Intelligent answer. I was basing my statements on the second article, which said that the Emerald cell was a membrane cell with separate anolyte/catholyte streams. Incidentally, I have worked at all three chlor-alkali plant types.
If this stuff is so simple, how come nobody is getting it right??
1) Hydrogen is NOT an antibiotic 2) Oxygen is not even produced in this reaction! 3) Neither is Sodium! 4) At least you got the chlorine right
On a possibly interesting side note, combine chlorine and hydrogen in the right proportions and they will explode too...to form gaseous hydrochloric acid (HCl).
While your chemistry is correct, this is not the reaction they are talking about. The production of sodium hypochlorite is not an electrochemical process. It takes place without the aid of an electrical current. This is why NaOH is commonly used as a scrubbing fluid to remove Cl2 from a gas stream.
The reaction we are talking about is the electrolysis of salt water:
H20 + NaCl + electricity -> NaOH + Cl2 + H2
A mixture of chlorine gas and weak brine called the anolyte leaves the cell on one side, and the caustic soda (NaOH) and hydrogen gas mixture called the catholyte leaves on the other.
The chemical reaction:
H2O + NaCl + e- -> Cl2 + H2 + NaOH
is one of the most important in chemistry and has been in industrial use for well over 110 years. To say this is "not exactly super-new technology" is a HUGE understatement, since this is the same basic technology that has been chlorinating drinking water in the U.S. since 1908.
The new (relatively speaking) technology here appears to be the miniaturization of the electrolytic cell and membrane. While this is interesting in and of itself, I cannot see how this will be the big lifesaver they are claiming. One would think that most hospitals can and do purchase disinfectants already and would not really need to generate these hazardous chemicals onsite, even in small quantities. I mean, think of the risks: Cl2 (poisonous gas), H2 (explosive gas), and NaOH (caustic soda). If a hospital does not have the resources to buy these relatively cheap chemicals, why would they have the resources (electricity to name one) to buy and operate these little machines?
While mostly true, this comment may be a little misleading. QNX is "free for non-commercial use". See get.qnx.com. QNX also has "accessible source", meaning that supposedly the entire OS except the microkernel will eventually be available. So far the source has been pretty slow in coming. To see what's available look at cvs.qnx.com
Thorough evaluations of several RTOS's can be found here. Free registration required.
For those that choose not to read the report, the worst-case scheduling latency for QNX is about an order of magnitude better than a preemtive Linux kernel (actually Windows CE 3.0 appears to be considerably more deterministic than Linux too).
More importantly the latency in QNX is deterministic, while the scheduling latency under Linux (IIRC) grows linearly with the number of threads in the system.
And how does this relate to running progams on a specific architecture?
It means use the right tool for the right job (a mind boggling idea for many Linux zealots). If the only tool you have is a hammer, everything looks like a nail.
I take it you've never been in a situation where you needed the ability do partition resources and access for specific purposes, people or customers?
Gee...and i here i thought it was the operating system's job to manage system resources...
Ah, yes, and what an "incredible" performance hit it is...
My bad, I guess that's why C++ is dead and everyone uses Java now...
Thank god that SUN isn't using proprietary hardware, because that would make SUN just as bad
For the record, I never claimed Sun was somehow better, just that IBM does not exactly embody the open source ideology of Linux
Naturally this article is going to be met with some skepticism because it appears to be a self-serving marketing piece from Sun. This is unfortunate because the author makes several good points. I think it is important to note that this is more of an attack on mainframes and VM architecture than it is against Linux. It really does not make much sense to run 10, 100 or 10,000 copies of Linux on one super-duper computer. Sure it's neat, but we need to remember that computers are supposed to do useful things. What a collosal waste of cpu and memory to have 10,000 operating systems when the right one (yes, 1) would do the job just fine. Add to that the inherent performance hit from running on a "virtual machine" and it makes even less sense. I actually tend to think that IBM's use of Linux is more self-serving than Sun's attack. It's just an attempt to sell more expensive proprietary hardware by capitalizing on the intellectual generosity of others.
When stainless steel goes, the results can be catastrophic. Especially considering that the stuff is used in Formula 1 engines, industrial equipment, and thousands of other places
In application where corrosion is a big concern, there are many different alloys and other metals that are very often used instead of plain 316SS. Two that jump to mind from my job at a chemical plant are titanium and nickel.
Any time you talk about tiny applications, you have to mention the 1.44MB QNX demo disk. It is several years old now, but can still be found here.
Incidentally, this is an older version of the OS than the free version at get.qnx.com
This is not a hack nor is it Linux. It is a hoax. This is simply Audrey running a shell inside of a QNXPhoton window.
You can tell from the 'ls -l' command. He is in the root directory and one of the files listed is "nto". The name of the microkernel of QNX6 (also called QNX Realtime Platform) is Neutrino. The "nto" file is the resource manager frontend for the microkernel.
And is it really a hack to install Linux over a cool free realtime microkernel OS like QNX? Or is it just stupidity?;-)
So you "heard" something about some RT system which may have been RTLinux. Impressive
Yes, I "heard" this from a realtime Linux vendor at a technical conference on the use of realtime operating systems in industrial control systems. Dumbass.
The 40us is nonsense: depending on the motherboard/processor it can go from 1 to 15. As for the submicrosecond claim
40us is correct for Montavista. I searched for RTLinux numbers but was unable to find any detailed report(surprise, surprise). I generally saw numbers ranging from 15-30us. Some QNX numbers are here. I understand VxWorks is a little better
I would guess the same is true of the realtime Linuxe" --- You guessed wrong.
Maybe you should read the analysis section above where it talks about the number of processes on the system affecting interrupt latency! Again, dumbass. I only wish RTLinux had some decent documentation so i could prove you wrong about them too.
being naive is no crime, I guess
but being an arrogant dumbass should be!
This is just more evidence of what I have tried (unsuccessfully) to point out many times. Two facts:
1) RtLinux is not a very good Linux
2) RTLinux is not a very good RTOS
Why do I say this? Well it should be obvious now. RTLinux is not a Linux distribution, but rather a realtime executive that can ran a "Linux image". Similar approaches have been taken by several groups, like Radisys and Nematron, to make Windoze a "realtime OS". The results are generally all the same. Because of the special tricks that must be used, you end up with an OS that is less stable than the off-the-shelf product. And you really do not get many of the benefits of using an off-the-shelf OS, because anything you do that needs to be realtime has to be run by and programmed for the "realtime kernel" (not the OS kernel!)and its proprietary API.
As far as realtime performance is concerned, the last numbers I heard at the 2000 ISA show showed that RTLinux (actually it may have been Montavista) was well behind the major players (i.e. QNX, VXWorks) in terms of realtime performance. Worst case interrupt latencies were on the order of 40 microseconds, compared to sub-microsecond latencies for others. This is only to be expected with the overhead of running two OS's. In all fairness, it did beat Windows CE.:-) An interesting thing to note if you read about Nematron's HyperKernel (above) is that realtime latencies actually get worse when the Windows NT side is heavily utilized! I would guess the same is true of the realtime Linuxes. So don't play Quake or your reactor may meltdown...;-)
Sorry folks, but I've been using QNX every day for the last three years so your "efficiency" bullshit just doesn't fly with me. It still annoys me that Amiga dumped QNX in favor of kowtowing to the Linux crowd.
FYI, Tao's JVM also runs in QNX which runs on multiple CPU's. And as for developers:
QNX has a "special kernel feature" for hot-swapping just about everything too! It's called/bin/kill. To restart stuff try/bin/sh:-)
As for changing hardware, what happens to your Linux box if you pull out your PCI network card while it's running? My QNX4 (the "old" QNX) box will simply terminate the network driver for the card and rebalance the load to my redundant card.
The hardware? An Intel motherboard with two SMC 100Mbit ethernet cards.
The "special" software configuration? From the command line:
Net &
Net.epic -l1 &
Net.epic -l2 &
Voila, redundant load-balancing transparent networking in three lines. Damn QNX kicks ass!
I this comment has been inexplicably modded up, I will take it upon myself to debunk some of your ill-informed comments. You are obviously woefully misinformed, so I will forgive you, this time.
Yes, you can download a demo disk.
Hellooo...this is not the demodisk. This is the full Neutrino OS with Photon GUI and GNU tools
But you don't get full source and you're not allowed to use it for any real work.
Wrong again...almost all source (see below) is included. You can do all the work you want with it too, just don't try to sell a product without giving them some money. Duh.
kernel source is absolutely essential for debugging, not only the application but also the kernel.
NOT. That is exactly the point of a microkernel! You do not need kernel code to debug drivers and applications because they are NOT PART OF THE KERNEL. The kernel contains only about 12kb of highly tested C code (Yes AFAIK the QNX kernel is pure C). We have written numerous high performance device drivers without a scrap of kernel source!
Since all OS tasks use the same SEND/RCV/REPLY messaging as user apps, there are no "hidden" kernel interfaces and thus no need to know the innerworkings of the kernel.
Finally I work for a company that has been developing software in QNX since the early 80's hazardous industrial applications. Not once have we even CARED what the kernel code looked like because it JUST WORKS.
I was lucky enough to be one of the folks that got the pre-beta back in May. The first thing I did after installing was pop the Matrix in my DVD drive and startup Doom in another window. I could drag the Doom window around the screen and both Doom and the Matrix kept right on without a hiccup.
QNXStart.com is a new third party developers forum for QNX. Unfortunately it is not a mirror site
But it has some downloads: Gimp,ICQ,AbiWord among others. By the way, some other sites of interest:
NNTP: inn.qnx.com
WWW: support.qnx.com
USENET: comp.os.qnx
I went to an industrial software conference recently where they had a panel discussion about real time operating systems. I heard some specs for "Realtime" Linux and "Realtime" WindowsCE. The benchmarks used most often are interrupt latency and context switch time. I won't go into a technical description but the sum of these numbers is basically the amount of time between when the computer receives a HW interupt and when the correct SW starts to run. (Times are approximate)
Slashdot Mirror
. . .when the commonest grade is A. . .
;-)
hopefully he is not a professor of english...
Intelligent answer. I was basing my statements on the second article, which said that the Emerald cell was a membrane cell with separate anolyte/catholyte streams. Incidentally, I have worked at all three chlor-alkali plant types.
If this stuff is so simple, how come nobody is getting it right??
1) Hydrogen is NOT an antibiotic
2) Oxygen is not even produced in this reaction!
3) Neither is Sodium!
4) At least you got the chlorine right
On a possibly interesting side note, combine chlorine and hydrogen in the right proportions and they will explode too...to form gaseous hydrochloric acid (HCl).
While your chemistry is correct, this is not the reaction they are talking about. The production of sodium hypochlorite is not an electrochemical process. It takes place without the aid of an electrical current. This is why NaOH is commonly used as a scrubbing fluid to remove Cl2 from a gas stream.
The reaction we are talking about is the electrolysis of salt water:
H20 + NaCl + electricity -> NaOH + Cl2 + H2
A mixture of chlorine gas and weak brine called the anolyte leaves the cell on one side, and the caustic soda (NaOH) and hydrogen gas mixture called the catholyte leaves on the other.
H2O + NaCl + e- -> Cl2 + H2 + NaOH
is one of the most important in chemistry and has been in industrial use for well over 110 years. To say this is "not exactly super-new technology" is a HUGE understatement, since this is the same basic technology that has been chlorinating drinking water in the U.S. since 1908.
The new (relatively speaking) technology here appears to be the miniaturization of the electrolytic cell and membrane. While this is interesting in and of itself, I cannot see how this will be the big lifesaver they are claiming. One would think that most hospitals can and do purchase disinfectants already and would not really need to generate these hazardous chemicals onsite, even in small quantities. I mean, think of the risks: Cl2 (poisonous gas), H2 (explosive gas), and NaOH (caustic soda). If a hospital does not have the resources to buy these relatively cheap chemicals, why would they have the resources (electricity to name one) to buy and operate these little machines?
Just my $.02
While mostly true, this comment may be a little misleading. QNX is "free for non-commercial use". See get.qnx.com. QNX also has "accessible source", meaning that supposedly the entire OS except the microkernel will eventually be available. So far the source has been pretty slow in coming. To see what's available look at cvs.qnx.com
Thorough evaluations of several RTOS's can be found here. Free registration required.
For those that choose not to read the report, the worst-case scheduling latency for QNX is about an order of magnitude better than a preemtive Linux kernel (actually Windows CE 3.0 appears to be considerably more deterministic than Linux too).
More importantly the latency in QNX is deterministic, while the scheduling latency under Linux (IIRC) grows linearly with the number of threads in the system.
It means use the right tool for the right job (a mind boggling idea for many Linux zealots). If the only tool you have is a hammer, everything looks like a nail.
I take it you've never been in a situation where you needed the ability do partition resources and access for specific purposes, people or customers?
Gee...and i here i thought it was the operating system's job to manage system resources...
Ah, yes, and what an "incredible" performance hit it is...
My bad, I guess that's why C++ is dead and everyone uses Java now...
Thank god that SUN isn't using proprietary hardware, because that would make SUN just as bad
For the record, I never claimed Sun was somehow better, just that IBM does not exactly embody the open source ideology of Linux
Naturally this article is going to be met with some skepticism because it appears to be a self-serving marketing piece from Sun. This is unfortunate because the author makes several good points. I think it is important to note that this is more of an attack on mainframes and VM architecture than it is against Linux. It really does not make much sense to run 10, 100 or 10,000 copies of Linux on one super-duper computer. Sure it's neat, but we need to remember that computers are supposed to do useful things. What a collosal waste of cpu and memory to have 10,000 operating systems when the right one (yes, 1) would do the job just fine. Add to that the inherent performance hit from running on a "virtual machine" and it makes even less sense. I actually tend to think that IBM's use of Linux is more self-serving than Sun's attack. It's just an attempt to sell more expensive proprietary hardware by capitalizing on the intellectual generosity of others.
When stainless steel goes, the results can be catastrophic. Especially considering that the stuff is used in Formula 1 engines, industrial equipment, and thousands of other places
In application where corrosion is a big concern, there are many different alloys and other metals that are very often used instead of plain 316SS. Two that jump to mind from my job at a chemical plant are titanium and nickel.
Any time you talk about tiny applications, you have to mention the 1.44MB QNX demo disk. It is several years old now, but can still be found here.
Incidentally, this is an older version of the OS than the free version at get.qnx.com
You can tell from the 'ls -l' command. He is in the root directory and one of the files listed is "nto". The name of the microkernel of QNX6 (also called QNX Realtime Platform) is Neutrino. The "nto" file is the resource manager frontend for the microkernel.
And is it really a hack to install Linux over a cool free realtime microkernel OS like QNX? Or is it just stupidity? ;-)
Yes, I "heard" this from a realtime Linux vendor at a technical conference on the use of realtime operating systems in industrial control systems. Dumbass.
The 40us is nonsense: depending on the motherboard/processor it can go from 1 to 15. As for the submicrosecond claim
40us is correct for Montavista. I searched for RTLinux numbers but was unable to find any detailed report(surprise, surprise). I generally saw numbers ranging from 15-30us. Some QNX numbers are here. I understand VxWorks is a little better
I would guess the same is true of the realtime Linuxe" --- You guessed wrong.
Maybe you should read the analysis section above where it talks about the number of processes on the system affecting interrupt latency! Again, dumbass. I only wish RTLinux had some decent documentation so i could prove you wrong about them too.
being naive is no crime, I guess
but being an arrogant dumbass should be!
1) RtLinux is not a very good Linux
2) RTLinux is not a very good RTOS
Why do I say this? Well it should be obvious now. RTLinux is not a Linux distribution, but rather a realtime executive that can ran a "Linux image". Similar approaches have been taken by several groups, like Radisys and Nematron, to make Windoze a "realtime OS". The results are generally all the same. Because of the special tricks that must be used, you end up with an OS that is less stable than the off-the-shelf product. And you really do not get many of the benefits of using an off-the-shelf OS, because anything you do that needs to be realtime has to be run by and programmed for the "realtime kernel" (not the OS kernel!)and its proprietary API.
As far as realtime performance is concerned, the last numbers I heard at the 2000 ISA show showed that RTLinux (actually it may have been Montavista) was well behind the major players (i.e. QNX, VXWorks) in terms of realtime performance. Worst case interrupt latencies were on the order of 40 microseconds, compared to sub-microsecond latencies for others. This is only to be expected with the overhead of running two OS's. In all fairness, it did beat Windows CE. :-) An interesting thing to note if you read about Nematron's HyperKernel (above) is that realtime latencies actually get worse when the Windows NT side is heavily utilized! I would guess the same is true of the realtime Linuxes. So don't play Quake or your reactor may meltdown... ;-)
I just thought a view people might want to read a review from a *gasp* non-linux point of view
Hmmm...let's see... //2/bin/disktrap
//2/bin/nettrap
# kill 23 74
#
#
:-)
Sorry folks, but I've been using QNX every day for the last three years so your "efficiency" bullshit just doesn't fly with me. It still annoys me that Amiga dumped QNX in favor of kowtowing to the Linux crowd.
FYI, Tao's JVM also runs in QNX which runs on multiple CPU's. And as for developers:
Amiga: 15,000
QNX: 300,000
Efficiency???
ROTFLMAO!!!
Let's see...A Java virtual machine that runs on top of Tao's Elate OS that runs on top of Linux. Sounds sooooo efficient to me.
QNX has a "special kernel feature" for hot-swapping just about everything too! It's called /bin/kill. To restart stuff try /bin/sh :-)
As for changing hardware, what happens to your Linux box if you pull out your PCI network card while it's running? My QNX4 (the "old" QNX) box will simply terminate the network driver for the card and rebalance the load to my redundant card.
The hardware? An Intel motherboard with two SMC 100Mbit ethernet cards.
The "special" software configuration? From the command line:
Net &
Net.epic -l1 &
Net.epic -l2 &
Voila, redundant load-balancing transparent networking in three lines. Damn QNX kicks ass!
I this comment has been inexplicably modded up, I will take it upon myself to debunk some of your ill-informed comments. You are obviously woefully misinformed, so I will forgive you, this time.
Yes, you can download a demo disk.
Hellooo...this is not the demodisk. This is the full Neutrino OS with Photon GUI and GNU tools
But you don't get full source and you're not allowed to use it for any real work.
Wrong again...almost all source (see below) is included. You can do all the work you want with it too, just don't try to sell a product without giving them some money. Duh.
kernel source is absolutely essential for debugging, not only the application but also the kernel.
NOT. That is exactly the point of a microkernel! You do not need kernel code to debug drivers and applications because they are NOT PART OF THE KERNEL. The kernel contains only about 12kb of highly tested C code (Yes AFAIK the QNX kernel is pure C). We have written numerous high performance device drivers without a scrap of kernel source!
Since all OS tasks use the same SEND/RCV/REPLY messaging as user apps, there are no "hidden" kernel interfaces and thus no need to know the innerworkings of the kernel.
Finally I work for a company that has been developing software in QNX since the early 80's hazardous industrial applications. Not once have we even CARED what the kernel code looked like because it JUST WORKS.
They are a mirror now
Try posting at the qnx news server inn.qnx.com
I was lucky enough to be one of the folks that got the pre-beta back in May. The first thing I did after installing was pop the Matrix in my DVD drive and startup Doom in another window. I could drag the Doom window around the screen and both Doom and the Matrix kept right on without a hiccup.
:-)
Cool
QNXStart.com is a new third party developers forum for QNX. Unfortunately it is not a mirror site
But it has some downloads: Gimp,ICQ,AbiWord among others. By the way, some other sites of interest:
NNTP: inn.qnx.com
WWW: support.qnx.com
USENET: comp.os.qnx
I went to an industrial software conference recently where they had a panel discussion about real time operating systems. I heard some specs for "Realtime" Linux and "Realtime" WindowsCE. The benchmarks used most often are interrupt latency and context switch time. I won't go into a technical description but the sum of these numbers is basically the amount of time between when the computer receives a HW interupt and when the correct SW starts to run. (Times are approximate)
WindowsNT/Linux ~? milliseconds
WindowsCE ~100 microseconds
RTLinux ~10 microseconds
QNX ~0.8 microseconds
I just thought I would post this so that when someone talks abput realtime windows/linux you realize that QNX is in a whole different ballpark.
You may be thinking, why the hell do I need 0.8 microsecond realtime determinism? Well, why the HELL would you not want it??