Assuming, very conservatively, that they can spend 50% on developers, and 50% on everything else, you can get a lot of brilliant people employed for that kind of money. Of course software development isn't really scalable by throwing people at the problem without a structure to support them. But they should be able to afford software engineers who can design the innards in such a way that the work can be done in parallel on many isolated pieces. Perhaps a bigger problem is that there are no good tools to support this kind of work. Ideally you'd want something that integrates version control, bug tracking, collaborative document editing, etc. Any systems out there that pretend to do that are "enterprisey" enough to make you puke, and are really useless and counterproductive.
OT: it was interesting to see Opera as the browser on Nintendo DSi. I used to use Opera exclusively in times of Windows 95 and 98. Heck, I even paid for it back then -- a couple times, no less. It offered really refreshing experience when the alternatives were Netscape (a clusterfuck it was, it seemed) and IE.
Morass -- that's exactly what I thought of it. Not only you have to dredge for Google, but you have to inspect the links used by those add-ons -- many show off Google logo but have nothing to do with Google, they go to some 3rd party url. It's creepy because I'm sure many people must fall for that.
Please be careful. The add-on gallery displayed in IE is seeded with 3rd party "providers" that use Google logo, yet the searches definitely do NOT go to Google. I don't know why MS/Google won't litigate those to hell (or simply kick them out), but that's a fact. Every time I upgrade IE and get presented with the add-on gallery, the first Google-branded providers have nothing to do with Google. The concept of this add-on gallery is fundamentally broken, and I wonder how many drive-by infections those "providers" are accountable for.
This completely fails to take into account Jobs's deals with MS. Guess what: MS is a money making software development house. Apple used to have deals with them, this had nothing to do with any antitrust poseurship.
Gee whiz. For $300M a year Firefox should be something else than it currently is. That's a whole lot of money. If their developers cost $300k per year in salary and benefits, that'd cover what -- perhaps 500 developers, with the other $150M going towards overheads, hosting costs, etc. I think that Mozilla is quite complacent and inefficient with how they spend their money.
Mr Henry Reinecke seems to disagree. I've downloaded the paper and they do use current drivers and current mirrors to drive inputs and couple stages (including feedback from outputs to inputs), but the logic itself is all diodes. I've done a quick simulation of the most complex network he used in the multiplier, and with modern diodes and well laid out board you could probably run it at 10MHz. In the paper he shows that diode logic has dual representation -- one uses voltages as signals, another uses currents as signals. The voltage signal based logic is simply slower because various capacitances play a big role, but you can have exactly same logic done for voltage signals or current signals.
Do note that I think his logic could be running with an AC carrier (yep), and you could use transformers to couple stages, and it'd work without any passive devices for moderately sized networks. I'm thinking of prototyping such a thing just to show that his multiplier, even if impractical, can be done completely using diodes and passive devices.
You're right as to debit cards, I had same experience with those. They seem somehow different from credit cards as far as reissuance is concerned. For credit cards, they had simply sent me new ones a couple months before the expiration date, and they'd usually have new expiration = old expiration + 36 months.
Cover yourself from both ends: have one password per account (a must!) and have them complex. If you do the former, then you'll need a password manager anyway, so the latter becomes trivial.
The paper shows that the current representation is merely a faster dual of the voltage representation. The circuits be mechanically transformed from one form to another. Current-driven diodes do work as flip-flops, but this logic of course needs external active components to inject input currents and to propagate currents between combinatorial stages. That's how you get flip-flops or any other function that requires feedback: you put a current mirror between output and the input.
If you want purely diode-based logic with no other kinds of active components, then you need tunnel diodes. Look up Esaki Diode Logic Circuits by Neff, Butler and Critchlow (again, from the 60s). You can also implement this logic using modern two-terminal devices such as diacs (or their transistor-based implementation).
You must not have any credit cards, then. I haven't had any credit cards (and I have a dozen) that are not renewed with the account number intact. The expiration date is bumped ahead by some predictable number of months (12, 24, 48, etc), and that's it. Those "expired" numbers are as good as unexpired ones: in either case the account could have been closed, but other than that it's a simple thing to brute force the renewed expiration date. You should get it right on 3rd or 4th try at worst. You can then cache the initial expiration date delta with the first 4 digits of the account number as the cache lookup key.
I think you're wrong. You can build logic for any given truth table, using only "plain old" diodes, nothing exotic. This was state of the art in late 50s/early 60s. I'm pretty sure you could do programmable logic as long as you'd use an active device like an SCR to retain the state of the programmable "fuse". LUTs and multiplexers, the staples of modern programmable logic, are fairly easy to do with nothing but diodes. And they aren't terribly slow either, you could probably build a current-driven 10 LUT "PLD" that would operate at more than 1MHz, using nothing but Schottky diodes.
Here's an abstract for ya. And this is nothing new: it's from work done in late 50s:
The realization of switching functions using current-operated diode logic gates, which employ the direction of current as the binary variable, is presented. Two realization methods are discussed. The dual method consists of a set of rules which are analogous to the procedures employed for the realization of voltage-operated circuits. The lattice method is based on the transmission characteristics of a lattice network of four series-connected diodes. Either method is capable of realizing any arbitrary transmission function, although the number of diodes required may be different. Hybrid networks, which combine the advantages of both methods, are described to illustrate the versatility of current-operated techniques. Practical design procedures are included to guide the designer in the application of the realization rules. A static multiplier, capable of simultaneously multiplying two 4-bit binary numbers, was designed and built to demonstrate the practicability of current-operated diode logic gates. Approximately 270 diodes were required to construct the twenty gates used in the static multiplier. Dynamic tests of the assembled system indicated a reliable capability of 333,000 multiplications per second.
If you can make a 300kHz 4x4 multiplier using diodes, then I'd say this is hardly some logic -- in my book, at least. The wikipedia article on diode logic, and most other intro-level articles I could find, really miss on how diode logic was (and is) used, and provide only some lame, almost useless examples.
Those diodes perform an auxiliary function and are not doing any sort of logic by themselves (as they would were it diode, not relay, logic). If you're careful about it, you can do without diodes, using a snubber instead. Heck, there are applications where you don't want a diode across a coil at all -- that's when you want to control broadband emissions. A snubber-on-coil circuit is tuned and has high damping, you can tune it to have relatively low frequency oscillations. With a diode you have fast switching action, high dV/dt and lots of nasty, broadband emissions.
An optically controlled switch is easy. Any medium where you get optical saturation lets you implement a light-controlled switch. You can also have media that, say, change opacity when exposed to light of one wavelength, so you can control transmission of say red light using UV. You can also have a light-controlled-gain device, like, say, a light-pumped laser -- turn off the pumping light and gain drops below 1. Turn on pumping light and you have positive gain. The power levels involved are not very practical, and the lower power devices can be slow, but you can definitely achieve light-controlled amplification of light -- an optical transistor. You can also easily achieve voltage-controlled amplification using a semiconductor laser. It's the lack of practical implementations that slows things down, that's all -- as far as I understand it.
You most definitely can, even complex logic like multipliers:
A static multiplier, capable of simultaneously multiplying two 4-bit binary numbers, was designed and built to demonstrate the practicability of current-operated diode logic gates. Approximately 270 diodes were required to construct the twenty gates used in the static multiplier. Dynamic tests of the assembled system indicated a reliable capability of 333,000 multiplications per second.
Just google for some ideas. You can even build voltage-controlled multiplexers using nothing but diodes -- quite good ones, even. Your basic high-frequency sampler (going up to tens of GHz) is nothing but a sampling capacitor in a sampling diode bridge. Such bridges maintain symmetry that preserves integrity of the sampled differential signal and are the simplest way to quite accurately sample a quickly changing signal. They have incredible bandwidth given their simplicity.
It does not operate on the principle of voltage drops, it's like saying that cars operate on the principle of heating up their environment (65%+ of your gasoline heats up the air around you). Diode logic operates, obviously enough, utilizing the large ratio of forward-to-backward current flow across an isolated semiconductor junction. Voltage polarity across a diode turns it on/off, but what is turned on is the current flow. I don't know where the idea about level shifting came from, it's not necessary at all for diode logic.
However, electricity was not originally used for cooking, refrigeration, or air conditioning. Light bulbs were the application that really got the technology deployed.
That's true. In some countries, paying an electricity bill is still called "paying for light".
Certain things are true not because Newton said so, but because that's how Nature happens to work;)
As for Pascal: it's pretty much C without syntax insanity. You can still shoot yourself in the foot with pointers, but you have to be more explicit about it. I think that using a language that completely obscures pointers is not a good choice for teaching at college level. You can do high order functions in both Pascal and C, you just need a library for it, and the syntax would be devoid of sugar since the language doesn't support it with built-in primitives. I do high order functions using C++'s template syntactic sugar, but that's a very light dusting. I have done them in Pascal back in high school, without even knowing what they were called.
Taking a function as an input is of course supported directly in both Pascal and C. Returning functions is trickier, depending on whether it's a bare function or a continuation -- and I admit that the distinction is entirely artificial when you lack native support. That's when you use virtual methods and function-classes; in C glib, er, GObject, will do that part of the trick.
I agree. A "small" solar panel goes quite a long way when your needs are measured in tens of watts. All of that presumes that heating and cooking could be powered with natural gas. I also don't think that small solar panels are enough to provide forced air circulation, you'd need hydronics for heating, and the only way to cool single family homes then is to use forced air circulation and a zig-zagging subterranean duct.
I think everyone but me missed on the big red flag in the troll parent: WTF should we defeat every other nation?! How can that be anyone's goal?? What kind of a fucked up ideology is that? If that guy/gal seriously thinks that and claims themselves to be Christian, they need to take a long view in the mirror because they are really, truly fucked up, no other word for that. Christian my ass. Sigh.
Slashdot Mirror
Assuming, very conservatively, that they can spend 50% on developers, and 50% on everything else, you can get a lot of brilliant people employed for that kind of money. Of course software development isn't really scalable by throwing people at the problem without a structure to support them. But they should be able to afford software engineers who can design the innards in such a way that the work can be done in parallel on many isolated pieces. Perhaps a bigger problem is that there are no good tools to support this kind of work. Ideally you'd want something that integrates version control, bug tracking, collaborative document editing, etc. Any systems out there that pretend to do that are "enterprisey" enough to make you puke, and are really useless and counterproductive.
OT: it was interesting to see Opera as the browser on Nintendo DSi. I used to use Opera exclusively in times of Windows 95 and 98. Heck, I even paid for it back then -- a couple times, no less. It offered really refreshing experience when the alternatives were Netscape (a clusterfuck it was, it seemed) and IE.
Morass -- that's exactly what I thought of it. Not only you have to dredge for Google, but you have to inspect the links used by those add-ons -- many show off Google logo but have nothing to do with Google, they go to some 3rd party url. It's creepy because I'm sure many people must fall for that.
Please be careful. The add-on gallery displayed in IE is seeded with 3rd party "providers" that use Google logo, yet the searches definitely do NOT go to Google. I don't know why MS/Google won't litigate those to hell (or simply kick them out), but that's a fact. Every time I upgrade IE and get presented with the add-on gallery, the first Google-branded providers have nothing to do with Google. The concept of this add-on gallery is fundamentally broken, and I wonder how many drive-by infections those "providers" are accountable for.
This completely fails to take into account Jobs's deals with MS. Guess what: MS is a money making software development house. Apple used to have deals with them, this had nothing to do with any antitrust poseurship.
Gee whiz. For $300M a year Firefox should be something else than it currently is. That's a whole lot of money. If their developers cost $300k per year in salary and benefits, that'd cover what -- perhaps 500 developers, with the other $150M going towards overheads, hosting costs, etc. I think that Mozilla is quite complacent and inefficient with how they spend their money.
Mr Henry Reinecke seems to disagree. I've downloaded the paper and they do use current drivers and current mirrors to drive inputs and couple stages (including feedback from outputs to inputs), but the logic itself is all diodes. I've done a quick simulation of the most complex network he used in the multiplier, and with modern diodes and well laid out board you could probably run it at 10MHz. In the paper he shows that diode logic has dual representation -- one uses voltages as signals, another uses currents as signals. The voltage signal based logic is simply slower because various capacitances play a big role, but you can have exactly same logic done for voltage signals or current signals.
Do note that I think his logic could be running with an AC carrier (yep), and you could use transformers to couple stages, and it'd work without any passive devices for moderately sized networks. I'm thinking of prototyping such a thing just to show that his multiplier, even if impractical, can be done completely using diodes and passive devices.
You're right as to debit cards, I had same experience with those. They seem somehow different from credit cards as far as reissuance is concerned. For credit cards, they had simply sent me new ones a couple months before the expiration date, and they'd usually have new expiration = old expiration + 36 months.
Hmm, this is insightful. Some places do not need CCV, though. I haven't checked TFA: did they store CCVs?!
Cover yourself from both ends: have one password per account (a must!) and have them complex. If you do the former, then you'll need a password manager anyway, so the latter becomes trivial.
With two fibers you can encode information in phase difference, and I bet that would "polarize" a two-input optical diode OK.
The paper shows that the current representation is merely a faster dual of the voltage representation. The circuits be mechanically transformed from one form to another. Current-driven diodes do work as flip-flops, but this logic of course needs external active components to inject input currents and to propagate currents between combinatorial stages. That's how you get flip-flops or any other function that requires feedback: you put a current mirror between output and the input.
If you want purely diode-based logic with no other kinds of active components, then you need tunnel diodes. Look up Esaki Diode Logic Circuits by Neff, Butler and Critchlow (again, from the 60s). You can also implement this logic using modern two-terminal devices such as diacs (or their transistor-based implementation).
You must not have any credit cards, then. I haven't had any credit cards (and I have a dozen) that are not renewed with the account number intact. The expiration date is bumped ahead by some predictable number of months (12, 24, 48, etc), and that's it. Those "expired" numbers are as good as unexpired ones: in either case the account could have been closed, but other than that it's a simple thing to brute force the renewed expiration date. You should get it right on 3rd or 4th try at worst. You can then cache the initial expiration date delta with the first 4 digits of the account number as the cache lookup key.
+1 funny as hell.
I think you're wrong. You can build logic for any given truth table, using only "plain old" diodes, nothing exotic. This was state of the art in late 50s/early 60s. I'm pretty sure you could do programmable logic as long as you'd use an active device like an SCR to retain the state of the programmable "fuse". LUTs and multiplexers, the staples of modern programmable logic, are fairly easy to do with nothing but diodes. And they aren't terribly slow either, you could probably build a current-driven 10 LUT "PLD" that would operate at more than 1MHz, using nothing but Schottky diodes.
Here's an abstract for ya. And this is nothing new: it's from work done in late 50s:
The realization of switching functions using current-operated diode logic gates, which employ the direction of current as the binary variable, is presented. Two realization methods are discussed. The dual method consists of a set of rules which are analogous to the procedures employed for the realization of voltage-operated circuits. The lattice method is based on the transmission characteristics of a lattice network of four series-connected diodes. Either method is capable of realizing any arbitrary transmission function, although the number of diodes required may be different. Hybrid networks, which combine the advantages of both methods, are described to illustrate the versatility of current-operated techniques. Practical design procedures are included to guide the designer in the application of the realization rules. A static multiplier, capable of simultaneously multiplying two 4-bit binary numbers, was designed and built to demonstrate the practicability of current-operated diode logic gates. Approximately 270 diodes were required to construct the twenty gates used in the static multiplier. Dynamic tests of the assembled system indicated a reliable capability of 333,000 multiplications per second.
If you can make a 300kHz 4x4 multiplier using diodes, then I'd say this is hardly some logic -- in my book, at least. The wikipedia article on diode logic, and most other intro-level articles I could find, really miss on how diode logic was (and is) used, and provide only some lame, almost useless examples.
Those diodes perform an auxiliary function and are not doing any sort of logic by themselves (as they would were it diode, not relay, logic). If you're careful about it, you can do without diodes, using a snubber instead. Heck, there are applications where you don't want a diode across a coil at all -- that's when you want to control broadband emissions. A snubber-on-coil circuit is tuned and has high damping, you can tune it to have relatively low frequency oscillations. With a diode you have fast switching action, high dV/dt and lots of nasty, broadband emissions.
An optically controlled switch is easy. Any medium where you get optical saturation lets you implement a light-controlled switch. You can also have media that, say, change opacity when exposed to light of one wavelength, so you can control transmission of say red light using UV. You can also have a light-controlled-gain device, like, say, a light-pumped laser -- turn off the pumping light and gain drops below 1. Turn on pumping light and you have positive gain. The power levels involved are not very practical, and the lower power devices can be slow, but you can definitely achieve light-controlled amplification of light -- an optical transistor. You can also easily achieve voltage-controlled amplification using a semiconductor laser. It's the lack of practical implementations that slows things down, that's all -- as far as I understand it.
You can't build logic from diodes.
You most definitely can, even complex logic like multipliers:
A static multiplier, capable of simultaneously multiplying two 4-bit binary numbers, was designed and built to demonstrate the practicability of current-operated diode logic gates. Approximately 270 diodes were required to construct the twenty gates used in the static multiplier. Dynamic tests of the assembled system indicated a reliable capability of 333,000 multiplications per second.
Just google for some ideas. You can even build voltage-controlled multiplexers using nothing but diodes -- quite good ones, even. Your basic high-frequency sampler (going up to tens of GHz) is nothing but a sampling capacitor in a sampling diode bridge. Such bridges maintain symmetry that preserves integrity of the sampled differential signal and are the simplest way to quite accurately sample a quickly changing signal. They have incredible bandwidth given their simplicity.
The paper is out online only.
It does not operate on the principle of voltage drops, it's like saying that cars operate on the principle of heating up their environment (65%+ of your gasoline heats up the air around you). Diode logic operates, obviously enough, utilizing the large ratio of forward-to-backward current flow across an isolated semiconductor junction. Voltage polarity across a diode turns it on/off, but what is turned on is the current flow. I don't know where the idea about level shifting came from, it's not necessary at all for diode logic.
However, electricity was not originally used for cooking, refrigeration, or air conditioning. Light bulbs were the application that really got the technology deployed.
That's true. In some countries, paying an electricity bill is still called "paying for light".
Certain things are true not because Newton said so, but because that's how Nature happens to work ;)
As for Pascal: it's pretty much C without syntax insanity. You can still shoot yourself in the foot with pointers, but you have to be more explicit about it. I think that using a language that completely obscures pointers is not a good choice for teaching at college level. You can do high order functions in both Pascal and C, you just need a library for it, and the syntax would be devoid of sugar since the language doesn't support it with built-in primitives. I do high order functions using C++'s template syntactic sugar, but that's a very light dusting. I have done them in Pascal back in high school, without even knowing what they were called.
Taking a function as an input is of course supported directly in both Pascal and C. Returning functions is trickier, depending on whether it's a bare function or a continuation -- and I admit that the distinction is entirely artificial when you lack native support. That's when you use virtual methods and function-classes; in C glib, er, GObject, will do that part of the trick.
I agree. A "small" solar panel goes quite a long way when your needs are measured in tens of watts. All of that presumes that heating and cooking could be powered with natural gas. I also don't think that small solar panels are enough to provide forced air circulation, you'd need hydronics for heating, and the only way to cool single family homes then is to use forced air circulation and a zig-zagging subterranean duct.
I think everyone but me missed on the big red flag in the troll parent: WTF should we defeat every other nation?! How can that be anyone's goal?? What kind of a fucked up ideology is that? If that guy/gal seriously thinks that and claims themselves to be Christian, they need to take a long view in the mirror because they are really, truly fucked up, no other word for that. Christian my ass. Sigh.