The penalty isn't that substantial. On the Intel X25-M it's less than half slower (44% to be precise). With CrystalDiskMark, I get 77.12MB/s for sequential writes and 42.50MB/s for 4K random writes. http://www.flickr.com/photos/33524247@N06/3119124721/
Wikipedia's Clearwire entry says at the top: "Clearwire currently uses Expedience wireless technology, dubbed Pre-WiMax, transmitted from cell sites over licensed spectrum of 2.5-2.6 GHz in the U.S. and 3.5 GHz in Europe."
So it looks like it's something like WiMAX because it's using the same type of signal multiplexing method. As Wikipedia says, Expedience is something like "Pre-WiMAX.
As far as WiMAX being the 56k of the future - well, I'm sure that's what Intel is hoping for.:)
The iPhone has two processors each has it's own firmware. The iPhone software is at 1.1.2 - it controls the functions of the screens, programs, the touchscreen, etc. The iPhone baseband is either 3.9, or 4.6 - it controls the radio, WiFi, bluetooth, etc. The two processors talk back and forth using highspeed Hayes modem AT commands.:)
Downgrading the main 1.1.2 firmware only changes the software - so you can reenable the.TIFF exploit should you want to. But to do anything to radio reception, you would need to change the baseband firmware. Currently no one knows how to downgrade the baseband software.
In a nutshell, anyone downgrading their software to 1.1.2 or 1.1.1 or lower and who says they experiencing better cell phone reception is working under the placebo effect, because the firmware they are downgrading doesn't affect the radio at all. And no one knows how to downgrade the baseband firmware - or if they do, the technique isn't being publicized.
As far as reception, on T-Mobile in the US, my reception has generally been good. There's a bit of a funky "bug" that I've seen that if the reception is low or "no service" and you move into an area with service, it takes the phone a while to recognize this. So if you are in an underground tunnel and have no reception, then when you leave the tunnel it can take minutes for the iPhone to notice it has service again. This may be a "feature" since they are trying to save power or something, but it can be annoying to wait 3 minutes or more for the iPhone to decide it has service. There's also a rare odd effect that the phone will think it has all 5 bars, but will, in fact, have no service at all. Any time I have either of these issues, they correct themselves with time - or I can just power down the phone.
I've been to several of Dr. Sampath's lectures. You are correct - both Prof. Sampath and his team have been at this for quite a while. In his presentations, he usually he quotes a number more like $2/Watt - not $1/Watt. As you mentioned, they are using a "low-grade vacuum" and a continuous assembly line approach. I've seen their prototype assembly line at CSU and it's remarkably low-tech in external appearance (although, of course, with the magic happening inside, the external appearance doesn't matter). It's not correct to say that they don't make anything yet - they have a small scale assembly line working at CSU. In fact, it's their second prototype line - they had a less automated one working back in the 90's. The have been producing small panels for several years, and they have collected a fairly large amount of reliability data.
I don't, however, have any links for any of what I've written... as I say I've just been to several of his lectures, and I've toured the CSU engineering building.
As you noted, others have been working with CdTe - most notably, First Solar (http://www.firstsolar.com/). The "breakthrough" in this case, is the use of a low-grade vacuum, and a continuous assembly line style approach.
Calpine's "Geysers" geothermal power plant network in Lake County, California, are still online. http://www.geysers.com/ According to Wikipedia and Calpine's web page it is the largest geothermal network of power plants in the world (http://en.wikipedia.org/wiki/Calpine & http://en.wikipedia.org/wiki/The_Geysers). According to the same sources, it is currently producing 750MW and they are pumping about 11 million gallons of "treated wastewater" (read: sewage) from Santa Rosa PER DAY into a geothermal area and producing steam to spin turbines to generate electricity. I haven't read that they are losing output - where did you read that? If anything the output has been steadily increasing. It was 700MW a few years ago, and it has been rising. http://www.renewableenergyaccess.com/rea/news/stor y?id=48784
For all it's non-CO2 generating goodness, however, it definitely produces a LOT of earthquakes. We have a house near Pine Grove, CA, (near the Geysers) and throughout the day the earthquakes are so frequent that it's like living next to a major freeway. Look at this map of California and Nevada http://quake.usgs.gov/recenteqs/latest.htm and then note the massive number of squares just NNW of the SF Bay Area on the map - or look at this list: http://quake.usgs.gov/recenteqs/Quakes/quakes0.htm and note the extremely high number that are situated around "The Geysers".
Geothermal is a neat solution to producing power, but to say that it has "nearly zero impact on the climate or the environment" as the original article states is a bit misleading. It may have zero impact on the environment around the world, but it has profound (and frequent) impacts if you happen to live near the power plant stations. No matter what anyone says, you never quite get used to them - either. They wake you up at night, they rattle the dishes during dinner - some of them feel like the house just dropped a foot, some shake like a large truck crossing on a bridge.
>> As long as you dont boost the voltage too much (Which these guys prpbably did), you can not damage anything, so go for it.
The thermal stress caused by varying rates of thermal expansion for silicon, the resin underfill and the package puts a a lot of stress of the flip-chip bumps cycling between "room temp" and cryogenic temperatures. I'm not so sure that I'd say this isn't going to damage anything.
There'd like be no problem if you do it a couple of times, but over more thermal cycles, I'm certain the some of the bumps would start to shear from metal fatigue. There's been studies of flip-chip designs on Mars examining long-term reliability of the bump solder connections thermally cycled from day to night, and most conventional design last less than 100 cycles. If you design for this, you can fix it but I am pretty confident that the Pentium 4 was not designed for cryogenic cycling.
There have been reports of lithium polymer batteries spontaneously igniting after being damaged, while being charged incorrectly, after being shorted, and for a variety of unexplained reasons.
Although someone else posted it - but have a score of 0 presently and are probably filtered by most people - the wikipedia entry for this type of memory is: http://en.wikipedia.org/wiki/Phase-change_memory
I did a literature search on this type of memory, and found a paper by Samsung on a 64-Mb PRAM published earlier this year. "Enhanced write performance of a 64-mb phase-change random access memory" Hyung-rok Oh; Beak-hyung Cho; Woo Yeong Cho; Sangbeom Kang; Byung-gil Choi; Hye-jin Kim; Ki-sung Kim; Du-eung Kim; Choong-keun Kwak; Hyun-geun Byun; Gi-tae Jeong; Hong-sik Jeong; Kinam Kim; Solid-State Circuits, IEEE Journal of, Volume 41, Issue 1, Jan. 2006 Page(s):122 - 126
My summary: The 64-Mb PRAM was produced on a 0.12um CMOS technology, and had a voltage of 1.8V. The "0" resistance is 1.2kohms, "1" resistance is 100kohms (a nice delta which could mean that you could use the cell to store intermediate states ie. 4-states per cell, instead of just 2 (binary) ). Random access time is 68ns, and write time is 180ns, at 1.8V at room temperature.
This abstract at the Japanese Journal of Applied Physics seems to be on a similar 64-Mb chip from Samsung (although some details are different): "Ge2Sb2Te5 Confined Structures and Integration of 64 Mb Phase-Change Random Access Memory", Fai Yeung*, Su-Jin Ahn, Young-Nam Hwang, Chang-Wook Jeong, Yoon-Jong Song, Su-Youn Lee, Se-Ho Lee, Kyung-Chang Ryoo, Jae-Hyun Park, Jae-Min Shin, Won-Cheol Jeong, Young-Tae Kim1, Gwan-Hyeob Koh, Gi-Tae Jeong, Hong-Sik Jeong and Kinam Kim,
Cutting and pasting the abstract: Phase-change random access memory is considered a potential challenger for conventional memories, such as dynamic random access memory and flash memory due to its numerous advantages. Nevertheless, high reset current is the ultimate problem in developing high-density phase-change random access memory (PRAM). We focus on the adoption of Ge2Sb2Te5 confined structures to achieve lower reset currents. By changing from a normal to a GST confined structure, the reset current drops to as low as 0.8 mA. Eventually, our integrated 64 Mb PRAM based on 0.18 m CMOS technology offers a large sensing margin: Rreset 200 k and Rset 2 k, as well as reasonable reliability: an endurance of 1.0×109 cycles and a retention time of 2 years at 85C.
In a nutshell, on a CMOS transistor on an SOI process (such as used by AMD and IBM, but not used by anyone else that I can think of... Intel, TI, TSMC, NEC, Samsung, etc), the delay of the transistor (how fast the transistor is) depends on the history of the signals that were applied previously to the terminals. So the transistor has a memory of previously applied values. Which, now that I write this, seems like it's obvious that this would make a possible memory storage element, but normally this "feature" is a major pain - because it's difficult to track the history of signals on a transistor using current CAD tools for, for example, determining the speed of the final design, you have to assume the worst case (so that your chip works no matter what).
So normally this "feature" is considered a liability, or at least something that designers wish could be an asset but which is too hard to utilize effectively and is thus ignored.
In more gory details, this exerpt from EETimes explains it pretty well: ( http://ww.eetimes.com/issue/bb/showArti...D%3D5730 0076+body+hysteresis+soi&hl=en ) In partially depleted MOS transistors -- the only kind used in production SOI today -- the body of the transistor is a small, electrically isolated piece of silicon trapped between the active portions of the transistor and the insulating layer underneath. If this body is allowed to float, it will take on a voltage determined by the capacitive coupling between it and the other portions of the transistor. But the voltage -- or, more properly, charge -- on this floating body can affect threshold voltage, and hence the drive current, of the transistor.
Ideally, the floating-body effect can deliver a formidable performance gain. Two circumstances arise from that gain, Soisic's Pelloie said. First, the voltage on the body influences the transistor's threshold voltage. "If you switch the gate of the transistor from off to on, then the body potential increases, which yields a decrease of the threshold voltage and then an increase of the drive current," he said. "The switch is then faster than in the bulk CMOS case, where the body is grounded."
The second effect is another mechanism for influencing the threshold voltage. "When you use stacked transistors in a gate, like NAND, NOR and any other combinational gate with multiple inputs, the body-to-source voltage of the transistors corresponds to a forward-bias condition, and the threshold voltage is lowered," Pelloie said. "For bulk CMOS or in a grounded-body situation, if the source has a high voltage value, for instance Vdd [the power supply voltage], the body source voltage then becomes - Vdd and the transistor body source junction is reverse-biased." That increases the threshold voltage and lowers the drive current. Analyzed at the circuit level, he said, these two SOI advantages are combined and globally yield a higher-speed operation.
But there is a catch to these threshold-voltage-lowering mechanisms, as Pelloie explained: "Since the body is floating, it follows the variation of the other terminals of the transistor. The body voltage never keeps the same value, as the transistors are, most of the time, switching in normal operation mode. This results in what we call the history effect: The propagation delay and some other features of the gates depend on the history of the signals applied to their terminals."
-------- end EETimes snippet -----
It will be interesting to see how this particular use of the floating body effect scales as we continue to move to 45nm and beyond. It will also be interesting how it handles low-voltage quantum-induced soft-errors. Also, similar to DRAM, this type of memory will need to be refreshed - if AMD uses it in a design, it will interesting to see how the impact of refreshing, and trying to read a very small effect and amplify it to make a signal will impact the speed of the devices when used in a large cache array.
The new Chase Visa card that arrived for me last month had an RIFD chip in it (at least that's what I think it was - and that's waht it looks like). It's called Chase "Blink" and based on the way that it works it sounds like the same scheme.
I've never seen any merchants that can use it. There's a Flash demo of it at this site: http://www.chaseblink.com/
Like many other posters here, I don't see the point of this. It's not more secure than a regular credit card, and, as many pointed out, if someone figures out a way to read the information remotely, then it's a security nightmare. I don't understand the motivation for why the credit card companies are doing this - the risk/reward ratio doesn't seem to favor it.
Then take apart a broken CDROM or floppy drive. Take out the 3-phase brushless motor being very careful not to break the motor, unwind the stator and rewind it with (typically) thicker wire and more winds to increase the torque. See (among many other sites): ahref=http://www.flyelectric.ukgateway.net/motors. htmhttp://www.flyelectric.ukgateway.net/motors.htm >
Make a DIY brushless motor controller. These can be a bit involved but there are plenty of people flying on these. For a summary of designs, see: ahref=http://www.rcgroups.com/forums/showthread.ph p?t=140454http://www.rcgroups.com/forums/showthrea d.php?t=140454>
There are probably limits to how far you want to take the DIY approach though. So, go to a hobby shop and buy a couple of servos, a propeller, a transmitter and receiver and a couple of battery packs. Ideally, if you want something like the "wasp", you want to buy a 3S lithium polymer pack.
But to make something that can track GPS points and fly itself, you need some form of "Autopilot". And fortunately for us there are some awesome people who have put together an Open Source autopilot system. See: ahref=http://autopilot.sourceforge.net/http://auto pilot.sourceforge.net/>
Lastly, you need some form of imaging system. Again, my DIY enthusiasm starts to wane when it comes to complex devices like CMOS/CCD imagers. Luckily, Ebay to the rescue. Search for something like "Wireless pinhole" and pick up a wireless system (that may violate local FCC regulation) for under $50.
Lastly, you may find that this cheap Ebay system doesn't have the range that one might like for long range video surveillance, and so you probably will want to upgrade the antenna. Enter, the ingenious "Mr. RC-CAM" and his "goof-proof patch antenna" design which can be put together with some old video cables and some sheet metal from Home Depot. See: ahref=http://www.rc-cam.com/gp_patch.htmhttp://www.rc-cam.com/gp_patch.htm>
I have a daughter and motivating her to start to learn to read has been a bit of a challenge. We'd get out a fairly simple book, sit next to her on the couch and we try to get her to sound out the letters, but more often than not this became more of test of wills ("I don't want to... you tell me"). And while as the parent you can (usually) win a test of wills with a small child, one doesn't get the impression that this method is going to instill in her a great love of reading.
So, hoping to make reading a little more interesting/fun we turned to technology. There's such a huge selection of software out there that we couldn't seem to figure which titles were good. Looking around some more we tried Leapfrog's Leappads. These held her interest, but we didn't get the impression that she was learning anything. She certainly didn't seem to be learning to read. She'd play with it for quite a a while, but there didn't seem to be much information actually sticking. And they had 'bugs' in them (irony in a company whose logo is a frog); the 'books' frequently didn't work like they were supposed to. In a nutshell, when it worked it kept her amused, but then, so do a pile of wooden blocks. Neither seemed to help her to learn to start to read.
We tried two other of the newer Leapfrog products and they didn't seem to work well either. In the end, the one product that seemed to help was Leapfrog's older Phonics Writing Desk. As she used that more, she seemed to have less furstration with the process of sounding our letters. She always wants to do things "on my own" and I think the biggest part of the problem was that she didn't want to be told how the letters should sound, she wanted to know it already herself.
It seems to me that Leapfrog's been making their products more and more complex. This may allow them to command a higher retail price - and perhaps to better compete with computer software - but I think they have moved away from what made their earlier success... simpler educational products. This pen seems like it's likely to repeat our daughter experience with the Leappads: buggy and too much of a toy. But I guess we'll see.
It's not "free fuel" exactly. A 10x10 array would require about 100 180W solar panels at a cost of about $600 each. So that's $60000 in order to have "free fuel". And these numbers aren't made up - go Google for solar panels and look at the cost of 180W panels. If anything, $60k is optimistic, and doesn't include any other infrastructure costs.
When lithium polymer batteries were ramping up in production current disharge rates were limited to somewhere between 4C and 6C (where "C" is the capacity of the pack in A/h). So a 1A/h battery was limited to about 4A to 6A. Newer lithium polymer batteries can discharge at rates as high as 20 times the capacity (about 10C to 15C is more typical). Practically any newer lithium polymer battery that would give you a decent run time for your application, will be able to deliver enough current for it. It's definitely something to watch out for when buying the pack though.
A typical lithium polymer battery has a carbon-lithium anode separated by a conducting salt or a polymer with a LiCoO2 or LiMn2O4 cathode with a polymer gelled to a conducting salt. Batteries with a true Li anode are, to the best of my knowledge, not available on the market. So a lipoly battery will not explode when exposed to air or water. Lipoly cells can get very hot when they are ruptured or shorted and thus should be treated carefully if there is the possibility that this occured, but it's not due to a reaction with the air but is through discharge through a low-resistance path. The primary way that a lipoly battery catches on fire is due to overcharging which leads to the breakdown of the electrolyte which can cause a thermal-runaway condition.
Cheaper digital cameras for aerial photography
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Build Your Own KiteCam
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· Score: 5, Informative
There are several pretty good, really cheap cameras out there that take decent pictures and don't weigh a lot that would work better in this application.
For example, the AIPTek Pencam 1.3 weighs 2.4oz and takes 1.3MP pictures. The imager is CMOS (rather than CCD) and so the pictures are sensitive to the lighting, but they usually come out pretty good. AIPTek also makes several other models that work well. You can buy them at Circuit City and Walmart and if you hit the sales right, you can buy one for $50.
The Mustek Mini 3 is also very light and takes pretty good pictures and can be purchased for less than $100.
A good resource for aerial photography - although aimed at R/C airplane aerial photography - is the aerial photography forum at RCGroups.Com. Check out the thread at the top labelled "Digital Cameras under 5oz for aerial photography".
For triggering, you could rig an R/C servo to the switch, or use some form of PIC circuit to trigger it on a timed basis. Some projects like this are listed here.
There's been increasing regulation in the US in the area of model airplanes as well. The Dept. of Transportation and the FAA issued a notice N8700.25 in Oct. last year that regulated "Unmanned Aerospace Vehicles" (link here). Reading through this document a lot of model airplane hobbyists are becoming increasingly alarmed about goverment regulation of their (my) hobby. The notice specifically states that it does not affect model airplanes but then states that model airplanes are flown at an altitude of less than 400 feet - which, if you have been to any model airplane flying field is about 400 feet less than reality.
If model airplanes that fly above 400 feet (which a high percentage of them) are no longer considered model airplanes, but are now UAV's, then they may fall under new regulations.
There are plenty of threads on the RC websites where hobbyists are trying to figure out what to do to try to limit the impact of new regulations on their hobby. One good example is This one.
I was thinking this is the case with the Epson display as well. I can clearly see a line running down the middle of the display in the close-up picture.
The EETimes carried this same story with more technical details and a few criticisms as a cover story in the week's paper edition. It's also available online here at the EEtimes website.
For a modest increase in budget, you can get a big increase in the quality of the photos. In the really light, fairly cheap, and better quality digtal camera catagory are the AIPTek Pencam 1.3 and Mustek Mini3 cameras. I bought my AIPTek Pencam for about $70 and it takes pretty good digital photos at 1.3MP.
Both of them are fairly easy to modify as well and there are sites that show in detail how to take them apart and enable other triggering options - such as a 555 or a radio controlled trigger. One example: http://www.rc-cam.com/camman.htm
They didn't say that you never win on the "double of nothing" games, they said that it's predetermined whether or not you will win. So you have an option to play double or nothing as to whether you can guess if the next number will be higher or lower than the number that they show on the screen. It is predetermined that you will win or lose this regardless of the number that they show and what you happen to choose.
This isn't a claim that you can't win - but that winning is predetermined.
While what you are saying is completely true, and I wish I had mod points to mod you up, I have the same feeling while reading your post as when someone talks about my home town that has grown from 20k people to 125k people and talks about progress by pointing to the new Best Buy, the Bed, Bath & Beyond and all of the Starbucks everywhere. I admire the progress of the WWW and don't deny that it's more useful than it was 15 years ago, but I certainly have fond memories for the days before it was "invaded".
One thing to note is that using a Pencam on a gas-powered plane (or helicopter) pretty much doesn't work due to motor vibration. You need an electric with the ability to turn off the motor, or a glider.
To trigger the shutter, I used a heat glue gun to glue a servo to the top of the camera and adjusted the throw so that max rudder triggers the shutter.
This is probably the least elegant approach and there are people who have done a wide variety of improvements over this. One of the best is an electronic circuit that triggers the shutter when the throttle is off - which thus works with 3-channel radios, and doesn't require a servo. Since the camera takes pretty lousy pictures with the engine on this works pretty well. There are others - some people have made circuits that use something like a 555 timer to take pictures at fixed intervals, some have made fully electronic systems that allow you to change the camera mode (from stills to movies, etc.).
Slashdot Mirror
The penalty isn't that substantial. On the Intel X25-M it's less than half slower (44% to be precise). With CrystalDiskMark, I get 77.12MB/s for sequential writes and 42.50MB/s for 4K random writes. http://www.flickr.com/photos/33524247@N06/3119124721/
Wikipedia's Clearwire entry says at the top:
:)
"Clearwire currently uses Expedience wireless technology, dubbed Pre-WiMax, transmitted from cell sites over licensed spectrum of 2.5-2.6 GHz in the U.S. and 3.5 GHz in Europe."
And Clearwire's site says that they are using OFDM ( http://en.wikipedia.org/wiki/OFDM )
Motorola's Expedience overview is here:
http://www.nextnetwireless.com/overview.asp
So it looks like it's something like WiMAX because it's using the same type of signal multiplexing method. As Wikipedia says, Expedience is something like "Pre-WiMAX.
As far as WiMAX being the 56k of the future - well, I'm sure that's what Intel is hoping for.
Good advice - thanks. Yeah, that's working for me too and it solves the problem. Thank you!
The iPhone has two processors each has it's own firmware. The iPhone software is at 1.1.2 - it controls the functions of the screens, programs, the touchscreen, etc. The iPhone baseband is either 3.9, or 4.6 - it controls the radio, WiFi, bluetooth, etc. The two processors talk back and forth using highspeed Hayes modem AT commands. :)
.TIFF exploit should you want to. But to do anything to radio reception, you would need to change the baseband firmware. Currently no one knows how to downgrade the baseband software.
Downgrading the main 1.1.2 firmware only changes the software - so you can reenable the
There's details in this thread:
http://www.hackint0sh.org/forum/showthread.php?t=16571
In a nutshell, anyone downgrading their software to 1.1.2 or 1.1.1 or lower and who says they experiencing better cell phone reception is working under the placebo effect, because the firmware they are downgrading doesn't affect the radio at all. And no one knows how to downgrade the baseband firmware - or if they do, the technique isn't being publicized.
As far as reception, on T-Mobile in the US, my reception has generally been good. There's a bit of a funky "bug" that I've seen that if the reception is low or "no service" and you move into an area with service, it takes the phone a while to recognize this. So if you are in an underground tunnel and have no reception, then when you leave the tunnel it can take minutes for the iPhone to notice it has service again. This may be a "feature" since they are trying to save power or something, but it can be annoying to wait 3 minutes or more for the iPhone to decide it has service. There's also a rare odd effect that the phone will think it has all 5 bars, but will, in fact, have no service at all. Any time I have either of these issues, they correct themselves with time - or I can just power down the phone.
I've been to several of Dr. Sampath's lectures. You are correct - both Prof. Sampath and his team have been at this for quite a while. In his presentations, he usually he quotes a number more like $2/Watt - not $1/Watt. As you mentioned, they are using a "low-grade vacuum" and a continuous assembly line approach. I've seen their prototype assembly line at CSU and it's remarkably low-tech in external appearance (although, of course, with the magic happening inside, the external appearance doesn't matter). It's not correct to say that they don't make anything yet - they have a small scale assembly line working at CSU. In fact, it's their second prototype line - they had a less automated one working back in the 90's. The have been producing small panels for several years, and they have collected a fairly large amount of reliability data.
I don't, however, have any links for any of what I've written... as I say I've just been to several of his lectures, and I've toured the CSU engineering building.
As you noted, others have been working with CdTe - most notably, First Solar (http://www.firstsolar.com/). The "breakthrough" in this case, is the use of a low-grade vacuum, and a continuous assembly line style approach.
Calpine's "Geysers" geothermal power plant network in Lake County, California, are still online. http://www.geysers.com/ According to Wikipedia and Calpine's web page it is the largest geothermal network of power plants in the world (http://en.wikipedia.org/wiki/Calpine & http://en.wikipedia.org/wiki/The_Geysers). According to the same sources, it is currently producing 750MW and they are pumping about 11 million gallons of "treated wastewater" (read: sewage) from Santa Rosa PER DAY into a geothermal area and producing steam to spin turbines to generate electricity. I haven't read that they are losing output - where did you read that? If anything the output has been steadily increasing. It was 700MW a few years ago, and it has been rising. http://www.renewableenergyaccess.com/rea/news/stor y?id=48784
m and note the extremely high number that are situated around "The Geysers".
For all it's non-CO2 generating goodness, however, it definitely produces a LOT of earthquakes. We have a house near Pine Grove, CA, (near the Geysers) and throughout the day the earthquakes are so frequent that it's like living next to a major freeway. Look at this map of California and Nevada http://quake.usgs.gov/recenteqs/latest.htm and then note the massive number of squares just NNW of the SF Bay Area on the map - or look at this list: http://quake.usgs.gov/recenteqs/Quakes/quakes0.ht
Geothermal is a neat solution to producing power, but to say that it has "nearly zero impact on the climate or the environment" as the original article states is a bit misleading. It may have zero impact on the environment around the world, but it has profound (and frequent) impacts if you happen to live near the power plant stations. No matter what anyone says, you never quite get used to them - either. They wake you up at night, they rattle the dishes during dinner - some of them feel like the house just dropped a foot, some shake like a large truck crossing on a bridge.
>> As long as you dont boost the voltage too much (Which these guys prpbably did), you can not damage anything, so go for it.
The thermal stress caused by varying rates of thermal expansion for silicon, the resin underfill and the package puts a a lot of stress of the flip-chip bumps cycling between "room temp" and cryogenic temperatures. I'm not so sure that I'd say this isn't going to damage anything.
There'd like be no problem if you do it a couple of times, but over more thermal cycles, I'm certain the some of the bumps would start to shear from metal fatigue. There's been studies of flip-chip designs on Mars examining long-term reliability of the bump solder connections thermally cycled from day to night, and most conventional design last less than 100 cycles. If you design for this, you can fix it but I am pretty confident that the Pentium 4 was not designed for cryogenic cycling.
There have been reports of lithium polymer batteries spontaneously igniting after being damaged, while being charged incorrectly, after being shorted, and for a variety of unexplained reasons.
0 9187
See this thread entitled "Data - Complete Guide to Lithium Polymer Batteries and LiPo Failure Reports": http://www.rcgroups.com/forums/showthread.php?t=2
Although someone else posted it - but have a score of 0 presently and are probably filtered by most people - the wikipedia entry for this type of memory is: http://en.wikipedia.org/wiki/Phase-change_memory
p hase-change%20random%20access%20memory%20reliabili ty%22
I did a literature search on this type of memory, and found a paper by Samsung on a 64-Mb PRAM published earlier this year.
"Enhanced write performance of a 64-mb phase-change random access memory"
Hyung-rok Oh; Beak-hyung Cho; Woo Yeong Cho; Sangbeom Kang; Byung-gil Choi; Hye-jin Kim; Ki-sung Kim; Du-eung Kim; Choong-keun Kwak; Hyun-geun Byun; Gi-tae Jeong; Hong-sik Jeong; Kinam Kim; Solid-State Circuits, IEEE Journal of, Volume 41, Issue 1, Jan. 2006 Page(s):122 - 126
My summary:
The 64-Mb PRAM was produced on a 0.12um CMOS technology, and had a voltage of 1.8V. The "0" resistance is 1.2kohms, "1" resistance is 100kohms (a nice delta which could mean that you could use the cell to store intermediate states ie. 4-states per cell, instead of just 2 (binary) ). Random access time is 68ns, and write time is 180ns, at 1.8V at room temperature.
This abstract at the Japanese Journal of Applied Physics seems to be on a similar 64-Mb chip from Samsung (although some details are different):
"Ge2Sb2Te5 Confined Structures and Integration of 64 Mb Phase-Change Random Access Memory", Fai Yeung*, Su-Jin Ahn, Young-Nam Hwang, Chang-Wook Jeong, Yoon-Jong Song, Su-Youn Lee, Se-Ho Lee, Kyung-Chang Ryoo, Jae-Hyun Park, Jae-Min Shin, Won-Cheol Jeong, Young-Tae Kim1, Gwan-Hyeob Koh, Gi-Tae Jeong, Hong-Sik Jeong and Kinam Kim,
http://jjap.ipap.jp/link?JJAP/44/2691/#search=%22
Cutting and pasting the abstract:
Phase-change random access memory is considered a potential challenger for conventional memories, such as dynamic random access memory and flash memory due to its numerous advantages. Nevertheless, high reset current is the ultimate problem in developing high-density phase-change random access memory (PRAM). We focus on the adoption of Ge2Sb2Te5 confined structures to achieve lower reset currents. By changing from a normal to a GST confined structure, the reset current drops to as low as 0.8 mA. Eventually, our integrated 64 Mb PRAM based on 0.18 m CMOS technology offers a large sensing margin: Rreset 200 k and Rset 2 k, as well as reasonable reliability: an endurance of 1.0×109 cycles and a retention time of 2 years at 85C.
1E9 cycles is pretty impressive.
In a nutshell, on a CMOS transistor on an SOI process (such as used by AMD and IBM, but not used by anyone else that I can think of... Intel, TI, TSMC, NEC, Samsung, etc), the delay of the transistor (how fast the transistor is) depends on the history of the signals that were applied previously to the terminals. So the transistor has a memory of previously applied values. Which, now that I write this, seems like it's obvious that this would make a possible memory storage element, but normally this "feature" is a major pain - because it's difficult to track the history of signals on a transistor using current CAD tools for, for example, determining the speed of the final design, you have to assume the worst case (so that your chip works no matter what).
0 0076+body+hysteresis+soi&hl=en )
So normally this "feature" is considered a liability, or at least something that designers wish could be an asset but which is too hard to utilize effectively and is thus ignored.
In more gory details, this exerpt from EETimes explains it pretty well:
( http://ww.eetimes.com/issue/bb/showArti...D%3D573
In partially depleted MOS transistors -- the only kind used in production SOI today -- the body of the transistor is a small, electrically isolated piece of silicon trapped between the active portions of the transistor and the insulating layer underneath. If this body is allowed to float, it will take on a voltage determined by the capacitive coupling between it and the other portions of the transistor. But the voltage -- or, more properly, charge -- on this floating body can affect threshold voltage, and hence the drive current, of the transistor.
Ideally, the floating-body effect can deliver a formidable performance gain. Two circumstances arise from that gain, Soisic's Pelloie said. First, the voltage on the body influences the transistor's threshold voltage. "If you switch the gate of the transistor from off to on, then the body potential increases, which yields a decrease of the threshold voltage and then an increase of the drive current," he said. "The switch is then faster than in the bulk CMOS case, where the body is grounded."
The second effect is another mechanism for influencing the threshold voltage. "When you use stacked transistors in a gate, like NAND, NOR and any other combinational gate with multiple inputs, the body-to-source voltage of the transistors corresponds to a forward-bias condition, and the threshold voltage is lowered," Pelloie said. "For bulk CMOS or in a grounded-body situation, if the source has a high voltage value, for instance Vdd [the power supply voltage], the body source voltage then becomes - Vdd and the transistor body source junction is reverse-biased." That increases the threshold voltage and lowers the drive current. Analyzed at the circuit level, he said, these two SOI advantages are combined and globally yield a higher-speed operation.
But there is a catch to these threshold-voltage-lowering mechanisms, as Pelloie explained: "Since the body is floating, it follows the variation of the other terminals of the transistor. The body voltage never keeps the same value, as the transistors are, most of the time, switching in normal operation mode. This results in what we call the history effect: The propagation delay and some other features of the gates depend on the history of the signals applied to their terminals."
-------- end EETimes snippet -----
It will be interesting to see how this particular use of the floating body effect scales as we continue to move to 45nm and beyond. It will also be interesting how it handles low-voltage quantum-induced soft-errors. Also, similar to DRAM, this type of memory will need to be refreshed - if AMD uses it in a design, it will interesting to see how the impact of refreshing, and trying to read a very small effect and amplify it to make a signal will impact the speed of the devices when used in a large cache array.
The new Chase Visa card that arrived for me last month had an RIFD chip in it (at least that's what I think it was - and that's waht it looks like). It's called Chase "Blink" and based on the way that it works it sounds like the same scheme.
I've never seen any merchants that can use it.
There's a Flash demo of it at this site:
http://www.chaseblink.com/
Like many other posters here, I don't see the point of this. It's not more secure than a regular credit card, and, as many pointed out, if someone figures out a way to read the information remotely, then it's a security nightmare. I don't understand the motivation for why the credit card companies are doing this - the risk/reward ratio doesn't seem to favor it.
Sorry. I messed up the links. They looked ok in preview... I even clicked them. Oh well.
You can come close to an Open Source version:
/ www.tornlogic.com/avov/st1.pdf>r view.htmlhttp://rharazin.tripod.com/models/F3/f3_o verview.html>
. htmhttp://www.flyelectric.ukgateway.net/motors.htm >
h p?t=140454http://www.rcgroups.com/forums/showthrea d.php?t=140454>
o pilot.sourceforge.net/>
w .rc-cam.com/gp_patch.htm>
First, pick up some Depron or similar foam insulation material from Home Depot.
Second, get some of the free airplane plans that are available on the internet, such as:
ahref=http://www.tornlogic.com/avov/st1.pdfhttp:/
Or, if you simply have to have the "Wasp" look, try this one:
ahref=http://rharazin.tripod.com/models/F3/f3_ove
Then take apart a broken CDROM or floppy drive. Take out the 3-phase brushless motor being very careful not to break the motor, unwind the stator and rewind it with (typically) thicker wire and more winds to increase the torque. See (among many other sites):
ahref=http://www.flyelectric.ukgateway.net/motors
Make a DIY brushless motor controller. These can be a bit involved but there are plenty of people flying on these. For a summary of designs, see:
ahref=http://www.rcgroups.com/forums/showthread.p
There are probably limits to how far you want to take the DIY approach though. So, go to a hobby shop and buy a couple of servos, a propeller, a transmitter and receiver and a couple of battery packs. Ideally, if you want something like the "wasp", you want to buy a 3S lithium polymer pack.
But to make something that can track GPS points and fly itself, you need some form of "Autopilot". And fortunately for us there are some awesome people who have put together an Open Source autopilot system.
See: ahref=http://autopilot.sourceforge.net/http://aut
Lastly, you need some form of imaging system. Again, my DIY enthusiasm starts to wane when it comes to complex devices like CMOS/CCD imagers. Luckily, Ebay to the rescue. Search for something like "Wireless pinhole" and pick up a wireless system (that may violate local FCC regulation) for under $50.
Lastly, you may find that this cheap Ebay system doesn't have the range that one might like for long range video surveillance, and so you probably will want to upgrade the antenna. Enter, the ingenious "Mr. RC-CAM" and his "goof-proof patch antenna" design which can be put together with some old video cables and some sheet metal from Home Depot.
See: ahref=http://www.rc-cam.com/gp_patch.htmhttp://ww
I have a daughter and motivating her to start to learn to read has been a bit of a challenge. We'd get out a fairly simple book, sit next to her on the couch and we try to get her to sound out the letters, but more often than not this became more of test of wills ("I don't want to... you tell me"). And while as the parent you can (usually) win a test of wills with a small child, one doesn't get the impression that this method is going to instill in her a great love of reading.
So, hoping to make reading a little more interesting/fun we turned to technology. There's such a huge selection of software out there that we couldn't seem to figure which titles were good. Looking around some more we tried Leapfrog's Leappads. These held her interest, but we didn't get the impression that she was learning anything. She certainly didn't seem to be learning to read. She'd play with it for quite a a while, but there didn't seem to be much information actually sticking. And they had 'bugs' in them (irony in a company whose logo is a frog); the 'books' frequently didn't work like they were supposed to. In a nutshell, when it worked it kept her amused, but then, so do a pile of wooden blocks. Neither seemed to help her to learn to start to read.
We tried two other of the newer Leapfrog products and they didn't seem to work well either. In the end, the one product that seemed to help was Leapfrog's older Phonics Writing Desk. As she used that more, she seemed to have less furstration with the process of sounding our letters. She always wants to do things "on my own" and I think the biggest part of the problem was that she didn't want to be told how the letters should sound, she wanted to know it already herself.
It seems to me that Leapfrog's been making their products more and more complex. This may allow them to command a higher retail price - and perhaps to better compete with computer software - but I think they have moved away from what made their earlier success... simpler educational products. This pen seems like it's likely to repeat our daughter experience with the Leappads: buggy and too much of a toy. But I guess we'll see.
It's not "free fuel" exactly. A 10x10 array would require about 100 180W solar panels at a cost of about $600 each. So that's $60000 in order to have "free fuel". And these numbers aren't made up - go Google for solar panels and look at the cost of 180W panels. If anything, $60k is optimistic, and doesn't include any other infrastructure costs.
When lithium polymer batteries were ramping up in production current disharge rates were limited to somewhere between 4C and 6C (where "C" is the capacity of the pack in A/h). So a 1A/h battery was limited to about 4A to 6A. Newer lithium polymer batteries can discharge at rates as high as 20 times the capacity (about 10C to 15C is more typical). Practically any newer lithium polymer battery that would give you a decent run time for your application, will be able to deliver enough current for it. It's definitely something to watch out for when buying the pack though.
A typical lithium polymer battery has a carbon-lithium anode separated by a conducting salt or a polymer with a LiCoO2 or LiMn2O4 cathode with a polymer gelled to a conducting salt. Batteries with a true Li anode are, to the best of my knowledge, not available on the market. So a lipoly battery will not explode when exposed to air or water. Lipoly cells can get very hot when they are ruptured or shorted and thus should be treated carefully if there is the possibility that this occured, but it's not due to a reaction with the air but is through discharge through a low-resistance path. The primary way that a lipoly battery catches on fire is due to overcharging which leads to the breakdown of the electrolyte which can cause a thermal-runaway condition.
There are several pretty good, really cheap cameras out there that take decent pictures and don't weigh a lot that would work better in this application.
For example, the AIPTek Pencam 1.3 weighs 2.4oz and takes 1.3MP pictures. The imager is CMOS (rather than CCD) and so the pictures are sensitive to the lighting, but they usually come out pretty good. AIPTek also makes several other models that work well. You can buy them at Circuit City and Walmart and if you hit the sales right, you can buy one for $50.
The Mustek Mini 3 is also very light and takes pretty good pictures and can be purchased for less than $100.
A good resource for aerial photography - although aimed at R/C airplane aerial photography - is the aerial photography forum at RCGroups.Com. Check out the thread at the top labelled "Digital Cameras under 5oz for aerial photography".
For triggering, you could rig an R/C servo to the switch, or use some form of PIC circuit to trigger it on a timed basis. Some projects like this are listed here.
There's been increasing regulation in the US in the area of model airplanes as well. The Dept. of Transportation and the FAA issued a notice N8700.25 in Oct. last year that regulated "Unmanned Aerospace Vehicles" (link here). Reading through this document a lot of model airplane hobbyists are becoming increasingly alarmed about goverment regulation of their (my) hobby. The notice specifically states that it does not affect model airplanes but then states that model airplanes are flown at an altitude of less than 400 feet - which, if you have been to any model airplane flying field is about 400 feet less than reality.
If model airplanes that fly above 400 feet (which a high percentage of them) are no longer considered model airplanes, but are now UAV's, then they may fall under new regulations.
There are plenty of threads on the RC websites where hobbyists are trying to figure out what to do to try to limit the impact of new regulations on their hobby. One good example is This one.
I was thinking this is the case with the Epson display as well. I can clearly see a line running down the middle of the display in the close-up picture.
The EETimes carried this same story with more technical details and a few criticisms as a cover story in the week's paper edition. It's also available online here at the EEtimes website.
For a modest increase in budget, you can get a big increase in the quality of the photos. In the really light, fairly cheap, and better quality digtal camera catagory are the AIPTek Pencam 1.3 and Mustek Mini3 cameras. I bought my AIPTek Pencam for about $70 and it takes pretty good digital photos at 1.3MP.
Both of them are fairly easy to modify as well and there are sites that show in detail how to take them apart and enable other triggering options - such as a 555 or a radio controlled trigger. One example: http://www.rc-cam.com/camman.htm
They didn't say that you never win on the "double of nothing" games, they said that it's predetermined whether or not you will win. So you have an option to play double or nothing as to whether you can guess if the next number will be higher or lower than the number that they show on the screen. It is predetermined that you will win or lose this regardless of the number that they show and what you happen to choose.
This isn't a claim that you can't win - but that winning is predetermined.
While what you are saying is completely true, and I wish I had mod points to mod you up, I have the same feeling while reading your post as when someone talks about my home town that has grown from 20k people to 125k people and talks about progress by pointing to the new Best Buy, the Bed, Bath & Beyond and all of the Starbucks everywhere. I admire the progress of the WWW and don't deny that it's more useful than it was 15 years ago, but I certainly have fond memories for the days before it was "invaded".
One thing to note is that using a Pencam on a gas-powered plane (or helicopter) pretty much doesn't work due to motor vibration. You need an electric with the ability to turn off the motor, or a glider.
To trigger the shutter, I used a heat glue gun to glue a servo to the top of the camera and adjusted the throw so that max rudder triggers the shutter.
This is probably the least elegant approach and there are people who have done a wide variety of improvements over this. One of the best is an electronic circuit that triggers the shutter when the throttle is off - which thus works with 3-channel radios, and doesn't require a servo. Since the camera takes pretty lousy pictures with the engine on this works pretty well. There are others - some people have made circuits that use something like a 555 timer to take pictures at fixed intervals, some have made fully electronic systems that allow you to change the camera mode (from stills to movies, etc.).
The best resource that I have found is this Aerial Photography Forum at E-Zone