The argument for AC to DC conversion on each device is that individual power supplies provide isolation e.g. no direct current path from DC ground of one device to another device. This is why Ethernet is transformer coupled. Eliminates ground loops and propagation of damage during major hardware meltdowns, nearby lightning strike etc.
Why can't you just slap a diode on the ground for each individual device? That way no device could push current into another device via the ground. You'll lose a diode drop's worth of voltage but what other reason is there not to do this?
ever seen someone drop a screwdriver between 5V and 0V buses on a 300A distribution system!?
No problem at all. Turns immediately to metal vapour and will likely not even interrupt server operation. And with todays computers that would more likely be 12V/3000A;-)
This isn't true. 300 amps flowing across 5 volts will generate 1500 watts. That's really not that much. Far more than 300 amps would flow through a screwdriver if you put it between 5 volts on a serious power supply. What would happen is you would trip the overcurrent protection in the power supply (or blow the fuse if it's archaic) and your power would go down.
The screwdriver wouldn't even melt, much less even come close to vaporizing. At 3000 amps you're looking at possibly melting the screwdriver but you'll still do some serious damage to the system.
The point is that power supplies are designed to protect against shorts, and a screwdriver between the terminals is definitely a short. The end result of doing this isn't going to be "nothing."
Re:a char with a value of 65535?
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Java Puzzlers
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· Score: 1
My point is, a character is not the binary representation of a text unit on disk.
No. As I already pointed out, a character is an abstract concept. "The uppercase Latin letter 'A'" is a character. Decimal 65, a number, is the character code of that character in the ASCII and Latin1 character sets.
You seem to be wishing for some abstract concept called "character" to exist as a concrete element in a computer language. Since it cannot, you call for arbitrarily masking the true nature of the object (which is a number) for no good reason that you've yet explained.
In this example, String is a static class, so the variables declared in that class are also static. The class serves merely as a namespace. So I don't see what the mystery is here -- it will print "hello goodbye" because the s variable is shared between all "instances."
Re:a char with a value of 65535?
on
Java Puzzlers
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· Score: 1
char, being a character datatype, shouldn't have its value expressed as an integer. The correct value of c is the glyph or other character [...]
Now you're confusing the issue. You have conflated three distinct concepts -- a character code, which is a value denoting a specific character within a given encoding; a character, which is the abstract identity of a specific written glyph; and the glyph itself, which is a physical realization of the character in question. So no wonder you are confused.
A "char," in C, C++, Java, and several other languages, is a character code. That is, it is a numeric value which, when coupled with a given encoding, can be used to refer to a character.
There is nothing particularly arcane about the concept of using a numeric value to refer to a character. And it is to be expected that a "char" type would be a numeric type. This is in fact the case, notwithstanding your bizarre confusion between a character and its character code.
Re:disappointed -- try the java cert exam
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Java Puzzlers
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· Score: 3, Informative
At least you get a warning when compiling that code: "finally clause cannot complete normally."
When the Java syntax was being invented (borrowed from C is more like it), this should have been addressed by disallowing return statements within finally blocks. The only way control should exit a finally clause is by falling out the end.
Would a car company get away with cars breaking down on real-life roads an average 26 minutes after they're purchased? The thought is totally ridiculous, yet we accept the same from Microsoft. Why?
The answer is that traditionally, people have always viewed computer software as Magical -- we stand in awe at the fact that it functions at all, much less perfectly. In the past, when computers were new, scary, powerful, and incomprehensible, this viewpoint may have made sense. But in today's world, I think our attitudes need to shift toward expecting more reliability from our software. It isn't magical, any moreso than a suspension bridge. An impressive feat of engineering, but not magical.
We're like little kids who are so easily impressed that we overlook what should be considered as enormous flaws.
That's one of the most bizarre questions I've seen asked. The answer is obviously that it would be a waste of time.
What on earth does game soundtrack composition have to do with computability, context free grammars, operating system resource allocation, space and time complexity analysis, etc? The entire premise of the question is insane.
It sounds like this person thinks that CS is where you go to learn to use a computer. That would be like sending an aspiring painter to get a degree in physics so he could learn to use a paintbrush.
Wow, I never knew about this simple.wikipedia.org. I feel utterly insulted having just read that. It reminds me of my "Learning Encyclopedia For Children" I used to read when I was 5.
When Marx initially wrote about religion being the opiate, he was actually paying it a (albeit backhanded) compliment, that awareness of a religious idea can steer people toward a more noble life. It makes the oppressed fell better about their condition.
Your limited understanding of how to use a dictionary (i.e., stopping as soon as you've found the meaning that you are referring to and not reading on or trying to see what other meanings the word has) just shows how shallow and unthinking your post was.
The dictionary I use is the one Google links to when you type in a search term. That dictionary had only a single definition: Not usual, common, or ordinary.
But I'll be generous, and list all the synonyms that popped up in the thesaurus:
(like my LJ community DIERIAA {legal links to music offered freely for public download on the net by the record labels/copyright owners themselves} was terminated for no reason, never even had it's first post made, it just got wiped out, just for it's name.)
Wow, you're a conspiracy theorist. Hint: they probably wiped the group because of the offensive name (it looks like a poor attempt at spelling "diarrhea.")
Do a google search for orbital resonance mars. It may be that planet orbits aren't as stable as we think. After all, we weren't around 60,000 years ago to witness the orbits.
Uhhh, humans were certainly around 60,000 years ago.
It's still not "unusual" -- these orbits have been known and tracked since ancient times and are fully predictable.
Looking in a dictionary, I don't see any connection between the concepts of "unusual" and "unpredictable." Unusual literally means "not usual." The usual state of affairs is for Mars to be further away than this. Therefore, Mars is "not usually" this close (God, I can't believe I have to spell it out for you), and this occurrence is "unusual."
Still, Mega Points for actually attempting to blog, but he's missed the feedback section in his implementation, I think on purpose. Can't have any nasty liberals leaving him messages, can we?
Think about it. His blog is hosted on www.speaker.gov -- a US government website. As such, anything that even remotely looks like suppression of free speech would be taboo. The blog would immediately be "crap flooded", essentially DDoS'd by a rain of shit, and he'd be legally unable to remove any of the messages. Crap-flooding contains no useful information, but it is still "speech" and because the web site is a formal entity of the United States Government there would be nothing he could do to stop it.
Not everything boils down to Liberals vs. Conservatives, you know.
Considering the amount of overhead that would be required to encrypt and decrypt a constant data stream such as VoIP, it seems to me that you'd have pretty bad performance problems.
Then you are ignorant. Assuming a bit rate of 32 kbps (which is generous for voice), that's 4 kilobytes of data per second that need to be encrypted.
Oh woe is me, where oh where am I going to find an encryption algorithm that can encrypt a mighty 4 kilobytes per second? I mean sheesh, it only has a quarter of a millisecond per byte! Hell, at today's CPU speeds we'll have to encrypt a byte using fewer than half a million instructions! God, it just seems impossible!
the color values have been floating point numbers [...] which are of course much slower than very simple integer calculations.
You say this as if it is both true and obvious. In fact, it is false. For several years now, floating point arithmetic has been just fast (and in many cases, faster) than integer arithmetic. I have actually sped up code which was previously cleverly written to use integers, just by switching to doubles.
What is still very slow is converting from integers to floats, and vice versa. Avoid casts, and feel free to use floating point wherever you wish you had it. Your code won't suffer in the slightest.
They don't care what happens to their chips at -80C or +180C. All they do is test them a little bit beyond the limits of their recommended operating range.
I highly doubt it. I have some pretty intimate knowledge of what sorts of things go on at a certain giant chipmaker, and believe me, all kinds of crazy shit has been done that you don't know about simply because they don't tell you. I imagine ATI is similar. I don't know if they've done anything exactly like this, but the experiments certainly reach into this realm of the bizarre.
The difference is, they have specific reasons for conducting those tests other than "Whooo, look what I did!"
Yes, but a lot of different chips have different overclocking potential. It's interesting to see which can be pushed the furthest, even if its impractical.
Really, I don't think it's interesting whatsoever. It's like testing the strength of various bulletproof glass samples at a temperature of -100 C. The fact is, bulletproof glass is not used in such environments so the test gives no useful information.
Beside, since when are geeky pursuits practical?
I can't believe you're being serious. My geeky pursuits pay for my house.
If the elevator is *stopped* or *moved at a constant speed* you would be weightless only at geosynchronous orbit.
I don't understand why you think this. At geosynchronous orbit, your body's natural tendency will be to continue in the orbit -- NOT to go higher. Whether the elevator is moving at a constant speed relative to the cable makes no difference in the matter. You are being pushed into a higher orbit and thus you must experience a force (and therefore weight).
If you cool a chip, you can make it run faster. This is a matter of physics that doesn't need to be tested any more than it already has been. In some small way I appreciate the geek factor but I'm far more interested in geek projects that have some practical use.
And as for being the first people in the world to do this... the chances of that are small. I'm sure there are people at Radeon (and other companies) who have done things far more bizarre, but didn't announce it to the world.
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Why can't you just slap a diode on the ground for each individual device? That way no device could push current into another device via the ground. You'll lose a diode drop's worth of voltage but what other reason is there not to do this?
No problem at all. Turns immediately to metal vapour and will likely not even interrupt server operation. And with todays computers that would more likely be 12V/3000A ;-)
This isn't true. 300 amps flowing across 5 volts will generate 1500 watts. That's really not that much. Far more than 300 amps would flow through a screwdriver if you put it between 5 volts on a serious power supply. What would happen is you would trip the overcurrent protection in the power supply (or blow the fuse if it's archaic) and your power would go down.
The screwdriver wouldn't even melt, much less even come close to vaporizing. At 3000 amps you're looking at possibly melting the screwdriver but you'll still do some serious damage to the system.
The point is that power supplies are designed to protect against shorts, and a screwdriver between the terminals is definitely a short. The end result of doing this isn't going to be "nothing."
No. As I already pointed out, a character is an abstract concept. "The uppercase Latin letter 'A'" is a character. Decimal 65, a number, is the character code of that character in the ASCII and Latin1 character sets.
You seem to be wishing for some abstract concept called "character" to exist as a concrete element in a computer language. Since it cannot, you call for arbitrarily masking the true nature of the object (which is a number) for no good reason that you've yet explained.
In this example, String is a static class, so the variables declared in that class are also static. The class serves merely as a namespace. So I don't see what the mystery is here -- it will print "hello goodbye" because the s variable is shared between all "instances."
Now you're confusing the issue. You have conflated three distinct concepts -- a character code, which is a value denoting a specific character within a given encoding; a character, which is the abstract identity of a specific written glyph; and the glyph itself, which is a physical realization of the character in question. So no wonder you are confused.
A "char," in C, C++, Java, and several other languages, is a character code. That is, it is a numeric value which, when coupled with a given encoding, can be used to refer to a character.
There is nothing particularly arcane about the concept of using a numeric value to refer to a character. And it is to be expected that a "char" type would be a numeric type. This is in fact the case, notwithstanding your bizarre confusion between a character and its character code.
When the Java syntax was being invented (borrowed from C is more like it), this should have been addressed by disallowing return statements within finally blocks. The only way control should exit a finally clause is by falling out the end.
Hah. The "spirit" of a file sharing network. What a load of crap.
Yeah... And it's even MORE vigilante if they do it in cooperation with a Federal agency!
Sheesh.
So destroy your current passport and have a new one reissued right before they institute the chips. You'll have 10 more years of RFID-free travel.
The answer is that traditionally, people have always viewed computer software as Magical -- we stand in awe at the fact that it functions at all, much less perfectly. In the past, when computers were new, scary, powerful, and incomprehensible, this viewpoint may have made sense. But in today's world, I think our attitudes need to shift toward expecting more reliability from our software. It isn't magical, any moreso than a suspension bridge. An impressive feat of engineering, but not magical.
We're like little kids who are so easily impressed that we overlook what should be considered as enormous flaws.
What on earth does game soundtrack composition have to do with computability, context free grammars, operating system resource allocation, space and time complexity analysis, etc? The entire premise of the question is insane.
It sounds like this person thinks that CS is where you go to learn to use a computer. That would be like sending an aspiring painter to get a degree in physics so he could learn to use a paintbrush.
Wow, I never knew about this simple.wikipedia.org. I feel utterly insulted having just read that. It reminds me of my "Learning Encyclopedia For Children" I used to read when I was 5.
Yes. Here's the real full quote, from Wikipedia:
"Religion is the sign of the oppressed creature, the heart of a heartless world and the soul of soulless conditions. It is the opium of the people."
Religion is the "heart of a heartless world?" The "soul of soulless conditions?" It hardly seems that Marx was trying to insult religion.
I consider misquotation to be a horrific intellectual crime, right up there with fabricating data.
The dictionary I use is the one Google links to when you type in a search term. That dictionary had only a single definition: Not usual, common, or ordinary.
But I'll be generous, and list all the synonyms that popped up in the thesaurus:
infrequent, occasional, rare, scarce, sporadic, uncommon, atypic, atypical, novel, unconventional, unordinary, unwonted, offbeat, bizarre, cranky, curious, eccentric, erratic, freakish, idiosyncratic, odd, outlandish, peculiar, quaint, queer, quirky, singular, strange, unnatural, weird, exceptional, extraordinary, magnificent, outstanding, preeminent, rare, remarkable, singular, towering, uncommon.
Now tell me which of those means "unexpected." I didn't think so.
Wow, you're a conspiracy theorist. Hint: they probably wiped the group because of the offensive name (it looks like a poor attempt at spelling "diarrhea.")
Uhhh, humans were certainly around 60,000 years ago.
Looking in a dictionary, I don't see any connection between the concepts of "unusual" and "unpredictable." Unusual literally means "not usual." The usual state of affairs is for Mars to be further away than this. Therefore, Mars is "not usually" this close (God, I can't believe I have to spell it out for you), and this occurrence is "unusual."
Think about it. His blog is hosted on www.speaker.gov -- a US government website. As such, anything that even remotely looks like suppression of free speech would be taboo. The blog would immediately be "crap flooded", essentially DDoS'd by a rain of shit, and he'd be legally unable to remove any of the messages. Crap-flooding contains no useful information, but it is still "speech" and because the web site is a formal entity of the United States Government there would be nothing he could do to stop it.
Not everything boils down to Liberals vs. Conservatives, you know.
Then you are ignorant. Assuming a bit rate of 32 kbps (which is generous for voice), that's 4 kilobytes of data per second that need to be encrypted.
Oh woe is me, where oh where am I going to find an encryption algorithm that can encrypt a mighty 4 kilobytes per second? I mean sheesh, it only has a quarter of a millisecond per byte! Hell, at today's CPU speeds we'll have to encrypt a byte using fewer than half a million instructions! God, it just seems impossible!
You say this as if it is both true and obvious. In fact, it is false. For several years now, floating point arithmetic has been just fast (and in many cases, faster) than integer arithmetic. I have actually sped up code which was previously cleverly written to use integers, just by switching to doubles.
What is still very slow is converting from integers to floats, and vice versa. Avoid casts, and feel free to use floating point wherever you wish you had it. Your code won't suffer in the slightest.
Yeah I goofed, sorry.
They don't care what happens to their chips at -80C or +180C. All they do is test them a little bit beyond the limits of their recommended operating range.
I highly doubt it. I have some pretty intimate knowledge of what sorts of things go on at a certain giant chipmaker, and believe me, all kinds of crazy shit has been done that you don't know about simply because they don't tell you. I imagine ATI is similar. I don't know if they've done anything exactly like this, but the experiments certainly reach into this realm of the bizarre.
The difference is, they have specific reasons for conducting those tests other than "Whooo, look what I did!"
Really, I don't think it's interesting whatsoever. It's like testing the strength of various bulletproof glass samples at a temperature of -100 C. The fact is, bulletproof glass is not used in such environments so the test gives no useful information.
Beside, since when are geeky pursuits practical?
I can't believe you're being serious. My geeky pursuits pay for my house.
I don't understand why you think this. At geosynchronous orbit, your body's natural tendency will be to continue in the orbit -- NOT to go higher. Whether the elevator is moving at a constant speed relative to the cable makes no difference in the matter. You are being pushed into a higher orbit and thus you must experience a force (and therefore weight).
And as for being the first people in the world to do this... the chances of that are small. I'm sure there are people at Radeon (and other companies) who have done things far more bizarre, but didn't announce it to the world.
WTF? I'd say that an actual shot of heroin right before you die of a heroin overdose feels quite a fucking bit like that.