UIL calculator? Do they still do that? Always struck me as an incredibly silly contest, though that didn't stop me from taking a few tests (and doing.)
Back when I was in high school ('87), the HP 12C reigned supreme. RPN and fast.
The HP 48S and 48G's are much slower than the 12C was for simple arithmetic, which is mostly what those tests were. The slowness for simple arithmetic is probably due to the bit mapped display. Still, they're faster than you can mash the keys...
But once you start using the calculator's symbolic and graphing functions, you'll realize just how slow they really are.
Still, they're awesome calculators, and I love mine. (I've also got a HP 28C, the predecesor to the HP 48 line. God, I love these calculators!)
If somebody needs one, check the local Goodwills, Usenet, newspaper classifieds and if you're desperate, Ebay. (Ebay will cost a good deal more, but will get you one quickly.)
Tomorrow, we may care a great deal if our phone/data networks or municipal services control systems are knocked offline because an underlying wireless network failed.
Actually, I was going to continue along these lines, but got distracted and forgot to finish my post.
People care if their cell phones work during a crisis *today*. This is nothing new, and it's not likely to stop being important tomorrow.
We (as in the human race) have been using microwave links to transmit phone data for decades now. How they handle bad weather is very well known, and I'll bet a few minutes of google searching will find you lots of data on that.
(From what I've found, the error rate goes up in very heavy rain, but the links continue to work. Of course, if the wind knocks the tower over, pulls the dish off or knocks out power, it's going to break.)
WiFi does use microwaves to transmit it's data, but the name `WiFi' itself limits you to networks based on IEEE 802.11 specifications. If you're not using 802.11 specifications, it's not WiFi... it's something else.
Cell phone data is not routed over WiFi networks to any signifigant degree now, and this isn't likely to change in the future. Phone companies do use similar technologies, but they don't call it WiFi.
And that's why what happens to WiFi during a storm isn't *that* important in the grand scheme of things.
It will be interesting to see if any building-to-building WiFi links or other wireless networking tech can operate in a hurricane.
It'll be more interesting to see if there's anybody at work to even care if the network is up:)
After a hurricane, I imagine that people are more concerned that the windows didn't break and that the place didn't flood than if the database (backup, porn, whatever) copy succeeded to the other across the microwave link:)
most universities certainly are NOT setup that way.. of course they are using NAT.. what the fuck are you talking about? did you even go to university?
How very clever of you to question my education!
Here's a few universities that ARE set up this way --
These are the sites that 1) have.edu in their name and 2) have at least three different hostnames that include `.dorm.', `.resenet.' or `.housing.' signed onto the EFnet IRC network right now. This methodology certainly skips those sites that don't have lots of IRC users, and those with non-standard naming conventions (for example, dhcp-whatever might be a dorm network, or might not -- I don't list it) but it's a start.
It should give you an idea of many universities that do NOT hide their dorms behind a single IP address. Many (most?) universities of any size have a class B or even a class A network (like MIT - 18.0.0.0 -> 18.255.255.255, even though they're not in my list) assigned to them, and therefore have *plenty* of IP addresses to work with. It's one of the benefits of having been on the Internet since long before it was `trendy'...
Also, I did go to and graduate (twice!) from one of the unversities listed, though I never did live in the dorms. Your (minor -- it's not hard!) challenge, should you choose to accept it, `Anonymous Coward', is to determine which one!
Hmmm- so every MIT-Dorm computer is directly accessible from a public IP?
I don't really know the answer to that question but I'm guessing it's "no"
I'm not familiar with MIT specifically, but most universites *are* set up that way.
My point being that any organization larger than a fe people is likely to have a firewall doing NAT-
Incorrect. Businesses usually put their users behind a NAT, but ISPs rarely do, and schools rarely do as well. End users do not want usually want to be behind a NAT -- it breaks things.
Meaning that *only* the orginization itself will be able to see mac addresses and be able to tie them to individual users.
And this has *nothing* to do with NAT. As long as you are on the same ethernet segment, you can see MAC addresses of other computers on your segment. Once a packet traverses a router, you cannot see their MAC address anymore (instead, you see that of the most recent router.)
A NAT will (usually) hide IP addresses, but MAC addresses are already hidden by routers, NAT or not. And even a NAT isn't proof against RIAA prosecution -- the NAT should keep logs of the `real' IP that opened a given connection, which could be used to track somebody down.
Perhaps you're confusing IP address with MAC address? A MAC address is of the form 00:01:02:CD:2D:EC, and an IPv4 address is of the form 216.218.248.174, six bytes vs. four bytes.
any organization of any small size is going to have everything behind NAT
So, do you consider MIT to be an organization of any small size? I'm not aware of any schools that put their dorms behind a NAT. I haven't been paying attention lately, but it used to be that A&M was the only large school that even put their dorms behind a firewall (and it wasn't a NAT)!
Or an ISP? AOL is the only ISP of any size that I'm aware of that puts it's customers behind a NAT.
so nobody is going to be doing any MAC-address *anything*
I don't think you understand much of what was said.
MAC addresses are broadcast -- but they only go as far as the first router. So you'll never see somebody's MAC address over the Internet, NAT or not, because it's going to have to go through some routers.
But at MIT, if a new MAC address is encountered, apparantly the routers send you over to a login screen where you give a MIT login and then it works. The original poster was talking about sniffing the network for somebody else's MAC address (even on a switched network this is easy), and then using it once they turned their computer off. This has nothing to do with a NAT.
With the MIT system, when the RIAA says that IP whatever was being bad at this time, MIT looks at their logs, see what MAC address was using that IP, then looks at their login records to see who logged in with that MAC address. And then they give the RIAA the name (assuming that all the legal procedures are followed.)
This isn't very different from what cable modem providers do -- but instead of looking at a login logs, they look at DHCP logs.
There are hardware devices (personal firewalls) that allow you to CHANGE the broadcasted MAC address on the fly.
You don't need a personal firewall to do this. You can do it with many (most? all?) ethernet cards as well.
I would have, theoretically, obtained multiple IP addresses
Except that the system requires you to `log in' with each new MAC address...
Or, better yet, I could just change my broadcasted MAC address to one that I know is already registered.
That would certainly do it.
So, are MAC addresses about to become as `sensitive' as social sercurity numbers? (of course, just like your SSN, your MAC address is broadcast with every packet you send out, at least to the first router:) )
Mr McBride should really check his facts before making such open and accusatory statements.
Oh, he knows his facts just fine. He just chose to tell half the story. What he said is technically accurate, but carefully crafted to imply something that is totally different than the truth.
Also he took Bruce Perens completely out of context on that quote.
Well, duh! That was the idea!
McBride is not interested in telling `the truth'... he's interested in convincing people that SCO is right and everybody else is wrong -- probably with the intent of pumping up the stock price. This sort of doublespeak isn't likely to hold up in court, but it may have some weight in the court of public opinion.
The morse code requirement was part of an international agreement between the US and many other countries -- a treaty. So, it wasn't always up to the FCC to remove it -- only in the last few months has it become an option, because --
A major step forward occured on July 5, 2003, when WRC-03 adopted changes to the ITU Radio Regulations that remove the international requirement that all administrations require Morse tests, leaving that determination to the individual administrations, but the work does not end there.
(from nocode.org)
Other countries are already moving in this direction, so it sounds like it's just a matter of time before morse code is removed entirely or reduced even more.
For the sake of completeness, I'm KD5YRD, just Technician class. I've passed the General and Extra tests, but failed the Morse code test when I tried it (yesterday!)... so I'll need to work on it bit more (perhaps in two weeks I'll try again.) The written tests are quite simple, especially since you have access to all possible test questions, but the morse code part can be a lot harder for many people, even though 5 wpm is extremely slow.
In any event, don't get the idea that you need to know morse code to do ham radio, even today. You absolutely do not -- the Technician class license does not require it, and gets you access to many (most?) of the `fun' things that ham radio has to offer. But you may want to learn it eventually -- you'll hear a lot of it even mixed in with voice communications.
Don't say that too loudly -- the FCC prohibits the use of encryption or even obfuscation (for the sake of obfuscation -- abbreviating things is ok) in amateur radio use.
The only exception is if you're controlling a satellite, in which case you can use `special uplink codes specifically intented to obscure the meaning of messages'.
(Unless you're using `ssh -c none', but I don't think any modern variants allow that anymore.)
A molecule of water weighs 16+1+1 or 18 atomic mass units. Air is mostly nitrogen and oxygen, with masses of 28 or 32 amu per molecule (remember, you never find single oxygen or nitrogen atoms, only O^2 and N^2 molecules. Ozone is O^3, btw, but it's relatively rare.)
What does this mean? It means that water vapor actually weighs *less* than the air (mostly oxygen and nitrogen) it displaces.
Pilots care about this a lot -- they will calculate the density of the air where they are taking off, taking into account altitude, temperature, barometer reading and humidity.
Using this information, they'll estimate how much space they'll need to take off, and how much weight they can safely take off with. If the humidity is high, this may mean that they must leave behind some fuel, cargo or passengers.
Of course, clouds are visible because some of the water vapor has condensed into tiny droplets of water, and that certainly does weigh more than the air it displaces. Water vapor is invisible -- droplets are not. Of course, if the droplets become too big, they'll fall as precipitation.
Toys have refused to say bad words for a while now...
For example, my daughter has an Alpha Bug (it's not exactly like that, but really close.) One of the first things adults do with this sort of thing is see what kind of bad words you can make it say... but it won't do it. It'll go F... U... ohhh that tickles!
We mentioned this to a friend of ours who also had an Alpha Bug, and he must have had an earlier version -- while it looked identical, it *would* let you make bad word sounds. Oddly enough, as soon as we mentioned that we had an alpha bug, he immediately picked it up and starting showing us how it can say bad words (even before we got to that part. So obviously we're not alone in this:)
And yesterday, I bought some other Leap Frog toy for my daughter at a garage sale. It's a cylindrical thing that you can rotate the sides to pick letters, and it apparantly knows every 3 letter word, and even has recordings of somebody saying each and every one (it's not just speech synthesis.) If it doesn't know the word, it will spell out the sounds, but if it does it'll say it perfectly. (Pretty impressive for $2!) (It's very similar to this but not quite identical.)
In any event, it won't even spell out things that sound like a bad word -- it says `F... U... pick another word!'. (Oddly enough, even `JAP' is a bad word according to it.:)
In any event, if you have friends with young kids, but they're not really good friends, you buy them stuff like this -- stuff that makes noise. Very annoying:)
I used to use fsp to download stuff from my shell account to my home box, over my 24x7 dialup line.
fsp had very little effect on my other uses of the line, so I could have it downloading while I'm doing other stuff and not even notice. Other forms of file transfer would send my ping times up to about one second.
Alas, I finally got rid of it when I got my cable modem. I considered keeping it around, but it just wasn't needed.
Looks like I still have my log file around!
% tail -2 ~/tmp/fsp/logs/logfile
Sat Oct 24 23:51:42 1998 xyz.foo.com GETDIR/
Sat Oct 24 23:51:43 1998 xyz.foo.com GETDIR/incoming
so that tells exactly how long it's been since I've used it. And I think I was one of the last ones:)
Once there was control-line model aircraft. Now they use radio controls.
People still fly control line planes. They still do free flight planes too.
(Personally, I like my R/C planes:)
Perhaps laptops with WiFi and big amplifiers and antennas will be the ham-radio of the future.
Hams (and non hams) play with this now. Of course, the rules prohibit big amplifiers, but good antennas can be used.
There's no shame in retiring a long-loved technology
Perhaps not, but it's not being retired either. Morse code is big with hams, even now -- and it's even still useful, filling a niche (low power, getting through interference, not requiring a computer) that other transmission modes don't.
Think of all the amateur astronomers whose telescopes became useless due to light polution.
Useless is much too strong of a word. Less useful is much more appropriate -- after all, you could use your telescope to take a nice picture of the moon, even in downtown New York.
Still, the light pollution analogy is pretty apt for describing the power line broadband ideas. Of course, I suspect that the hams won't be the only ones affected...
I wouldn't leave it unused, just try to shift things so that, say, two bands with extremely high power and use aren't directly "integered."
Easier (and cheaper) said than done.:)
Also, I believe the relative power of the nth harmonic goes down directly with n, correct?
It probably goes down exponentially -- 2nd harmonic is 1%, 3rd is 1% of 1%, etc. Not sure.
According to This site you can actually listen to the harmonics of an FM radio station in the hundreds of MHz region.
Absolutely. I don't have a scanner that can do 72.450 mhz, but I can definately hear my R/C transmitter by tuning my 2m ham radio to 144.900 mhz. The range is greatly reduced, but I can still pick it up up to about 100 ft away.
Do they try anything to avoid that? If I were the FCC, I would try to keep major bands from being integer multiples of each other - and that 800/2400 looks like potential disaster there.
Impossible, or at least impractical. It would require losing the ability to use most of the spectrum -- because after all, whatever frequency you're talking about, there's a frequency that's 1/2, 1/3rd, 1/4th etc. of it, that could interfere with it.
Good transmitters have filters that almost completely kill the harmonics. Not quite, but almost.
There are other factors too -- for example, dual conversion R/C receivers have a 455 khz intermediate stage that can set them up to receive interference from 455 mhz away. I don't fully understand all of it, but let's just say there's lots of ways to cause interference.:)
I have - I'm a chemist, so I do some spectroscopy.;)
Neat! My degrees are in physics and astrononmy, but alas I don't get to use them much `in real life'... that would kick much ass if I make my living at it!
I was more referring to the license situation the FCC has. It allots you, say, a 0.5 MHz bandwidth. Your transmitter is supposed to transmit in this band. However, say it sucks - the spectrum might not be as tight as it's supposed to be, and it might bleed over more.
Right. But people were talking about frequencies like 800.0000001 mhz... as if you could somehow make a perfect radio that would allow lots of data to be pushed into 0.0000001 mhz, which you definately cannot do. Shannon and Nyquist and all.
But, as you've said, radios are not perfect. They should not transmit outside of their band, but of course small amounts of emissions escape anyways, and you cannot prevent this 100%.
Alas, when your transmitter is 1000+ watts, the amount can become signifigant. And then there's harmonics -- 2.4 ghz should not affect 800 mhz, but the harmonics of 800 mhz could certainly interfere with 2.4 ghz (WiFi) signals.
for analogue voice, you need at least a bandwidth of ~30 Khz
No, you don't need anywhere near that much to send a reasonably clear voice. Police and HAM radios and such do it on 3-6 khz. Of course, you don't hear police radio advertising that says you can hear `a pin drop' either:)
(As an added bonus, they don't walk around going `Can you hear me now!')
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Back when I was in high school ('87), the HP 12C reigned supreme. RPN and fast.
The HP 48S and 48G's are much slower than the 12C was for simple arithmetic, which is mostly what those tests were. The slowness for simple arithmetic is probably due to the bit mapped display. Still, they're faster than you can mash the keys ...
But once you start using the calculator's symbolic and graphing functions, you'll realize just how slow they really are.
Still, they're awesome calculators, and I love mine. (I've also got a HP 28C, the predecesor to the HP 48 line. God, I love these calculators!)
If somebody needs one, check the local Goodwills, Usenet, newspaper classifieds and if you're desperate, Ebay. (Ebay will cost a good deal more, but will get you one quickly.)
People care if their cell phones work during a crisis *today*. This is nothing new, and it's not likely to stop being important tomorrow.
We (as in the human race) have been using microwave links to transmit phone data for decades now. How they handle bad weather is very well known, and I'll bet a few minutes of google searching will find you lots of data on that.
(From what I've found, the error rate goes up in very heavy rain, but the links continue to work. Of course, if the wind knocks the tower over, pulls the dish off or knocks out power, it's going to break.)
WiFi does use microwaves to transmit it's data, but the name `WiFi' itself limits you to networks based on IEEE 802.11 specifications. If you're not using 802.11 specifications, it's not WiFi ... it's something else.
Cell phone data is not routed over WiFi networks to any signifigant degree now, and this isn't likely to change in the future. Phone companies do use similar technologies, but they don't call it WiFi.
And that's why what happens to WiFi during a storm isn't *that* important in the grand scheme of things.
After a hurricane, I imagine that people are more concerned that the windows didn't break and that the place didn't flood than if the database (backup, porn, whatever) copy succeeded to the other across the microwave link :)
I'm 34. I just got into ham radio. I'm often the youngest guy around :)
Here's a few universities that ARE set up this way --
These are the sites that 1) haveIt should give you an idea of many universities that do NOT hide their dorms behind a single IP address. Many (most?) universities of any size have a class B or even a class A network (like MIT - 18.0.0.0 -> 18.255.255.255, even though they're not in my list) assigned to them, and therefore have *plenty* of IP addresses to work with. It's one of the benefits of having been on the Internet since long before it was `trendy' ...
Also, I did go to and graduate (twice!) from one of the unversities listed, though I never did live in the dorms. Your (minor -- it's not hard!) challenge, should you choose to accept it, `Anonymous Coward', is to determine which one!
A NAT will (usually) hide IP addresses, but MAC addresses are already hidden by routers, NAT or not. And even a NAT isn't proof against RIAA prosecution -- the NAT should keep logs of the `real' IP that opened a given connection, which could be used to track somebody down.
Perhaps you're confusing IP address with MAC address? A MAC address is of the form 00:01:02:CD:2D:EC, and an IPv4 address is of the form 216.218.248.174, six bytes vs. four bytes.
Or an ISP? AOL is the only ISP of any size that I'm aware of that puts it's customers behind a NAT.
I don't think you understand much of what was said.MAC addresses are broadcast -- but they only go as far as the first router. So you'll never see somebody's MAC address over the Internet, NAT or not, because it's going to have to go through some routers.
But at MIT, if a new MAC address is encountered, apparantly the routers send you over to a login screen where you give a MIT login and then it works. The original poster was talking about sniffing the network for somebody else's MAC address (even on a switched network this is easy), and then using it once they turned their computer off. This has nothing to do with a NAT.
With the MIT system, when the RIAA says that IP whatever was being bad at this time, MIT looks at their logs, see what MAC address was using that IP, then looks at their login records to see who logged in with that MAC address. And then they give the RIAA the name (assuming that all the legal procedures are followed.)
This isn't very different from what cable modem providers do -- but instead of looking at a login logs, they look at DHCP logs.
So, are MAC addresses about to become as `sensitive' as social sercurity numbers? (of course, just like your SSN, your MAC address is broadcast with every packet you send out, at least to the first router :) )
McBride is not interested in telling `the truth' ... he's interested in convincing people that SCO is right and everybody else is wrong -- probably with the intent of pumping up the stock price. This sort of doublespeak isn't likely to hold up in court, but it may have some weight in the court of public opinion.
Other countries are already moving in this direction, so it sounds like it's just a matter of time before morse code is removed entirely or reduced even more.
More details here and here and here.
For the sake of completeness, I'm KD5YRD, just Technician class. I've passed the General and Extra tests, but failed the Morse code test when I tried it (yesterday!) ... so I'll need to work on it bit more (perhaps in two weeks I'll try again.) The written tests are quite simple, especially since you have access to all possible test questions, but the morse code part can be a lot harder for many people, even though 5 wpm is extremely slow.
In any event, don't get the idea that you need to know morse code to do ham radio, even today. You absolutely do not -- the Technician class license does not require it, and gets you access to many (most?) of the `fun' things that ham radio has to offer. But you may want to learn it eventually -- you'll hear a lot of it even mixed in with voice communications.
The only exception is if you're controlling a satellite, in which case you can use `special uplink codes specifically intented to obscure the meaning of messages'.
(Unless you're using `ssh -c none', but I don't think any modern variants allow that anymore.)
(Yes, I know it was a joke. :)
What does this mean? It means that water vapor actually weighs *less* than the air (mostly oxygen and nitrogen) it displaces.
Pilots care about this a lot -- they will calculate the density of the air where they are taking off, taking into account altitude, temperature, barometer reading and humidity. Using this information, they'll estimate how much space they'll need to take off, and how much weight they can safely take off with. If the humidity is high, this may mean that they must leave behind some fuel, cargo or passengers.
Of course, clouds are visible because some of the water vapor has condensed into tiny droplets of water, and that certainly does weigh more than the air it displaces. Water vapor is invisible -- droplets are not. Of course, if the droplets become too big, they'll fall as precipitation.
Perhaps it's Something Awful that's doing it?
Fark seems to think so.
(Ever feel like you're writing for memepool or Everything2? I sure do!)
Or was that not large scale or legitimate enough for you? :)
(There are other examples, but that's the largest one I can think of off the top of my head.)
Sweet! Thanks!
For example, my daughter has an Alpha Bug (it's not exactly like that, but really close.) One of the first things adults do with this sort of thing is see what kind of bad words you can make it say ... but it won't do it. It'll go F ... U ... ohhh that tickles!
We mentioned this to a friend of ours who also had an Alpha Bug, and he must have had an earlier version -- while it looked identical, it *would* let you make bad word sounds. Oddly enough, as soon as we mentioned that we had an alpha bug, he immediately picked it up and starting showing us how it can say bad words (even before we got to that part. So obviously we're not alone in this :)
And yesterday, I bought some other Leap Frog toy for my daughter at a garage sale. It's a cylindrical thing that you can rotate the sides to pick letters, and it apparantly knows every 3 letter word, and even has recordings of somebody saying each and every one (it's not just speech synthesis.) If it doesn't know the word, it will spell out the sounds, but if it does it'll say it perfectly. (Pretty impressive for $2!) (It's very similar to this but not quite identical.)
In any event, it won't even spell out things that sound like a bad word -- it says `F ... U ... pick another word!'. (Oddly enough, even `JAP' is a bad word according to it. :)
In any event, if you have friends with young kids, but they're not really good friends, you buy them stuff like this -- stuff that makes noise. Very annoying :)
Alas, there's still no Linux version of Echolink, which is a pretty clever combination of ham radio and the Internet.
fsp had very little effect on my other uses of the line, so I could have it downloading while I'm doing other stuff and not even notice. Other forms of file transfer would send my ping times up to about one second.
Alas, I finally got rid of it when I got my cable modem. I considered keeping it around, but it just wasn't needed.
Looks like I still have my log file around!
so that tells exactly how long it's been since I've used it. And I think I was one of the last ones(Personally, I like my R/C planes :)
Hams (and non hams) play with this now. Of course, the rules prohibit big amplifiers, but good antennas can be used. Perhaps not, but it's not being retired either. Morse code is big with hams, even now -- and it's even still useful, filling a niche (low power, getting through interference, not requiring a computer) that other transmission modes don't. Useless is much too strong of a word. Less useful is much more appropriate -- after all, you could use your telescope to take a nice picture of the moon, even in downtown New York.Still, the light pollution analogy is pretty apt for describing the power line broadband ideas. Of course, I suspect that the hams won't be the only ones affected ...
Good transmitters have filters that almost completely kill the harmonics. Not quite, but almost.
There are other factors too -- for example, dual conversion R/C receivers have a 455 khz intermediate stage that can set them up to receive interference from 455 mhz away. I don't fully understand all of it, but let's just say there's lots of ways to cause interference. :)
But, as you've said, radios are not perfect. They should not transmit outside of their band, but of course small amounts of emissions escape anyways, and you cannot prevent this 100%. Alas, when your transmitter is 1000+ watts, the amount can become signifigant. And then there's harmonics -- 2.4 ghz should not affect 800 mhz, but the harmonics of 800 mhz could certainly interfere with 2.4 ghz (WiFi) signals.
This allows it to reproduce frequencies up to 4 khz or so ... your ears can hear much higher than that, but it's not really needed for speech.
(As an added bonus, they don't walk around going `Can you hear me now!')