Yup, Reddit got nailed. Here's the tweet on @redditstatus. According to them "We are having some Java/Cassandra issues related to the leap second at 5pm PST."
The basic issue here has to do with gamma curves and the way they're being handled (they're not).
Most image files on your computer (BMP, JPG, PNG, etc.) are stored in the sRGB color space. sRGB defines the use of a gamma curve, which is a nonlinear transformation applied to each of the components (R, G, and B). The issue here is that most scalers make the assumption that the components are linear, rather than try to process the gamma curve. While this does save processing time (undoing the gamma curve then redoing it), it does add some error, especially when the values being scaled are not near each other.
So does this matter? Well, in some pathological cases where there are repeated sharp boundaries (such as alternating black-white lines or fine checkerboard patterns), this would make a difference. This is because the linear average of the pixels (what most image scalers use) yields a different result than if the gamma value was taken into account.
For most images (both photographic and computer generated), this shouldn't be a big problem. Most samples are close in value to other nearby samples, so the error resulting from the gamma curve is very small. Sparse light-dark transitions also wouldn't be noticeable as there would only be an error right on the boundary. Only when you exercise this case over a large area does it become obvious.
One final point: this gamma scaling effect would occur regardless of the actual scaling algorithm. Bilinear, bicubic, and sinc would all have the same issue. Nearest neighbor interpolation would be unaffected, but in these cases, the output would look far worse.
It's missing s**t?! Isn't that one on the short list of four letter expletives? I mean, they've got "boob", "shag", and "tits"; how could they forget "shit"?
You can. Check out MOSIS. They will fab chips on one of several different fab lines for a reasonable price. For example, it cost about $8000 for 25 3mm by 3mm chips in 0.5 micron.
Okay, somehow I totally missed that Tech link. You are right about the fans, though. I just found the hardware list page, and I do find the hardware requirements rather high. 256 megs of RAM?? 700 MHz processor? I can excuse the high processor speed (as that may be easier to obtain) but the memory is major overkill. I've played MP3s and Vorbis files on my K6-2/300 with 64 megs of ram and I have never had a problem (except when compiling a kernel and running Mozilla while listening to music).
Okay, I just noticied the hardware link on the top of this story. How it took me an hour to notice it I have no clue. Guess I'll shut up now and get some sleep... *thunk*
Okay, I don't see who would want it, other than to have something that plays OGGs. This thing looks like an old PC (and probably is), only supports MP3 and OGG (where's FLAC or WAV or anything else?), requires an internet connection, and the thing is huge (there's no excuse for it being anywhere near that size). The display is a 20 char by 4 line LED backlit LCD display. While this is easy to implement, they could have used a graphical display and had different font sizes, cool graphics, and maybe a better user interface. I also have to wonder how noisy it is, considering that most PCs have at least two fans. This thing really looks like a hack: if someone built one of these for himself it might be impressive, paying $1000 for it is simply a ripoff.
I don't see what the market for this thing is: the real geeks would simply build their own that's both cheaper and has more features, while the average users would simply shrug it off for being ugly and for lack of features. Worse, it probably won't play any copy protected CDs^H^H^Hshiny plastic discs with music encoded on them.
I found the paper
on this project, and I found a few things disturbing. First of all, there was no clock: the circuit was completely asynchronous. In other words, the only timing reference they had was the timing of the FPGA itself. Trying to do something like this in silicon is difficult, and doing it in an FPGA is just plain insane. Delays in a circuit vary with just about everything: power supply voltage (and noise), temperature, different chips, the current state of the circuit, and so on. While you might be able to deal with these problems in a custom chip, an FPGA was never designed to be stable in these respects.
Also mentioned is that there are several cells in the circuit that appear to have no real use, but when removed, the circuit ceases to operate. As they mention, this could be because of electromagnetic coupling or coupling through the power supplies. Again, I would never want to see something like that in one of my chips.
Another thing that bothers me, how the heck does he know which cells are being used? Last time I checked, the bitstream (programming) files for these chips is extremely proprietary, and nobody (except XILINX) has the formats for these files. I really want to know how they know how this thing is wired.
Now I should mention, this is pretty cool from an academic standpoint, and it would be interesting if they could produce something that is both stable and useful using these techniques. It's also pretty cool that they could get this to work at all.
What really scared me about the Sept. 11 attacks was not that I would get killed/injured/harmed by a terrorist attack, it's that people would effectively give the government free reign to do whatever they want. Right now, President Bush's approval rating is an astonishingly high 89% -- this is at least close to the highest it's ever been. Doesn't that scare anyone out there?
The problem is that everybody's still shell shocked over the Sept 11 attacks and everybody wants closure over this and the feeling of security. Sure, airports security has been stepped up, but has it gotten any better? They're collecting far more nail clippers now, but
they're still getting knives through. No matter how much security they place at the airport, or any other place for that matter, "bad stuff" will still get through. And even if they made something completely safe, the terrorists will simply go elsewhere.
Let's face it, had the government pulled this shit a year ago, people would have been absolutely pissed. People would have been writing to their congressmen, there may have been protests, but bottom line it would not have happened. Does anybody out there think that government documents like this would have been pulled a year ago? Do you think there would have been an anti-terrorism bill a year ago?
The only good thing is that this will probably come full circle. Maybe it will be in a year, maybe two years, maybe longer, the general public will want this stuff public again. Some accident will occur, people will want to know more about what their local chemical plant is doing, people will want to know where their water is coming from, and after all this terrorist fear has blown over the people will want this stuff back.
Just wait.
Actually, you can get short-run IC fabrication for a reasonable price. Check out the MOSIS website, they will do fabrication runs of 25 chips or so. For a price example, we did a 3mm by 3mm chip in 0.5 micron Agilent (HP-14B), that cost about $8000 for 25 chips, all packaged. If you are a university student, you may be able to get fabrication donated, so you might want to check that out.
I've had one chip made through this program. (It's a PIC16C6x compatible microcontroller, for those interested.) And if you want a layout tool, there is a freely available program called MAGIC that can handle this task (sorry too lazy to find link).
Yeah, that is MSN. And he's also using a recent version of Windows (98 or higher). You can tell by looking at the folder he has open on the right half of the screen. Not very Linux-ish if you ask me.
But I like cookies... especially the chocolate chip ones!:-)
Seriously though, if you really don't like cookies, you can disable them through almost any (if not every) browser. The only problem is that some sites require them in order to use the site. Can you log in to Slashdot without cookies? I haven't tried, but I'm pretty sure you can't. And if you could, you would have to log in again every time you start your browser.
This product looks like a way to create extremely fast logic that approaches the performace of dynamic logic. It looks like it would be used either to make FPGA or CPLD devices, or full custom logic (the site isn't clear on this). They claim this could be used for any high performance logic (which would imply it could be used in processors). Their site is extremely short on details and it looks like this product could be vapor, especially given the fact they start with a Flash animation...
You're right about the gravity thing, this is still relatively close to Earth (roughly 18-19 miles) and the altitude alone would not cause a significant decrease in gravity. The way orbits around a celestial body (such as Earth) work is that the force of attraction between the satellite and the planet (gravity) is equal to the centripital outward force from the speed of the orbit. Technically speaking, it is possible to have an orbit around Earth at sea level, the obvious downsides are resistance from the air and all the objects at this altitude (ships, people, buildings, mountains, etc.). I don't remember the speed of travel required at sea level to be in orbit, but it is many miles per second relative to the surface. Virtually all satellites travel faster than 20 MPH relative to the surface. The exception to this rule is satellites in a geosynchronous orbit, and the altitude for this is many times higher (no I don't remember this altitude, but I understand it is getting pretty crowded).
The only way this thing could give you zero gravity is if it fell out of the sky. And that would only give you about 80 seconds, assuming you didn't reach terminal velocity. (You would be hitting the ground at about 1700 MPH.) On the other hand, 100,000 feet would put you above most of the atmosphere, which would be useful in many research and communications applications.
When I first glanced at this article, I saw the words "NASA" and "breaks" and I immediately thought they screwed something up again.... Anyway, the idea that they can keep this thing up indefinitely (or until a component fails) on solar power is pretty amazing.
Okay, we're talking about new Linux users here and what distro would be best for them, not what distro would be best for the Slashdot community. I realize that this discussion will likely degrade in places to the latter, and since this is Slashdot, that should be expected. However, we are talking about new Linux users, and I can't see too many new users trying out multiple distros and finding out for themselves what's best for them.
Let's face it, most people are impatient. They don't have the time (or don't want to spend the time) to install several different distros and try each one out. Worse, I can see a lot of people trying out an "advanced" distro like Debian or Slackware, get totally lost during the installation or configuration, and then abandon Linux completely because they thought it was waay too difficult (based on one distribution). This is exactly what we should be trying to prevent! What we should be doing is providing a few suggestions, let them learn on a easier-to-use system, and then let them explore later on if they want to.
Personally I use Debian, but I would not recommend it to a new user. Instead, I would recomment Mandrake 8, as it is quite easy to set up and it has virtually every program you'll want available on the cdroms.
Okay, I can't legally drive right now and the scary part is I currently have moderator access and I can barely type "cd/pub/linux/kernel/v2.4". But somehow I managed to patch evcerything and I am already reconfiguring. Recompiling a kernel is'nt that big a deal, is it? (Although it would be better if they released on Monday night, rather than Friday night...)
The EDA tool industry already rents software on a subscription basis, and from what I have seen, what usually ends up happening is that anyone currently using the product is given a permanent license but no more support. I have seen this with both companies going under and with companies discontinuing their product (usually by "selling" their product to a competitor, but not giving them any of the IP for the product). I have not heard of licenses for these tools getting cracked as this is very specialized software, but that doesn't mean it hasn't happened. They usually use a licensing system called FlexLM, and it usually uses licenses that are both time limited and node locked (can only exist on/be served from one specific machine with a particular serial number (or in the case of PCs, the Ethernet card's MAC address, as most PCs don't have a serial number)). Either of these limits can be removed (to make non-expiring keys, for example). The only real problem is if the machine on which the key resides dies (or the Ethernet card dies) those "permanent" licenses have effectively expired, as you no longer have a machine to run them on (and you have no one to turn to to get a replacementkey ).
Hasn't this been around a while?
on
Focusing Audio
·
· Score: 2
This is not new at all. American Technology Corporation already has such a system called Hyper Sonic Sound (HSS). Their site also shows that they have filed for patents as early as July 1996 (first patent allowed August 1998). I hate to break everyone's excitement, but the other thing about this company is that they don't manufacture anything themselves: they only license the OEMs (at least for HSS). It is interesting to note that one of their current contracts is to implement and test HSS technology for use on Navy Ships. I first heard of this technology about 5 years ago, to be honest, I don't know why more hasn't been seen of it.
First of all, RDRAM, SDRAM, and DDR SDRAM are all forms of DRAM, the only difference is in the interface between the memory array itself and the outside world. SDRAM and DDR SDRAM both accept an address from the address bus and output the data on (or write the data from) the data lines. RDRAM uses a packetized interface which can be more efficient for linearly accessing memory, however, it is extremely slow for randomly accessing data. However, all of these types of memory are forms of DRAM that have single transistor/capacitor cells which can each store a bit. One interesting thing to note about DRAM is that it may not be able to scale down much more: As processes get smaller, capacitances get smaller and transistors no longer completely turn off (meaning charges can leak off). This means that the cells need to be refreshed (recharged) more frequently, limiting the usefulness of the device.
MRAM is a new technology that stores data magnetically. I don't know too much about this, but I would be guessing it would be quite a while until we see this in every computer. It will probably be available in portable devices in 2 to 5 years, however, low production quantites (and high prices that go along with this) will almost certainly keep this memory technolgy from entering the desktop market for ten years or so. Then again, I could be wrong.
I have seen flash memory mentioned as a possibility. Flash works by storing (or not storing) a charge on a floating polysilicon gate. The charge is stored or removed by using a high voltage to tunnel through the silicon dioxide insulator. While flash can be read about as fast as any other memory technology, writing flash typically takes a long time (from 100's of microseconds to milliseconds). Also, the tunneling action erodes the silicon dioxide and can wear out flash cells after 1,000 to 1,000,000 rewrites (depending on the process).
So what is the next big memory technology? For now, I would say it is DDR SDRAM. However, DRAM technology will eventually fizzle out and I am sure that either SRAM (Static RAM), MRAM (if it is available), or some other new memory technology will take its place.
First of all, I have been working on MicroMouse for the last two years, and one of the things I have been really been hunting around for is a microcontroller that has enough memory (both flash and RAM) as well as enough processing horsepower to do motor control, navigation, etc. We needed something with built-in serial interfaces, timers, interrupts, I/O ports, etc. because we wanted to make this thing as small as possible. I have looked at many different parts including PICs, the SX, various 80186 processors, the Hitachi H8 and SuperH, ARM, and many others that I'm not thinking of right now. The first thing I've learned about these devices is that the newest ones (and the ones we wanted to use) use either insanely small pin spacings (which requires a custom PCB) or they are of the BGA type (which requires a minimum 4-layer PCB with soldermask as well as special mounting equipment). We finally settled on the Hitachi H8S/2357 even though it was a 128 pin QFP with 0.5 mm pin spacing.
The things I don't like like about these newer, highly integrated processors are that they are more expensive, they tend to be a pain to mount, and chances are, you probably don't need that much processing capacity anyway. While our current versoin of the MicroMouse uses an H8 as the main processor, it also uses a couple of SXs to operate the sensor array. While these SOC's will certainly have a market, it will certainly not eliminate devices like PICs and other smaller microcontrollers from the industry.
Slashdot Mirror
Yup, Reddit got nailed.
Here's the tweet on @redditstatus. According to them "We are having some Java/Cassandra issues related to the leap second at 5pm PST."
Apple IIe in 1978?! It was probably an Apple II (released in 1977). The Apple IIe wasn't released until 1983. See Timeline and History of the Apple II series
The basic issue here has to do with gamma curves and the way they're being handled (they're not).
Most image files on your computer (BMP, JPG, PNG, etc.) are stored in the sRGB color space. sRGB defines the use of a gamma curve, which is a nonlinear transformation applied to each of the components (R, G, and B). The issue here is that most scalers make the assumption that the components are linear, rather than try to process the gamma curve. While this does save processing time (undoing the gamma curve then redoing it), it does add some error, especially when the values being scaled are not near each other.
So does this matter? Well, in some pathological cases where there are repeated sharp boundaries (such as alternating black-white lines or fine checkerboard patterns), this would make a difference. This is because the linear average of the pixels (what most image scalers use) yields a different result than if the gamma value was taken into account. For most images (both photographic and computer generated), this shouldn't be a big problem. Most samples are close in value to other nearby samples, so the error resulting from the gamma curve is very small. Sparse light-dark transitions also wouldn't be noticeable as there would only be an error right on the boundary. Only when you exercise this case over a large area does it become obvious.
One final point: this gamma scaling effect would occur regardless of the actual scaling algorithm. Bilinear, bicubic, and sinc would all have the same issue. Nearest neighbor interpolation would be unaffected, but in these cases, the output would look far worse.
It's missing s**t?! Isn't that one on the short list of four letter expletives? I mean, they've got "boob", "shag", and "tits"; how could they forget "shit"?
Why can't an individual outsource too?
You can. Check out MOSIS. They will fab chips on one of several different fab lines for a reasonable price. For example, it cost about $8000 for 25 3mm by 3mm chips in 0.5 micron.
Okay, somehow I totally missed that Tech link. You are right about the fans, though. I just found the hardware list page, and I do find the hardware requirements rather high. 256 megs of RAM?? 700 MHz processor? I can excuse the high processor speed (as that may be easier to obtain) but the memory is major overkill. I've played MP3s and Vorbis files on my K6-2/300 with 64 megs of ram and I have never had a problem (except when compiling a kernel and running Mozilla while listening to music).
Okay, I just noticied the hardware link on the top of this story. How it took me an hour to notice it I have no clue. Guess I'll shut up now and get some sleep... *thunk*
Okay, I don't see who would want it, other than to have something that plays OGGs. This thing looks like an old PC (and probably is), only supports MP3 and OGG (where's FLAC or WAV or anything else?), requires an internet connection, and the thing is huge (there's no excuse for it being anywhere near that size). The display is a 20 char by 4 line LED backlit LCD display. While this is easy to implement, they could have used a graphical display and had different font sizes, cool graphics, and maybe a better user interface. I also have to wonder how noisy it is, considering that most PCs have at least two fans. This thing really looks like a hack: if someone built one of these for himself it might be impressive, paying $1000 for it is simply a ripoff.
I don't see what the market for this thing is: the real geeks would simply build their own that's both cheaper and has more features, while the average users would simply shrug it off for being ugly and for lack of features. Worse, it probably won't play any copy protected CDs^H^H^Hshiny plastic discs with music encoded on them.
I found the paper on this project, and I found a few things disturbing. First of all, there was no clock: the circuit was completely asynchronous. In other words, the only timing reference they had was the timing of the FPGA itself. Trying to do something like this in silicon is difficult, and doing it in an FPGA is just plain insane. Delays in a circuit vary with just about everything: power supply voltage (and noise), temperature, different chips, the current state of the circuit, and so on. While you might be able to deal with these problems in a custom chip, an FPGA was never designed to be stable in these respects. Also mentioned is that there are several cells in the circuit that appear to have no real use, but when removed, the circuit ceases to operate. As they mention, this could be because of electromagnetic coupling or coupling through the power supplies. Again, I would never want to see something like that in one of my chips.
Another thing that bothers me, how the heck does he know which cells are being used? Last time I checked, the bitstream (programming) files for these chips is extremely proprietary, and nobody (except XILINX) has the formats for these files. I really want to know how they know how this thing is wired.
Now I should mention, this is pretty cool from an academic standpoint, and it would be interesting if they could produce something that is both stable and useful using these techniques. It's also pretty cool that they could get this to work at all.
Yes it's 89%, and it was 92% for a while in October (which is the highest for any president back to at least 1938).
Here's the source. (It's about one page down).
What really scared me about the Sept. 11 attacks was not that I would get killed/injured/harmed by a terrorist attack, it's that people would effectively give the government free reign to do whatever they want. Right now, President Bush's approval rating is an astonishingly high 89% -- this is at least close to the highest it's ever been. Doesn't that scare anyone out there?
The problem is that everybody's still shell shocked over the Sept 11 attacks and everybody wants closure over this and the feeling of security. Sure, airports security has been stepped up, but has it gotten any better? They're collecting far more nail clippers now, but they're still getting knives through. No matter how much security they place at the airport, or any other place for that matter, "bad stuff" will still get through. And even if they made something completely safe, the terrorists will simply go elsewhere.
Let's face it, had the government pulled this shit a year ago, people would have been absolutely pissed. People would have been writing to their congressmen, there may have been protests, but bottom line it would not have happened. Does anybody out there think that government documents like this would have been pulled a year ago? Do you think there would have been an anti-terrorism bill a year ago?
The only good thing is that this will probably come full circle. Maybe it will be in a year, maybe two years, maybe longer, the general public will want this stuff public again. Some accident will occur, people will want to know more about what their local chemical plant is doing, people will want to know where their water is coming from, and after all this terrorist fear has blown over the people will want this stuff back.
Just wait.
Actually, you can get short-run IC fabrication for a reasonable price. Check out the MOSIS website, they will do fabrication runs of 25 chips or so. For a price example, we did a 3mm by 3mm chip in 0.5 micron Agilent (HP-14B), that cost about $8000 for 25 chips, all packaged. If you are a university student, you may be able to get fabrication donated, so you might want to check that out. I've had one chip made through this program. (It's a PIC16C6x compatible microcontroller, for those interested.) And if you want a layout tool, there is a freely available program called MAGIC that can handle this task (sorry too lazy to find link).
Yeah, that is MSN. And he's also using a recent version of Windows (98 or higher). You can tell by looking at the folder he has open on the right half of the screen. Not very Linux-ish if you ask me.
But I like cookies... especially the chocolate chip ones! :-)
Seriously though, if you really don't like cookies, you can disable them through almost any (if not every) browser. The only problem is that some sites require them in order to use the site. Can you log in to Slashdot without cookies? I haven't tried, but I'm pretty sure you can't. And if you could, you would have to log in again every time you start your browser.
Time to get to airport: 2 hours
Time waiting at airport: 1 hour
Flight time: 30 minutes (probably longer or shorter, depending on destination, weather, etc.)
Time waiting for bags: 1 hour
Time getting transportation: 30 minutes
Time getting to where you want to go: 2 hours
(Yes, all numbers are approximate. YMMV)
I don't think flying faster would help...
This product looks like a way to create extremely fast logic that approaches the performace of dynamic logic. It looks like it would be used either to make FPGA or CPLD devices, or full custom logic (the site isn't clear on this). They claim this could be used for any high performance logic (which would imply it could be used in processors). Their site is extremely short on details and it looks like this product could be vapor, especially given the fact they start with a Flash animation...
You're right about the gravity thing, this is still relatively close to Earth (roughly 18-19 miles) and the altitude alone would not cause a significant decrease in gravity. The way orbits around a celestial body (such as Earth) work is that the force of attraction between the satellite and the planet (gravity) is equal to the centripital outward force from the speed of the orbit. Technically speaking, it is possible to have an orbit around Earth at sea level, the obvious downsides are resistance from the air and all the objects at this altitude (ships, people, buildings, mountains, etc.). I don't remember the speed of travel required at sea level to be in orbit, but it is many miles per second relative to the surface. Virtually all satellites travel faster than 20 MPH relative to the surface. The exception to this rule is satellites in a geosynchronous orbit, and the altitude for this is many times higher (no I don't remember this altitude, but I understand it is getting pretty crowded).
The only way this thing could give you zero gravity is if it fell out of the sky. And that would only give you about 80 seconds, assuming you didn't reach terminal velocity. (You would be hitting the ground at about 1700 MPH.) On the other hand, 100,000 feet would put you above most of the atmosphere, which would be useful in many research and communications applications.
When I first glanced at this article, I saw the words "NASA" and "breaks" and I immediately thought they screwed something up again.... Anyway, the idea that they can keep this thing up indefinitely (or until a component fails) on solar power is pretty amazing.
Okay, we're talking about new Linux users here and what distro would be best for them, not what distro would be best for the Slashdot community. I realize that this discussion will likely degrade in places to the latter, and since this is Slashdot, that should be expected. However, we are talking about new Linux users, and I can't see too many new users trying out multiple distros and finding out for themselves what's best for them.
Let's face it, most people are impatient. They don't have the time (or don't want to spend the time) to install several different distros and try each one out. Worse, I can see a lot of people trying out an "advanced" distro like Debian or Slackware, get totally lost during the installation or configuration, and then abandon Linux completely because they thought it was waay too difficult (based on one distribution). This is exactly what we should be trying to prevent! What we should be doing is providing a few suggestions, let them learn on a easier-to-use system, and then let them explore later on if they want to.
Personally I use Debian, but I would not recommend it to a new user. Instead, I would recomment Mandrake 8, as it is quite easy to set up and it has virtually every program you'll want available on the cdroms.
So when are we going to see this at ICFP? Oh wait, we already did, all the ruby entries failed.
What, and buy a Naked PC? (warning, that page linked is huge!)
No, you probably don't want to...
Okay, I can't legally drive right now and the scary part is I currently have moderator access and I can barely type "cd /pub/linux/kernel/v2.4". But somehow I managed to patch evcerything and I am already reconfiguring. Recompiling a kernel is'nt that big a deal, is it? (Although it would be better if they released on Monday night, rather than Friday night...)
The EDA tool industry already rents software on a subscription basis, and from what I have seen, what usually ends up happening is that anyone currently using the product is given a permanent license but no more support. I have seen this with both companies going under and with companies discontinuing their product (usually by "selling" their product to a competitor, but not giving them any of the IP for the product). I have not heard of licenses for these tools getting cracked as this is very specialized software, but that doesn't mean it hasn't happened. They usually use a licensing system called FlexLM, and it usually uses licenses that are both time limited and node locked (can only exist on/be served from one specific machine with a particular serial number (or in the case of PCs, the Ethernet card's MAC address, as most PCs don't have a serial number)). Either of these limits can be removed (to make non-expiring keys, for example). The only real problem is if the machine on which the key resides dies (or the Ethernet card dies) those "permanent" licenses have effectively expired, as you no longer have a machine to run them on (and you have no one to turn to to get a replacementkey ).
This is not new at all. American Technology Corporation already has such a system called Hyper Sonic Sound (HSS). Their site also shows that they have filed for patents as early as July 1996 (first patent allowed August 1998). I hate to break everyone's excitement, but the other thing about this company is that they don't manufacture anything themselves: they only license the OEMs (at least for HSS). It is interesting to note that one of their current contracts is to implement and test HSS technology for use on Navy Ships. I first heard of this technology about 5 years ago, to be honest, I don't know why more hasn't been seen of it.
First of all, RDRAM, SDRAM, and DDR SDRAM are all forms of DRAM, the only difference is in the interface between the memory array itself and the outside world. SDRAM and DDR SDRAM both accept an address from the address bus and output the data on (or write the data from) the data lines. RDRAM uses a packetized interface which can be more efficient for linearly accessing memory, however, it is extremely slow for randomly accessing data. However, all of these types of memory are forms of DRAM that have single transistor/capacitor cells which can each store a bit. One interesting thing to note about DRAM is that it may not be able to scale down much more: As processes get smaller, capacitances get smaller and transistors no longer completely turn off (meaning charges can leak off). This means that the cells need to be refreshed (recharged) more frequently, limiting the usefulness of the device.
MRAM is a new technology that stores data magnetically. I don't know too much about this, but I would be guessing it would be quite a while until we see this in every computer. It will probably be available in portable devices in 2 to 5 years, however, low production quantites (and high prices that go along with this) will almost certainly keep this memory technolgy from entering the desktop market for ten years or so. Then again, I could be wrong.
I have seen flash memory mentioned as a possibility. Flash works by storing (or not storing) a charge on a floating polysilicon gate. The charge is stored or removed by using a high voltage to tunnel through the silicon dioxide insulator. While flash can be read about as fast as any other memory technology, writing flash typically takes a long time (from 100's of microseconds to milliseconds). Also, the tunneling action erodes the silicon dioxide and can wear out flash cells after 1,000 to 1,000,000 rewrites (depending on the process).
So what is the next big memory technology? For now, I would say it is DDR SDRAM. However, DRAM technology will eventually fizzle out and I am sure that either SRAM (Static RAM), MRAM (if it is available), or some other new memory technology will take its place.
First of all, I have been working on MicroMouse for the last two years, and one of the things I have been really been hunting around for is a microcontroller that has enough memory (both flash and RAM) as well as enough processing horsepower to do motor control, navigation, etc. We needed something with built-in serial interfaces, timers, interrupts, I/O ports, etc. because we wanted to make this thing as small as possible. I have looked at many different parts including PICs, the SX, various 80186 processors, the Hitachi H8 and SuperH, ARM, and many others that I'm not thinking of right now. The first thing I've learned about these devices is that the newest ones (and the ones we wanted to use) use either insanely small pin spacings (which requires a custom PCB) or they are of the BGA type (which requires a minimum 4-layer PCB with soldermask as well as special mounting equipment). We finally settled on the Hitachi H8S/2357 even though it was a 128 pin QFP with 0.5 mm pin spacing.
The things I don't like like about these newer, highly integrated processors are that they are more expensive, they tend to be a pain to mount, and chances are, you probably don't need that much processing capacity anyway. While our current versoin of the MicroMouse uses an H8 as the main processor, it also uses a couple of SXs to operate the sensor array. While these SOC's will certainly have a market, it will certainly not eliminate devices like PICs and other smaller microcontrollers from the industry.