A case of chicken and egg. Many people stopped using them because the quality was so bad. There was a market failure in that even if you were willing to pay more, you couldn't buy stuff that worked reliably. Anyone interested in producing a quality product had left the market.
The free market doesn't always produce socially desirable results. Manufacturers can also get trapped in a race to the bottom. Just look at the current quality of floppy disk drives and their media. I can remember when they actually worked.
If you want to be thorough about it, you need to determine the acceptable probability of an uncorrectable error in the memory system, the rate at which errors occur, and the scrub rate needed to meet or exceed your reliability target. If you scrub when the system is idle, you will probably find that the scrub rate is much higher than the minimum rate needed to meet your reliability target. In really hostile environments, you may need a stronger ECC and/or a different memory organization.
Scrubbing for RAM is an insignificant amount of overhead. All it involves is doing periodic read/write cycles on each memory location to detect and correct errors. This can be done as a low-priority kernel task or as part of the timer interrupt-service-routine.
Why not have an operating system that only runs code that has been audited and signed by a trusted party? You might not want such a thing but many people would be better off with a system that was more difficult to exploit.
All the hospital has to do is stabilize you and kick your ass out the door. They are under no obligation to provide non-emergency medical treatment. Have a serious illness? Sucks to be you.
It may not be Dickensian England, but the idea that anyone can make it in this society with a little effort is laughable. Many people have problems that make it difficult or impossible to get and hold a job. Some are self-inflicted, some are a result of genetics, their upbringing, location, or bad luck. Getting any job, let alone a job with health insurance, is difficult. Even in a healthy economy, they are the last to be hired and the first to be laid off. It doesn't help that there are a large number of illegal immigrants willing to take all of the low-end jobs that used to be available to people with minimal skills.
My father sold me a used car for a dollar. The DMV stuck me with a hefty tax bill. They didn't care if it was a junker, they wanted real money for the legislature's booze and hookers fund.
A major problem is that water is composed of a number of hydrogen and oxygen isotopes. The proportions of these isotopes varies depending on where you collect the water. While very useful for scientists, it means that the weight of a given volume of water is not a constant.
I definitely get better reception with ATSC. The NTSC signals where I live are very weak due to lack of an unobstructed path to the transmitters.
The relevant issue is the FCC's computer models that they use for spectrum planning. The FCC uses these models to assign frequencies and determine whether there are any open channels at a specific location. With ATSC they can tweak their models to accept higher levels of interference from stations on the same and adjacent frequencies. These models are also used to set the authorized maximum transmitter power and antenna gain to try to replicate the station's analog coverage.
I saved a fair amount of money by buying a factory refurbed Samsung ATSC tuner. It looks and works like new, and came with everything that you would expect with a new item.
That would screw up their business model of making extra profits on pay-per-view and video-on-demand. They want everyone to have a two-way set-top-box, running the cable company's software.
The VHF bands are not being vacated in the USA. The FCC has given stations the option to move back to their old VHF channel when the transition is complete. This was a big issue for stations in rural areas that complained that UHF reduced their coverage and increased their power bill.
Best Buy is selling a 13" color TV with integrated ATSC digital tuner for under $100. A similar 20" set is about $140. That suggests that the manufacturer isn't paying very much for the circuitry needed to handle ATSC.
Actually about 15% of the population relies on OTA broadcast television. That doesn't count the people who have additional TV sets that are not connected to cable or satellite.
The store is supposed to post a notice on any analog TV that it will not receive digital broadcasts, to warn the consumer. The problem is that some stores don't post these notices, just the amazing low price. I suspect that many store managers are more interested in quickly clearing out their existing stock of analog TVs.
NTSC and ATSC use the same amount of bandwidth (6 MHz). The spectrum savings are from the ability to pack the stations more tightly, in space and frequency, in the broadcast band. ATSC is more resistant to interference, so less spectrum is wasted on guard bands and geographic separation.
Minimum standards for television receiver quality could limit the amount of interference from devices that use white-space. Unfortunately, the FCC doesn't seem to be interested in the subject. They did set standards for UHF tuners back when it was new technology and the commercial viability of UHF broadcasting was threatened by the poor quality of most UHF tuners.
Bad idea. Battery chemistry and construction are rapidly evolving. From what I've read on the design of devices that use Lithium batteries, the power subsystem (charger, power supply, battery) must be designed as a matched system. The limited margin for error makes old-style design techniques unsafe. These are not generic batteries, which can be substituted without much thought. The charging circuits, safety circuits, and power supply must be designed to match the characteristics of a specific battery. The safety and performance of the power subsystem are only guaranteed when you use the proper battery.
I once saw a Navy weapons storage facility where many of the bunkers had their doors blocked with 20,000 pound blocks of concrete. You needed a big crane to remove the block before you could open the door of the bunker. Official policy was to neither confirm or deny the presence of nuclear weapons, but most people assumed that they were being stored there. This was back when the Navy still had tactical nukes.
A nuclear weapon without its pit is not a threat to anyone. The pit is the fissionable plutonium sphere that is imploded to produce a nuclear detonation. In early U.S. nuclear weapons, the pit was stored separately from the rest of the bomb. To arm the bomb, the weapons officer opened the bomb casing and inserted the pit. This was usually done in flight, to reduce the danger of an accident during take-off. Since it took hours to reach the target, the crew had plenty of time to perform the procedure.
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A case of chicken and egg. Many people stopped using them because the quality was so bad. There was a market failure in that even if you were willing to pay more, you couldn't buy stuff that worked reliably. Anyone interested in producing a quality product had left the market.
The free market doesn't always produce socially desirable results. Manufacturers can also get trapped in a race to the bottom. Just look at the current quality of floppy disk drives and their media. I can remember when they actually worked.
If you want to be thorough about it, you need to determine the acceptable probability of an uncorrectable error in the memory system, the rate at which errors occur, and the scrub rate needed to meet or exceed your reliability target. If you scrub when the system is idle, you will probably find that the scrub rate is much higher than the minimum rate needed to meet your reliability target. In really hostile environments, you may need a stronger ECC and/or a different memory organization.
Scrubbing for RAM is an insignificant amount of overhead. All it involves is doing periodic read/write cycles on each memory location to detect and correct errors. This can be done as a low-priority kernel task or as part of the timer interrupt-service-routine.
Why not have an operating system that only runs code that has been audited and signed by a trusted party? You might not want such a thing but many people would be better off with a system that was more difficult to exploit.
All the hospital has to do is stabilize you and kick your ass out the door. They are under no obligation to provide non-emergency medical treatment. Have a serious illness? Sucks to be you.
It may not be Dickensian England, but the idea that anyone can make it in this society with a little effort is laughable. Many people have problems that make it difficult or impossible to get and hold a job. Some are self-inflicted, some are a result of genetics, their upbringing, location, or bad luck. Getting any job, let alone a job with health insurance, is difficult. Even in a healthy economy, they are the last to be hired and the first to be laid off. It doesn't help that there are a large number of illegal immigrants willing to take all of the low-end jobs that used to be available to people with minimal skills.
My father sold me a used car for a dollar. The DMV stuck me with a hefty tax bill. They didn't care if it was a junker, they wanted real money for the legislature's booze and hookers fund.
How do you obtain a mole of Carbon 12? Carbon has a bunch of isotopes, two of which are stable. Then you have the problem of how to count the atoms.
A major problem is that water is composed of a number of hydrogen and oxygen isotopes. The proportions of these isotopes varies depending on where you collect the water. While very useful for scientists, it means that the weight of a given volume of water is not a constant.
That was the original idea. The distance of the Paris meridian between the equator and the North Pole was defined as 10,000 km.
The relevant issue is the FCC's computer models that they use for spectrum planning. The FCC uses these models to assign frequencies and determine whether there are any open channels at a specific location. With ATSC they can tweak their models to accept higher levels of interference from stations on the same and adjacent frequencies. These models are also used to set the authorized maximum transmitter power and antenna gain to try to replicate the station's analog coverage.
See here for their current deal.
That would screw up their business model of making extra profits on pay-per-view and video-on-demand. They want everyone to have a two-way set-top-box, running the cable company's software.
The VHF bands are not being vacated in the USA. The FCC has given stations the option to move back to their old VHF channel when the transition is complete. This was a big issue for stations in rural areas that complained that UHF reduced their coverage and increased their power bill.
Best Buy is selling a 13" color TV with integrated ATSC digital tuner for under $100. A similar 20" set is about $140. That suggests that the manufacturer isn't paying very much for the circuitry needed to handle ATSC.
Actually about 15% of the population relies on OTA broadcast television. That doesn't count the people who have additional TV sets that are not connected to cable or satellite.
The store is supposed to post a notice on any analog TV that it will not receive digital broadcasts, to warn the consumer. The problem is that some stores don't post these notices, just the amazing low price. I suspect that many store managers are more interested in quickly clearing out their existing stock of analog TVs.
NTSC and ATSC use the same amount of bandwidth (6 MHz). The spectrum savings are from the ability to pack the stations more tightly, in space and frequency, in the broadcast band. ATSC is more resistant to interference, so less spectrum is wasted on guard bands and geographic separation.
Minimum standards for television receiver quality could limit the amount of interference from devices that use white-space. Unfortunately, the FCC doesn't seem to be interested in the subject. They did set standards for UHF tuners back when it was new technology and the commercial viability of UHF broadcasting was threatened by the poor quality of most UHF tuners.
G.I. Joe would have fragged their asses.
I thought that's what virtual memory was for. You build a huge world and page bits of it in and out as needed.
Bad idea. Battery chemistry and construction are rapidly evolving. From what I've read on the design of devices that use Lithium batteries, the power subsystem (charger, power supply, battery) must be designed as a matched system. The limited margin for error makes old-style design techniques unsafe. These are not generic batteries, which can be substituted without much thought. The charging circuits, safety circuits, and power supply must be designed to match the characteristics of a specific battery. The safety and performance of the power subsystem are only guaranteed when you use the proper battery.
I once saw a Navy weapons storage facility where many of the bunkers had their doors blocked with 20,000 pound blocks of concrete. You needed a big crane to remove the block before you could open the door of the bunker. Official policy was to neither confirm or deny the presence of nuclear weapons, but most people assumed that they were being stored there. This was back when the Navy still had tactical nukes.
A nuclear weapon without its pit is not a threat to anyone. The pit is the fissionable plutonium sphere that is imploded to produce a nuclear detonation. In early U.S. nuclear weapons, the pit was stored separately from the rest of the bomb. To arm the bomb, the weapons officer opened the bomb casing and inserted the pit. This was usually done in flight, to reduce the danger of an accident during take-off. Since it took hours to reach the target, the crew had plenty of time to perform the procedure.