> so in other words, you're open to extraditing americans to saudi arabia because they violated saudi religious heresy laws?
If I was using servers and resources in Saudi Arabian's to commit acts of heresy there, then I would fully expect to get extradited.
The internet IS NOT boundaryless, and like it allows you to communicate with other people all over the world, it exposes you to the laws all over the world. You should consider what laws you are exposing yourself to before you do anything on a system that is in another country.
That IS a scary thought, and I hope that the sheer expense and difficulty of extradition makes it difficult to do on a wide spread basis for minor infractions.
> Did you not read, 'copy on update' (I think I missed out the o)
This is an operating system feature, not an application programming feature. To use copy on update for an application program, the program would:
1) need to dictate VM stratagy. This is not a good idea because it will interfere with the OS's job, which is to manage memory usage. 2) Each string would need to be put into their own page, so the OS could determine what string needed to be copied on an update. This is a terrible waste of memory and VM space, which is at a premium on current 32bit machines. 3) If the string IS updated, performance would be staggeringly bad. A page fault would be generated when the app attempted to update the string. This would invoke an interrupt inside the OS. The OS would then need to determine which page(string) needed to be copied, perform the copy, and finally return control to the program. The pipeline and cache stalls such an interrupt create would be far worse then just copying the string in the first place.
Thats assuming that you are using the Operating system's write on copy feature. However, it would also be possible to implement this feature directly in the language. This would have its own overheads and problems too though.
Also, copying the string rather then using a pointer is simply a safer way for a programmer to perform this function. Due the complexity of most modern software, a single programmer would probably not know if using a shortcut like this is safe. What if some function that this string is passed to actually DOES change the string occasionally, without clearly documenting it. This can introduce very tricky and difficult to find bugs especially if these shortcuts are used everywhere.
Actually, having the pins on the motherboard is much better cost wise then the CPU.
High end CPU's can cost a great deal more then the motherboards they are installed in. If you bend the pins on such an expensive CPU, then you have to try to unbend them, which is very very hard on modern chips. With the pins on the motherboard, if you can't repair the pins, the lost investment is much less.
To be fair though, without the Pentium 4, the pentium-m would never have been this good.
With the pentium 4, Intel was forced to face the problems that plauge pipelined chips and create solutions that worked with excessively long pinelines. The experience gained by intel engineers in tackling these problems has been critical during the redesign of the P3 core into the P-M core.
Errr, unless your link is of the same capacity as the high capacity cables that were cut, its not going to make an ounce of difference.
A slower link would instantly become overcongested to the point where TCP retries dominated the traffic transmittions, and absolutely no useful data will be transferred over the link.
find a Radeon 9200SE card with TV out... should only cost about $50US. Or maybe an nvidia 5200se. Both should provide good TV out for very little money.
err, why didn't you just get her some decent hardware.
Just because you can get away with it, doesn't mean you can dump positively ancient computers on people.
I would at least recommend a 1ghz computer with a good 7200rpm hard drive, 512meg ram and fast 2d video card (most even bad 3d cards meet this requirement). Sure, teach her linux because it is less succeptable to internet abuse then windows, (means less maintenence in the long term) but don't skimp on the hardware just because you can.
Computers are a tool to serve people, and you should be looking out for the BEST experience for your customers. Even if that means their CPU stays idle for 99% of the time.
The reason DRAM prices have remained static (or have even risen a bit) and flash prices have fallen is because memory manufacturers have been moving a lot of their production off DRAM and onto flash ram.
This means that the supply of DRAM remains fairly tight, and that prevents further price reductions. Meanwhile, a glut of flash ram is now developing, and the resulting oversupply is driving flash memory prices into the floor.
> If these sound like attacks on PRNGs to you, > you're catching on. What a predictable universe > does is turn any attempt at a true random number > generator into a pseudo-random number generator, > which can then be attacked using any of the > standard approaches.
Most well written crypto random number generaters make it computationally complex to determine the current state or previous states of the "random" source. It does this by using either an encryption or hashing algorithm to generate derivatives of the "random" source, rather then exposing the "random" source itself.
But, DRAM will hold its state without a refresh for MUCH longer then the time the chip actually spends between refreshes. This ensures that a cells don't discharge too far and loose their correct state. An DRAM chip that refreshes every 64ms will have cells that could hold their state for 200ms or longer.
There are external events that can cause a bit flip, but their occurance is so exceedingly rare, I would be suprised if more then one such event happened per year to people.
Err, then the PC and ram Anandtech have been using are dodgy.
Due to the design of Dynamic RAM chips, memory bit flip errors are not influenced by how long the memory sits "idle". I emphise idle here because Dynamic ram is never really idle. Each cell in a DRAM chip contains a capacitor and a transistor. If a DRAM cell is left to its own devices, the capacitor soon discarges and the cell looses its state. To stop this from happening, in the background, the RAM controller on the chip is constantly recharging the capacitors. Each cell is read and rewritten about every few milliseconds.
Because DRAM chips are never idle, the whole methodolgy of the anandtech test is WRONG, and the most obvious conclusion is that anandtech is using dodgy ram, or is simply pushing the RAM beyond their specs to forcibly generate errors.
Bill Gates did not decide on the 640K limit in DOS.
This limitation was fostered upon us by Intel, who designed the 8086 processor, with a 20 bit address bus (1 meg accessable memory space). It was then endorsed and solidfied by IBM using intel's processor, and only allocating the first 640K for memory, and the remaining 384K for ROM/video memory.
DOS was merely written to utilize the system intel/IBM designed.
Furthermore, it is rather harsh to demonise Intel/IBM for this limitation. The processor was designed in 1978, and the system in the early eighties. DOS persisted far longer then it should have!
Re:VI is everywhere.
on
JOE Hits 3.0
·
· Score: 2, Informative
Meh,
I just installed JOE into my home directory at uni after I got sick of using VI. A few path tweaks and it all runs smoothly.
So... Someone could infect one of your floppy disks without knowing it. You can then put that floppy into your computer thinking it was uninfected and actually infect your computer.
The user doesn't have to explicitly know they are sharing data with other users to become infected by a virus.
How many times do you Linux lusers have to be told that we don't want to use linux. (Note, this argument is based mostly towards linux lusers who think everyone should switch to linux. Macs are ok, but still suffer these problems to a lesser degree)
There are many GOOD reasons to run windows, including:
1) Good computer game support. Not only are most games windows based, but the API's for games in windows are well defined and provide good performance.
2) Good software support. Many windows programs are just faster, smoother, and better then their linux counterparts. Linux is about as good (sometimes better too) in terms of web browers/email programs, and other net software, but almost always falls flat in other areas.
3) It just works. I don't need to fuck around with shit too often to get windows to work with most of my programs. There is the occasional stupid program/setting, but that occurs on linux much more regularly. With linux too, I have found the supposedly easy to setup linux distributions are fragile and far too easy to break. The auto-config tools ussually only barely work, are ussually slow as snot, and are annoying.
4) Eventually, if everyone moves to linux, we will have the same problems as windows users wrt worms and viruses. There have been many many holes and exploits found in linux software, and with viruses only coming out days after an exploit is announced, no-one is really that safe that they can be smug about it.
A lot of programs/routines in linux will have to be refined if there is any chance of linux become a usable desktop operating system.
That action is to be directly accessable on a very large network, which is virtually the same as sharing disks between untrusted computers on a constant basis.
Most biological viruses also require human intervention to spread. A cough, sneeze, blood transfer, sex, ect are required to transfer it. Diseases caused by virus and infection rarely just appear. They are transmitted between people as they go about their normal lives
Most computer viruses live this way. In DOS/Win3.1 days, this meant hitching a ride on floppy disks as users moved data between machines. In modern days, its either hitching a ride on an email attachment or (like this one), by direct contact.
There is nothing really unusual about these infection vectors. The virus simply uses whatever vector is avaliable in everyday computer use.
I still think old viruses are more interesting, they contain features that are non-existant on most modern viruses.
Some interesting features of old viruses: * They often worked hard to hide themselves from detection. They replaced DOS/BIOS interrupt vectors and supplied the uninfected file information so their presence was completely undetectable while the virus was running. * They encrypted themselves so that anti-virus software could not easily detect their signatures. * They mutated themselves for the same purpose, by reassembling themselves in a different bytestream that was still functionally the same as the original, but different in the eyes of a virus scanner. * I remember that one virus even encrypted a portion of a systems fixed disk, then unencrypted it for system requests. Trying to remove this virus is diffcult because the system becomes dependant on it for normal operation. Once it's payload is triggered, the virus discontinues decrypting your hard drive contents, leaving the user high and dry.
Back in DOS and Win3.1 days, many viruses operated with the intent of eventually destroying the user's data.
Re:This isn't like overclocking your hard drive...
on
Recovering Secret HD Space
·
· Score: 5, Informative
Your information is off. Either you haven't used hard drives for about 15 years, or you are making the whole thing up.
The MBR does not store the bad block information. The MBR hasn't stored bad block information since IDE became popular and people stopped being able to low format your their hard drives (no a zero wipe is not a low level format, it simply gives the firmware a good time to reallocate developed bad sectors)
The bad block information is stored in areas of the drive that are completely unaccessable to the outside world, most probably near the servo information on the same track as the actual bad sector. It is only accessed by the LBA mapper in the drive firmware.
The drive actually keeps count of how many sectors it has had to reallocate in its life, and how many sectors it is waiting for a good moment to reallocate. You can get this info from most drives by inspecting the SMART values. Bad sectors do not ussually develop very often after the drive is shipped. You should not see this value be more then 1 or 2 in a young, properly working hard drive.
When the drive detects a sector is going bad, it does not automaticly reallocate it unless it can be correctly read. (or ECC corrected by the drive) This gives recovery software a slim chance of getting lucky and recoving the data from the bad block. The drive simply notes the sector is going bad. If it is read correctly at some late, the hard drive will automaticly reallocate it somewhere else. Alternatively, if a write is issued to a sector awaiting reallocation, then the drive will it perform then rather then wait for a good read.
Also, manufacturers still use aluminium platters in most drives. The embedded servo infomation is used to keep the drive tracking correctly regardless of the temperature of the drive (within specified limits)
Since you didn't read the article, nor any of the comments prevously written, you are completely wrong about this magical utility. It is simply an exploitation of a bug in Norton Ghost that makes your hard drive look larger then it is by overlapping partitions. Attempt to write data to one partition and you will trash the data on the other.
Actually, most well designed programs are clean and fast. The best way to optimise programs is to:
1) design the program well, so that it does not need to frob needlessly through un-needed abstraction and control code. 2) choose good algorithms for the problems size. This is more important than any other choice made, since the cost of poor algorithms can be devestating. 3) If more performance is needed, find the routines that require optimization (that use the most CPU) and only optimize those routines.
The adavantage of todays fast CPUs is that it actually focuses where optimization is required. Now, 99% of any program can be written with clean, understandable code. That other 1% can have the agressive, unclean optimization applied, and not completely ruin the maintainability of a program.
no, this is not a good way to clean keyboards... at least not properly.
To properly clean a modernish keyboard, you:
1) unscrew the screws on the bottom and remove the insides from the case. You can clean the case. 2) remove all the keys from the keyboard, and clean them. 3) remove and clean the silicone key mat. (this has the springy buttons on it. 4) remove the circutry and the clear plastic keyboard terminal layouts, but do not clean them unless you need to. If you clean them, dry them immediately with a hair drier to avoid corrosion. 5) clean anything that is left over and not electrical. 6) reassemble. Use silicon oil around the keys if desired.
It is time consuming, and may not be worth it for many, but it really cleans the keyboard well.
Slashdot Mirror
> so in other words, you're open to extraditing americans to saudi arabia because they violated saudi religious heresy laws?
If I was using servers and resources in Saudi Arabian's to commit acts of heresy there, then I would fully expect to get extradited.
The internet IS NOT boundaryless, and like it allows you to communicate with other people all over the world, it exposes you to the laws all over the world. You should consider what laws you are exposing yourself to before you do anything on a system that is in another country.
That IS a scary thought, and I hope that the sheer expense and difficulty of extradition makes it difficult to do on a wide spread basis for minor infractions.
> Did you not read, 'copy on update' (I think I missed out the o)
This is an operating system feature, not an application programming feature. To use copy on update for an application program, the program would:
1) need to dictate VM stratagy. This is not a good idea because it will interfere with the OS's job, which is to manage memory usage.
2) Each string would need to be put into their own page, so the OS could determine what string needed to be copied on an update. This is a terrible waste of memory and VM space, which is at a premium on current 32bit machines.
3) If the string IS updated, performance would be staggeringly bad. A page fault would be generated when the app attempted to update the string. This would invoke an interrupt inside the OS. The OS would then need to determine which page(string) needed to be copied, perform the copy, and finally return control to the program. The pipeline and cache stalls such an interrupt create would be far worse then just copying the string in the first place.
Thats assuming that you are using the Operating system's write on copy feature. However, it would also be possible to implement this feature directly in the language. This would have its own overheads and problems too though.
Also, copying the string rather then using a pointer is simply a safer way for a programmer to perform this function. Due the complexity of most modern software, a single programmer would probably not know if using a shortcut like this is safe. What if some function that this string is passed to actually DOES change the string occasionally, without clearly documenting it. This can introduce very tricky and difficult to find bugs especially if these shortcuts are used everywhere.
Actually, having the pins on the motherboard is much better cost wise then the CPU.
High end CPU's can cost a great deal more then the motherboards they are installed in. If you bend the pins on such an expensive CPU, then you have to try to unbend them, which is very very hard on modern chips. With the pins on the motherboard, if you can't repair the pins, the lost investment is much less.
To be fair though, without the Pentium 4, the pentium-m would never have been this good.
With the pentium 4, Intel was forced to face the problems that plauge pipelined chips and create solutions that worked with excessively long pinelines. The experience gained by intel engineers in tackling these problems has been critical during the redesign of the P3 core into the P-M core.
Ever heard of a thing called professional emotional detachment?
You are being paid to clean their computer, there is no need to be upset about it.
They will either keep paying you $60 every few weeks to clean their computer, or learn how to deal with it themselves.
Errr, unless your link is of the same capacity as the high capacity cables that were cut, its not going to make an ounce of difference.
A slower link would instantly become overcongested to the point where TCP retries dominated the traffic transmittions, and absolutely no useful data will be transferred over the link.
find a Radeon 9200SE card with TV out ... should only cost about $50US. Or maybe an nvidia 5200se. Both should provide good TV out for very little money.
err, why didn't you just get her some decent hardware.
Just because you can get away with it, doesn't mean you can dump positively ancient computers on people.
I would at least recommend a 1ghz computer with a good 7200rpm hard drive, 512meg ram and fast 2d video card (most even bad 3d cards meet this requirement). Sure, teach her linux because it is less succeptable to internet abuse then windows, (means less maintenence in the long term) but don't skimp on the hardware just because you can.
Computers are a tool to serve people, and you should be looking out for the BEST experience for your customers. Even if that means their CPU stays idle for 99% of the time.
The reason DRAM prices have remained static (or have even risen a bit) and flash prices have fallen is because memory manufacturers have been moving a lot of their production off DRAM and onto flash ram.
This means that the supply of DRAM remains fairly tight, and that prevents further price reductions. Meanwhile, a glut of flash ram is now developing, and the resulting oversupply is driving flash memory prices into the floor.
> If these sound like attacks on PRNGs to you,
> you're catching on. What a predictable universe
> does is turn any attempt at a true random number
> generator into a pseudo-random number generator,
> which can then be attacked using any of the
> standard approaches.
Most well written crypto random number generaters make it computationally complex to determine the current state or previous states of the "random" source. It does this by using either an encryption or hashing algorithm to generate derivatives of the "random" source, rather then exposing the "random" source itself.
But, DRAM will hold its state without a refresh for MUCH longer then the time the chip actually spends between refreshes. This ensures that a cells don't discharge too far and loose their correct state. An DRAM chip that refreshes every 64ms will have cells that could hold their state for 200ms or longer.
There are external events that can cause a bit flip, but their occurance is so exceedingly rare, I would be suprised if more then one such event happened per year to people.
Err, then the PC and ram Anandtech have been using are dodgy.
Due to the design of Dynamic RAM chips, memory bit flip errors are not influenced by how long the memory sits "idle". I emphise idle here because Dynamic ram is never really idle. Each cell in a DRAM chip contains a capacitor and a transistor. If a DRAM cell is left to its own devices, the capacitor soon discarges and the cell looses its state. To stop this from happening, in the background, the RAM controller on the chip is constantly recharging the capacitors. Each cell is read and rewritten about every few milliseconds.
Because DRAM chips are never idle, the whole methodolgy of the anandtech test is WRONG, and the most obvious conclusion is that anandtech is using dodgy ram, or is simply pushing the RAM beyond their specs to forcibly generate errors.
Bill Gates did not decide on the 640K limit in DOS.
This limitation was fostered upon us by Intel, who designed the 8086 processor, with a 20 bit address bus (1 meg accessable memory space). It was then endorsed and solidfied by IBM using intel's processor, and only allocating the first 640K for memory, and the remaining 384K for ROM/video memory.
DOS was merely written to utilize the system intel/IBM designed.
Furthermore, it is rather harsh to demonise Intel/IBM for this limitation. The processor was designed in 1978, and the system in the early eighties. DOS persisted far longer then it should have!
Meh,
I just installed JOE into my home directory at uni after I got sick of using VI. A few path tweaks and it all runs smoothly.
I can use VI, but I hate using it.
So... Someone could infect one of your floppy disks without knowing it. You can then put that floppy into your computer thinking it was uninfected and actually infect your computer.
The user doesn't have to explicitly know they are sharing data with other users to become infected by a virus.
Watch me take a karma hit for this, but:
How many times do you Linux lusers have to be told that we don't want to use linux. (Note, this argument is based mostly towards linux lusers who think everyone should switch to linux. Macs are ok, but still suffer these problems to a lesser degree)
There are many GOOD reasons to run windows, including:
1) Good computer game support. Not only are most games windows based, but the API's for games in windows are well defined and provide good performance.
2) Good software support. Many windows programs are just faster, smoother, and better then their linux counterparts. Linux is about as good (sometimes better too) in terms of web browers/email programs, and other net software, but almost always falls flat in other areas.
3) It just works. I don't need to fuck around with shit too often to get windows to work with most of my programs. There is the occasional stupid program/setting, but that occurs on linux much more regularly. With linux too, I have found the supposedly easy to setup linux distributions are fragile and far too easy to break. The auto-config tools ussually only barely work, are ussually slow as snot, and are annoying.
4) Eventually, if everyone moves to linux, we will have the same problems as windows users wrt worms and viruses. There have been many many holes and exploits found in linux software, and with viruses only coming out days after an exploit is announced, no-one is really that safe that they can be smug about it.
A lot of programs/routines in linux will have to be refined if there is any chance of linux become a usable desktop operating system.
No, its still an action.
That action is to be directly accessable on a very large network, which is virtually the same as sharing disks between untrusted computers on a constant basis.
Most biological viruses also require human intervention to spread. A cough, sneeze, blood transfer, sex, ect are required to transfer it. Diseases caused by virus and infection rarely just appear. They are transmitted between people as they go about their normal lives
Most computer viruses live this way. In DOS/Win3.1 days, this meant hitching a ride on floppy disks as users moved data between machines. In modern days, its either hitching a ride on an email attachment or (like this one), by direct contact.
There is nothing really unusual about these infection vectors. The virus simply uses whatever vector is avaliable in everyday computer use.
I still think old viruses are more interesting, they contain features that are non-existant on most modern viruses.
Some interesting features of old viruses:
* They often worked hard to hide themselves from detection. They replaced DOS/BIOS interrupt vectors and supplied the uninfected file information so their presence was completely undetectable while the virus was running.
* They encrypted themselves so that anti-virus software could not easily detect their signatures.
* They mutated themselves for the same purpose, by reassembling themselves in a different bytestream that was still functionally the same as the original, but different in the eyes of a virus scanner.
* I remember that one virus even encrypted a portion of a systems fixed disk, then unencrypted it for system requests. Trying to remove this virus is diffcult because the system becomes dependant on it for normal operation. Once it's payload is triggered, the virus discontinues decrypting your hard drive contents, leaving the user high and dry.
Hardly all that interesting.
Back in DOS and Win3.1 days, many viruses operated with the intent of eventually destroying the user's data.
Your information is off. Either you haven't used hard drives for about 15 years, or you are making the whole thing up.
The MBR does not store the bad block information. The MBR hasn't stored bad block information since IDE became popular and people stopped being able to low format your their hard drives (no a zero wipe is not a low level format, it simply gives the firmware a good time to reallocate developed bad sectors)
The bad block information is stored in areas of the drive that are completely unaccessable to the outside world, most probably near the servo information on the same track as the actual bad sector. It is only accessed by the LBA mapper in the drive firmware.
The drive actually keeps count of how many sectors it has had to reallocate in its life, and how many sectors it is waiting for a good moment to reallocate. You can get this info from most drives by inspecting the SMART values. Bad sectors do not ussually develop very often after the drive is shipped. You should not see this value be more then 1 or 2 in a young, properly working hard drive.
When the drive detects a sector is going bad, it does not automaticly reallocate it unless it can be correctly read. (or ECC corrected by the drive) This gives recovery software a slim chance of getting lucky and recoving the data from the bad block. The drive simply notes the sector is going bad. If it is read correctly at some late, the hard drive will automaticly reallocate it somewhere else. Alternatively, if a write is issued to a sector awaiting reallocation, then the drive will it perform then rather then wait for a good read.
Also, manufacturers still use aluminium platters in most drives. The embedded servo infomation is used to keep the drive tracking correctly regardless of the temperature of the drive (within specified limits)
Since you didn't read the article, nor any of the comments prevously written, you are completely wrong about this magical utility. It is simply an exploitation of a bug in Norton Ghost that makes your hard drive look larger then it is by overlapping partitions. Attempt to write data to one partition and you will trash the data on the other.
Actually, most well designed programs are clean and fast. The best way to optimise programs is to:
1) design the program well, so that it does not need to frob needlessly through un-needed abstraction and control code.
2) choose good algorithms for the problems size. This is more important than any other choice made, since the cost of poor algorithms can be devestating.
3) If more performance is needed, find the routines that require optimization (that use the most CPU) and only optimize those routines.
The adavantage of todays fast CPUs is that it actually focuses where optimization is required. Now, 99% of any program can be written with clean, understandable code. That other 1% can have the agressive, unclean optimization applied, and not completely ruin the maintainability of a program.
no, this is not a good way to clean keyboards ... at least not properly.
To properly clean a modernish keyboard, you:
1) unscrew the screws on the bottom and remove the insides from the case. You can clean the case.
2) remove all the keys from the keyboard, and clean them.
3) remove and clean the silicone key mat. (this has the springy buttons on it.
4) remove the circutry and the clear plastic keyboard terminal layouts, but do not clean them unless you need to. If you clean them, dry them immediately with a hair drier to avoid corrosion.
5) clean anything that is left over and not electrical.
6) reassemble. Use silicon oil around the keys if desired.
It is time consuming, and may not be worth it for many, but it really cleans the keyboard well.
its easy for 64bit machines to beat 32bit machines in encryption code, especially encryption code that deals with big integers ... like RSA and DSA.
RSA of a given keysize requires about 25% of the work on a 64bit cpu it requires on a 32bit cpu.
Coffee kills them (IBM Model Keyboards) quickly.
:(
And you can't pull them apart and repair them. Well not easily