If there's anything I've learned...
on
Juicebox Hacking
·
· Score: 4, Insightful
...it's that hardware intended for kids is usually useless for anything else. I've seen quite a few electronic gizmos in recent years, and every time I look at hacking them into a more general purpose device, I find that they are far too mission specific to be of any real-world use. Half the time you open them up and find nothing more than a chip, small PCB, and some epoxy holding the whole thing together.
If you're interested in replicating this, it might make a "fun" home project to build one using services like Pad2Pad, Digikey, and a handful of parts. Once you have the design down, you can sell them in bulk for a similar cost. Perhaps even as "developer kits" that allow others to fool around with them. Just don't waste your time on a toy.:-/
Avnet publishes *some* prices. Note that large runs are quite a bit less expensive. IIRC, Xilnix claims something like $5 per Spartan chip for runs of more than 250,000. I forget what their claims are for their large Vertex chip runs.
Actually, you have to pick an FPGA "core" that supports an FPU. They are available, but the basic FPGA only supports fixed point math in most cases.
Ugh. My poor head is reeling at this confusing statement. Are you trying to say that you need to choose a proper software core with an FPU (I agree) or that FPGAs naturally have a given set of math functions? The former is true, the latter is not. Your FPGA is only as good as the processor core you load into it. If you load a multi-pipelined, FPU capable behemoth, then you'll have all those features available. If you load an "embedded" core that is designed for simplcitiy and fewer logic cells, then you'll have to deal with few features.
Considering how much a Cray costs, I'd think they could splurge for a few Virtexes to load an FPU on.
Number 1, they don't currently have great floating point performance - this is a killer for most scientific apps.
Eh? An FPGA is a blank slate. You can code an FPU into it. Are you referring to the underlying hardware performance being slow for FP calculations?
Number 2, they are hard to feed because the rate they can compute at versus the rate memory can feed them is quite skewed.
This is true of all computers except for custom designed supercomputers. Most general purpose CPUs sit and do nothing for a good portion of the time, while many Crays are designed to stream the memory at 1 cycle == 1 memory retrieval, but can't handle heavy branched logic very vell.
FWIW, this is not a new idea. FPGAs (i.e. dynamically reconfigurable processors) have been around for about 20 years now, and have allowed hardware developers to produce custom hardware in many situations. The key, you see, is that hardware designed for a specific task is almost always going to perform that task better than a general purpose processor. That's why the SaarCore can outperform a P4, and why your computer has a custom built GPU.
As a result, the idea of runtime-dynamic hardware sounds great. Unfortunately, the issue that developers run into in developing a runtime-dynamic processor is the matter of knowing how to configure the chip. One tack is to allow programs to load chip designs themselves, thus creating specific hardware for that individual program. The down side to this tack is that someone must go through the time consuming task of manually writing the chip in a Hardware Design Language such as VHDL or Verilog. Most programmers aren't going to do this when they can get the program out faster with a general purpose CPU.
This has led to another tack of using software to analyze a program and automatically create a machine to optimize it. This is conceptually similar to the Java JIT method, but is more complex by far. A lot of research is being done into this area (as this story shows), but I wouldn't hold my breath for now.
Another design that makes a lot of sense is the concept of "hardware on demand". i.e. Imagine if you had a library of accelerator chip designs. Whenever a program needs a particular form of common hardware acceleration (e.g. GPU, Sound, DSP, etc.), the onboard FPGAs could be reconfigured to meet the demand. This wouldn't have the same punch as task-specific hardware, but it would provide an inexpensive method for obtaining a bundle of hardware that would otherwise be extremely expensive and use up a lot of bus space.
I am surprised why not many developers are using SWT to improve the GUI.
SWT has just as many disadvantages as advantages. It's really just an alternative to Swing, not "better" as many may claim. Azureus is one of my favorite programs, but its GUI also has a large number of minor issues on my Mac because of the SWT GUI. Had it used Swing, it would have been just as snappy as JEdit, Netbeans, and a few other Swing GUIs I run.
Really, I have no grudge against IBM for releasing SWT, but programmers need to be careful not to get swept up into the fanboyish "It's new, thus better!" take on things. That same sort of unchecked enthusiasm was what let Microsoft take over the market with Windows so long ago. Only *after* geeks everywhere proclaimed their love for Windows did they finally wake up and say, "Hey, this sucks!"
Oh yes. Java is great for P2P programs, going all the way back to the original Furi program for Gnutella. (It's too bad that Limewire came along and killed such a great little proggie. Grrr...)
Video gaming is a huge industry, bigger than music, bigger than movies, bigger than cellphones.
Says who? The movie and cell phone industry are FAR larger than the video game industry. The music industry is actually kind of pathetic, but they make a great loss-leader for the electronics companies.
Why? Because I got some disrepectful asshole modded into oblivion? Do you LIKE trolls or what? What's with the sudden groundswell support for the scum of the earth? This article is REAL news worth REAL attention. Not some Google-lovefest as claimed. You people can be such jerks.
I thought Slashdot readers would be interested WRONG!!
Hold on a moment. They are offering Slashdotters money to program open source! How is that not right up the alley of "News for Nerds" and "Stuff that Matters?"
I think in my current company it is handled by Accenture - good experience so far
You have to be the first person I've ever seen to mix the words "Accenture" and "Good Experience". I assume that you're three degrees removed from the management of the Accenture relationship?
tell me why they need a beryllium source, vice using intrinsic neutrons from spontaneous fission
I was thinking about this one, and I think I misunderstood the question. Crushing polonium/beryllium together provides a wash of nuetron particles, thus providing a powerful trigger for the detonation.
Does your theoretical standpoint include tossing as much Plutonium onto a pile until it goes boom?
Lord, I hope not. It's not going to go "boom", it's going to get REALLY hot and burn through a few things. Anybody standing near by would be wise to back off.
tell me why they need a beryllium source, vice using intrinsic neutrons from spontaneous fission
Because nuclear devices are dangerous? Gun type devices are no longer used in most applications because they're far too easy to detonate. Any accidental detonation of the internal munitions could result in the device being triggered. As a result, nuclear scientists prefer to have a controllable nuetron source for safety. i.e. A neutron source "trigger".
Why is a reflector needed if the bomb is designed to burn through from the center out?
Are we talking implosion or H-Bomb? The reflector on H-Bombs is a bit trickier. It's designed to temporarily withstand the power of the atomic detonation in order to compress the dueterium/lithium into a fusion event. The shaping of the reflector is EXTREMELY important to the success of the fusion event. That's part of the reason why H-Bombs are so tricky. (Even more so than an implosion weapon.)
On implosion weapons, the reflectors are designed to direct the charges inward toward the plutonium core. Without this outer shell, the bomb would fizzle. (This fact was used by some movie, who's name I no longer remember, to disable the "backpack nuke" by prying a plate free from the bomb.)
Reflectors are also used to help maintain the materials in a subcritical state.
What fraction of the fuel is actually burned?
The goal is "as much as possible", although the performance of weapons rarely reaches that degree. Off hand, I don't remember how much is usually burned, but I believe it's a fairly low amount.
Why are the specific energies of high energy neutrons released from fission more important than the average?
Ite all comes down to cross-section and capture ratios. Unlike the model often shown to the public, the nucleus of an atom is not directly "smashed" apart. The neutrons are instead captured by the atom. This destablizes the atom and causes it to split. Slower moving neutrons are more easily captured, and thus tend to be desirable in a reaction. However, since high speed neutrons are more common, they must be slowed down with some form of moderator. As I understand it, this is accomplished in bombs by making the material into a paste. Fast breeder reactors use these fast neutrons directly to create plutonium.
How is the fuel orientated to minimize the effect of gammas heating the fuel?
Off the top of my head? Dunno. Google has answers to this, but I believe it's something that can be easily found through experimentation.
Did I pass? Hopefully I understood all the questions well enough.:-)
Seriously, are you suggesting that even with access to the basic nuclear information, plus the publically available equations, nuclear weapons are too difficult for most counties to build? Because the sheer number of counties who have them would seem to suggest otherwise.
Building nuclear weapons is stupidly simply from a theoretical standpoint. Understanding *why* they work, and developing new engineering concepts isn't so simple.
Basically, it's the traditional "once someone has done it, it's easy" conundrum. Columbus and the Egg is a particularly good example of this situation, even if the story is fiction.
My favorite method is the Buckets method of separating the UHF in your backyard. Quick (yeah, right), easy (if you are REALLY strong), and safe (you'll be dead when you're done)! What could be better?;-)
Big deal, my high school physics textbook had all this information as well.
Actually, your high school physics book probably has *more* information. This "in-depth article" is nothing more than a few graphs and a description.
That being said, nuclear fission technology is stupidly simple in it theoretical foundations. Once one is able to build an atomic pile (demonstrating sufficient purity of U235), it's only a short period of time until a gun-type A-Bomb can be made. All you need is two sub-critical masses of U235 that add up to a critical mass. Mount one mass in a stationary (and strong!) holder. Take the other piece and mount in some sort of gun. The more force the gun can impart on the second piece, the better. Fire the first piece at the second, and viola! You're dead!
Ermm... I mean... you can see a pretty light show from the U235 compressing into a super-critical bundle.
Nuclear reactors and Implosion bombs are a bit more difficult, but not beyond any country with sufficient industrial capability. This article from the magazine "The Progressive" tells you how to build a hydrogen bomb. Good luck on that, though. Implosion bombs aren't too bad with computer modelling, but H-Bombs are REALLY, REALLY tricky.
Of course, if a Slashdotter with no formal training in nuclear science can desribe how bombs are built, is there any question as to why nuclear materials are carefully controlled?
Sun did bind Java to its next flagship OS. "Java Desktop System" (JDS) is an attempt to slowly integrate Java subsystems into a traditional desktop environment. Future versions of the desktop are expected to fully migrate to the Looking Glass Desktop Environment, which is based on the Java3D API.
JDS is currently available as a complete Linux OS, or a Desktop option for Solaris Sparc/x86/AMD64.
Oh, and BTW: Sun has been integrating Java with Solaris for a very long time. Previous versions of Solaris had many of the CDE components done in Java, including the volume control, media player, and administrative interface.
As for the cell phone (which I assume is part of why you call me rude)
No, I'm only talking about being in a coffee shop for more than an hour or two. A lot of people conduct all kinds of business from these shops. As long as you're not abusing the hospitality (e.g. hanging around for >2 hours at a time) then you're not really in the category I'm referring to as rude.
People who do hang around for hours on end are rude because they are monopolizing the limited space that coffee shops provide. These shops need space for other customers otherwise they can't make money. That's my only point. I really don't mind people with cell phones, laptops, blackberries, whatever as long as they're not distirbing myself and other paying customers.:-)
I'm a full time, home-based consultant. My home is 30 miles away from the vast majority of my market. Coffee shops are the way I check my email, the way I IM people. They, and cell phones, allow me to run my business.
Do you spend more than an hour or two in the coffee shop? Because if you do, you're really being rude. These businesses offer Wifi as a convenience to people such as yourself. Abusing that hospitality only ruins it for everyone. If you're just there for a little while though, then you have nothing to worry about.:-)
Slashdot Mirror
...it's that hardware intended for kids is usually useless for anything else. I've seen quite a few electronic gizmos in recent years, and every time I look at hacking them into a more general purpose device, I find that they are far too mission specific to be of any real-world use. Half the time you open them up and find nothing more than a chip, small PCB, and some epoxy holding the whole thing together.
:-/
If you're interested in replicating this, it might make a "fun" home project to build one using services like Pad2Pad, Digikey, and a handful of parts. Once you have the design down, you can sell them in bulk for a similar cost. Perhaps even as "developer kits" that allow others to fool around with them. Just don't waste your time on a toy.
Most of the game developers I know cheat by using an ODE library. e.g.:
ODE.org
ODEJava.org (Java bindings for ODE)
Avnet publishes *some* prices. Note that large runs are quite a bit less expensive. IIRC, Xilnix claims something like $5 per Spartan chip for runs of more than 250,000. I forget what their claims are for their large Vertex chip runs.
Spartan 3 pricing
Virtex 4 pricing
Actually, you have to pick an FPGA "core" that supports an FPU. They are available, but the basic FPGA only supports fixed point math in most cases.
Ugh. My poor head is reeling at this confusing statement. Are you trying to say that you need to choose a proper software core with an FPU (I agree) or that FPGAs naturally have a given set of math functions? The former is true, the latter is not. Your FPGA is only as good as the processor core you load into it. If you load a multi-pipelined, FPU capable behemoth, then you'll have all those features available. If you load an "embedded" core that is designed for simplcitiy and fewer logic cells, then you'll have to deal with few features.
Considering how much a Cray costs, I'd think they could splurge for a few Virtexes to load an FPU on.
Number 1, they don't currently have great floating point performance - this is a killer for most scientific apps.
Eh? An FPGA is a blank slate. You can code an FPU into it. Are you referring to the underlying hardware performance being slow for FP calculations?
Number 2, they are hard to feed because the rate they can compute at versus the rate memory can feed them is quite skewed.
This is true of all computers except for custom designed supercomputers. Most general purpose CPUs sit and do nothing for a good portion of the time, while many Crays are designed to stream the memory at 1 cycle == 1 memory retrieval, but can't handle heavy branched logic very vell.
FWIW, this is not a new idea. FPGAs (i.e. dynamically reconfigurable processors) have been around for about 20 years now, and have allowed hardware developers to produce custom hardware in many situations. The key, you see, is that hardware designed for a specific task is almost always going to perform that task better than a general purpose processor. That's why the SaarCore can outperform a P4, and why your computer has a custom built GPU.
As a result, the idea of runtime-dynamic hardware sounds great. Unfortunately, the issue that developers run into in developing a runtime-dynamic processor is the matter of knowing how to configure the chip. One tack is to allow programs to load chip designs themselves, thus creating specific hardware for that individual program. The down side to this tack is that someone must go through the time consuming task of manually writing the chip in a Hardware Design Language such as VHDL or Verilog. Most programmers aren't going to do this when they can get the program out faster with a general purpose CPU.
This has led to another tack of using software to analyze a program and automatically create a machine to optimize it. This is conceptually similar to the Java JIT method, but is more complex by far. A lot of research is being done into this area (as this story shows), but I wouldn't hold my breath for now.
Another design that makes a lot of sense is the concept of "hardware on demand". i.e. Imagine if you had a library of accelerator chip designs. Whenever a program needs a particular form of common hardware acceleration (e.g. GPU, Sound, DSP, etc.), the onboard FPGAs could be reconfigured to meet the demand. This wouldn't have the same punch as task-specific hardware, but it would provide an inexpensive method for obtaining a bundle of hardware that would otherwise be extremely expensive and use up a lot of bus space.
I am surprised why not many developers are using SWT to improve the GUI.
;-)
SWT has just as many disadvantages as advantages. It's really just an alternative to Swing, not "better" as many may claim. Azureus is one of my favorite programs, but its GUI also has a large number of minor issues on my Mac because of the SWT GUI. Had it used Swing, it would have been just as snappy as JEdit, Netbeans, and a few other Swing GUIs I run.
Really, I have no grudge against IBM for releasing SWT, but programmers need to be careful not to get swept up into the fanboyish "It's new, thus better!" take on things. That same sort of unchecked enthusiasm was what let Microsoft take over the market with Windows so long ago. Only *after* geeks everywhere proclaimed their love for Windows did they finally wake up and say, "Hey, this sucks!"
An interesting link for you: http://www.jgoodies.com/
The Metamorphasis app is particularly interesting. It was originally designed to show that Swing can successfully replicate the L&F of SWT.
Nope. Java...nuff said.
Oh yes. Java is great for P2P programs, going all the way back to the original Furi program for Gnutella. (It's too bad that Limewire came along and killed such a great little proggie. Grrr...)
Video gaming is a huge industry, bigger than music, bigger than movies, bigger than cellphones.
Says who? The movie and cell phone industry are FAR larger than the video game industry. The music industry is actually kind of pathetic, but they make a great loss-leader for the electronics companies.
Why? Because I got some disrepectful asshole modded into oblivion? Do you LIKE trolls or what? What's with the sudden groundswell support for the scum of the earth? This article is REAL news worth REAL attention. Not some Google-lovefest as claimed. You people can be such jerks.
See that link on my post that says "Parent"?
This is where you go "Oh." and apologize.
What an asshole. This is REAL and interesting news. Far better than the crapola "rumors" that are usually posted. Mod parent down for being a jackass.
I thought Slashdot readers would be interested WRONG!!
Hold on a moment. They are offering Slashdotters money to program open source! How is that not right up the alley of "News for Nerds" and "Stuff that Matters?"
I think in my current company it is handled by Accenture - good experience so far
You have to be the first person I've ever seen to mix the words "Accenture" and "Good Experience". I assume that you're three degrees removed from the management of the Accenture relationship?
tell me why they need a beryllium source, vice using intrinsic neutrons from spontaneous fission
I was thinking about this one, and I think I misunderstood the question. Crushing polonium/beryllium together provides a wash of nuetron particles, thus providing a powerful trigger for the detonation.
Does your theoretical standpoint include tossing as much Plutonium onto a pile until it goes boom?
:-)
Lord, I hope not. It's not going to go "boom", it's going to get REALLY hot and burn through a few things. Anybody standing near by would be wise to back off.
tell me why they need a beryllium source, vice using intrinsic neutrons from spontaneous fission
Because nuclear devices are dangerous? Gun type devices are no longer used in most applications because they're far too easy to detonate. Any accidental detonation of the internal munitions could result in the device being triggered. As a result, nuclear scientists prefer to have a controllable nuetron source for safety. i.e. A neutron source "trigger".
Why is a reflector needed if the bomb is designed to burn through from the center out?
Are we talking implosion or H-Bomb? The reflector on H-Bombs is a bit trickier. It's designed to temporarily withstand the power of the atomic detonation in order to compress the dueterium/lithium into a fusion event. The shaping of the reflector is EXTREMELY important to the success of the fusion event. That's part of the reason why H-Bombs are so tricky. (Even more so than an implosion weapon.)
On implosion weapons, the reflectors are designed to direct the charges inward toward the plutonium core. Without this outer shell, the bomb would fizzle. (This fact was used by some movie, who's name I no longer remember, to disable the "backpack nuke" by prying a plate free from the bomb.)
Reflectors are also used to help maintain the materials in a subcritical state.
What fraction of the fuel is actually burned?
The goal is "as much as possible", although the performance of weapons rarely reaches that degree. Off hand, I don't remember how much is usually burned, but I believe it's a fairly low amount.
Why are the specific energies of high energy neutrons released from fission more important than the average?
Ite all comes down to cross-section and capture ratios. Unlike the model often shown to the public, the nucleus of an atom is not directly "smashed" apart. The neutrons are instead captured by the atom. This destablizes the atom and causes it to split. Slower moving neutrons are more easily captured, and thus tend to be desirable in a reaction. However, since high speed neutrons are more common, they must be slowed down with some form of moderator. As I understand it, this is accomplished in bombs by making the material into a paste. Fast breeder reactors use these fast neutrons directly to create plutonium.
How is the fuel orientated to minimize the effect of gammas heating the fuel?
Off the top of my head? Dunno. Google has answers to this, but I believe it's something that can be easily found through experimentation.
Did I pass? Hopefully I understood all the questions well enough.
Seriously, are you suggesting that even with access to the basic nuclear information, plus the publically available equations, nuclear weapons are too difficult for most counties to build? Because the sheer number of counties who have them would seem to suggest otherwise.
You should not be so quick to separate yourself from those lowly slashdotters with no formal training.
(raises eyebrow) I was referring to myself.
Nuclear Engineering != Nuclear Weapons
Building nuclear weapons is stupidly simply from a theoretical standpoint. Understanding *why* they work, and developing new engineering concepts isn't so simple.
Basically, it's the traditional "once someone has done it, it's easy" conundrum. Columbus and the Egg is a particularly good example of this situation, even if the story is fiction.
My favorite method is the Buckets method of separating the UHF in your backyard. Quick (yeah, right), easy (if you are REALLY strong), and safe (you'll be dead when you're done)! What could be better? ;-)
Big deal, my high school physics textbook had all this information as well.
Actually, your high school physics book probably has *more* information. This "in-depth article" is nothing more than a few graphs and a description.
That being said, nuclear fission technology is stupidly simple in it theoretical foundations. Once one is able to build an atomic pile (demonstrating sufficient purity of U235), it's only a short period of time until a gun-type A-Bomb can be made. All you need is two sub-critical masses of U235 that add up to a critical mass. Mount one mass in a stationary (and strong!) holder. Take the other piece and mount in some sort of gun. The more force the gun can impart on the second piece, the better. Fire the first piece at the second, and viola! You're dead!
Ermm... I mean... you can see a pretty light show from the U235 compressing into a super-critical bundle.
Nuclear reactors and Implosion bombs are a bit more difficult, but not beyond any country with sufficient industrial capability. This article from the magazine "The Progressive" tells you how to build a hydrogen bomb. Good luck on that, though. Implosion bombs aren't too bad with computer modelling, but H-Bombs are REALLY, REALLY tricky.
Of course, if a Slashdotter with no formal training in nuclear science can desribe how bombs are built, is there any question as to why nuclear materials are carefully controlled?
Sun did bind Java to its next flagship OS. "Java Desktop System" (JDS) is an attempt to slowly integrate Java subsystems into a traditional desktop environment. Future versions of the desktop are expected to fully migrate to the Looking Glass Desktop Environment, which is based on the Java3D API.
JDS is currently available as a complete Linux OS, or a Desktop option for Solaris Sparc/x86/AMD64.
Oh, and BTW: Sun has been integrating Java with Solaris for a very long time. Previous versions of Solaris had many of the CDE components done in Java, including the volume control, media player, and administrative interface.
Dude, he made a mistake. Chill. He even apologized a few posts up. Don't get so worked up. It'll take years off your life. ;-)
As for the cell phone (which I assume is part of why you call me rude)
:-)
No, I'm only talking about being in a coffee shop for more than an hour or two. A lot of people conduct all kinds of business from these shops. As long as you're not abusing the hospitality (e.g. hanging around for >2 hours at a time) then you're not really in the category I'm referring to as rude.
People who do hang around for hours on end are rude because they are monopolizing the limited space that coffee shops provide. These shops need space for other customers otherwise they can't make money. That's my only point. I really don't mind people with cell phones, laptops, blackberries, whatever as long as they're not distirbing myself and other paying customers.
No worries. Happens to the best of us. :-)
I'm a full time, home-based consultant. My home is 30 miles away from the vast majority of my market. Coffee shops are the way I check my email, the way I IM people. They, and cell phones, allow me to run my business.
:-)
Do you spend more than an hour or two in the coffee shop? Because if you do, you're really being rude. These businesses offer Wifi as a convenience to people such as yourself. Abusing that hospitality only ruins it for everyone. If you're just there for a little while though, then you have nothing to worry about.