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I was wrong about exponentially, but I do recall reading that in college in our computer system design course. Googling for it, I found this equation, which shows how as the clock frequency of the flip-flops decrease, the MTBF would increase. Inversely proportional, though, not exponential.

http://www.usb.org/developers/usbfaq#sig6
http://www.interfacebus.com/Design_Connector_Serial_ATA.html
the other link i found, on fciconnect, the impedance stated "100ohm minimum".

so, thank you for pointing out that it's critical to find good connectors!

we didn't pick PCMCIA because "it's cool", we picked it because it's still a mass-volume part (Conditional Access Modules) but is legacy as far as portable computers are concerned. and because it's user-removable. and because, quite simply, there isn't anything better. yes i looked at MiniPCI, i found _one_ image of a removable MiniPCI with ejector assembly: could i find who made it? could i hell.

COM express - saw that one. it's not user-removable - factory only. that defeats the object.

remember also: we're aiming for *mass-volume*. "enthusiasts" happen to be a critical link in the chain to bootstrap our way _up_ to mass-volume.

in other words, by the time we get _to_ mass-volume, we can always go and either raise some funds or spend existing funds raised by that point to get a proper impedance-matched PCMCIA connector specially made. or, say "what the heck" and get something else made.

regarding 0.1" headers: PCMCIA's 68-pin connector was designed for repeated insertion/removal. 0.1" headers are not. yes i looked around, tried to find a low-cost connector that would go onto the end of a PCMCIA card (in place of the 68-pin one). couldn't find one. if in your experience you know of something that would work, here please do tell me!

the other thing to take into account is that by sticking to PCMCIA 68-pin connectors we can even re-use pre-existing casework.

*sigh* absolute absolute last resort: both the SATA _and_ USB2 can be ramped down in top speed. SATA i think you can do as low as 150mbits/sec, something like that. i did look this up as part of the evaluation process. didn't quite do as experienced a job as you, though, so thank you for the heads-up.

In my 4 year old desktop (E6300 processor; 4x1GB ram; nVidia 9500 GT; 2x HDD), total power draw goes between 150watts and 220 (full load) watts, as measured by an in-line watt meter.

Laptops tend to use quite a bit less power; 15-60watts is what I found from some quick googling, and the last laptop I had was around 18 watts as measured with laptop-tools under linux.

This indicates 10 watts for DDR2, vs 4 watts for DDR3, vs (presumably) 4*.6= 2.4 watts for DDR4. Not sure whether that link is accurate, or whether that is accurate for laptops; take it with a grain of salt.

The over-current trick has been used in MANY systems to bypass hardware restrictions by forcing it into a failure mode for repair. From Tom-Tom devices, to the original XBox console, now it's been used on the PS3.

Here's your requested information. I gave you more than you needed so you could grab a PS3 for yourself, pop out the mobo, flip it over, and start hacking for yourself so maybe you can help us figure out WTF these other UNKs are.

http://www.interfacebus.com/ps3-connector-pinouts.html

Those speaker cables aren't digital: the sound card converts digital signals to analog signals using a D/A converter and that analog signal coming out of the output of your sound card through the cable to your speakers is not the same as the digital signal running through a SATA cable between the hard drive and disk controller.

It is unlikely that your ears are sensitive enough to hear a 1.5GHz or 3GHz signal interfere with the 10Hz-20kHz coming out of your PC speakers.

However, I will agree, the quality of the connectors on the sound card, connectors on PC speakers and the connectors on the cable probably made all that popping audible: the mechanical connection is an inherent source of noise, not to mention the fact that the cable also acts as an antenna of sorts, allowing all kinds of noise through.

It's not analog in the sense that we use op amps, we still use gates

What's the difference? A gate is just a high speed high gain ultra high distortion opamp.

Forgot your introductory digital design courses already?

Digital circuits are designed to reliably transmit or compute a digital value in to presence of noise. The way this is done is by excluding huge ranges of voltages and making very high gain op-amps that, while fast, do not need to be accurate. Accuracy is thrown out the window in favor of speed and noise immunity. You will (or should) never see a properly operating op-amp in a digital circuit putting out a voltage other than something in the range representing a 0 or 1 (in TTL-compatible circuits for example, 0 to 0.2 V for a 0 and 4.7 to 5.0V for a 1 ... note that I'm quoting output ranges not input ranges). The acceptable voltage ranges were designed such that a valid 0 signal when combined with inevitable noise would still be read as a 0 at the next stage; mid-range values are not permitted. See, eg, http://www.interfacebus.com/voltage_threshold.html .

Op-amps designed for accurate reproduction of analog values are an entirely different creature, one where accuracy is among the primary design requirements. In contrast to digital circuits, a mid-range value is not only permissible, but expected.

So while both digital and analog logic use op-amps, the design requirements and valid signal ranges are vastly different.

You both are mistaken. Electrical cables almost all carry signals at about two thirds c, whether coaxial or twisted pair doesn't make much difference.

Anyway, the thing is that the IS2 protocol apparently has a maximum clock speed of 3.125 MHz. So the signal length is about 63 meters, which is much much larger than the length of their entire cable.

I assume that you used the proper type of sign, though.

Something along the lines of:

http://www.interfacebus.com/rf-radiation-hazard.jpg

or

http://www.celltowersafety.com/assets/images/RF.JPG

The symbol used on the "hamsexy" car is NOT appropriate, being intended for use with ionizing radiation sources.

http://frenchquarterradiationfree.com/img/dangerrads.jpg

It is (i^2)*R actually, and for a typical computer power cable we are looking at 18 gauge wire which is 6.5/1000 feet, http://www.interfacebus.com/Copper_Wire_AWG_SIze.html (i hate the customary system but god dammit I hate mixed units even more) and at 1030 watts, http://www.dell.com/us/en/business/servers/server-poweredge-r900/pd.aspx?refid=server-poweredge-r900&s=bsd&cs=04, which will vary from server to server. The line voltage to the servers will all be the same so the resistive losses will increase exponentially relative current or linearly relative to the line length. So when you need to run on backup power, having the backup power supply immediately next to the server will either allow you to buy relatively less powerful units and or just get equally powerful units and run longer in case of a power outage.
For the sake of argument lets say its only 100 feet between the servers and backup power units, which at 120volts on the power cable(assuming its the same as desktop computers) we have ~8.6 amps. Which at 100ft and 6.5/1000 ft we get ~48 watts of power losses which is a 4.6% loss before you get any power to the actually server which Im sure will take at least another 15% loss.

a realistic joystick

What is that then? A Bluetooth device? Do you swing your iPhone around like a stick while trying to look at your waggling screen?

Do you plug your surplus Atari VCS stick into the serial port via a 9-pin D-SUB port converter?

I'm going to go with David Lynch on this one, who famously ranted that "you can't watch a movie on a fscking phone." You can't have a "realistic" joystick on a phone, because an image of a joystick is not realistic, nor does it even approximate the input device. It's a neat toy, not a reproduction heirloom.

Why do I nitpick? Frankly I don't like reading obvious marketing text in my summary. This goes for "beautifully crafted" too. Report, don't advertise, please.

--
Toro

Hmm, I don't know. Not according to here... And according to an AMD page, "Energy-efficient DDR2 memory uses up to 30% less power than DDR1 and up to 58% less power than FBDIMM."

According to here a DDR2 DIMM needs 4.4 watts. Let's round up to 10 watts and say each DIMM is, oh, 4gb (pretty low, I'd say). That's 48 DIMMs to get up to 192, 96 to get up to 384. At a whopping 10 watts (pretty high) that's still ~ 500W for 192gb and ~1000W for 384gb. Cut the wattage down to 5W per DIMM and you get half (250W, 500W). >1000W "home user" power supplies aren't too uncommon these days (1600W on tigerdirect.com...)

I'll assume this is a serious query. It isn't all that obvious.

A 20gauge cord is most likely not capable of carrying enough amperage to power your beer fridge without either A)heating up, or B)outright failing.

Situation A: A 100ft cord that heats up to unsafe temperatures may start a fire with any number of low-flashpoint items between your garage and basement.

Situation B: Failing outright means that the cord heats up to sufficient temperatures in order melt the insulation off, exposing bare, high-temperature, semi-high voltage wires to the environment. They may spark, which can easily start a fire, the insulation might burn or char, and the exposed wires represent an electrocution hazard. This would be unsafe for a 4ft core, but a 100ft cord represents a line of death stretching the length of your house.

Take a look at http://www.interfacebus.com/Reference_Cable_AWG_Sizes.html . Those are conservative numbers for load carrying capacity, and deemed "safe" for 100ft or longer runs. You can potentially multiply those numbers by 2-3 for shorter runs.

Even so, 20 gauge wire should really only be used for a 2-6 amp load; and on the lower end of that scale for a longer (100 ft+) run. A pretty average, smallish home fridge has a "max" current draw of 15 amps. Even your beer-mini-fridge probably draws 7-8 peak. 7-8 is greater than 2, and as such, is a fire hazard. And, with a 100ft run, most people would probably stick it under a rug, which results in even MORE heat buildup.

The thing about it that makes it worse is that the circuit breaker will only protect you against over-current based upon the wiring load (assuming the electrician did a good job), not electrical cords, particularly wimpy electric cords. The only time the circuit breaker will kick in is after the electrical cord has shorted, and it may be too late by that point. If its a ground fault, and not a fire, and not an electrocution, a GFCI circuit might protect you, but it'll probably be too late for that, as well.

That all being said, it's not common knowledge; but it should be. It takes a bit to educate yourself on this stuff, but its important knowledge, and a lot of lives could be saved, and fires stopped, if they taught this stuff in highschool.

IMHO, its a bit pretentious to say that this, stuff is "common sense". The little endian nature of the gauge scale (not to mention that it is logarithmic so 19 gauge is 2x the diameter of 20 gauge), and the unclear nature of the warnings on the stuff is kinda useless. It would make far more sense to make the Amperage of all devices clearer (peak), and simply put "This cable can carrying X amps at Y temperature, and is unsafe for use at higher temperatures" on extension cables.

I don't know if I would refer to CAN bus as 'a simplified Ethernet in crude terms.' Apparently you've never coded for CAN bus. It's by no means crude.

I get it now it's the connectors not the length of the cable that matters.

Things actually are worse.

Supposedly, storage is on their servers, and it's right that their 15 000 rpm SCSI disks will be faster that your 7 200 rpm ATA one.

What will be transfered however is, on your side, mouse and keyboard events (basically, almost nothing), and on their side, graphic commands, textures, ...
That is, what's fair is not comparing your disk transfer speed but your AGP/PCIe transfer speed against network speed.

PCIe 16x can achieve 4000 MB/s (100x your hard disk speed)...

First, anyone planning on a high-definition in-flight entertainment system over Bluetooth would have to be nucking futs.

1. Why would it have to be hi-def? We're talking about seat-back TV Screens. Transmitted anything higher than 640x480 stereo is a waste of bandwidth.

2. Assuming they can get FAA approval, they could use higher bandwidth devices like WIFI. Perhaps even on normally disallowed channels. (Since the plane won't be interfering with nearby radio devices.)

If we were talking about one optic fibre, that would be one thing, but aviation protocols seem to be point to point, not busses, so you need one physical or virtual connection for EVERY possible combination of end-points.

That's a fair point. However, busses are allowed under the ARINC standards. I imagine they're still highly redundant, though.

CNR stands for "Communication and Networking Riser", an interface standard developed by Intel that mostly flopped.

Link 1

Link 2

Oh wait, is that not the TLA (three-letter acronym) that the submitter intended? Should have specified then, instead of assuming that everyone know what the hell "Click-n-Run" is.

Honestly, how many serial buses do we need?

Many. I'd rather not get into it, but I'd say most of the serial protocols listed on this page bring something different and necessary to the table. (Price/Speed/Expandibility/Fault Tolerence tradeoffs) To sum it up, you wouldn't want to use a serial protocol capable of 10Gbps over 100Km of fiber to communicate between your keyboard and your PC.

Ethernet and TCP/IP are both protocols. They're just at different levels of the OSI network stack:

Application Layer: Applications that use the data transferred
Presentation Layer: Data formats like GIF, ASCII
Session Layer: SQL, NFS, HTTP etc. are here
Transport Layer: Flow control, error recovery (TCP, UDP are here)
Network Layer: Logical addressing, end to end delivery of packets (IP is here)
Data Link Layer: Transcodes data into frames and adds CRC (Ethernet is here)
Physical Layer: Encodes and transmits data bits

From OSI stack description.

Yah, OK, but my gigbit ethernet connector (8P8C USOC modular jack derivative) is the same as used for the old 4800bps serial lines feeding VT52 terminals! Furthermore, MCA was a double/staggered contact design (like the AGP slot) with up to 55 pins (x2) whereas PCI and PCI express are single row, up to 82 pins. When you check out the pinouts for PCI Express compared to MCA, you'd have to have a pretty far-out imagination tosay one was derived from the other in any way.

Yah, OK, but my gigbit ethernet connector (8P8C USOC modular jack derivative) is the same as used for the old 4800bps serial lines feeding VT52 terminals! Furthermore, MCA was a double/staggered contact design (like the AGP slot) with up to 55 pins (x2) whereas PCI and PCI express are single row, up to 82 pins. When you check out the pinouts for PCI Express compared to MCA, you'd have to have a pretty far-out imagination tosay one was derived from the other in any way.

Look up some info. Just because YOU can't think of any other logic doesn't mean it doesn't exist. Now go back to your LEDs.

I seem to recall reading that the Ducati 999 uses a CAN bus to send data between the computer (under the seat) and the front-end electrics, which includes the lights and instrument cluster in a compact unit.

According to Honeywell's release, Samsung licensed their technology.

According to Samsung, Sony and Samsung have a joint partnership in lcds: SAMSUNG and Sony Signed a MOU for TFT LCD Joint Venture

So, Sony buys its lcd panels as OEMs from Samsung. So, Sony is purchasing its lcds from a licensee of the technology.

If you look at some lists of lcd manufacturers and LCD/LED Driver IC Manufacturers, you'll notice that very few of the listed defendents actually manufacture panels. There's Fujitsu, Kyocera, Sanyo, and Toshiba/Matsushita.

Nice how this sparked a discussion about everything but what the article is accually about. So... in usual /. fasion I will post good techical info, lets see if it gets ignored.

CAN (controller area network) bus, seems to be mostly what he was taking about, and the hint that the information is public? Try this site about CAN. It is an ISO standard and is used for everything from automobile's to factory automation. The author of the above site doesn't have the ISO docs but he does have some good pdf's. If your interrested in tools or more info there is of course google google.

Nice how this sparked a discussion about everything but what the article is accually about. So... in usual /. fasion I will post good techical info, lets see if it gets ignored.

CAN (controller area network) bus, seems to be mostly what he was taking about, and the hint that the information is public? Try this site about CAN. It is an ISO standard and is used for everything from automobile's to factory automation. The author of the above site doesn't have the ISO docs but he does have some good pdf's. If your interrested in tools or more info there is of course google google.