I believe the main issue here is how both devices behave at the extremes of their linearity ranges. (i.e. where they distort) - Transistors tend to be pretty linear up to the point where they clip, while tubes have a more gentle gain compression, which is why their harmonics are different.
I wonder what the audiophiles would think of a truly linear amplifier. (Either using devices that are backed off far from their peak power - low efficiency warning!, or by using distortion-correction techniques similar to those used by manufacturers of CDMA RF power amilifiers)
hmm... An audio predistortion amp would be a cool hack.:)
In order from the distro that holds back the most for testing and the one that pushes the bar too far: Debian - Seems to be eternally trapped in testing.:) Also, sometimes the QC can go TOO far, as another reply to your post on issues with php4 and other packages mentions RedHat - Middle ground. Reasonably modern, pretty good QC Mandrake - While they have the "bleeding edge", every Mandrake install I've used has felt unpolished. BOTH have had serious hardware compatibility problems. To Mandrake's credit, RedHat had similar problems in one case (Broken UDMA support on my mobo chipser), but in another case, Mandrake tried to "optimize" the hard drives at bootup, resulting in the system freezing. RedHat happily ran for months on end on the same machine.
Some Intel chipsets (Triton/Natoma, aka PIIXn) have broken UDMA support. If you enable UDMA on your HD/CDROM, your system WILL crash within a few minutes, esp. with heavy HD usage.
I had this problem with RH7.3 on my old laptop - But Mandrake 8.2 wasn't much better. While the installer doesn't use DMA, it turned on UDMA as soon as it was done, resulting in a system just as unstable as the RH installer.
You have to go into the config files and specifically force one of the multiword DMA modes, which does work.
For one: People have been bashing RedHat for the changes they've made to KDE.
Wonderful hypocrites - The GNOME implementation in Mandrake 8.2 has to be the butt-ugliest desktop I've seen. I'd rather be running twm - This is coming from a hardcore GNOME user.
For another: Mandrake consistently tries to push the limits of the hardware and software. It's *too* bleeding-edge, which is probably why you experience it as "broken" - I've had the same experience. I remember installing Mandrake on one system - It tried to perform some weird "hard drive optimizations" that rendered the system unbootable 50% of the time and horrendously unstable when it did boot. I installed RedHat and it was rock-solid. (To their credit and RH's detriment, RH always enables DMA if available in their installer. Normally this is a good thing, but both RH and Mandrake should contain checks for Intel Triton/Natoma chipsets which have broken UDMA support and drop into multiword DMA which works. To Mandrake's detriment, while their installer didn't have problems, UDMA was turned on as soon as the installer finished.)
Overall, while RedHat may be a bit "behind" Mandrake as far as the "latest and greatest", RedHat usually seems to do a better job of QC and provides a more polished product.
"cell" is a shortening of "cellular", which itself gets its name from the word "cell" - A cellular network comprises of a number of small cells with low-power base stations used to provide coverage rather than one extremely large high-power base station. (An example of that case - Police/fire/rescue squad VHF/UHF repeaters and amateur radio (ham) repeaters Many such systems operate at 14+ watts/channel as opposed to most CDMA systems operating around 200 mW/channel)
Let's see, valid reasons for Boston: Apparently, tradition. Until 1998, Boston is where MW Expo was held for 12 years in a row Cost - Boston has offered some pretty serious discounts on the cost of renting their convention center for this show
Valid reasons for disliking a move to Boston: None that I can think of. Apple hasn't given a *SINGLE* reason for their desire to stay in New York.
If Apple was based in the NYC area, I could understand it... But once you're crossing from the West Coast to the East Coast, who cares if you're going 200 or so extra miles? The difference in travel cost is negligible, especially considering the cost of actually hosting the show will apparently be far less in Boston.
I'm forced to agree with the guy who got marked down to -1 Flamebait for making the comment about Steve Jobs and a baby bottle. This decision by Apple is stupid, immature, and nonsensical (especially given Apple's financial state...)
This occurred in an episode of CSI once, or at least something similar.
While CSI is fiction, the trick made sense to me.
Some guy who owned a chain of grocery stores and happened to be a gun afficionado (Could pack his own cartridges with powder/a bullet) made the bullets out of meat instead of lead. So by the time the body was discovered, the ballistics evidence had melted.
The bullet won't be as strong/fly as well as a lead one, you say? Doesn't matter at close range - Even blanks pointed at the head can kill you when point-blank.
Making the bullet out of ice could probably be done too.
It'll probably be an improvement, but not the "2-3 times faster at the same clock speed" myth so many Mac fans spout. I estimate 10-15% at *absolute* best. (Note: Pentium-GCC, back when GCC's native Pentium optimizations sucked, got an average of less than 5% improvement. The best it did (gzip and one other program) was 25%.
It IS possible to generate benchmarks where a G4 is 2-3 times faster than an Pentium-class processor or more. But it's an entirely artificial benchmark specifically designed to make the G4 look good - That is any benchmark where AltiVec optimizations are made but SSE optimizations are not used. But that's like comparing apples and oranges. If you use SIMD instructions on both processors, the G4's magical efficiency vanishes again.
SPEC benchmarks for the G4 processors. (Not a synthetic benchmark issued by Apple, but by an unbiased third party, SPEC)
G4 1 GHz SPECs at 306 integer 187 floating-point Interestingly, the 1 GHz G4 was almost neck-and-neck with a 1 GHz PIII (http://www.heise.de/ct/english/02/05/182/qpic02.j pg)
http://www.spec.org/osg/cpu2000/results/cpu2000. ht ml A large archive of SPEC results for many CPUs, including x86.
A few choice results: 1.2 GHz Athlon (Ancient by today's standards) - 443 integer, 387 FP Athlon XP 1700+ on an Epox EP-8KHA (Happens to be my mobo - Slowst Athlon XP listed for this mobo): 633 integer, 561 FP Dell Precision Workstation 330, 1.3 GHz P4 - 474 integer, 502 FP (The P4 doesn't seem to be taking too much of a branch misprediction hit here)
So in the case of G4s, while they may be a bit more efficient MHz for MHz (And the P3 vs. G4 benchmarks so that this isn't even necessarily the case), the fact that they're so far behind on the clock speed curve hurts them badly.
If you want to see a good example of MHz not being everything, check out the benchmarks of Alpha systems - The 750 MHz ones chew even 1.2 GHz Athlons for lunch. But don't look at Apple...
Also interesting in the case of the SPEC benchmarks run by Heise - MS C pays a 10-15% performance hit over GCC in the SPEC benchmarks.
The forums there have some excellent antenna discussions.
I know www.fab-corp.com has some "blade" antennas that will stick on the back of a laptop, but I'm sure these suffer from some pretty nasty pattern distortion due to the display occluding half the antenna pattern. Still, they're not too cumbersome and should be an improvement.
There are a few small "desktop" antennas available at www.fab-corp.com and www.hdcom.com (I think that second URL is correct...)
Also, even a homebrew quarter-wave "toothpick" antenna (see the NS forums) is a pretty good improvement over the internal antenna of an Orinoco or similar card. Probably wouldn't be too hard to devise a way to clip it or stick it to the back of the upper edge of a laptop's display casing.
Some are noisier than others. For example, you can make a cheapo preamp using a MiniCircuits MMIC for $10, it has a NF of 3-5 dB
Some of MCL's units are better, in the 2.5 dB range - A full preamp unit might cost $20 to make
You can get a 2.4 GHz preamp with a 0.5 dB nF for $100 or so.
And there are parts worse than the MCL units - Even a 5 dB NF MCL unit put in front of an Orinoco will yield significant improvements.
So in short, the people who made this card upgraded the receiver performance to match the transmitter. (This is why there is a point to those 500 mW external amps - All of them include pretty nice recieve preamps too.)
If the company spent the time and money to modify the Prism2/2.5/3 reference designs for 200 mW transmit, there's a good chance they improved receive sensitivity too.
Not sure about the Engenius card listed in this article, but it is a close relative of the Demarctech ReliaWave 200 mW card, which has a receive sensitivity spec that's significantly better (-96 dBm) than even Orinoco cards, which are one of the best ones receive-wise. FAR better than average Prism2 cards, which suck.
And you're also wrong about the antenna position - Look at the pictures in the article, the antenna is on the end of the card, it is NOT inside the box.
Lastly, the article mentions availability of an external antenna option for these cards - Not an option for the internal AirPort card.
These three things added up equals a solution that will blow away the internal AirPort configuration away.
A lot of radio devices nowadays (Some WLAN cards included) support automatic power control - Power is automatically reduced to the minimum needed for communication.
The RF portion is probably in the 20-40% range. Either way, it's a difference of maybe 2 watts consumption vs. 1 watt consumption at the worst, which is a tiny fraction of the power consumed by most laptops these days...
Stay FAR away from Broadcast Warehouse (http://www.broadcastwarehouse.com/)
Note to self: Call these guys to figure out why the order we placed 2 months ago for some hardware to use for testing purposes hasn't arrived yet...
Probably you're best off dealing with something built from a kit such as the Ramsey kits (I can't remember how good the Ramsey kits are though - I believe some of em' are subpar but have plenty of modifications that improve them drastically.) or other kit manufacturers.
If you buy from one of the main players in the broadcast industry (BE, Harris, Nautel, etc.) you're going to be spending major $$$.
I don't recall the exact wording, but I'm positive the DMCA is intended to cover publishing vulnerabilities about *other people's software* - This is publishing information about THEIR OWN PRODUCT. Seems like someone is overreacting on this one to me.
DAoC had a card game of some sort added a few patches ago. Don't remember exactly what card game it implements though. I never play it, too busy crafting. (Hitting a single key multiple times while watching TV...)
One technique used in radar today is "pulse compression", that of modulating a radar pulse with a sequence that produces a large spike when correlated with itself. The most common such codes for actual pulses are called Barker codes, the longest of which is 13 bits. So, for example, with a 13-bit Barker code, a 13 microsecond "pulse" at 1 megawatt can produce nearly the same resolution and signal/noise performance as a 1 microsecond actual pulse at 13 megawatts.
There are also cyclic orthogonal codes that allow for even larger code lengths, turning a modulated CW signal into a virtual "pulsed" signal. Radio astronomers at Arecibo used this technique for radar imaging of Venus. The transmitter transmitted a megawatt or so CW, modulated with a sequence that was something on the order of 8000 bits long. The cyclic codes aren't as orthogonal to themselves as the Barker codes, but I believe they got an effective gain of around 5000-6000, giving an effective 5-6 gigawatt pulsed transmitter.
Note that CDMA happens to rely on orthogonal codes...
Slashdot Mirror
I believe the main issue here is how both devices behave at the extremes of their linearity ranges. (i.e. where they distort) - Transistors tend to be pretty linear up to the point where they clip, while tubes have a more gentle gain compression, which is why their harmonics are different.
:)
I wonder what the audiophiles would think of a truly linear amplifier. (Either using devices that are backed off far from their peak power - low efficiency warning!, or by using distortion-correction techniques similar to those used by manufacturers of CDMA RF power amilifiers)
hmm... An audio predistortion amp would be a cool hack.
In order from the distro that holds back the most for testing and the one that pushes the bar too far: :) Also, sometimes the QC can go TOO far, as another reply to your post on issues with php4 and other packages mentions
Debian - Seems to be eternally trapped in testing.
RedHat - Middle ground. Reasonably modern, pretty good QC
Mandrake - While they have the "bleeding edge", every Mandrake install I've used has felt unpolished. BOTH have had serious hardware compatibility problems. To Mandrake's credit, RedHat had similar problems in one case (Broken UDMA support on my mobo chipser), but in another case, Mandrake tried to "optimize" the hard drives at bootup, resulting in the system freezing. RedHat happily ran for months on end on the same machine.
Which motherboard chipset do you have?
Some Intel chipsets (Triton/Natoma, aka PIIXn) have broken UDMA support. If you enable UDMA on your HD/CDROM, your system WILL crash within a few minutes, esp. with heavy HD usage.
I had this problem with RH7.3 on my old laptop - But Mandrake 8.2 wasn't much better. While the installer doesn't use DMA, it turned on UDMA as soon as it was done, resulting in a system just as unstable as the RH installer.
You have to go into the config files and specifically force one of the multiword DMA modes, which does work.
For one: People have been bashing RedHat for the changes they've made to KDE.
Wonderful hypocrites - The GNOME implementation in Mandrake 8.2 has to be the butt-ugliest desktop I've seen. I'd rather be running twm - This is coming from a hardcore GNOME user.
For another: Mandrake consistently tries to push the limits of the hardware and software. It's *too* bleeding-edge, which is probably why you experience it as "broken" - I've had the same experience. I remember installing Mandrake on one system - It tried to perform some weird "hard drive optimizations" that rendered the system unbootable 50% of the time and horrendously unstable when it did boot. I installed RedHat and it was rock-solid. (To their credit and RH's detriment, RH always enables DMA if available in their installer. Normally this is a good thing, but both RH and Mandrake should contain checks for Intel Triton/Natoma chipsets which have broken UDMA support and drop into multiword DMA which works. To Mandrake's detriment, while their installer didn't have problems, UDMA was turned on as soon as the installer finished.)
Overall, while RedHat may be a bit "behind" Mandrake as far as the "latest and greatest", RedHat usually seems to do a better job of QC and provides a more polished product.
It's "cell phone" not "cel phone"
"cell" is a shortening of "cellular", which itself gets its name from the word "cell" - A cellular network comprises of a number of small cells with low-power base stations used to provide coverage rather than one extremely large high-power base station. (An example of that case - Police/fire/rescue squad VHF/UHF repeaters and amateur radio (ham) repeaters Many such systems operate at 14+ watts/channel as opposed to most CDMA systems operating around 200 mW/channel)
Then why aren't they joining the likes of the annual Consumer Electronics Show in Vegas?
You want "flashy splash", NYC isn't the place to go - It's all about Vegas.
So the convention is held in a different city.
*WHY* is Apple having such an immature hissy-fit.
Let's see, valid reasons for Boston:
Apparently, tradition. Until 1998, Boston is where MW Expo was held for 12 years in a row
Cost - Boston has offered some pretty serious discounts on the cost of renting their convention center for this show
Valid reasons for disliking a move to Boston:
None that I can think of. Apple hasn't given a *SINGLE* reason for their desire to stay in New York.
If Apple was based in the NYC area, I could understand it... But once you're crossing from the West Coast to the East Coast, who cares if you're going 200 or so extra miles? The difference in travel cost is negligible, especially considering the cost of actually hosting the show will apparently be far less in Boston.
I'm forced to agree with the guy who got marked down to -1 Flamebait for making the comment about Steve Jobs and a baby bottle. This decision by Apple is stupid, immature, and nonsensical (especially given Apple's financial state...)
This occurred in an episode of CSI once, or at least something similar.
While CSI is fiction, the trick made sense to me.
Some guy who owned a chain of grocery stores and happened to be a gun afficionado (Could pack his own cartridges with powder/a bullet) made the bullets out of meat instead of lead. So by the time the body was discovered, the ballistics evidence had melted.
The bullet won't be as strong/fly as well as a lead one, you say? Doesn't matter at close range - Even blanks pointed at the head can kill you when point-blank.
Making the bullet out of ice could probably be done too.
It'll probably be an improvement, but not the "2-3 times faster at the same clock speed" myth so many Mac fans spout. I estimate 10-15% at *absolute* best. (Note: Pentium-GCC, back when GCC's native Pentium optimizations sucked, got an average of less than 5% improvement. The best it did (gzip and one other program) was 25%.
It IS possible to generate benchmarks where a G4 is 2-3 times faster than an Pentium-class processor or more. But it's an entirely artificial benchmark specifically designed to make the G4 look good - That is any benchmark where AltiVec optimizations are made but SSE optimizations are not used. But that's like comparing apples and oranges. If you use SIMD instructions on both processors, the G4's magical efficiency vanishes again.
14.4 is definately not the fastest you can go.
The GRAPES and WA4DSY modems are (I believe) 56k units, designed for 440 and above. (One of those might be a G3RUH-compatible 9600 design...)
In Europe, 76k on 440 is common, and the Baycom folks have quite a bit of hardware for this.
Some guys in Slovenia are doing 1.1 Mbps in the 1.2 GHz band.
http://www.heise.de/ct/english/02/05/182/
j pg)
. ht ml
SPEC benchmarks for the G4 processors. (Not a synthetic benchmark issued by Apple, but by an unbiased third party, SPEC)
G4 1 GHz SPECs at 306 integer 187 floating-point
Interestingly, the 1 GHz G4 was almost neck-and-neck with a 1 GHz PIII (http://www.heise.de/ct/english/02/05/182/qpic02.
http://www.spec.org/osg/cpu2000/results/cpu2000
A large archive of SPEC results for many CPUs, including x86.
A few choice results:
1.2 GHz Athlon (Ancient by today's standards) - 443 integer, 387 FP
Athlon XP 1700+ on an Epox EP-8KHA (Happens to be my mobo - Slowst Athlon XP listed for this mobo):
633 integer, 561 FP
Dell Precision Workstation 330, 1.3 GHz P4 - 474 integer, 502 FP (The P4 doesn't seem to be taking too much of a branch misprediction hit here)
So in the case of G4s, while they may be a bit more efficient MHz for MHz (And the P3 vs. G4 benchmarks so that this isn't even necessarily the case), the fact that they're so far behind on the clock speed curve hurts them badly.
If you want to see a good example of MHz not being everything, check out the benchmarks of Alpha systems - The 750 MHz ones chew even 1.2 GHz Athlons for lunch. But don't look at Apple...
Also interesting in the case of the SPEC benchmarks run by Heise - MS C pays a 10-15% performance hit over GCC in the SPEC benchmarks.
The forums there have some excellent antenna discussions.
I know www.fab-corp.com has some "blade" antennas that will stick on the back of a laptop, but I'm sure these suffer from some pretty nasty pattern distortion due to the display occluding half the antenna pattern. Still, they're not too cumbersome and should be an improvement.
There are a few small "desktop" antennas available at www.fab-corp.com and www.hdcom.com (I think that second URL is correct...)
Also, even a homebrew quarter-wave "toothpick" antenna (see the NS forums) is a pretty good improvement over the internal antenna of an Orinoco or similar card. Probably wouldn't be too hard to devise a way to clip it or stick it to the back of the upper edge of a laptop's display casing.
Not all receive preamps are created equal.
Some are noisier than others. For example, you can make a cheapo preamp using a MiniCircuits MMIC for $10, it has a NF of 3-5 dB
Some of MCL's units are better, in the 2.5 dB range - A full preamp unit might cost $20 to make
You can get a 2.4 GHz preamp with a 0.5 dB nF for $100 or so.
And there are parts worse than the MCL units - Even a 5 dB NF MCL unit put in front of an Orinoco will yield significant improvements.
So in short, the people who made this card upgraded the receiver performance to match the transmitter. (This is why there is a point to those 500 mW external amps - All of them include pretty nice recieve preamps too.)
Info on the Demarctech card:
z /r eliawave-rwz-200mw-prism2-5-pcmcia-card.html
http://www.demarctech.com/products/reliawave-rw
They get pretty good reviews on the NetStumbler forums.
If the company spent the time and money to modify the Prism2/2.5/3 reference designs for 200 mW transmit, there's a good chance they improved receive sensitivity too.
Not sure about the Engenius card listed in this article, but it is a close relative of the Demarctech ReliaWave 200 mW card, which has a receive sensitivity spec that's significantly better (-96 dBm) than even Orinoco cards, which are one of the best ones receive-wise. FAR better than average Prism2 cards, which suck.
And you're also wrong about the antenna position - Look at the pictures in the article, the antenna is on the end of the card, it is NOT inside the box.
Lastly, the article mentions availability of an external antenna option for these cards - Not an option for the internal AirPort card.
These three things added up equals a solution that will blow away the internal AirPort configuration away.
A lot of radio devices nowadays (Some WLAN cards included) support automatic power control - Power is automatically reduced to the minimum needed for communication.
The RF portion is probably in the 20-40% range. Either way, it's a difference of maybe 2 watts consumption vs. 1 watt consumption at the worst, which is a tiny fraction of the power consumed by most laptops these days...
No Apple systems are listed in the SpecCPU95 or CPU2000 results at www.spec.org
Where did you get your specmarks?
(Methinks Apple has something to hide...)
So the patch itself is illegal by their (silly) definition, because it is itself documentation of the vulnerability (and how to fix it).
And if this were properly-written GPL software, the patch would be commented... (Don't know if it is or not - It should be.)
Stay FAR away from Broadcast Warehouse (http://www.broadcastwarehouse.com/)
Note to self: Call these guys to figure out why the order we placed 2 months ago for some hardware to use for testing purposes hasn't arrived yet...
Probably you're best off dealing with something built from a kit such as the Ramsey kits (I can't remember how good the Ramsey kits are though - I believe some of em' are subpar but have plenty of modifications that improve them drastically.) or other kit manufacturers.
If you buy from one of the main players in the broadcast industry (BE, Harris, Nautel, etc.) you're going to be spending major $$$.
I don't recall the exact wording, but I'm positive the DMCA is intended to cover publishing vulnerabilities about *other people's software* - This is publishing information about THEIR OWN PRODUCT. Seems like someone is overreacting on this one to me.
And hence have no idea how their monetary system works.
I saw "Platinum" and immediately thought "Dark Age of Camelot". (Not that I've seen evidence of things like this happening over there...)
Many of the modchip kits out (e.g. the Matrix Xbox modchip) have included "burner" (or more appropriately "flasher") hardware.
Stick burner on your parport, fire up software, flash on some BIOS, you're done. This is how Easybuy2000 is still selling modchips.
What if you really have to use the restroom? /group brb bio
DAoC had a card game of some sort added a few patches ago. Don't remember exactly what card game it implements though. I never play it, too busy crafting. (Hitting a single key multiple times while watching TV...)
One technique used in radar today is "pulse compression", that of modulating a radar pulse with a sequence that produces a large spike when correlated with itself. The most common such codes for actual pulses are called Barker codes, the longest of which is 13 bits. So, for example, with a 13-bit Barker code, a 13 microsecond "pulse" at 1 megawatt can produce nearly the same resolution and signal/noise performance as a 1 microsecond actual pulse at 13 megawatts.
There are also cyclic orthogonal codes that allow for even larger code lengths, turning a modulated CW signal into a virtual "pulsed" signal. Radio astronomers at Arecibo used this technique for radar imaging of Venus. The transmitter transmitted a megawatt or so CW, modulated with a sequence that was something on the order of 8000 bits long. The cyclic codes aren't as orthogonal to themselves as the Barker codes, but I believe they got an effective gain of around 5000-6000, giving an effective 5-6 gigawatt pulsed transmitter.
Note that CDMA happens to rely on orthogonal codes...