Pingflooding dialup users when you, yourself, were on dialup was not always the most trivial thing in the world: Theoretically, I only had a 28.8 or 33.6 upstream, and they the same. It should not have worked at all, but it did at least for Linux and Windows [Trumpet Winsock] users.
I had other OS/2 using friends, back then, and we couldn't really touch eachother...whether with the same ISP, or a different one: Things would get very slow, but not fail. (I did not have the tools or knowledge to sort out this OS-dependent discrepancy back then.)
ANSI / VT100 codes were also fun, on IRC at least, but a clever person would quickly figure out how to restore things to sanity. (Most didn't, but the social aspects of IRC made it have limited utility since I usually liked the channels in which I was abusing folks.)
I never tried dumping stuff into another user's/dev/tty: Though I'm sure it would've been interesting, I really liked the FreeBSD shell account I was using and it had competent admins who I didn't want to give a reason to get rid of me. )
But X, with sound? Dude: It's half-past 2011, and audio with X are still completely different entities, with sound being a complete crapshoot. I don't want to doubt you, so I'll just ask: How did you make that work? Have I missed something in the past 16 years?
This, exactly: "Avoid highways" sometimes is almost always shorter, and usually just as fast in the real world. The change from 65-90MPH divided highway driving to "look at that," or "let's stop at this diner" is refreshing and makes trips far more enjoyable whenever time is not of the essence (and sometimes, even when it is)...and the food is better.:)
But sometimes, I wish my GPS had more than an "Avoid Highways" setting; maybe even "Avoid US route" and "Avoid state routes" toggles.
"Avoid Highways," both on my Droid and my Garmin, still tends to keep me pretty well on the beaten path: It seems happy to pick a 2-lane US route and stick with it for an eternity, and that's just boring.
Even for work, when I might drive 2 hours to get to where I've got to be, I often don't want to take the same route back home. I'm already wore out from one moderate drive and a day's work; the last thing I want is to see the same scenery again on a straight section of 2-lane road that seems to never end, as that would only add to my fatigue.
The Droid will allow me to choose from a variety of alternate routes, but those invariably consist of the most major "non-highway" roads it can come up with: Generally, a choice of longer routes consisting of the same boring shit. And that's not what I want: I want stop signs. I want little towns. I want curvy roads, ups and downs, and scenery. I do enjoy generally enjoy driving, but I want anything but the dangers of this.
I assume by "people" you mean folks who aren't also hikers/snowmobilers.
Half of the fun of hiking is paying attention to surroundings and finding a different/more interesting/faster path from A to B. And for that, an arrow pointing the way might even be ideal over a map or a chart.
I don't do much hiking, so I have no use for standalone basic GPS+compass gear which has long battery life. But I do the same thing in the car, sometimes, with the Droid: Set a waypoint with [random GPS app], and go there -- no map needed.
It's not typically an efficient way to navigate in car, but that's OK: I occasionally burn up a day or two at a time driving just for fun, and this adds to my enjoyment. (Though using dead reckoning on a cloudy day to reach a distant point is fun, too.)
It always irritates me when I get an obviously sub-optimal route from Google Maps, but it's never clear to me how to actually fix the problem. If Google took feedback from where I actually drove instead, over time the problem might fix itself.
Interestingly enough, they do: Google Map Maker. It was (somewhat negatively) covered here on Slashdot awhile back, but I can't be bothered to find TFA just now.
It's not automatic, but then I don't know that it should be: A lot of what's wrong with a routing system (any of them) are factual errors which in turn lead to incorrect routing.
I've fixed/added/deleted a number of things around my own town, and have had every change (that I didn't screw up myself somehow) be accepted. (Rejected edits came with feedback to improve the submission.)
In particular, Google had some completely bizarre and/or plainly impossible routes to get from my house to the nearest interstate, which made trips out of town very annoying whenever I'd actually take the time to set a destination before leaving.
For instance: I know the right and proper way to get to the highway; but the bitch inside my phone always insisted I was doing it wrong and that I should both drive around the block and use an entrance ramp an extra mile away for no good reason.
It turned out that some intersections were described improperly, with wrong-wayed streets leading to them, and incorrect turn restrictions. A few edits later (and some passage of time), and it's working fine.
Map Maker is a crowd-sourced moderator-based system, apparently including some concept of karma/reputation: Your edits are reviewed by your peers (and if not, eventually by Google), and if they're sane, they're applied. And if you have enough sanity in your edits, eventually it gets get easier/faster to have your edits "stick."
Previous to Map Maker they had a system on their regular Google Maps web interface where you could describe what was wrong (ie: complain) and they'd try to fix it themselves if you bothered to fill out the rather non-complicated form...but I only had about 50% luck with that actually producing correct results.
Punctuation. Note the colon below, just after the word "iPhone":
It costs $350 per year to develop for the iPhone: $1000 for a MacBook, $250 or thereabouts for an iPod touch, and $500 for a 5-year iOS developer certificate.
$1000 + 250 + 500 = $1750 for five years of development. $1750 / 5 = $350 per year.
According to GP, that's what it costs to develop for iOS.
Developing for OSX has its own costs in that you at least need to have Apple hardware to have an easy go at it, but GP wasn't talking about that at all...
I agree; P25 is crap. (Qualification, for whatever it's worth: I've installed/programmed/fixed/pondered-upon many thousands of such radios, all from a company with the initials "M" and am entrusted with keys to the tower sites all over a certain midwest state.).
Nobody really likes it. Some agencies are happy because they've got new radios which aren't yet as broken as their old ones were, but they cost 5-10x as much to buy, each. Plus a monthly fee, per radio, for service. The only reason they're even slightly happy is because they were all pretty much "free" through a state-funded grant program, which to me (as a taxpayer) is not free at all.
Nobody is happier with coverage except in the off case that they're out of their jurisdiction (which does happen, but not routinely by anyone who needs to communicate regularly). Nobody is happier with audio quality (narrowband FM can sound rather good from 300-3000Hz; digital P25 is always robotic-sounding from codec artifacts). They all want to be happier with interoperability for individual units, but nobody ever uses that and therefore won't remember how when a Big Event happens.
Consequently, anything that involves multiple agencies things still get patched together on dispatch consoles and mobile communications centers, with dedicated radios per channel (or talkgroup) -- exactly as it always had been, pre-P25.
And nobody's going to be happy when the radios start to get tired after a few years and needing repairs.
I'm happy with it as someone who earns a meager hourly wage working on it, because the initial push kept me very busy for a few years in a rough economy.
But as a professional who enjoys doing good work, I'm unhappy with it because it inherently sucks, as built, and therefore I have to give people dumb answers to their legitimate questions and problems instead of just -- you know -- fixing it.
And as a (perhaps too-well) informed citizen, I hate it. The way I see it, the old stuff worked better, and allowed me better protection.
Of the many places I visit that require badges, all but one use a generic reusable badge (sometimes plastic, sometimes just laminated paper). This new tech doesn't beat that on a cost-of-materials basis.
The one facility I do visit which has badges printed with the name of the visitor also uses a special process wherein the printing on the badge becomes contaminated with a red striped background after 24 hours or so, such that they self-expire in a visible and irreversible way....and this new widget doesn't do that, either.
Tickets? Please. This is spoken by someone who has never done any printing or automated document processing: Trying to handle stock after it's been shoved into a pocket for a few hours/days is going to be very expensive, whereas cardstock is cheap. (Besides, I like to keep my tickets.)
Soup-du-jour sign? Seriously? So a single sign can be reused 260 times, maybe, but only saves just over half a ream of paper...and costs a new printer.
Another example that doesn't work:
Shipping industry for packing slips and bills of lading. It's hard enough to get whole pallets send back in decent shape to be reused, let alone a sheet of e-paper.
I don't want to be negative, but I just don't see the use of it. I print out manuals for stuff from time to time (when fixing something mechanical/greasy where I don't want to get my laptop all covered in funk) and it often seems wasteful, but reusable e-paper no good for that either for the same reason the laptop isn't.
I still print out maps for long trips (despite being armed with a good GPS and an Android phone), and it might be useful for that, but meh: It doesn't happen enough to be worth the cost of the printer, or the trouble of trying to keep the stuff clean and keeping track of it.
However, more recently, most police bands have gone encrypted.
Define "most."
I work in communications. Of the five or six counties I typically work in, all but one has recently moved to a statewide system based on P25 where law enforcement has been issued radios capable of encryption.
Of those four or five counties which have encryption-capable radios, only one agency in one single town uses it by default. Everyone else transmits in the clear by default, as a matter of policy.
One, of course, was ping -f from a sufficiently fast pipe (or just an equally-slow pipe with better buffer management). I had a custom REXX script under OS/2 which took a username as input, and would finger each of the terminal servers of a local ISP, derive the IP address of that user, then issue a ping -f for that particular dialup user.
It would cause their PPP sessions to timeout, at which point they'd disconnect. And it was fun, because I actually knew the people who I was disconnecting.
Tougher (or farther) targets at other hosts would get a ping -f from a blistering-fast (hah!) shared FreeBSD machine with a T1 connection. If -f didn't do it alone, increasing the packet size always did. Sometimes, it seemed that different packet sizes (not just larger ones) would make it happen sooner.
Around the same time, it was discovered (not by me) that sending an ICMP ping packet containing "+++ATH0" would instantly disconnect any user with a cheap modem by very neatly instructing their modem to do exactly that.
This worked because Hayes (rest their souls) had a patent on requiring a one second delay between +++ (aka "enter command mode") and any subsequent commands (ATH0 hangs up the modem). Makers of cheap modems wanted to pay as few royalties as possible, and they got their wish.
On most premium modems, or most old modems, it wasn't a problem, since it was required to have a delay between "+++" and any other command. But during the early winmodem days, it was a blast: Those cheap modems instantly dropped to command mode, and immediately executed anything after that.
You tell it to hang up, and that's just what it does.
It wasn't even really necessary to use ATH0, either: any old AT command would work, and would leave the modem in command mode instead of data mode. +++ATLM2L3, for instance, would result in a lot of noise from the modem speaker until their session timed out...
The ATH0 trick could be accomplished with IRCII using/ctcp [target] PING +++ATH0 or more generally with ping -p 2B2B2B41544829 [target IP or hostname] from a suitable *nix host.
It was fun being a kid back then, with OS-agnostic ways to be annoying. (I've grown up just slightly since then...)
Both Toro and Deere mowers are made by MTD, these days. They might as well be branded "Yard Man" or "Huskee" or "Murray," because it's the same shit with a different paint code.
Finally, you can use a high-gain external directional antenna to provide coverage for just your section of the floor at high enough gain to drown out everybody else (e.g. a 25 dBi yagi pointed down from the ceiling or something). Bear in mind that this is the Wi-Fi equivalent of a tactical nuke, so you should expect retaliation from other vendors the following year....
Maybe.
If the receiving electronics in the mobile devices themselves are already being desensed from all of the local RFI, which may be the real problem here (we don't know if it is, or is not), it won't help.
A practical analogy: At a rock concert which is already loud enough that your ears distort, it's still hard to understand the person right next to you who is shouting near your ear: You can hear them well enough (people can produce a mighty big SPL at close range), but all you get is noise that vaguely resembles human speech. They could shout at you with a megaphone (ie: 25dBi Yagi), and it'd just get worse.
RF is no different.
But since you like firepower analogies: If you're already covered from head to toe in burning napalm, your body will be so overcome that you won't even notice being shot in the leg (you are desensitized to any potential additional pain by already experiencing the maximum amount of pain sensation possible).
Shielding works, though:
You can cup your hands between your mouth and the person's ear, and they'll suddenly be able to understand you. Not because you're louder (though you are), but because the concert becomes quieter.
You can wear an insulated fireproof suit, get covered in burning napalm, and get shot in the leg. You'll feel the gunshot wound just fine, then...
You can use a Faraday cage. Or part of one.
More power (or higher gain), or better distribution (Xirrus, et al), doesn't really help. The former just provokes everyone else to do the same (raising the stakes), while the latter doesn't work at all because everything is already shouting.
A well-designed and distributed system provided by the event's organizers would work well to keep things quiet, but it sounds like that's not really happening, and is out of the control of the individual presenters. It can't just be bolted onto an environment that is already full of shit with any real expectation of accomplishing anything more than wasting money.
A Faraday cage to block or strongly reduce 2.4Ghz signals doesn't have to be that ugly, since the allowable size of holes in the mesh is dependent on the wavelength. 2.4Ghz is a wavelength of just under 5 inches. A 2-inch grid could easily be incorporated in to the right kind of industrial-themed decor.
This. Or window screen. Or chicken wire. Or... (It doesn't have to be copper.)
Also, a Faraday cage doesn't have to be small. And the goal is not to create a totally isolated environment, but simply an environment which is quiet enough for things to work, so it doesn't have to be anywhere near perfect either.
So. Surround the booth, or just a dedicated demonstration area within the booth, with appropriate conductive mesh.
I don't know the booth in question, but if it already has three sides, it'd be easy to get a fair bit of RFI reduction just by using conductive materials instead of (or in addition to) whatever they are made from now.
Adding even a partial roof would help more.
Bond the sections together with non-insulated copper wire. It's easy to work with, easy to find in a pinch (craft stores), very adjustable for differing layouts, and cheap enough to throw away when you're done with the show.
Grounding would also be good measure. The armchair electrician in me says that the grounding should be substantial so that in case the thing accidentally gets energized somehow, it won't present a safety hazard for those around it...but I doubt that anyone else bothers with that for random metal stuff on their other booths, even if they should.
And the RF guy in me says that a couple of runs tied to different parts of the "cage" (or more, depending on the size of the booth) of 12 AWG stranded copper, connected to an available outlet or conduit or structural steel or [insert thing here] should work just fine for RF shielding purposes.
And the inspector asshat in me says the grounding conductor should have appropriately-colored insulation, which varies by locality: Green for the US, brown in some other places, but whatever it is can be found at the local hardware store. This will make it abundantly clear what the intent of the wire is to anyone with enough clue to be questioning things like that, and will reduce their questioning to a minimum.
Oh. And try to avoid creating a parabola if using curved panels for any of this, or the partial cage may variously do the opposite of what is wanted...
Just tromp outside with a wristwatch, look at any old meter, and start counting revolutions. Some simple multiplication later, and you can see how much power you're using.
Usage over time is easy, too: Just record the positions of the dials, and come back later to do it again. Subtract. Done.
When I am rich (I don't care if that involves being famous or not), I will make sure that my home has at least the usual kitchen fridge, and a multitude of dedicated freezers, and a kegerator in the home theater, and a kegerator in the office, and a kegerator in the garage. (I will only require one popcorn maker, but I will have a dedicated person to ferry it and its freshly-made popcorn joy to wherever I desire.)
I will also install a tunnel to the garage (thanks for the tip!), but I will not be using Segways to traverse that stretch. Instead, I will install an electric narrow-gauge railroad, powered by catalytic fuel cell fed by the fermented remains of the hand-harvested garden slugs that I will have imported from Spain. There will be a turntable at either end to turn the train 'round, which will be steam operated (just try to find a better actuator than a steam-driven piston!) using geothermal energy.
(All kidding aside: I've installed home theaters, too -- including at a place which had a helipad and a (singular) Porsche in the garage. I found the important amenities to be generally lesser than I have in my own, positively meager, home. But I wouldn't mind having a walk-in freezer and/or a cold room -- it doesn't seem like it'd be very expensive at all, and it would be terribly convenient for everything from storing hanging beef or venison, to dumping heat from a tweaked-out water-cooled PC rig.)
My BMW came with a sticker in the upper-left corner of the windshield. Its text is verbatim:
"Important: Installation and operation of non-BMW approved accessories such as alarms, radios, amplifiers, radar detectors, wheels, suspension components, brake dust shields, telephones (including operation of any portable cellular phone from within the vehicle without using an externally mounted antenna) or transceiver equipment (eg. C.B., walkie-talkie, ham radio or similar) may cause extensive damage to the vehicle, compromise its safety, interfere with the vehicle's electrical system or affect the validity of the BMW Limited Warranty. Refer to your owner's manual and see your authorized BMW dealer for additional information."
(Yep, it says all that. The sticker is small. The print is smaller.)
It was made in 1995.
I'm not saying that it's anything other than fearmongering (as the E36 BMW has proven itself to be very receptive to all manner of electronic hacks and accessories), but that's what it says...
Slashdot Mirror
The Garmin I have already has a checkbox for "Avoid tolls."
It seems to work fine. It once delivered me from downtown Chicago to NW Ohio without spending a dime on tolls.
Pingflooding dialup users when you, yourself, were on dialup was not always the most trivial thing in the world: Theoretically, I only had a 28.8 or 33.6 upstream, and they the same. It should not have worked at all, but it did at least for Linux and Windows [Trumpet Winsock] users.
I had other OS/2 using friends, back then, and we couldn't really touch eachother...whether with the same ISP, or a different one: Things would get very slow, but not fail. (I did not have the tools or knowledge to sort out this OS-dependent discrepancy back then.)
ANSI / VT100 codes were also fun, on IRC at least, but a clever person would quickly figure out how to restore things to sanity. (Most didn't, but the social aspects of IRC made it have limited utility since I usually liked the channels in which I was abusing folks.)
I never tried dumping stuff into another user's /dev/tty: Though I'm sure it would've been interesting, I really liked the FreeBSD shell account I was using and it had competent admins who I didn't want to give a reason to get rid of me. )
But X, with sound? Dude: It's half-past 2011, and audio with X are still completely different entities, with sound being a complete crapshoot. I don't want to doubt you, so I'll just ask: How did you make that work? Have I missed something in the past 16 years?
This, exactly: "Avoid highways" sometimes is almost always shorter, and usually just as fast in the real world. The change from 65-90MPH divided highway driving to "look at that," or "let's stop at this diner" is refreshing and makes trips far more enjoyable whenever time is not of the essence (and sometimes, even when it is)...and the food is better. :)
But sometimes, I wish my GPS had more than an "Avoid Highways" setting; maybe even "Avoid US route" and "Avoid state routes" toggles.
"Avoid Highways," both on my Droid and my Garmin, still tends to keep me pretty well on the beaten path: It seems happy to pick a 2-lane US route and stick with it for an eternity, and that's just boring.
Even for work, when I might drive 2 hours to get to where I've got to be, I often don't want to take the same route back home. I'm already wore out from one moderate drive and a day's work; the last thing I want is to see the same scenery again on a straight section of 2-lane road that seems to never end, as that would only add to my fatigue.
The Droid will allow me to choose from a variety of alternate routes, but those invariably consist of the most major "non-highway" roads it can come up with: Generally, a choice of longer routes consisting of the same boring shit. And that's not what I want: I want stop signs. I want little towns. I want curvy roads, ups and downs, and scenery. I do enjoy generally enjoy driving, but I want anything but the dangers of this.
I assume by "people" you mean folks who aren't also hikers/snowmobilers.
Half of the fun of hiking is paying attention to surroundings and finding a different/more interesting/faster path from A to B. And for that, an arrow pointing the way might even be ideal over a map or a chart.
I don't do much hiking, so I have no use for standalone basic GPS+compass gear which has long battery life. But I do the same thing in the car, sometimes, with the Droid: Set a waypoint with [random GPS app], and go there -- no map needed.
It's not typically an efficient way to navigate in car, but that's OK: I occasionally burn up a day or two at a time driving just for fun, and this adds to my enjoyment. (Though using dead reckoning on a cloudy day to reach a distant point is fun, too.)
Interestingly enough, they do: Google Map Maker. It was (somewhat negatively) covered here on Slashdot awhile back, but I can't be bothered to find TFA just now.
It's not automatic, but then I don't know that it should be: A lot of what's wrong with a routing system (any of them) are factual errors which in turn lead to incorrect routing.
I've fixed/added/deleted a number of things around my own town, and have had every change (that I didn't screw up myself somehow) be accepted. (Rejected edits came with feedback to improve the submission.)
In particular, Google had some completely bizarre and/or plainly impossible routes to get from my house to the nearest interstate, which made trips out of town very annoying whenever I'd actually take the time to set a destination before leaving.
For instance: I know the right and proper way to get to the highway; but the bitch inside my phone always insisted I was doing it wrong and that I should both drive around the block and use an entrance ramp an extra mile away for no good reason.
It turned out that some intersections were described improperly, with wrong-wayed streets leading to them, and incorrect turn restrictions. A few edits later (and some passage of time), and it's working fine.
Map Maker is a crowd-sourced moderator-based system, apparently including some concept of karma/reputation: Your edits are reviewed by your peers (and if not, eventually by Google), and if they're sane, they're applied. And if you have enough sanity in your edits, eventually it gets get easier/faster to have your edits "stick."
Previous to Map Maker they had a system on their regular Google Maps web interface where you could describe what was wrong (ie: complain) and they'd try to fix it themselves if you bothered to fill out the rather non-complicated form...but I only had about 50% luck with that actually producing correct results.
I find your idea to be very compelling, but I think it may have a flaw:
What happens when you pick up HIV from the hookers and accidentally wind up living for a extra quarter-century?
Punctuation. Note the colon below, just after the word "iPhone":
$1000 + 250 + 500 = $1750 for five years of development. $1750 / 5 = $350 per year.
According to GP, that's what it costs to develop for iOS.
Developing for OSX has its own costs in that you at least need to have Apple hardware to have an easy go at it, but GP wasn't talking about that at all...
I agree; P25 is crap. (Qualification, for whatever it's worth: I've installed/programmed/fixed/pondered-upon many thousands of such radios, all from a company with the initials "M" and am entrusted with keys to the tower sites all over a certain midwest state.).
Nobody really likes it. Some agencies are happy because they've got new radios which aren't yet as broken as their old ones were, but they cost 5-10x as much to buy, each. Plus a monthly fee, per radio, for service. The only reason they're even slightly happy is because they were all pretty much "free" through a state-funded grant program, which to me (as a taxpayer) is not free at all.
Nobody is happier with coverage except in the off case that they're out of their jurisdiction (which does happen, but not routinely by anyone who needs to communicate regularly). Nobody is happier with audio quality (narrowband FM can sound rather good from 300-3000Hz; digital P25 is always robotic-sounding from codec artifacts). They all want to be happier with interoperability for individual units, but nobody ever uses that and therefore won't remember how when a Big Event happens.
Consequently, anything that involves multiple agencies things still get patched together on dispatch consoles and mobile communications centers, with dedicated radios per channel (or talkgroup) -- exactly as it always had been, pre-P25.
And nobody's going to be happy when the radios start to get tired after a few years and needing repairs.
I'm happy with it as someone who earns a meager hourly wage working on it, because the initial push kept me very busy for a few years in a rough economy.
But as a professional who enjoys doing good work, I'm unhappy with it because it inherently sucks, as built, and therefore I have to give people dumb answers to their legitimate questions and problems instead of just -- you know -- fixing it.
And as a (perhaps too-well) informed citizen, I hate it. The way I see it, the old stuff worked better, and allowed me better protection.
Of the many places I visit that require badges, all but one use a generic reusable badge (sometimes plastic, sometimes just laminated paper). This new tech doesn't beat that on a cost-of-materials basis.
The one facility I do visit which has badges printed with the name of the visitor also uses a special process wherein the printing on the badge becomes contaminated with a red striped background after 24 hours or so, such that they self-expire in a visible and irreversible way....and this new widget doesn't do that, either.
Tickets? Please. This is spoken by someone who has never done any printing or automated document processing: Trying to handle stock after it's been shoved into a pocket for a few hours/days is going to be very expensive, whereas cardstock is cheap. (Besides, I like to keep my tickets.)
Soup-du-jour sign? Seriously? So a single sign can be reused 260 times, maybe, but only saves just over half a ream of paper...and costs a new printer.
Another example that doesn't work:
Shipping industry for packing slips and bills of lading. It's hard enough to get whole pallets send back in decent shape to be reused, let alone a sheet of e-paper.
I don't want to be negative, but I just don't see the use of it. I print out manuals for stuff from time to time (when fixing something mechanical/greasy where I don't want to get my laptop all covered in funk) and it often seems wasteful, but reusable e-paper no good for that either for the same reason the laptop isn't.
I still print out maps for long trips (despite being armed with a good GPS and an Android phone), and it might be useful for that, but meh: It doesn't happen enough to be worth the cost of the printer, or the trouble of trying to keep the stuff clean and keeping track of it.
I believe the technical term for free (libre) sex that "is just about me, right now," is called masturbation.
Define "most."
I work in communications. Of the five or six counties I typically work in, all but one has recently moved to a statewide system based on P25 where law enforcement has been issued radios capable of encryption.
Of those four or five counties which have encryption-capable radios, only one agency in one single town uses it by default. Everyone else transmits in the clear by default, as a matter of policy.
I remember a few variations.
One, of course, was ping -f from a sufficiently fast pipe (or just an equally-slow pipe with better buffer management). I had a custom REXX script under OS/2 which took a username as input, and would finger each of the terminal servers of a local ISP, derive the IP address of that user, then issue a ping -f for that particular dialup user.
It would cause their PPP sessions to timeout, at which point they'd disconnect. And it was fun, because I actually knew the people who I was disconnecting.
Tougher (or farther) targets at other hosts would get a ping -f from a blistering-fast (hah!) shared FreeBSD machine with a T1 connection. If -f didn't do it alone, increasing the packet size always did. Sometimes, it seemed that different packet sizes (not just larger ones) would make it happen sooner.
Around the same time, it was discovered (not by me) that sending an ICMP ping packet containing "+++ATH0" would instantly disconnect any user with a cheap modem by very neatly instructing their modem to do exactly that.
This worked because Hayes (rest their souls) had a patent on requiring a one second delay between +++ (aka "enter command mode") and any subsequent commands (ATH0 hangs up the modem). Makers of cheap modems wanted to pay as few royalties as possible, and they got their wish.
On most premium modems, or most old modems, it wasn't a problem, since it was required to have a delay between "+++" and any other command. But during the early winmodem days, it was a blast: Those cheap modems instantly dropped to command mode, and immediately executed anything after that.
You tell it to hang up, and that's just what it does.
It wasn't even really necessary to use ATH0, either: any old AT command would work, and would leave the modem in command mode instead of data mode. +++ATLM2L3, for instance, would result in a lot of noise from the modem speaker until their session timed out...
The ATH0 trick could be accomplished with IRCII using /ctcp [target] PING +++ATH0 or more generally with ping -p 2B2B2B41544829 [target IP or hostname] from a suitable *nix host.
It was fun being a kid back then, with OS-agnostic ways to be annoying. (I've grown up just slightly since then...)
In what world is the application supposed to concern itself with such things?
And that, my friend, is why the good lord gave us RS-422 to use for long runs instead RS-232.
Balanced, differential signalling and sensible grounding FTW.
Perhaps it was simply a very long time ago, and he was referring to the Province of Carolina.
Both Toro and Deere mowers are made by MTD, these days. They might as well be branded "Yard Man" or "Huskee" or "Murray," because it's the same shit with a different paint code.
Maybe.
If the receiving electronics in the mobile devices themselves are already being desensed from all of the local RFI, which may be the real problem here (we don't know if it is, or is not), it won't help.
A practical analogy: At a rock concert which is already loud enough that your ears distort, it's still hard to understand the person right next to you who is shouting near your ear: You can hear them well enough (people can produce a mighty big SPL at close range), but all you get is noise that vaguely resembles human speech. They could shout at you with a megaphone (ie: 25dBi Yagi), and it'd just get worse.
RF is no different.
But since you like firepower analogies: If you're already covered from head to toe in burning napalm, your body will be so overcome that you won't even notice being shot in the leg (you are desensitized to any potential additional pain by already experiencing the maximum amount of pain sensation possible).
Shielding works, though:
You can cup your hands between your mouth and the person's ear, and they'll suddenly be able to understand you. Not because you're louder (though you are), but because the concert becomes quieter.
You can wear an insulated fireproof suit, get covered in burning napalm, and get shot in the leg. You'll feel the gunshot wound just fine, then...
You can use a Faraday cage. Or part of one.
More power (or higher gain), or better distribution (Xirrus, et al), doesn't really help. The former just provokes everyone else to do the same (raising the stakes), while the latter doesn't work at all because everything is already shouting.
A well-designed and distributed system provided by the event's organizers would work well to keep things quiet, but it sounds like that's not really happening, and is out of the control of the individual presenters. It can't just be bolted onto an environment that is already full of shit with any real expectation of accomplishing anything more than wasting money.
This. Or window screen. Or chicken wire. Or... (It doesn't have to be copper.)
Also, a Faraday cage doesn't have to be small. And the goal is not to create a totally isolated environment, but simply an environment which is quiet enough for things to work, so it doesn't have to be anywhere near perfect either.
So. Surround the booth, or just a dedicated demonstration area within the booth, with appropriate conductive mesh.
I don't know the booth in question, but if it already has three sides, it'd be easy to get a fair bit of RFI reduction just by using conductive materials instead of (or in addition to) whatever they are made from now.
Adding even a partial roof would help more.
Bond the sections together with non-insulated copper wire. It's easy to work with, easy to find in a pinch (craft stores), very adjustable for differing layouts, and cheap enough to throw away when you're done with the show.
Grounding would also be good measure. The armchair electrician in me says that the grounding should be substantial so that in case the thing accidentally gets energized somehow, it won't present a safety hazard for those around it...but I doubt that anyone else bothers with that for random metal stuff on their other booths, even if they should.
And the RF guy in me says that a couple of runs tied to different parts of the "cage" (or more, depending on the size of the booth) of 12 AWG stranded copper, connected to an available outlet or conduit or structural steel or [insert thing here] should work just fine for RF shielding purposes.
And the inspector asshat in me says the grounding conductor should have appropriately-colored insulation, which varies by locality: Green for the US, brown in some other places, but whatever it is can be found at the local hardware store. This will make it abundantly clear what the intent of the wire is to anyone with enough clue to be questioning things like that, and will reduce their questioning to a minimum.
Oh. And try to avoid creating a parabola if using curved panels for any of this, or the partial cage may variously do the opposite of what is wanted...
It will do every bit as good a job of it as a "smart meter" will.
You don't need a "smart" meter to do this:
Just tromp outside with a wristwatch, look at any old meter, and start counting revolutions. Some simple multiplication later, and you can see how much power you're using.
Usage over time is easy, too: Just record the positions of the dials, and come back later to do it again. Subtract. Done.
Dear Lumpy,
You've inspired me.
When I am rich (I don't care if that involves being famous or not), I will make sure that my home has at least the usual kitchen fridge, and a multitude of dedicated freezers, and a kegerator in the home theater, and a kegerator in the office, and a kegerator in the garage. (I will only require one popcorn maker, but I will have a dedicated person to ferry it and its freshly-made popcorn joy to wherever I desire.)
I will also install a tunnel to the garage (thanks for the tip!), but I will not be using Segways to traverse that stretch. Instead, I will install an electric narrow-gauge railroad, powered by catalytic fuel cell fed by the fermented remains of the hand-harvested garden slugs that I will have imported from Spain. There will be a turntable at either end to turn the train 'round, which will be steam operated (just try to find a better actuator than a steam-driven piston!) using geothermal energy.
(All kidding aside: I've installed home theaters, too -- including at a place which had a helipad and a (singular) Porsche in the garage. I found the important amenities to be generally lesser than I have in my own, positively meager, home. But I wouldn't mind having a walk-in freezer and/or a cold room -- it doesn't seem like it'd be very expensive at all, and it would be terribly convenient for everything from storing hanging beef or venison, to dumping heat from a tweaked-out water-cooled PC rig.)
20% of nothin' is still nothin'.
Just saying...
The price of an app does not alter the compatibility concerns of that app.
My BMW came with a sticker in the upper-left corner of the windshield. Its text is verbatim:
"Important: Installation and operation of non-BMW approved accessories such as alarms, radios, amplifiers, radar detectors, wheels, suspension components, brake dust shields, telephones (including operation of any portable cellular phone from within the vehicle without using an externally mounted antenna) or transceiver equipment (eg. C.B., walkie-talkie, ham radio or similar) may cause extensive damage to the vehicle, compromise its safety, interfere with the vehicle's electrical system or affect the validity of the BMW Limited Warranty. Refer to your owner's manual and see your authorized BMW dealer for additional information."
(Yep, it says all that. The sticker is small. The print is smaller.)
It was made in 1995.
I'm not saying that it's anything other than fearmongering (as the E36 BMW has proven itself to be very receptive to all manner of electronic hacks and accessories), but that's what it says...
There's no reason to be unsure.
Just fire up nmap or Netscan and have a peek.