Thanks!   

[KL27x]

+1 Thanks.  kcbrown, too, for the practical illustration.

[hamster_nz]

Consider, for example, a very realistic and practical digital waveform that you can find in virtually any digital circuit since the late 1970s: a waveform with 1MHz frequency (i.e. << your 7MHz) and a 1% duty cycle, i.e. a 10ns wide pulse.

In digital circuits the only relevant parameter is risetime and the ability to observe it. A 100MHz scope will enable you to see the 3.5ns transitions and the pulse top. A 50MHz scope won't.

Even with a 100 MHz scope a 10 ns the wide pulse would be poorly represented, to the point of having very little useful information apart from "oh - a glitch?". 100 MHz is the -3db frequency (at least for the Rigol datasheet I looked at).

I could do the actual math (e.g. a FFT on 1000 points (10 high, 990 low), clip the high frequency stuff, attenuate around 100MHz  and IFFT), but it will be more truthful if I try it at home tonight on an actual scope (e.g. 5ns vs 10ns pulses on a 100MHz scope).

If I get a chance I will try it and post results...

[tggzzz]

Consider, for example, a very realistic and practical digital waveform that you can find in virtually any digital circuit since the late 1970s: a waveform with 1MHz frequency (i.e. << your 7MHz) and a 1% duty cycle, i.e. a 10ns wide pulse.

In digital circuits the only relevant parameter is risetime and the ability to observe it. A 100MHz scope will enable you to see the 3.5ns transitions and the pulse top. A 50MHz scope won't.

Even with a 100 MHz scope a 10 ns the wide pulse would be poorly represented, to the point of having very little useful information apart from "oh - a glitch?". 100 MHz is the -3db frequency (at least for the Rigol datasheet I looked at).

Agreed, but my simplification should be read in the context of the person's question - and subsequent questions for that matter.

[tggzzz]

All of which is to say: under what circumstances with modern digital components would 100 MHz be useful where 50 MHz wouldn't be?

This is well documented;  Google is your friend. " Bogotin rule of thumb" is a good starting point.

Start from the rule of thumb that the transition time is 0.35/BW.

That ... is a gold mine!   Thanks!   

You're welcome.

Don't forget that the most important rule of thumb is number 0.

[G0HZU]

Consider, for example, a very realistic and practical digital waveform that you can find in virtually any digital circuit since the late 1970s: a waveform with 1MHz frequency (i.e. << your 7MHz) and a 1% duty cycle, i.e. a 10ns wide pulse.

In digital circuits the only relevant parameter is risetime and the ability to observe it. A 100MHz scope will enable you to see the 3.5ns transitions and the pulse top. A 50MHz scope won't.

Even with a 100 MHz scope a 10 ns the wide pulse would be poorly represented, to the point of having very little useful information apart from "oh - a glitch?". 100 MHz is the -3db frequency (at least for the Rigol datasheet I looked at).

I could do the actual math (e.g. a FFT on 1000 points (10 high, 990 low), clip the high frequency stuff, attenuate around 100MHz  and IFFT), but it will be more truthful if I try it at home tonight on an actual scope (e.g. 5ns vs 10ns pulses on a 100MHz scope).

If I get a chance I will try it and post results...

Yet he defines it as a practical digital waveform found in virtually any digital circuit since the late 1970s. 

Many hobbyists today will tinker with MCUs from AVR or PIC and they will do it on poorly laid out breadboards or PCBs. A 50MHz scope will often be fine for stuff like this.

[vk6zgo]

You never look at square waves higher than 7 MHz or so?

What does frequency have to do with it? All square waves are infinite.

Square waves are infinite but the ability of your oscilloscope to display them is not.  That limitation is due not just to the frontend bandwidth, but also to things like the display itself.

The factor of 10 thing is a somewhat arbitrary cutoff.  It may be that you actually want to examine irregularities in the square wave that have a frequency characteristic greater than 10x of the primary frequency.  10x is just an easy frequency to still see in a square wave when you're viewing a few cycles of the wave on the scope, whilst 100x probably isn't (even if the scope has the bandwidth and sampling rate for that, the display's resolution probably prevents you from seeing frequencies that high as anything more than vertical lines until you zoom into the waveform).

The slower the base frequency of the wave, the more component frequencies you'll be able to see on the screen before you run into bandwidth limits.  Of course, you might run into display resolution limits first.

Ideal square waves are infinite,but the ones we deal with already have limits on their frequency composition caused by imperfections in real generators.
From memory,a square wave can be regarded as reasonable it it contains up to & including the 7th harmonic of the fundamental frequency.
This agrees with an earlier poster's comment about a 50Mhz 'scope & a 7MHz square wave.

If the 'scope response at 49MHz is already close to 3dB down,it will round off the waveform a bit.
70MHz would be a better choice,hence the "10x fundamental"rule.

[kcbrown]

Square waves are infinite but the ability of your oscilloscope to display them is not.  That limitation is due not just to the frontend bandwidth, but also to things like the display itself.

...

Ideal square waves are infinite,but the ones we deal with already have limits on their frequency composition caused by imperfections in real generators.

That's true, but in order to know what those limits are, you have to have something with enough bandwidth to examine them, or I guess the data sheet will tell you.

In any case, because that's basically a variable, and because (near as I can tell -- I might be mistaken) the primary frequency of ringing seems to be related to the rising edge time, you'd want a scope with enough bandwidth to handle the rising edge time at least.

From memory,a square wave can be regarded as reasonable it it contains up to & including the 7th harmonic of the fundamental frequency.
This agrees with an earlier poster's comment about a 50Mhz 'scope & a 7MHz square wave.

If the 'scope response at 49MHz is already close to 3dB down,it will round off the waveform a bit.
70MHz would be a better choice,hence the "10x fundamental"rule.

Yeah, makes sense for seeing that the square wave reasonably looks like a square wave.  But what about catching artifacts that could be screwing with your circuit (or be evidence of a problem)?


Don't get me wrong, I suspect that 50 MHz is pretty decent for a lot of hobbyist work.  Those scopes probably wouldn't sell all that well otherwise.  But it seems to me that bandwidth is kinda like horsepower: there's no such thing as too much.   

[Fungus]

Arguing what today's written laws say is pointless.

If something becomes widespread enough to affect a large company's business model then laws will appear. Bet on it.

I should note that this is an invalid argument.

It's not an argument, it's an observation.

Large companies can (and do) buy laws for themselves. Laws that can harm consumers.

Ask yourself why TTIP is being "negotiated" in secret with no public input.

Today's laws make the framework we currently operate under.  If you want to pretend that you operate under a more restrictive framework than that, you can certainly do so, but if you do that, then how far are you going to take it?  Are you going to make no modifications to your automobile, for instance, to improve its capability?  Are you going to refrain from improving anything you have, just because a future framework of law might forbid it?

It's your call, but I'd advise living for today (while ensuring, of course, that what you have remains sufficient for tomorrow).  Get the most of what you have while you can, because in all of this, time is your most precious and limited resource.

Thanks for the sympathy and kind words over my imaginary condition.

But ... save them for those who think that today's written laws are what define morality/right/wrong. Laws are bought and sold by the rich. People who believe this system is right/moral need your sympathy more than me.

[hamster_nz]

Even with a 100 MHz scope a 10 ns the wide pulse would be poorly represented, to the point of having very little useful information apart from "oh - a glitch?". 100 MHz is the -3db frequency (at least for the Rigol datasheet I looked at).

I could do the actual math (e.g. a FFT on 1000 points (10 high, 990 low), clip the high frequency stuff, attenuate around 100MHz  and IFFT), but it will be more truthful if I try it at home tonight on an actual scope (e.g. 5ns vs 10ns pulses on a 100MHz scope).

If I get a chance I will try it and post results...

Setup.
UUT: Digilent Arty FPGA board.
Scope- Rigol DS1102D.
Probe - standard 100 MHz
Test point : 'High speed' PMOD connector (no series resistor on the trace). with spring clip on the probe to the PMOD's GND
Signal - LVCMOS33, 1% at 10 MHz (10 ns pulse).

Results:

NewFile0 - no filter.
NewFile1 - digital LP filter set to 50MHz (as I assume it would be seen on an unhacked 50MHz scope)
NewFile2 - digital LP filter set to 25MHz.

Conclusion:

Yeah, as expected 50MHz can see the pulse, but not much detail, The 100MHz isn't significantly better. But it would still be detectable on a 25MHz scope, just smeared out

This is pretty much to be - with a 50Mhz square wave (50% duty cycle - 10ns on 10ns off) the harmonics would be 50MHz, 150MHz, 250MHz, and on a 50 MHz  or 100MHz scope you will only really see much detail in the first harmonic.

[tggzzz]

Square waves are infinite but the ability of your oscilloscope to display them is not.  That limitation is due not just to the frontend bandwidth, but also to things like the display itself.

...

Ideal square waves are infinite,but the ones we deal with already have limits on their frequency composition caused by imperfections in real generators.

That's true, but in order to know what those limits are, you have to have something with enough bandwidth to examine them, or I guess the data sheet will tell you.

In any case, because that's basically a variable, and because (near as I can tell -- I might be mistaken) the primary frequency of ringing seems to be related to the rising edge time, you'd want a scope with enough bandwidth to handle the rising edge time at least.

Not the ringing frequency, since that is determined by the circuit elements, particularly parasitics. The possibility of exciting the ringing frequency, or of suffering bad effects, yes.

Having said that, a scope which doesn't have quite that frequency response can still be useful - providing you have enough theoretical and practical experience. But if you do then you will probably avoid such problems in the first place. "Catch 22" and the Dunning Krueger effect both apply

The next point to understand is that you can't consider the scope on its own: you have to consider the scope+probe as one unit and consider the effect of the probes on the UUT. That's why probes can cost >$10000, and the latest Tek probe tips cost $5 each time they touch a circuit ($250 for 5, each with a lifetime of 10 applications). See https://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/ for theory, practice, safety and DIY probes.

Finally understand that a 6" ground lead is A Bad Thing when probing logic. See https://entertaininghacks.wordpress.com/2015/04/23/scope-probe-accessory-improves-signal-fidelity/ for the effect and a DIY workaround.

From memory,a square wave can be regarded as reasonable it it contains up to & including the 7th harmonic of the fundamental frequency.
This agrees with an earlier poster's comment about a 50Mhz 'scope & a 7MHz square wave.

If the 'scope response at 49MHz is already close to 3dB down,it will round off the waveform a bit.
70MHz would be a better choice,hence the "10x fundamental"rule.

Yeah, makes sense for seeing that the square wave reasonably looks like a square wave.  But what about catching artifacts that could be screwing with your circuit (or be evidence of a problem)?

Precisely.

And on poorly constructed circuits, e.g. on solderless breadboards with long leads, there may well be subtle problems. Doubly so if "high" currents are being switched. "Subtle" is any or all of infrequent, pattern sensitive, temperature/voltage dependent, parametretric degredation. Such things waste a lot of time and are very discouraging to beginners.

As can be seen from my link above, even a 6" ground lead in an otherwise perfect circuit can lead to surprisingly large damped oscillations. I learned that lesson the hard way in 1977, when building a 6800-based computer inspired by the Altair 8080.

Don't get me wrong, I suspect that 50 MHz is pretty decent for a lot of hobbyist work.  Those scopes probably wouldn't sell all that well otherwise.  But it seems to me that bandwidth is kinda like horsepower: there's no such thing as too much.   

Basically yes, unless ruthless pursuit of that parameter compromises something else that is important. Engineering is all about compromises. But you already knew that!

[kcbrown]

Arguing what today's written laws say is pointless.

If something becomes widespread enough to affect a large company's business model then laws will appear. Bet on it.

I should note that this is an invalid argument.

It's not an argument, it's an observation.

Large companies can (and do) buy laws for themselves. Laws that can harm consumers.

Ask yourself why TTIP is being "negotiated" in secret with no public input.

The observation is correct.  It's not the observation that's at issue, it's the implication that one should therefore refrain from taking the action in question that is.  I presumed you raised the observation for a reason, and that the reason you raised it (and thus the implied argument) was for the purpose of making clear what should be done (or, here, not done) to avoid it.

If that is not the implication of the observation, then what was the point of raising the observation in the first place?

Today's laws make the framework we currently operate under.  If you want to pretend that you operate under a more restrictive framework than that, you can certainly do so, but if you do that, then how far are you going to take it?  Are you going to make no modifications to your automobile, for instance, to improve its capability?  Are you going to refrain from improving anything you have, just because a future framework of law might forbid it?

It's your call, but I'd advise living for today (while ensuring, of course, that what you have remains sufficient for tomorrow).  Get the most of what you have while you can, because in all of this, time is your most precious and limited resource.

Thanks for the sympathy and kind words over my imaginary condition.

Well, okay, then I guess that means you don't have a problem with taking the action in question, or, at least, you don't hesitate to take it on the basis of the changes to the law that may occur.

Apologies, but that wasn't clear to me on the basis of what you said.

But ... save them for those who think that today's written laws are what define morality/right/wrong. Laws are bought and sold by the rich. People who believe this system is right/moral need your sympathy more than me.

Oh, I completely agree with you on that.  What I said wasn't for the purpose of expressing sympathy, it was for the purpose of highlighting a potentially more fulfilling approach than to refrain from an action because taking it might make it illegal in the future.

Do with it what you will.

[mnementh]

What people are arguing here, however, is that the seller should be able to unilaterally dictate to the buyer what he may and may not do with what he purchased, while the buyer has no equivalent power.

He can do w/e he wants with it, sure.

If it's the buyer you're talking about in the above (we've already established that the seller can do whatever he wants), well in that case, we have no disagreement. 

That was easy.   

you'd better read up on the history of monopolies and the abuses that have occurred at their hands.  A monopoly inherently gives the seller the ability to dictate terms).

What is the monopoly, here?

The point wasn't to say that a monopoly exists now, but to illustrate that businesses that have been given the power to dictate terms have used that power to ill effect.  It's an illustrative warning of what will happen if some people here were to have their preferences implemented.

I don't desire that they should give those features to everyone.  Whether they do or not is their choice.  What I do insist on is that they not demand that the customer artificially limit his actions in order to satisfy the manufacturer's desire to do things a certain way.

Which actions are you talking about, here, being artificially limited?

The action under discussion, that would be artificially limited if some had their way, is the ability to enter a magic code into the oscilloscope one owns so as to enable the features that were not enabled prior to that, even if he didn't obtain the code from the seller or one of the seller's authorized representatives.

What people are insisting on here is that the manufacturer should be artificially shielded from the consequences of being lazy

Not at all... WinZip is pretty lazy about how they charge for their software. And I'd venture that the majority of users do not pay for it. I don't think anyone should burn in hell for it, anymore than anyone would care about hobbyists unlocking a Rigol scope! I don't think anyone cares! I just don't agree that unlocking features, using the manufacturers own software, is "hacking" or "improving" something you own the same way as changing/modifying a physical good. Tweaking an ECU with a custom firmware to get more horsepower, that's hacking.

I fully agree that "hacking" is really a misnomer.  What we're talking about is not really any different than someone following directions to perform a simple modification to their car.

Well, seeing how I've already outlined exactly how the manufacturers can do what they want without imposing artificial limits on the actions of their customers, this objection doesn't fly.

Well, I think it is obvious that this increases the cost to other customers who just want the base model. So it's a tradeoff. And I already said I don't object to you hacking your scope.

If it really increased the cost of the base model to other customers, then how do you explain how Rigol manages to sell their DS1054Z for such a low price when they have arguably the most "hackable" (sorry, "easily modifiable") scope on the market?

No, you're looking at only one side of the economic equation.  The other side is that the customer base who have no problem with enabling the features in their scopes in this way will view a scope they can do that with as a better value for their money, and they'll thus buy the scope without hesitation.  The end result is that the manufacturer gets greater sales than their competitors, and thus more profit.

As I already said, a manufacturer will either price their goods in such a way as to take what customers are actually doing with them into account, or they'll have trouble staying in business.  It doesn't necessarily follow that their prices will be higher and, indeed, they may end up being lower due to better return on the mass production investment.

And additionally, you presume that implementing the locking system in the way I previously described is so much more costly that it'll have a significant effect on the prices.  But that's not the case at all.  The method of implementation is trivial.  Given that the Rigol codes clearly are derived from the serial number, it's even possible that Rigol's approach is more expensive than the method I outlined, because the approach I outlined is a standard one that is implemented throughout the software industry, as it is used as part of the SSL key verification mechanism in every browser in existence, and any other piece of software that has to do key verification.

Put another way, just because a customer can attempt to take actions to bypass a lock doesn't mean he has the right to succeed in that.  I do not argue that customers have the right to succeed in their attempts, only that they have the right to make the attempt.

This is one of the most curious things about your post. Very curious. I'll have to think on that. I'm thinking of Kwikset locks. They are the most common house/door/deadbolt lock in the US. And you can pick them with a couple of bobby pins in under a minute. But that doesn't matter, because the lock is just there to keep honest people honest. * In some way I think unlocking the Rigol for business use is not exactly honest, since there are other easy options to get what you need from Rigol and from other companies. Just an opinion.

Well, "honest" or not, it's not something most companies will find is worth doing, because they tend to value support more highly than the temporary financial benefits they might gain by unlocking the scope.

I'm also thinking back to my childhood where you could stick a pin in the bottom of the cable box and get the pay channels for free, lol.

Heh.  Yep.  Is it your fault the cable companies contracted with a hardware company that clearly didn't know what it was doing (or didn't care)?  Nope. 

At the end of the day, the deal is this: buyers are not responsible for the sellers' actions, and sellers are not responsible for the buyers' actions.  They each have to respond to the actions of the other, however, in whatever way suits their needs.  If they think of a mutually beneficial arrangement, they are free to make that arrangement, just as they are free to back out of it if it suits them.  There is no reason actors in the market cannot be (generally -- there are a few narrow exceptions, as with anything else) completely free in what they do, save for limits on distribution of trivially-copied works.  The latter limits exist to equalize the market in trivially-copied works with the market of physical goods, so as to encourage people to create trivially-copied works.

The action under discussion, that would be artificially limited if some had their way, is the ability to enter a magic code into the oscilloscope one owns so as to enable the features that were not enabled prior to that, even if he didn't obtain the code from the seller or one of the seller's authorized representatives.

Wow, this is really hamstringing the customers' ability to use the device as they see fit!    Who'd a thunk on my list of features when buying a scope I would be specifically looking for "the ability to enter a magic code... so as to enable features [that many customers willingly pay for]."

The action is a gating function.  It makes possible other actions.  So through prevention of this one action, other actions are also being prevented.

But even if the action itself were the only one being considered, being artificially restrained from performing it is still a restraint, a limitation on your freedom.  And limitations on freedom demand good reason.

No, you're looking at only one side of the economic equation.  The other side is that the customer base who have no problem with enabling the features in their scopes in this way will view a scope they can do that with as a better value for their money, and they'll thus buy the scope without hesitation.  The end result is that the manufacturer gets greater sales than their competitors, and thus more profit.

I disagree. There is no way you can make this conclusion.

My sincere apologies!

I wrote that really badly, because I didn't mean to say that I disagreed with you.  I only meant to add an additional possibility, not replace your possibility with mine!

Which is to say, it's entirely possible for both factors to be in play at the same time.

Which factor ends up dominating the equation is a very interesting question in its own right, and probably depends on the circumstances.

If it really increased the cost of the base model to other customers, then how do you explain how Rigol manages to sell their DS1054Z for such a low price when they have arguably the most "hackable" (sorry, "easily modifiable") scope on the market?

What does one have to do with the other? "Increased" cost is relative.

But it is also absolute, because we're talking about a competitive marketplace where other manufacturers are making roughly equivalent products and selling them in competition, and the cost of development adds to the floor on the price one can charge for what one is building.  Since R&D costs are spread across the number of units sold, it follows that one will get a greater return on R&D dollars if one sells a larger number of units, and therefore one can sell at a lower price and realize the same amount of profit from the same R&D if one sells a larger number of units.  And yes, there are many other factors involved, including the ones you mentioned.

If the "hackability" of a scope makes it more appealing to a large segment of the customer base, that represents the opportunity for greater sales and thus a greater return on investment.   That is counterbalanced by the potential of larger per-unit profit for models configured to be more capable, of course, so there is tension between the two approaches.  Each represents the possibility of greater profit.  And as these scopes are competing against those from other manufacturers, it may well be that the additional appeal from "hackability" is what makes the difference in which manufacturer dominates.   As Rigol appears to now be dominating the low-end market (I haven't seen any evidence that they were prior to the DS1054Z) and their scopes are more "hackable", there is every reason to suspect a link between the two.  But it may also be that the value proposition of the DS1054Z as it comes configured is sufficient to explain that, too.  And yet a third explanation is that Rigol got there with the DS1054Z first.

Yes, they sell the DS1054Z at a very attractive price, even if you leave out the "hackability." For a 4 channel 50MHz DSO, you will be shocked at how cheap this is compared to the competition. How cheap they sell it has no bearing on the fact that introducing a stronger key lock will increase their cost..... and how they distribute that cost is up them, but the most likely scenario, IMO, is an increase to the cost of the base unit.

That may be.  I'll put it plainly: if "hacking" of these scopes represented a significant financial downside relative to the profit the manufacturer could be making without it, then the manufacturer would easily make up the difference in implementation costs, and would therefore have plenty of incentive to implement the system I referred to.

So: either Rigol is being stupid in making it possible for their scopes to be "hacked" in this way, and as a result will suffer financially for it, or they aren't.  I submit that they aren't, and that the popularity of their low-end scopes is evidence of that.

Rigol is great for hobbyists. Hobbyists can buy and hack their Rigol. No one cares. But I don't agree with some of the reasoning/justifications that are being used.

Sure, I get that.   But the question can be framed one of two ways:

• Why should people "hack" their Rigol scope the way they are?
• Why shouldn't people "hack" their Rigol scope the way they are?

People have been focusing primarily on arguments around the latter.

I come back 6 days later, expecting to see the thread has died without me stirring sh** up; and I find YOU of all people making exactly the same arguments I was making. Why again were we arguing? 

I ESPECIALLY agree with THESE POINTS.

Please forgive me if I mistakenly attribute any of my highlighted points; in all honesty, even with the computer as a scorecard, this discussion has become so complicated and recursive it is hard to keep track.

I repeatedly used the word "lazy" in description of how Rigol chose to apply their "product limitations", and for GOOD REASON. If they WEREN'T being lazy, then they were either being downright STUPID, or they were deliberately "leaving the treasure map lying around" by not altering their security on the device after all these years. We're talking 7 years now, since the original "hack" was discovered, I believe.

If one argues that they haven't made their R&D back on this product by NOW, one is outright delusional. I know from my own time in the hot seat that if a company doesn't expect to recoup those costs and SEE PROFIT from the first one or two production runs, upper management is going to pull the plug on your project in a heartbeat. These people are NOTORIOUS for being interested in one thing: SHORT TERM PROFIT. Over and Over again. They have the attention span of gnats, and WILL NOT PLAN more than a few quarters ahead even if you tie them up and hold their feet to the fire. 

The only place this isn't true is in Military Contracting; where we the Taxpayer get to foot the R&D bill on a cost-plus basis. You know, that business model that pays Halliburton cost-plus to set fire to a $50K truck because they don't have spare tires or the motor blows up because they don't stock oil & filters for regular maintenance. 

I don't believe there's a lot of THAT Business Model happening in China-Direct electronics manufacturing.

If a manufacturer chooses to make a single product to cover numerous different product segments, they have the right to do so. If they choose to implement that choice in a manner that makes the product easy to modify into the higher-priced priced model, they have the right to do THAT as well. But they HAVE TO accept the consequences of that choice; namely, that some people are going to try and figure out HOW.

If a user chooses to mod their product into a more capable product, whether by dint of applying their own skills and knowledge to do so, or by using a tool devised by someone with the knowledge, they HAVE THAT RIGHT, provided they are willing to accept the consequences of their actions; namely that by choosing to do so, they GIVE UP the right to warranty service. PERIOD. Even if there is a failure that is rightly the responsibility of the manufacturer, it is unreasonable to expect them to fix it AFTER you have modified the product. You and they both have no way of knowing FOR SURE that you didn't cause the failure by modding the product or by accident WHILE modding the product; and truthfully, the manufacturer should NOT be expected to expend resources trying to figure that out.

Arguing that the user should be able to expect Warranty Service after attempting to mod their product is, in a way, arguing that they should be able to expect to succeed in that attempt.

Arguing what today's written laws say is pointless.

If something becomes widespread enough to affect a large company's business model then laws will appear. Bet on it.

I should note that this is an invalid argument.

It's not an argument, it's an observation.

Large companies can (and do) buy laws for themselves. Laws that can harm consumers.

Ask yourself why TTIP is being "negotiated" in secret with no public input.

Today's laws make the framework we currently operate under.  If you want to pretend that you operate under a more restrictive framework than that, you can certainly do so, but if you do that, then how far are you going to take it?  Are you going to make no modifications to your automobile, for instance, to improve its capability?  Are you going to refrain from improving anything you have, just because a future framework of law might forbid it?

It's your call, but I'd advise living for today (while ensuring, of course, that what you have remains sufficient for tomorrow).  Get the most of what you have while you can, because in all of this, time is your most precious and limited resource.

Thanks for the sympathy and kind words over my imaginary condition.

But ... save them for those who think that today's written laws are what define morality/right/wrong. Laws are bought and sold by the rich. People who believe this system is right/moral need your sympathy more than me.

Ummm... yup.

I made these very same points, expressed slightly differently, on several occasions. Law doesn't make right, and laws are bought and sold every day. Our Corporate Overlords have done such a good job of selling their right to their position of superiority that even intelligent, informed, and reasonably independent-minded folks possessed of all their faculties and reason tend to think FIRST of the Corporations' rights under the law (Or worse yet, what those Corporations WISH their rights were, whether so or not) rather than THEIR OWN rights.

Kindof sad, really. 


mnem
6 days later...

[Fungus]

Do with it what you will.

My point of view, written on the first or second page is that somewhere in this is a social contract. You say you're free to do whatever you like with your oscilloscope. Adults will recognize that society taught you to read and write, made you what you are and gave you that freedom, therefore you owe a debt to that society.

eg. If everybody paid Rigol for the features they use then maybe Rigol could sell the DS1054Z for $300 instead of $400. This would benefit society as a whole because oscilloscopes would be available to more people.

OTOH I recognize that almost nobody does that. Most people think of themselves first, society second, and the future of the planet as a whole somewhere near the bottom.

As a consequence almost everything you buy is marked up. Everything you buy in a big store has a markup included to compensate for the theft they suffer (about 20%, apparently), because of all the people who take big TVs home to watch The Superbowl then return them under the 30-day money-back garantee, etc. You give most people an inch and they'll happily take a mile.

It's sad, but it's a reality of life that isn't likely to change. To unilaterally decide to be the one of the few that does everything "correctly" seems foolish.

(and you can give back to society in other ways than paying extra for everything).

[KL27x]

I repeatedly used the word "lazy" in description of how Rigol chose to apply their "product limitations", and for GOOD REASON. If they WEREN'T being lazy, then they were either being downright STUPID, or they were deliberately "leaving the treasure map lying around" by not altering their security on the device after all these years. We're talking 7 years now, since the original "hack" was discovered, I believe.

True enough. The thing is, though, that even at 50MHz, this scope is still the cheapest 4 channel DSO available when it came out. And I think it still holds true today. So I don't see how this would be stupid (if they used better security). Even at 50MHz with no free upgrade, I would have bought this scope (if I hadn't already bought a 4 channel scope a few months earlier!)

They have no close competition in this particular arena. Their price is already fantastic. (Arguably less attractive pricing on the 100MHz variant, albeit).

[KL27x]

Re: reply #537
NZ Hamsters, thanks for this! I don't have a whole lot to comment, here. I think the pics speak for themselves. I just wanted to bump this before it gets lost in the endless circular argument that is this thread.

This is pretty much to be - with a 50Mhz square wave (50% duty cycle - 10ns on 10ns off) the harmonics would be 50MHz, 150MHz, 250MHz, and on a 50 MHz  or 100MHz scope you will only really see much detail in the first harmonic.

I find it curious that it is easily seen with the 25MHz filter, but the second harmonic can't be seen on the 100MHz setting. I guess it's just the lower amplitude plus all the extra noise without the filter. I wonder as you decreased the pulse width, where the 50MHz would no longer see the first harmonic, but the 100MHz would still show it. Or if it would also get lost in the noise at the same time the 50MHz loses sight.

At any rate, considering the differences in noise, I find the objection to "arbitrary manufacturer gimping" to be further weakened. The 50MHz filter obviously does something more than just arbitrarily lower the bandwidth of the scope. I am still not quite convinced of a significantly increased utility (other than theoretical) for the hacked version, if your model's filters are representative.

I'm obviously not deep into hardware design as many others, here. I more of a read the datasheet and follow the manufacturer's guidelines and things will usually work fine, kind of guy. The designers of the devices I am using are the ones that maybe really need the fancy scopes!

Basically, I have yet to run into the problem where doubling of my scope's already lowly bandwidth would have saved a week's worth of hair-pulling. Looking at NZ Hamster's pics, I think I am probably in good company.

[hamster_nz]

Re: reply #537
NZ Hamsters, thanks for this! I don't have a whole lot to comment, here. I think the pics speak for themselves. I just wanted to bump this before it gets lost in the endless circular argument that is this thread.

It's visible on the 25 MHz scope as the signal is a periodic at 1 MHz, so the first 25 harmonics (1 MHz,2 MHz, 3 MHz), can all contribute some power in the final waveform that is seen on the screen. If it repeated more often (e.g. 10 ns pulses at 4MHz) then it would look different - when you get to about 15 Mhz it will look like a lot like sine wave, as the second harmonic of 30MHz and all those above should be removed by the front end's filters.

[KL27x]

Ok, thanks.

Anyhow, to me it seems like the max observable frequency of a glitch/harmonic/ringing has much less to do with rise time, in this specific case, than it does max sampling rate. Obviously, the relative slope/amplitude will be affected, especially compared/relative to any signal that has a lower than max rise time, but it would be comparably observable. It is even debatable, for this specific signal, whether the 100MHz setting is even more useful than the 50MHz setting, in detecting/observing the first harmonic. One click of the voltage/division knob, and even the 25MHz setting might be more easy to "read." Also, the signal-to-noise ratio is obviously a factor, and it appears in "the hack," this ratio is not necessarily preserved.

Where the rise time of a signal will specifically matter, as I am envisioning it, is where your signal frequency, itself, is relatively high to where it matters in order to tune the signal (say the switching speed of a FET driver running at high frequency - in the lower end of FCC territory where switching losses start to be impractical and mostly low frequency RF signal transmission and high-speed data transmission might be of interest). Maybe I'm just showing my ignorance.

So am I the Dunning-Krueger poster boy, or is the opposing side using an over-abundance of theoretical information while missing the practical difference?

I feel like perhaps the Rigol has good performance at 50MHz, and maybe they could technically achieve -3dB at 100MHz, but with a resultant signal:noise that is borderline. Which will still be useful to someone with that specific need. But which won't affect the majority of users. So by charging double the price, those that actually are working on applications where this is helpful are happy, because they needed it. Those that are buying it because higher number iz betta are happy, because they don't know the difference. And those that are hacking the low end scope are happy, because more numbers iz betta, and look I got $400.00 worth of awesomeness for freez.

Of course, the double memory is obviously a joke. So are you going to really waste time scrolling through several windows of signal, just in case there's something interesting on the tail ends? Or are you going to maybe find it at least 20x faster to simply recapture until you find what you are looking for?

[Zero999]

As a consequence almost everything you buy is marked up. Everything you buy in a big store has a markup included to compensate for the theft they suffer (about 20%, apparently), because of all the My point of view, written on the first or second page is that somewhere in this is a social contract. You say you're free to do whatever you like with your oscilloscope. Adults will recognize that society taught you to read and write, made you what you are and gave you that freedom, therefore you owe a debt to that society.

eg. If everybody paid Rigol for the features they use then maybe Rigol could sell the DS1054Z for $300 instead of $400. This would benefit society as a whole because oscilloscopes would be available to more people.

OTOH I recognize that almost nobody does that. Most people think of themselves first, society second, and the future of the planet as a whole somewhere near the bottom.

As a consequence almost everything you buy is marked up. Everything you buy in a big store has a markup included to compensate for the theft they suffer (about 20%, apparently), because of all the people who take big TVs home to watch The Superbowl then return them under the 30-day money-back garantee, etc. You give most people an inch and they'll happily take a mile.

It's sad, but it's a reality of life that isn't likely to change. To unilaterally decide to be the one of the few that does everything "correctly" seems foolish.

(and you can give back to society in other ways than paying extra for everything).

Everything you buy is marked up to pay for the company's costs (theft is only one) and they of course need to make a profit.

As far as Rigol is concerned: the hackability seems to benefit hardware sales and it's ironic you talk about people being selfish, putting themselves before society, when it's very likely Rigol, like most other companies, are guilty of that too.

[Fungus]

As far as Rigol is concerned: the hackability seems to benefit hardware sales and it's ironic you talk about people being selfish, putting themselves before society, when it's very likely Rigol, like most other companies, are guilty of that too.

Two wrongs make a right?

[kcbrown]

My point of view, written on the first or second page is that somewhere in this is a social contract. You say you're free to do whatever you like with your oscilloscope. Adults will recognize that society taught you to read and write, made you what you are and gave you that freedom, therefore you owe a debt to that society.

Freedom is what you have absent external constraints.  Society takes away liberty at least as much as it protects it.

The "debt" I owe to society as a result of being taught to read and write, etc., was exacted from my parents, and is exacted from me every year, at gunpoint.  That's what taxes are.  Why should I believe I owe any debt greater than that?

eg. If everybody paid Rigol for the features they use then maybe Rigol could sell the DS1054Z for $300 instead of $400. This would benefit society as a whole because oscilloscopes would be available to more people.

OTOH I recognize that almost nobody does that. Most people think of themselves first, society second, and the future of the planet as a whole somewhere near the bottom.

As a consequence almost everything you buy is marked up. Everything you buy in a big store has a markup included to compensate for the theft they suffer (about 20%, apparently), because of all the people who take big TVs home to watch The Superbowl then return them under the 30-day money-back garantee, etc. You give most people an inch and they'll happily take a mile.

It's sad, but it's a reality of life that isn't likely to change. To unilaterally decide to be the one of the few that does everything "correctly" seems foolish.

Yes, that is the way of the world.

It's that way because we are products of evolution, and being generally selfish is the most effective way to maximize the probability of gene propagation.

The voluntarily cooperative situation you believe would be ideal is one that crumbles if anyone decides to not behave in a cooperative manner.  That person would suddenly find himself at a substantial advantage relative to the rest, which would be good for his genetic posterity and bad for everyone else's.  Others would take notice and, because they want to maximize their genetic propagation potential, do the same.  The situation would quickly devolve to one that looks similar to the one we're already in, except that it would be a lot more chaotic.

So: you can either achieve something resembling what you're after by insisting that everyone be voluntarily cooperative, so as to yield global optimization at the expense of local optimization, or you can do it by taking advantage of the innate desire of people to locally optimize.  The system we have operates on the latter principle.


I don't see any corporation out there attempting to minimize shareholder profits so as to be able to lower the prices to their customers even further than they already are.  I don't see any scope manufacturers (to use but one example) voluntarily publishing the source code to their firmware so as to allow people to make improvements to it and thus increase the utility of what they have.  I don't see corporations doing much of anything, in fact, that is in the same spirit that you seem to believe this "debt to society" demands (there are exceptions to everything, however, so I'm sure it's possible to find some examples of that sort of thing.  But they do not dominate).

When the very corporations that you have already said have the power to change law end up changing the law for the benefit of their customers instead of for their own benefit, then, and only then, will I believe that what you apparently desire is achievable.   But it seems unreasonable to complain that one group of people should act in a certain way without insisting that the group of people on the opposite end of the transaction do the same.

[Brumby]

Arguing what today's written laws say is pointless.

If something becomes widespread enough to affect a large company's business model then laws will appear. Bet on it.

I should note that this is an invalid argument.

It amounts to an argument that says "you shouldn't do X, because if you do X, then it will be made illegal and you won't be able to do X anymore".

But someone who is refraining from doing X because it might otherwise become illegal can't possibly be concerned about the legality of doing X, because at that point the legality of doing X makes absolutely no difference -- their behavior is already the same as it would be if X were illegal.

If you are concerned about some action becoming illegal, then you have to suggest something else other than refraining from the action as a means of preserving its legality.  Something that is legal but that nobody does for fear of it becoming illegal is something for which its legality is already irrelevant.

I should note that this is an invalid argument.

It completely ignores the reasoning for 'Not doing X because it might become illegal'.

One simple example is for someone developing a process which relies on a particular set of operations, would be unwise to base any critical components on an operation that could become unavailable.  While there may be circumstance that are powerful enough to accept that risk, I would be looking for less risky alternatives that could achieve the desired outcome.