Typical complex microprocessors like the Pentium 4 already ship with dozens of design defects. Including this technology on the chip would allow the manufacturer to patch around these defects on-chip, rather than leaving that responsibility to the OS and compiler developers, or being forced to recall millions of chips. This will actually lead to more-reliable hardware.
Basically, the idea is to include a small amount of reconfigurable logic on a conventional microprocessor. The configurable section would be used to detect conditions that trigger known design defects (or errata, as they're called in the industry), and work around the problem. The authors figure that for about 0.5% overhead in wires and silicon area, a chip manufacturer can patch around more than 60% of typical errata conditions.
It's an interesting idea. It's somewhat amusing that early on in the paper they mention the Pentium FDIV bug as an example of a processor defect that triggered an expensive recall, but their proposed mechanism wouldn't be able to detect and fix that sort of problem.
Regardless, it's nice to see some actual categorization of defects for various processors, and they do a good job of explaining why fixing the "easy" cases is very worthwhile.
The Wii Remote seems to detect orientation just fine without using the optical sensor. The Wii Sports games illustrate this very well. In Tennis, Baseball, and Golf, the orientation of the remote is mirrored onscreen by the position of the racket/bat/club, all without having to point at the screen.
Or maybe you're complaining about something else, and I'm misunderstanding the problem?
The article IS light on details, but the last paragraph does explain how the system would work. Basically, manufacturers of mass-market chips would provide a small amount of FPGA-like programmable logic in every chip they make. This programmable logic would sit idle until some defect was discovered in the chip.
At that point, you can send a "patch" to the chip that uses the programmable logic to detect the error condition (or conditions that trigger the error), and work around the problem.
It's fairly clever, and is similar in spirit to the microcode patches that varios x86 CPU manufacturers use to correct for errors in their chips after they're taped out. It would be interesting to read about what the actual design is. It seems like coming up with a generic logic patching mechanism that can deal with previously-unknown errors would be a pretty interesting task.
Satellites have a very predictable trajectory, and so blowing them up from the ground is easy.
This is true for certain kinds of satellites, but many (all?) spy satellites have some amount of manueverability, to allow them to image different parts of the globe, as needed. Even satellites with normally "stable" orbits will have thrusters for station-keeping that could be used to move them out of their "usual" orbit if they're threatened.
If you fire an interceptor missile at a spy satellite, I wouldn't be at all surprised if it wasn't in the predicted location by the time your interceptor achieved orbit. The obvious advantage of space-based anti-satellite weapons is the ability to strike essentially without warning. Ground-based laser and beam weapons have the same advantage in theory, but the atmosphere really drags down their efficiency - and they're prime targets for a cruise missile or ICBM.
Most navigation in subs is done based on dead reckoning, using highly-detailed charts of the sea floor. At least, that's how they do it in the movies:-) And it's always the reckless captain that endangers the sub by insisting on going faster than the navigator recommends, or trying to get a little too close to that underwater mountain...
Subs that are near the surface can send up tethered bouys to contact satellites for communication and location purposes, of course. I don't know if there are any position-indicating beacons permanently installed on the seabed, but I'd doubt it.
It can be up to 20 years under ideal conditions. Flash that's been erased many times will have a shorter data retention time, as will Flash stored at higher temperatures. A Google search on Flash Data Retention will lead to many pages from various semiconductor companies discussing the performance of their particular parts. There's a nice easy-to-read table in this document: http://www.spansion.com/application_notes/EndureRe tentn_AN_A0.pdf
Oops. Oh well, I guess it's all down to the enforceability of the EULA then, rather than Copyright law. I have this vague idea that I've read about a lawsuit based on someone bulk-reselling discounted (academic) software into another market, but I can't rmeember the details.
Given that you have to make a copy of the software on your local hard drive in order to run it, how do you propose to get around the EULA? Without agreeing to that "license to make one copy on a single computer for the purposes of running the program", you don't even have the right to install the software.
Now, I will agree that a license that you can't read until you've already paid for the software is not a particularly customer-friendly thing, but I don't see any reason why that invalidates the basic concept.
A quick spritz of Lysol isn't going to affect the DNA of the bacteria much, if at all. Denaturing the DNA is not how antiseptics kill bacteria. I think that data stored in this fashion would actually be a lot harder to destroy than magnetic storage. After all, they can extract (fragments of) DNA from fossils.
The obvious answer would be that they wanted to do something cool on a weekend afternoon without spending weeks soldering breadboards, writing and debugging firmware, etc, etc.
Printers like this are used in manufacturing prototyping aqll the time. Depending on the technology used, the solution to these sorts of problems usually involves changing the model to include thin supports for loose parts. You then break the supports off when the part is finished being built up.
I was just cleaning up my office and came across my Rhapsody for PC install discs, as well as the Yellow Box for Windows CD. I can't quite bring myself to throw them away - I should make a diorama of "stuff I worked on at Apple that never shipped".
The "feature" of sending video to random strangers on the Internet is disabled by default for Flash, and was enabled by default for QuickTime/Java beore this patch was issued.
I have no idea how it would be harder to read sequentially than any other way. Flash memory is just plain slow, period. Sequential or random access doesn't make any difference. I think what the other guy was trying to say was that the Flash APPEARS to be disproportionately slow in sequential reads as opposed to random access, because DISKS are so very slow at random access.
The main idea behind ReadyBoost is that the Flash cache can be read from while the disk is spinning up, which reduces the total resume from hibernate time. I can't imagine that that's going to make enough difference to be worthwhile.
1. Heads are one of the most expensive parts of the drive. 2. You'd need over a thousand heads for each disk surface, so even if they were REALLY REALLY cheap, they'd easily bury the savings of not having an actuator. If a disk drive head cost $0.01, and an actuator was $10, you'd just about come out even on a single-sided, single platter drive (and the actual prices aren't anything like that low/high, respectively). 3. All modern disk drives are dynamically servoed, meaning that there are magnetic marks on the disk itself to allow the drive to figure out which track it's reading from. If you had fixed heads, you'd have to put the data tracks farther apart, so thermal expansion wouldn't cause the tracks to migrate out from under the heads when the drive heats up. That would dramatically reduce data density.
For what it's worth, there have been dual-actuator hard drives made, from time to time. They have one arm on each side of the disk, which can each seek independently. They have approximately half the average seek time of an equivalent single-arm drive, and get better transfer rates, as well. On the downside, they cost significantly more, use more power, and have a lower MTBF (twice as many heads to crash, after all).
I'd really like to see someone build a (portable!) device that can erase a mag-stripe card at more than a foot or so of distance. The kind of magnetic field that you'd have to generate to wipe a mag-stripe card from a distance would probably violently attract every piece of loose iron in the vicinity, as well.
As far as the phone goes, I'd be pretty peeved if someone fried it with microwaves, but there's probably at least some protection built into the phone - otherwise, walking directly by a cell tower might damage your phone. Additionally, I don't depend on my phone to identify myself.
"Computer, open folder 'My Pictures'. Now open the subfolder "Romulan Ale Binges". Now open the subfolder "Counselor Troi Flashing Her Tits". Now open the subfolder "2365-12-31". Select pictures 1 through 137 and display, continuous loop."
Congratulations. You've just (re)invented AppleScript!
But even just RFID alone is in no way less secure than printing a number on your passport that uniquely identifies you.
That's a really strange thing to say. Here's short list of potential security problems an RFID presents that a printed number doesn't, off the top of my head:
1. Your RFID chip can be read & potentially copied without your peremission, or even your being aware of it. 2. An RFID-enabled ID allows anyone to build an "American Detector" that's 100% reliable, and works from a distance. This is a special case of #1, but a particularly worrisome one. 3. Someone can "invalidate" your passport remotely, by burning out the chip with high-powered RF. How do you convince the Homeland Security folks that you really DO have a valid passport, despite the fact that the "secure" chip is apparently missing? 4. The government or even private agencies can use the RFID to track you, at least in terms of entering or leaving a particular area, again without your knowledge. 5. Given that the RFID chip allows you to be "authenticated" easier, does that imply that the rest of the passport will be looked at LESS carefully?
Okay, so figure -32 Calories for each Diet Pepsi Slurpee. So, to lose 1 pound a month (a nice safe pace) without changing anything else in your diet...
1 lb fat = 3500 Calories 3500 / 32 = 78 Slurpees a month, or slightly more than 2.5 a day. Hmm. That's actually a lot less than I expected to see. Maybe the "Diet Pepsi Slurpee Diet" is actually reasonable. My 15 minutes of fame awaits!
The original iPod hard drives (from the 5 and 10 GB models) had a very short guaranteed run time. That wasn't a problem for the iPod as a music player, or for occasional file transfer, since the drive was turned off 90% or more of the time. OS X likes to write to the home directory frequently, though, so "Portable Home Directories" (as they were known at the time) had the potential to wear out the iPod's hard drive very quickly (a matter of weeks or months).
It turns out that the ACTUAL run time to failure for those drives was typically much longer than promised, so lots of folks have had success with using them as "live" drives. I have no idea what the specs on the current generation of iPod hard drives are, but I'd bet they're considerably more durable.
That page claims a "product life" of "5 years or 20,000 POH (Power-On-Hours)". 20,000 hours is just over 2.25 years of continuous operation. Given that you can get a 2-year warranty for an iPod through AppleCare these days, that doesn't sound like a very good risk.
I don't happen to have a copy of the original spec sheet we got with the first-generation drives, but my recollection is that the quoted life span was much shorter - short enough that warranty returns for worn-out drives was a real concern if they were kept running all the time, even with the shorter warranties offered at the time (anybody else remember 90-day iPod warranties?).
Of course, for Flash devices (like those in the Shuffle and Nano) the lifetime is specified in terms of a certain number of write operations, rather than total time "turned on". The expected lifetime for an iPod Shuffle used as a home directory is probably very very long - dozens of years.
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Typical complex microprocessors like the Pentium 4 already ship with dozens of design defects. Including this technology on the chip would allow the manufacturer to patch around these defects on-chip, rather than leaving that responsibility to the OS and compiler developers, or being forced to recall millions of chips. This will actually lead to more-reliable hardware.
An anonymous coward replied to my post below with this link to the original paper:h oenix.pdf
http://iacoma.cs.uiuc.edu/iacoma-papers/micro06_p
Basically, the idea is to include a small amount of reconfigurable logic on a conventional microprocessor. The configurable section would be used to detect conditions that trigger known design defects (or errata, as they're called in the industry), and work around the problem. The authors figure that for about 0.5% overhead in wires and silicon area, a chip manufacturer can patch around more than 60% of typical errata conditions.
It's an interesting idea. It's somewhat amusing that early on in the paper they mention the Pentium FDIV bug as an example of a processor defect that triggered an expensive recall, but their proposed mechanism wouldn't be able to detect and fix that sort of problem.
Regardless, it's nice to see some actual categorization of defects for various processors, and they do a good job of explaining why fixing the "easy" cases is very worthwhile.
The Wii Remote seems to detect orientation just fine without using the optical sensor. The Wii Sports games illustrate this very well. In Tennis, Baseball, and Golf, the orientation of the remote is mirrored onscreen by the position of the racket/bat/club, all without having to point at the screen.
Or maybe you're complaining about something else, and I'm misunderstanding the problem?
The article IS light on details, but the last paragraph does explain how the system would work. Basically, manufacturers of mass-market chips would provide a small amount of FPGA-like programmable logic in every chip they make. This programmable logic would sit idle until some defect was discovered in the chip.
At that point, you can send a "patch" to the chip that uses the programmable logic to detect the error condition (or conditions that trigger the error), and work around the problem.
It's fairly clever, and is similar in spirit to the microcode patches that varios x86 CPU manufacturers use to correct for errors in their chips after they're taped out. It would be interesting to read about what the actual design is. It seems like coming up with a generic logic patching mechanism that can deal with previously-unknown errors would be a pretty interesting task.
Satellites have a very predictable trajectory, and so blowing them up from the ground is easy.
This is true for certain kinds of satellites, but many (all?) spy satellites have some amount of manueverability, to allow them to image different parts of the globe, as needed. Even satellites with normally "stable" orbits will have thrusters for station-keeping that could be used to move them out of their "usual" orbit if they're threatened.
If you fire an interceptor missile at a spy satellite, I wouldn't be at all surprised if it wasn't in the predicted location by the time your interceptor achieved orbit. The obvious advantage of space-based anti-satellite weapons is the ability to strike essentially without warning. Ground-based laser and beam weapons have the same advantage in theory, but the atmosphere really drags down their efficiency - and they're prime targets for a cruise missile or ICBM.
Most navigation in subs is done based on dead reckoning, using highly-detailed charts of the sea floor. At least, that's how they do it in the movies :-) And it's always the reckless captain that endangers the sub by insisting on going faster than the navigator recommends, or trying to get a little too close to that underwater mountain...
Subs that are near the surface can send up tethered bouys to contact satellites for communication and location purposes, of course. I don't know if there are any position-indicating beacons permanently installed on the seabed, but I'd doubt it.
It can be up to 20 years under ideal conditions. Flash that's been erased many times will have a shorter data retention time, as will Flash stored at higher temperatures. A Google search on Flash Data Retention will lead to many pages from various semiconductor companies discussing the performance of their particular parts. There's a nice easy-to-read table in this document:e tentn_AN_A0.pdf
http://www.spansion.com/application_notes/EndureR
Oops. Oh well, I guess it's all down to the enforceability of the EULA then, rather than Copyright law. I have this vague idea that I've read about a lawsuit based on someone bulk-reselling discounted (academic) software into another market, but I can't rmeember the details.
Given that you have to make a copy of the software on your local hard drive in order to run it, how do you propose to get around the EULA? Without agreeing to that "license to make one copy on a single computer for the purposes of running the program", you don't even have the right to install the software.
Now, I will agree that a license that you can't read until you've already paid for the software is not a particularly customer-friendly thing, but I don't see any reason why that invalidates the basic concept.
A quick spritz of Lysol isn't going to affect the DNA of the bacteria much, if at all. Denaturing the DNA is not how antiseptics kill bacteria. I think that data stored in this fashion would actually be a lot harder to destroy than magnetic storage. After all, they can extract (fragments of) DNA from fossils.
Calling it "Quantum Encryption" just confuses what it is and how it works. Calling it "Quantum Key Exchange", would be a lot more accurate.
QNS-27 dmbqxoshnm, dg? H khjd hs. Ax sgd vzx, xnt lhrodkkdc "Nudqknqcr"
Anyways, my question is why use wii controllers?
The obvious answer would be that they wanted to do something cool on a weekend afternoon without spending weeks soldering breadboards, writing and debugging firmware, etc, etc.
Printers like this are used in manufacturing prototyping aqll the time. Depending on the technology used, the solution to these sorts of problems usually involves changing the model to include thin supports for loose parts. You then break the supports off when the part is finished being built up.
I was just cleaning up my office and came across my Rhapsody for PC install discs, as well as the Yellow Box for Windows CD. I can't quite bring myself to throw them away - I should make a diorama of "stuff I worked on at Apple that never shipped".
The "feature" of sending video to random strangers on the Internet is disabled by default for Flash, and was enabled by default for QuickTime/Java beore this patch was issued.
I have no idea how it would be harder to read sequentially than any other way.
Flash memory is just plain slow, period. Sequential or random access doesn't make any difference. I think what the other guy was trying to say was that the Flash APPEARS to be disproportionately slow in sequential reads as opposed to random access, because DISKS are so very slow at random access.
The main idea behind ReadyBoost is that the Flash cache can be read from while the disk is spinning up, which reduces the total resume from hibernate time. I can't imagine that that's going to make enough difference to be worthwhile.
Some that I've been to (these are all excellent):
Arizona Science Center (Phoenix, AZ)
St Louis Science Center
Tech Museum of Innovation (San Jose, CA)
The Exploratorium (San Francisco)
Some I have yet, even though I live in the area:
Children's Discovery Museum (San Jose, CA)
The Intel Museum (Santa Clara, CA)
Computer History Museum (Mountain View, CA)
If you're looking for geeky museums, the SF Bay Area probably has more of them in a smaller radius than anywhere else in the USA.
Couple of problems here -
1. Heads are one of the most expensive parts of the drive.
2. You'd need over a thousand heads for each disk surface, so even if they were REALLY REALLY cheap, they'd easily bury the savings of not having an actuator. If a disk drive head cost $0.01, and an actuator was $10, you'd just about come out even on a single-sided, single platter drive (and the actual prices aren't anything like that low/high, respectively).
3. All modern disk drives are dynamically servoed, meaning that there are magnetic marks on the disk itself to allow the drive to figure out which track it's reading from. If you had fixed heads, you'd have to put the data tracks farther apart, so thermal expansion wouldn't cause the tracks to migrate out from under the heads when the drive heats up. That would dramatically reduce data density.
For what it's worth, there have been dual-actuator hard drives made, from time to time. They have one arm on each side of the disk, which can each seek independently. They have approximately half the average seek time of an equivalent single-arm drive, and get better transfer rates, as well. On the downside, they cost significantly more, use more power, and have a lower MTBF (twice as many heads to crash, after all).
-Mark
I'd really like to see someone build a (portable!) device that can erase a mag-stripe card at more than a foot or so of distance. The kind of magnetic field that you'd have to generate to wipe a mag-stripe card from a distance would probably violently attract every piece of loose iron in the vicinity, as well.
As far as the phone goes, I'd be pretty peeved if someone fried it with microwaves, but there's probably at least some protection built into the phone - otherwise, walking directly by a cell tower might damage your phone. Additionally, I don't depend on my phone to identify myself.
-Mark
"Computer, open folder 'My Pictures'. Now open the subfolder "Romulan Ale Binges". Now open the subfolder "Counselor Troi Flashing Her Tits". Now open the subfolder "2365-12-31". Select pictures 1 through 137 and display, continuous loop."
Congratulations. You've just (re)invented AppleScript!
-Mark
But even just RFID alone is in no way less secure than printing a number on your passport that uniquely identifies you.
That's a really strange thing to say. Here's short list of potential security problems an RFID presents that a printed number doesn't, off the top of my head:
1. Your RFID chip can be read & potentially copied without your peremission, or even your being aware of it.
2. An RFID-enabled ID allows anyone to build an "American Detector" that's 100% reliable, and works from a distance. This is a special case of #1, but a particularly worrisome one.
3. Someone can "invalidate" your passport remotely, by burning out the chip with high-powered RF. How do you convince the Homeland Security folks that you really DO have a valid passport, despite the fact that the "secure" chip is apparently missing?
4. The government or even private agencies can use the RFID to track you, at least in terms of entering or leaving a particular area, again without your knowledge.
5. Given that the RFID chip allows you to be "authenticated" easier, does that imply that the rest of the passport will be looked at LESS carefully?
-Mark
Okay, so figure -32 Calories for each Diet Pepsi Slurpee. So, to lose 1 pound a month (a nice safe pace) without changing anything else in your diet...
1 lb fat = 3500 Calories
3500 / 32 = 78 Slurpees a month, or slightly more than 2.5 a day. Hmm. That's actually a lot less than I expected to see. Maybe the "Diet Pepsi Slurpee Diet" is actually reasonable. My 15 minutes of fame awaits!
The original iPod hard drives (from the 5 and 10 GB models) had a very short guaranteed run time. That wasn't a problem for the iPod as a music player, or for occasional file transfer, since the drive was turned off 90% or more of the time. OS X likes to write to the home directory frequently, though, so "Portable Home Directories" (as they were known at the time) had the potential to wear out the iPod's hard drive very quickly (a matter of weeks or months).
d /mk5002.htm#relia
It turns out that the ACTUAL run time to failure for those drives was typically much longer than promised, so lots of folks have had success with using them as "live" drives. I have no idea what the specs on the current generation of iPod hard drives are, but I'd bet they're considerably more durable.
Hey, what do you know - Toshiba has published the specifications for the original 5GB iPod drive online:
http://www3.toshiba.co.jp/storage/english/spec/hd
That page claims a "product life" of "5 years or 20,000 POH (Power-On-Hours)". 20,000 hours is just over 2.25 years of continuous operation. Given that you can get a 2-year warranty for an iPod through AppleCare these days, that doesn't sound like a very good risk.
I don't happen to have a copy of the original spec sheet we got with the first-generation drives, but my recollection is that the quoted life span was much shorter - short enough that warranty returns for worn-out drives was a real concern if they were kept running all the time, even with the shorter warranties offered at the time (anybody else remember 90-day iPod warranties?).
Of course, for Flash devices (like those in the Shuffle and Nano) the lifetime is specified in terms of a certain number of write operations, rather than total time "turned on". The expected lifetime for an iPod Shuffle used as a home directory is probably very very long - dozens of years.