Could energy be stored in a magnetic field? So instead of kinda uselessly being stored as chemical energy, maybe the energy could be used to deflect radiation? Of course the energy stored that did not get absorbed remains usable when withdrawn from the shield field?
A lot of missing stuff here... just a concept... but is it workable?
Yes.. exactly as I understand it too. From what I see, its much like a multitaking DOS kernel, where much R&D has gone into building a very tight and robust kernel. From what I see, they are trying to have the kernel itself as simple and bare-bones as possible so as to minimize any possibilities of losing control in such a manner as the kernel itself cannot restore order in the system.
This, like the assembler, is more on the order of tools an embedded programmer needs. But then, we are embedding huge things these days, and I am still used to embedding small things.
I followed your link... it was about the OSCAR Amateur Radio satellite, which is a helluva good job. I guess they used the RCA1802?
But, to the point, the processor designs for space usage have had a lot of being looked at for reliability.
Thats a helluva good thing.
In practice, a lot of ordinary business economics mandates good enough is good enough, despite the fact it crashes a lot. Look at our biggest software company and consider whether the product derives its value from its reliability, or from its marketing.
If one spends too much time on something the customers see of little value, you won't stay in business long.
Like many of you, the technical knowledge I have illustrates the foolishness of deploying non-robust technology, but most people do not see computers the way we do. Most people seem to see it like cars.
I am currently taking a class in auto mechanics tune up just to see the state of the art of the robotics and computerization in auto electronics. It amazes me how styling often mandates a very non-robust design, making the auto very difficult ( read: expensive ) to work on.
Example: leak-prone air conditioning connectors which are designed for rapid assembly at the factory, not designed for longevity. Ever try to find a slow leak in a freon system where everything is tucked under panels taking hours to access because all the mounting hardware has to be aesthetically designed so as not to be visible? Of course the customer does not see repair costs in the showroom. But there is little financial incentive to do it right. Car sells for the same whether or not the air conditioning seals are designed to last for the life of the car.
NASA and the Space Program provide the financial incentive to build robust stuff. Face it, it takes a helluva lot of R&D over and beyond "what works" to optimize the design for extreme robustness. As a government effort, all this R&D effort now trickles down to the commercial sector, where we can use the advanced technology without having to pay the premium for its development. If you were designing an ATM, and were lucky enough to work for a company who takes reliability seriously, wouldn't you love to take advantage of all the work NASA has funded on these rad-hard processors and fault-tolerant techniques? You know how many people get seriously inconvenienced whenever an ATM they are counting on to work doesn't? Most of the cost of technology is in R&D, not actual production. It would not surprise me at all to see the same advanced techniques developed for the Mars Rovers showing up in vending machines.
I was barking up the tree of spike on the power supply. For the exact same reasons.
I have had power supplies or bypassing go bad due to the increasing ESR of aging capacitors, and by golly they come up with the damndest intermittent failures you would ever want to see. They will have you debugging every process in the system until you put a storage oscilloscope on the power supply line and watch it like a hawk.
I don't know that much about VXWorks, but I heard that one of its main assets is having a very small tight multitasking kernel.
They were able to regain the system, despite loss of a major computational component. Remotely. Through a debug link. That sure says a helluva lot for the robustness of the OS and how they configured it.
Remember, when we launched this probe, no sooner than we had it in space, butt-nekid out there, we get assaulted with every kind of solar flare imaginable. So many I lost count, but they were the subject of numerous slashdot stories.
This is one of those "neighbor is working on his car" things.
Here in America, especially in small towns, there is almost some social norm that any guy with a car, hood up, in his front yard, seems a signal for every male in sight to come over for a visit and technical discussion of problems, loan of tools, etc. Its some sort of guy thing thats highly ingrained into me.
And I am watching the Spirit team, hood up, and I am pacing my cage like a tomcat smelling a queen in heat. I used to do that kind of stuff until I got into a hissyfit with a manager which wanted me to do things in such a way I thought my failure would be inevitable, then in which case I thought he would blame the screw up on me. I felt like I knew better. I had done that same kinda thing with disastrous results before. I would not conform. So I was out.
But that does not mean I lost interest in space stuff, it just means I know I do not have the psychological moxie it takes to deal with some of the management types they hire ( Dan Goldin types ).
So yes, I might be a little drunk with the mixed emotions of anger at being out of the loop, and rage about being told I can't play.
You might be surprised with what you can do with low speed machines. Believe it or not, we used to use old RCA CDP-1802 processors for this kind of stuff! 8 bit. Around 1 MHz on a good day. And a helluva bitch to program in assembly. But they were silicon-on-sapphire and they were the most resistant to radiation of anything we had.
A good violinist can make beautiful music with an old fiddle found in a garage sale. Someone ignorant of how to play the things will not get a decent note from even a Stradivarius.
Just for fun, I took a class in data structures at the local college, just to see how things have changed in 20 years. The classroom was filled with students having computers having at least 100 times the power of what I used. Just for the fun of it, I used my old Borland Turbo C++ for DOS with an old 386SX to do the coursework. Nostalgia, I suppose. like taking the old car out for a spin once in a while.
In our field, knowing what to do is a helluva lot more important than having the shiniest tool.
Yeh, I have been checking here quite often for news on our little bugger out there.
Here's my reason... some slashdotters are working right there, right in the middle of the fray, and if I am lucky enough, they will slip a comment over here. I would like to get it directly from an Engineer or Technician right on the flight line before its been muddled through the media. Its like getting a clean direct copy of music through the studio, rather than taping it off AM radio via a microphone.
This is why I wanna get it from a technical person.
For days, I thought we had completely lost our little bugger. The press releases told me they got nothing but noise. Finally, someone technical commented that it was pseudo-noise! DAMMIT! That made all the difference in the world! The carrier was still there! The OS kernel was possibly still intact. The RF sections were healthy enough to form carrier and send it. The bugger was Alive! What they were getting was a good strong carrier, generated from the linear-feedback shift registers which were generating the pseudorandom sequence carrier used to carry the quadrature amplitude modulated spread spectrum signal back to Earth. We had good constellation! We have Link! Therefore, we have a chance of re-establishing commlink, therefore we have an excellent chance of having the kernel load some debugging tools and finding out what went amiss.
If what I just discussed sounded like gibberish, don't worry, its gibberish to most people, but not to me and others that understand the RF Spread Spectrum techniques used to get signals through noisy environments. Either way, I hope it illustrated the point. I get very frustrated when the juicy technical stuff is filtered out before they release it to the press, and I have to settle for pablum when I can accept it at a much higher technical level. Its like having a teletype on a DSL line.
Many of us here are that way.
To those of us that understand it, it makes a helluva lot of sense. To those who do not understand it, if they fish through the words and terminology, it can be very educational.
That to me is what a nerd site like this is all about. We are not all nerds in the same subject, but if we have an interest, it allows us live samples of whats going on in that arena.
If my sharing stuff that others don't want me to share is "theft", then is others ( Equifax, TransUnion, TRW/Experian, Medical Information Bureau, etc. )sharing stuff about me without my implicit permission also considered "theft" and subject to the same infringement penalties?
If sharing is wrong, we don't need lawyers. We need education. We need the RIAA to show up, with armani suits and alligator brifcases, in droves across the nation to every kindergarten and elementary school to stress the evils of sharing your belongings. We need to stress to these young minds just how important it is to hog everything you can get your hands on in your pile and make sure no one else can enjoy it without your fee. Show the benefits of the Patent system, so no-one else can even do anything themselves without violating someone elses's "right". Imagine, they won't even be able to stack one block on top of another without paying a fee!!!
It seems one of the major problems facing our Congress is how to pen law that makes it illegal for some people to do something that cause others financial loss, while holding certain others indemnable for doing the exact same thing... while not looking like they are failing to represent the populace as a whole.
As America gets "down to business", we rely on the rest of the world to build stuff for us. We, here in the Free World of the United States of America will spend our bountiful resources and immense capital account surpluses bickering over whose entitled to what. Our business plan is built on our ability to exact fees to allow others to do anything. If we can sell the rest of the world on this plan, we can make our business executives rich beyond comprehension.
"When the [Rover's] radio is on without being presented with information, it just sends out to [the orbiting] Mars Global Surveyor data that's essentially pseudo-noise, that's random zeroes and ones, So we saw that pattern repeat just like we would expect."
Ok... so they saw the pattern. Repeating. It sure sounds like the pseudorandom sequence carrier used to encode spread-spectrum data onto. It sure sounds to me that at least the analog RF communication link is healthy, it sounds as if they are getting strong constellation, just that there is no data encoded onto it. ( "So we saw that pattern repeat just like we would expect." ).
To me, this is really good news. From this, I infer the analog/power/RF arena looks good. Apparently, we have a healthy commlink. Its just that nothing seems to be getting written to the port that XOR's the data with the pseudorandom carrier stream. Yet, the machine has enough intelligence to respond to pings.. so the kernel of the rover's OS seems to be intact. It is sure sounding more and more like a software corruption problem.
I sure hope they left some old-style "monitor" programs that they can access from the kernel and have them download and run some RF modulator diagnostics.
This does not sound near as scary to me as it did this time yesterday. I was fearing total loss of RF transmit capability, as in something messed up in the power amplifier or antenna/aiming mechanisms.
Good luck, JPL. I am going to sign off for tonight, but I sure look forward to seeing where you guys have some fruitful diagnostics run by the time I see this tomorrow. Once you know you can throw bits back at yourself via the UHF link, its then just gotta be a matter of reloading some software. I am sure hoping this to you is like some of the stuff I have fixed... the scariest looking ones ( totally dead ) are usually fixable.
Maybe a small set of hydraulically controlled wheels that lower, sideways, so that you pull adjacent to the space you want, then slide in on smaller six-inch solid rubber tires or so?
Absolutely. Although I consider myself quite anti-Microsoft, and would love to dump this on them, I can't. What you said is absolutely correct - running code you have not personally inspected for what it does is very risky indeed. It doesn't make any difference what OS you are running. Running unverified code is just as risky as signing legally binding documents you have not read nor understand.
I don't hate Microsoft because of having to pay for it. I gladly pay. Windows OS is one helluva bargain. Its having the code hidden from me that bothers me so... its as if somebody has figured out how to pull a fast one on me by requiring me to sign documents - legally binding - but I am not allowed to verify the contents of it, by enforcing my ignorance of the language used. I have to go on faith that whatever a vendor tells me is what it really does. And not all people tell the truth. And fewer yet tell the *whole* truth.
The main thing Linux has going for me is that its code is inspectable. I can personally verify it if I have to. Line by line if I feel its warranted. I don't mind paying for well-crafted code. But, for my own peace of mind, if I am going to be held accountable for my decision to use that code, I must know exactly what it does. And have any and all tools I need to verify their operation.
I have had supervisory types come in and extoll the virtues of ignorance by statements such as them not understanding how their car works - but that does not keep them from driving. Fine, if you explicitly trust your mechanic. When there's millions of dollars at stake, trust is sometimes not what it is stacked up to be. I don't like to be in positions where I am trying to explain to somebody else why things are so f*k*d up when I don't myself know why. By golly, I have had the training and skills to craft code personally, and run debuggers. I feel its my job and responsibility to my company to keep them out of hot water. And that means knowing exactly how their system works.
I know what you mean. I don't want RealSpyware on my machine either. I consider software like that to be corporate stuff, mostly suited for people who get paid the same whether or not it works. Its been my experience that people who specify stuff like that don't actually have to use it themselves, or take the hit for info leakage.
Unfortunately, there is a bit of a condrundrum here.
I mean, what we are trying to run is ad-blocking software, so we are taking it upon ourselves to re-author copyrighted information ( i.e. a web page content ) on the fly.
So, to me, they have the same right to try to force me to see the ad as I have to try to not see it. The ultimate decision is : do I even look at that web page or not.
I think this whole condrundrum is just like the RIAA's condrundrum. Yeh, you can pull lawyers into the fray and spend lots of money, but I do not think that will alter much of anything in the outcome. People will do mostly what they want, technology permitting. There will always be the cat and mouse game.
I am noting some sites fighting back against pop-up blockers by making content as well as ads as a popup. And hosting the ad on their server in the same directories as the content so you can't rely on your cached list of ad-servers to cull it out for you. Frustrating, as you really can not really identify until you have personally inspected the content if you wanted it or not.
I normally run java off because of all the annoyances ( and crashes ) I get as webmasters find sneaky javascript tricks to slip onto their pages. Although these tricks may work for some browsers, they may have quite different results on others. Especially older ones such as mine. From reading this article mentioned, a lot of people are running some sort of blockers, so it behooves the commercial business webmasters to steer clear of things on their site that mimic or use extended techniques.
The most recent example I have is I was looking for some data on washing machines. I visited www.sears.com to see the latest in Kenmores. Hmmm. blank page. I wasn't in the mood for examining source code and fishing the addresses from it, so I just visited Google. I ended up with lots of alternate sources that worked. I note that a lot of large businesses use weird stuff on their pages which trips up my system. But not all. Wal-Mart so far has had very clean pages that don't send me funny stuff that trips me up. I flat do not know why commercial webmasters slip funny proprietary stuff in that trips up peoples stuff. Its kinda like having a parking lot full of dog shit.
And while I am on this, why do commercial sites use proprietary stuff like.ra audio files or.rm video, when just about everything out there happily plays.mp3 or.mpg formats?
I don't think I would go as far as trying to set up a camera to film directly off a TV. As long as TV's use CRT's or their derivatives, a nice strong signal exists at the tube's cathodes. I would just tap in there, and re-insert the sync pulses which I could easily derive from current-sense pickups on the deflection yoke circuit.
And get the sound from the speaker circuit if I had to. Its not that hard to clip a current transformer onto the circuit and snare a sample of the signal.
Yeh, it would take a bit of doing, but as long as resistors, capacitors, transistors, wire, and bits of ferrite exist, I'll be ok.
Digitizers should always be around, as they are used for damn near everything.
I admit possibly closed-source OS may find ways of keeping most ignorant of how to get the OS to recognize foreign hardware, but as long as there's open source OS around, we will have ways of interfacing. If DRM on proprietary OS gets out of hand, there will be increased incentive for the masses to defect to open source and leave business with a system few people deeply understand. But then, most business does not need flexible systems anyhow. That is mostly the domain of research and academia.
Most of this DRM talk is for executives. It makes them feel a lot better if they are spending money. It gives them the illusion they are solving the problem while in actuality, they are just making stuff tougher for those who pay for things. In all things I have seen yet, Nature always seems to favor the most straightforward way of doing things - that is, the path of least resistance.
Companies which clog the works with unnecessary resistance just make it easier for the competition to replace them.
I just retrieved a copy of a document my credit-card issuer sent to me... On the cover letter they state how they are committed to protecting my privacy, but on the little multifold brochure they included, in what looks like 8-point font or so, are the words:
J. CREDIT INQUIRIES.
You authorize us to make or have made any credit, employment and investigative inquiries we deem appropriate related to the extension or collection of credit under the account....
K. SHARING OF TRANSACTION AND EXPERIENCE INFORMATION.
We may, to the extent permitted by applicable law, communicate information about our experiences and transactions with you to consumer reporting agencies, our affiliates, and others who may properly receive that information.
L. SHARING OF OTHER INFORMATION.
You may refer to our Privacy Statement for more details about how we collect, use, retain, disclose, and safeguard information about you and your account....
The "privacy statement" they included also has a form I must send back with a form with a checkbox entitled:
[ ] Please do not disclose my Nonpublic Personal Information to nonaffiliated third parties ( other than disclosures permitted by law)
I really got a warm fuzzy feeling inside ( nauseous, actually ) reading this shit.
I really feel protected. Do you think they would want to do business with me if I indicated I would haxor their system "only to the extent permitted by law" ? They know full well the RIAA apparently got by with haxoring others systems to find how much music was being shared by a little girl in the projects without repercussions for the haxoring, so would the courts take lightly to corporate systems being haxored to verify integrity of private information? Is this "permitted" by law? RIAA already seems to have already set a precedent that it is OK to haxor to protect their interests, so then can we protect our interests too?
There are so many gray words in there. I would much rather see them only share information as "required by law", not as "permitted by law". And better yet, have a requirement that I must be directly contacted to release any information. I note copyright law states $150,000 per infringement so precedent has been set to encourage compliance. I see nothing saying law was written only to protect corporate interests... this same law should be used to protect all.
As we enter a new age of "rights management", all should share in it. Not just those which are profitable for one entity.
Its in the LaGrange L2 point, opposite the earth from the sun.. ( so earth shields it from sunlight and solar interference, I suppose. ). Anyway, its mission is to map the picture of the Universe as seen by microwave radiation.
I feel like I am very highly qualified.. I am EE. I have a lot of experience in power electronics, switching regulators, embedded processors, assembler, embedded programming, even PCB layout/fabrication. A lot of my stuff involves calculus and ways to code it so that a microprocessor can solve the equations in real time for closed-loop motor control.
My entire house is a lab.
I have not had a steady job in ten years!!!
I occasionally get a job doing some special contract project. But once that's done, unless I want a ten dollar an hour job, its out the door. Sure, I get calls from headhunters telling me about a job 500 miles away... but then I am expected to take the loss on selling and buying another residence. For a job I can get no assurance it will even really exist?
I think AC is on the right track about getting into finance, management, or anything that doesn't actually involve building something, as we just don't build things in the USA anymore. I am very typical of your "45 year old virgin". I am in it way too deep to back out, but if I had a kid, I sure would not want to see him facing the frustration I face. Personally, I am trying to get into the car repair field for my bread and butter, despite my love of digital signal processing and control theory as a hobby.
I would think that there would be some sort of special encoding algorithm for compressing stereo pairs that would minimize differential noise between the two images. Noise to baseline is one thing, but spatial noise between images will be perceived as gross excursions in distance.
On another note, there is nothing special about having a "stereo" camera... nothing out there is moving. Its nice having two cameras for redundancy, but otherwise, you still get perfectly good stereo images from one camera, if that camera is moving. Take a photo, take another when the camera has moved a foot. Presto - those two images constitute a stereo image. Thats a neat way to get 3-D landscape images from a satellite camera as the satellite orbits.
I read the article... I was amazed at the website. Its one of the very few that didn't try to do funnies with my browser, it was clean, fast loading, efficient. The kind of thing you expect from a student doing his damm best to get an "A" from an old-school professor, not the kind of frilly crap that takes forever and a day to load as well as take all kinds of chances of hanging up nonconforming browsers as is typical in today's web programming.
Anyway, to get to the point, I knew of *none* of them! I knew I was "slipping sync" fast as I had disconnected from Kazaa and had lost the only feed I had for sampling music. I flat do not run the radio, due to all the frustration of dealing with fake "interrupts" the advertisers like to slip in, such as doorbells that sound just like mine, door knocks, phones ringing, etc. I really hated it when I am driving and heard what I thought was an emergency vehicle, go through all the risks of hastily trying to change lanes to clear a path, only to find out it was some damn advertiser on the radio. If I have anything on in the car, I know whats on it. By golly, driving is a serious responsibility. I can't have things willy-nilly interrupting my concentration on what I am doing. Any insurance agent will tell you what happens when you car's moving but your mind is somewhere else.
Don't tell me I have a single-track mind. I already know that.
Well, I didn't recognize not a one of 'em. I would say on that bit of data, the anti-piracy, anti Kazaa efforts of the RIAA have been very productive on me. I guess my ignorance is why the latest CD I now own is over a year old now.
Uh yeah, my alternative was a huge old ASR-33 teletype / paper tape punch-reader.
This thing was huge. And heavy. And noisy.
But if I were to want to save any block of memory, it was either use the monitor proggy to print/punch it, write it down on a notepad and key it in again, or build me a cassette drive interface, which I did.
I didn't have any other options. Remember, this was in the days before even the venerable Shugart-400. And how I longed for one of those 8" floppys, but the price was for me out of the question.
The magnetic domains on tape are nonlinear and would probably be tricky to get to work on any protocol needing linearity. To get audio on the tape, the analog people mix a 100KHz or so "bias frequency" into the record circuit. And very carefully watch the record levels.
The "flutter", or instantaneous speed variations of the tape - will wreak havoc with any phase-sensitive schemes. It will show up as a angular jitter ( rotation of the constellation ), otherwise known as phase noise.
Manchester is pretty robust. Its self-clocked. Its been used a lot for stuff like this in its day.
FSK works too, but it doesn't pack near as densely as Manchester. FSK is more like your 300 baud modem.
Way back when I was messing with my IMSAI, I used manchester code on an old answering machine I modified. Its transport was able to fast-forward, rewind, and read/write the tape under computer control. Just to simplify things, I used the "computer tape" cassettes which were loaded with a more nonlinear oxide mixture which had a higher tendency to snap to either N-S or S-N than regular audio tape. I drove the heads directly from tri-state logic drivers for write, and used an op-amp followed by a comparator for data read. I can't say I got stellar performance, but at the price ( free + a helluva lot of labor ) it was good enough. I think it was about 1500 bits/second I got out of the thing at around 1 7/8 ips tape speed. I had to code my own driver for it, and used redundant blocks because I didn't know anything about error correction codes at the time.
Slashdot Mirror
Space is cold.
Superconductors require cold.
Could energy be stored in a magnetic field? So instead of kinda uselessly being stored as chemical energy, maybe the energy could be used to deflect radiation? Of course the energy stored that did not get absorbed remains usable when withdrawn from the shield field?
A lot of missing stuff here... just a concept... but is it workable?
Yes.. exactly as I understand it too. From what I see, its much like a multitaking DOS kernel, where much R&D has gone into building a very tight and robust kernel. From what I see, they are trying to have the kernel itself as simple and bare-bones as possible so as to minimize any possibilities of losing control in such a manner as the kernel itself cannot restore order in the system.
This, like the assembler, is more on the order of tools an embedded programmer needs. But then, we are embedding huge things these days, and I am still used to embedding small things.
But, to the point, the processor designs for space usage have had a lot of being looked at for reliability.
Thats a helluva good thing.
In practice, a lot of ordinary business economics mandates good enough is good enough, despite the fact it crashes a lot. Look at our biggest software company and consider whether the product derives its value from its reliability, or from its marketing.
If one spends too much time on something the customers see of little value, you won't stay in business long.
Like many of you, the technical knowledge I have illustrates the foolishness of deploying non-robust technology, but most people do not see computers the way we do. Most people seem to see it like cars.
I am currently taking a class in auto mechanics tune up just to see the state of the art of the robotics and computerization in auto electronics. It amazes me how styling often mandates a very non-robust design, making the auto very difficult ( read: expensive ) to work on.
Example: leak-prone air conditioning connectors which are designed for rapid assembly at the factory, not designed for longevity. Ever try to find a slow leak in a freon system where everything is tucked under panels taking hours to access because all the mounting hardware has to be aesthetically designed so as not to be visible? Of course the customer does not see repair costs in the showroom. But there is little financial incentive to do it right. Car sells for the same whether or not the air conditioning seals are designed to last for the life of the car.
NASA and the Space Program provide the financial incentive to build robust stuff. Face it, it takes a helluva lot of R&D over and beyond "what works" to optimize the design for extreme robustness. As a government effort, all this R&D effort now trickles down to the commercial sector, where we can use the advanced technology without having to pay the premium for its development. If you were designing an ATM, and were lucky enough to work for a company who takes reliability seriously, wouldn't you love to take advantage of all the work NASA has funded on these rad-hard processors and fault-tolerant techniques? You know how many people get seriously inconvenienced whenever an ATM they are counting on to work doesn't? Most of the cost of technology is in R&D, not actual production. It would not surprise me at all to see the same advanced techniques developed for the Mars Rovers showing up in vending machines.
I was barking up the tree of spike on the power supply. For the exact same reasons.
I have had power supplies or bypassing go bad due to the increasing ESR of aging capacitors, and by golly they come up with the damndest intermittent failures you would ever want to see. They will have you debugging every process in the system until you put a storage oscilloscope on the power supply line and watch it like a hawk.
I don't know that much about VXWorks, but I heard that one of its main assets is having a very small tight multitasking kernel.
They were able to regain the system, despite loss of a major computational component. Remotely. Through a debug link. That sure says a helluva lot for the robustness of the OS and how they configured it.
Good job, JPL.
Remember, when we launched this probe, no sooner than we had it in space, butt-nekid out there, we get assaulted with every kind of solar flare imaginable. So many I lost count, but they were the subject of numerous slashdot stories.
Kudos, NASA, that this thing works at all!!!
This is one of those "neighbor is working on his car" things.
Here in America, especially in small towns, there is almost some social norm that any guy with a car, hood up, in his front yard, seems a signal for every male in sight to come over for a visit and technical discussion of problems, loan of tools, etc. Its some sort of guy thing thats highly ingrained into me.
And I am watching the Spirit team, hood up, and I am pacing my cage like a tomcat smelling a queen in heat. I used to do that kind of stuff until I got into a hissyfit with a manager which wanted me to do things in such a way I thought my failure would be inevitable, then in which case I thought he would blame the screw up on me. I felt like I knew better. I had done that same kinda thing with disastrous results before. I would not conform. So I was out.
But that does not mean I lost interest in space stuff, it just means I know I do not have the psychological moxie it takes to deal with some of the management types they hire ( Dan Goldin types ).
So yes, I might be a little drunk with the mixed emotions of anger at being out of the loop, and rage about being told I can't play.
A good violinist can make beautiful music with an old fiddle found in a garage sale. Someone ignorant of how to play the things will not get a decent note from even a Stradivarius.
Just for fun, I took a class in data structures at the local college, just to see how things have changed in 20 years. The classroom was filled with students having computers having at least 100 times the power of what I used. Just for the fun of it, I used my old Borland Turbo C++ for DOS with an old 386SX to do the coursework. Nostalgia, I suppose. like taking the old car out for a spin once in a while.
In our field, knowing what to do is a helluva lot more important than having the shiniest tool.
Here's my reason... some slashdotters are working right there, right in the middle of the fray, and if I am lucky enough, they will slip a comment over here. I would like to get it directly from an Engineer or Technician right on the flight line before its been muddled through the media. Its like getting a clean direct copy of music through the studio, rather than taping it off AM radio via a microphone.
This is why I wanna get it from a technical person.
For days, I thought we had completely lost our little bugger. The press releases told me they got nothing but noise. Finally, someone technical commented that it was pseudo-noise! DAMMIT! That made all the difference in the world! The carrier was still there! The OS kernel was possibly still intact. The RF sections were healthy enough to form carrier and send it. The bugger was Alive! What they were getting was a good strong carrier, generated from the linear-feedback shift registers which were generating the pseudorandom sequence carrier used to carry the quadrature amplitude modulated spread spectrum signal back to Earth. We had good constellation! We have Link! Therefore, we have a chance of re-establishing commlink, therefore we have an excellent chance of having the kernel load some debugging tools and finding out what went amiss.
If what I just discussed sounded like gibberish, don't worry, its gibberish to most people, but not to me and others that understand the RF Spread Spectrum techniques used to get signals through noisy environments. Either way, I hope it illustrated the point. I get very frustrated when the juicy technical stuff is filtered out before they release it to the press, and I have to settle for pablum when I can accept it at a much higher technical level. Its like having a teletype on a DSL line.
Many of us here are that way.
To those of us that understand it, it makes a helluva lot of sense. To those who do not understand it, if they fish through the words and terminology, it can be very educational.
That to me is what a nerd site like this is all about. We are not all nerds in the same subject, but if we have an interest, it allows us live samples of whats going on in that arena.
If sharing is wrong, we don't need lawyers. We need education. We need the RIAA to show up, with armani suits and alligator brifcases, in droves across the nation to every kindergarten and elementary school to stress the evils of sharing your belongings. We need to stress to these young minds just how important it is to hog everything you can get your hands on in your pile and make sure no one else can enjoy it without your fee. Show the benefits of the Patent system, so no-one else can even do anything themselves without violating someone elses's "right". Imagine, they won't even be able to stack one block on top of another without paying a fee!!!
It seems one of the major problems facing our Congress is how to pen law that makes it illegal for some people to do something that cause others financial loss, while holding certain others indemnable for doing the exact same thing... while not looking like they are failing to represent the populace as a whole.
As America gets "down to business", we rely on the rest of the world to build stuff for us. We, here in the Free World of the United States of America will spend our bountiful resources and immense capital account surpluses bickering over whose entitled to what. Our business plan is built on our ability to exact fees to allow others to do anything. If we can sell the rest of the world on this plan, we can make our business executives rich beyond comprehension.
To me, this is really good news. From this, I infer the analog/power/RF arena looks good. Apparently, we have a healthy commlink. Its just that nothing seems to be getting written to the port that XOR's the data with the pseudorandom carrier stream. Yet, the machine has enough intelligence to respond to pings.. so the kernel of the rover's OS seems to be intact. It is sure sounding more and more like a software corruption problem.
I sure hope they left some old-style "monitor" programs that they can access from the kernel and have them download and run some RF modulator diagnostics.
This does not sound near as scary to me as it did this time yesterday. I was fearing total loss of RF transmit capability, as in something messed up in the power amplifier or antenna/aiming mechanisms.
Good luck, JPL. I am going to sign off for tonight, but I sure look forward to seeing where you guys have some fruitful diagnostics run by the time I see this tomorrow. Once you know you can throw bits back at yourself via the UHF link, its then just gotta be a matter of reloading some software. I am sure hoping this to you is like some of the stuff I have fixed... the scariest looking ones ( totally dead ) are usually fixable.
GodSpeed, NASA.
I offer them this for a company jingle...
I don't hate Microsoft because of having to pay for it. I gladly pay. Windows OS is one helluva bargain. Its having the code hidden from me that bothers me so... its as if somebody has figured out how to pull a fast one on me by requiring me to sign documents - legally binding - but I am not allowed to verify the contents of it, by enforcing my ignorance of the language used. I have to go on faith that whatever a vendor tells me is what it really does. And not all people tell the truth. And fewer yet tell the *whole* truth.
The main thing Linux has going for me is that its code is inspectable. I can personally verify it if I have to. Line by line if I feel its warranted. I don't mind paying for well-crafted code. But, for my own peace of mind, if I am going to be held accountable for my decision to use that code, I must know exactly what it does. And have any and all tools I need to verify their operation.
I have had supervisory types come in and extoll the virtues of ignorance by statements such as them not understanding how their car works - but that does not keep them from driving. Fine, if you explicitly trust your mechanic. When there's millions of dollars at stake, trust is sometimes not what it is stacked up to be. I don't like to be in positions where I am trying to explain to somebody else why things are so f*k*d up when I don't myself know why. By golly, I have had the training and skills to craft code personally, and run debuggers. I feel its my job and responsibility to my company to keep them out of hot water. And that means knowing exactly how their system works.
Trusted Computing is Verifiable Computing.
I mean, what we are trying to run is ad-blocking software, so we are taking it upon ourselves to re-author copyrighted information ( i.e. a web page content ) on the fly.
So, to me, they have the same right to try to force me to see the ad as I have to try to not see it. The ultimate decision is : do I even look at that web page or not.
I think this whole condrundrum is just like the RIAA's condrundrum. Yeh, you can pull lawyers into the fray and spend lots of money, but I do not think that will alter much of anything in the outcome. People will do mostly what they want, technology permitting. There will always be the cat and mouse game.
I am noting some sites fighting back against pop-up blockers by making content as well as ads as a popup. And hosting the ad on their server in the same directories as the content so you can't rely on your cached list of ad-servers to cull it out for you. Frustrating, as you really can not really identify until you have personally inspected the content if you wanted it or not.
I normally run java off because of all the annoyances ( and crashes ) I get as webmasters find sneaky javascript tricks to slip onto their pages. Although these tricks may work for some browsers, they may have quite different results on others. Especially older ones such as mine. From reading this article mentioned, a lot of people are running some sort of blockers, so it behooves the commercial business webmasters to steer clear of things on their site that mimic or use extended techniques.
The most recent example I have is I was looking for some data on washing machines. I visited www.sears.com to see the latest in Kenmores. Hmmm. blank page. I wasn't in the mood for examining source code and fishing the addresses from it, so I just visited Google. I ended up with lots of alternate sources that worked. I note that a lot of large businesses use weird stuff on their pages which trips up my system. But not all. Wal-Mart so far has had very clean pages that don't send me funny stuff that trips me up. I flat do not know why commercial webmasters slip funny proprietary stuff in that trips up peoples stuff. Its kinda like having a parking lot full of dog shit.
And while I am on this, why do commercial sites use proprietary stuff like .ra audio files or .rm video, when just about everything out there happily plays .mp3 or .mpg formats?
And get the sound from the speaker circuit if I had to. Its not that hard to clip a current transformer onto the circuit and snare a sample of the signal.
Yeh, it would take a bit of doing, but as long as resistors, capacitors, transistors, wire, and bits of ferrite exist, I'll be ok.
Digitizers should always be around, as they are used for damn near everything.
I admit possibly closed-source OS may find ways of keeping most ignorant of how to get the OS to recognize foreign hardware, but as long as there's open source OS around, we will have ways of interfacing. If DRM on proprietary OS gets out of hand, there will be increased incentive for the masses to defect to open source and leave business with a system few people deeply understand. But then, most business does not need flexible systems anyhow. That is mostly the domain of research and academia.
Most of this DRM talk is for executives. It makes them feel a lot better if they are spending money. It gives them the illusion they are solving the problem while in actuality, they are just making stuff tougher for those who pay for things. In all things I have seen yet, Nature always seems to favor the most straightforward way of doing things - that is, the path of least resistance.
Companies which clog the works with unnecessary resistance just make it easier for the competition to replace them.
I just retrieved a copy of a document my credit-card issuer sent to me... On the cover letter they state how they are committed to protecting my privacy, but on the little multifold brochure they included, in what looks like 8-point font or so, are the words:
The "privacy statement" they included also has a form I must send back with a form with a checkbox entitled: I really got a warm fuzzy feeling inside ( nauseous, actually ) reading this shit.I really feel protected. Do you think they would want to do business with me if I indicated I would haxor their system "only to the extent permitted by law" ? They know full well the RIAA apparently got by with haxoring others systems to find how much music was being shared by a little girl in the projects without repercussions for the haxoring, so would the courts take lightly to corporate systems being haxored to verify integrity of private information? Is this "permitted" by law? RIAA already seems to have already set a precedent that it is OK to haxor to protect their interests, so then can we protect our interests too?
There are so many gray words in there. I would much rather see them only share information as "required by law", not as "permitted by law". And better yet, have a requirement that I must be directly contacted to release any information. I note copyright law states $150,000 per infringement so precedent has been set to encourage compliance. I see nothing saying law was written only to protect corporate interests... this same law should be used to protect all.
As we enter a new age of "rights management", all should share in it. Not just those which are profitable for one entity.
Its in the LaGrange L2 point, opposite the earth from the sun.. ( so earth shields it from sunlight and solar interference, I suppose. ). Anyway, its mission is to map the picture of the Universe as seen by microwave radiation.
Here's some links courtesy of Google...
I feel like I am very highly qualified.. I am EE. I have a lot of experience in power electronics, switching regulators, embedded processors, assembler, embedded programming, even PCB layout/fabrication. A lot of my stuff involves calculus and ways to code it so that a microprocessor can solve the equations in real time for closed-loop motor control.
My entire house is a lab.
I have not had a steady job in ten years!!!
I occasionally get a job doing some special contract project. But once that's done, unless I want a ten dollar an hour job, its out the door. Sure, I get calls from headhunters telling me about a job 500 miles away... but then I am expected to take the loss on selling and buying another residence. For a job I can get no assurance it will even really exist?
I think AC is on the right track about getting into finance, management, or anything that doesn't actually involve building something, as we just don't build things in the USA anymore. I am very typical of your "45 year old virgin". I am in it way too deep to back out, but if I had a kid, I sure would not want to see him facing the frustration I face. Personally, I am trying to get into the car repair field for my bread and butter, despite my love of digital signal processing and control theory as a hobby.
On another note, there is nothing special about having a "stereo" camera... nothing out there is moving. Its nice having two cameras for redundancy, but otherwise, you still get perfectly good stereo images from one camera, if that camera is moving. Take a photo, take another when the camera has moved a foot. Presto - those two images constitute a stereo image. Thats a neat way to get 3-D landscape images from a satellite camera as the satellite orbits.
I read the article... I was amazed at the website. Its one of the very few that didn't try to do funnies with my browser, it was clean, fast loading, efficient. The kind of thing you expect from a student doing his damm best to get an "A" from an old-school professor, not the kind of frilly crap that takes forever and a day to load as well as take all kinds of chances of hanging up nonconforming browsers as is typical in today's web programming.
Anyway, to get to the point, I knew of *none* of them! I knew I was "slipping sync" fast as I had disconnected from Kazaa and had lost the only feed I had for sampling music. I flat do not run the radio, due to all the frustration of dealing with fake "interrupts" the advertisers like to slip in, such as doorbells that sound just like mine, door knocks, phones ringing, etc. I really hated it when I am driving and heard what I thought was an emergency vehicle, go through all the risks of hastily trying to change lanes to clear a path, only to find out it was some damn advertiser on the radio. If I have anything on in the car, I know whats on it. By golly, driving is a serious responsibility. I can't have things willy-nilly interrupting my concentration on what I am doing. Any insurance agent will tell you what happens when you car's moving but your mind is somewhere else.
Don't tell me I have a single-track mind. I already know that.
Well, I didn't recognize not a one of 'em. I would say on that bit of data, the anti-piracy, anti Kazaa efforts of the RIAA have been very productive on me. I guess my ignorance is why the latest CD I now own is over a year old now.
This thing was huge. And heavy. And noisy.
But if I were to want to save any block of memory, it was either use the monitor proggy to print/punch it, write it down on a notepad and key it in again, or build me a cassette drive interface, which I did.
I didn't have any other options. Remember, this was in the days before even the venerable Shugart-400. And how I longed for one of those 8" floppys, but the price was for me out of the question.
The magnetic domains on tape are nonlinear and would probably be tricky to get to work on any protocol needing linearity. To get audio on the tape, the analog people mix a 100KHz or so "bias frequency" into the record circuit. And very carefully watch the record levels.
The "flutter", or instantaneous speed variations of the tape - will wreak havoc with any phase-sensitive schemes. It will show up as a angular jitter ( rotation of the constellation ), otherwise known as phase noise.
Manchester is pretty robust. Its self-clocked. Its been used a lot for stuff like this in its day.
FSK works too, but it doesn't pack near as densely as Manchester. FSK is more like your 300 baud modem.
Way back when I was messing with my IMSAI, I used manchester code on an old answering machine I modified. Its transport was able to fast-forward, rewind, and read/write the tape under computer control. Just to simplify things, I used the "computer tape" cassettes which were loaded with a more nonlinear oxide mixture which had a higher tendency to snap to either N-S or S-N than regular audio tape. I drove the heads directly from tri-state logic drivers for write, and used an op-amp followed by a comparator for data read. I can't say I got stellar performance, but at the price ( free + a helluva lot of labor ) it was good enough. I think it was about 1500 bits/second I got out of the thing at around 1 7/8 ips tape speed. I had to code my own driver for it, and used redundant blocks because I didn't know anything about error correction codes at the time.