Here's the answer I found in the telecom digest FAQ:
Q: Why use a negative charge (-48 volts) for Ring instead of a positive charge (such as +48 volts)?
A: The reason for doing this is galvanic corrosion protection. A conductor with a negative charge will repel chlorine ions, as Cl (chlorine) ions are negative also. If the line were to have a positive charge, Cl ions would be attracted.
This form of corrosion protection is called cathodic protection. It is often used for pipelines, bridges, etc. Such protection was very important in the days of open wire transmission lines.
From:
http://mirror.lcs.mit.edu/telecom-archives/archi ve s/new-readers/frequent-ask-questions-97
(Take out the spaces)
You could use the -48V DC computer power supplies that are common in telephone applications.
(Since most of the telephone switch equipment runs on -48V DC...)
They're a bit more expensive than the normal ones...
Then just use a big 110VAC to -48VDC converter, tie in a bank of batteries, and you've got the UPS end of it handled as well.
Pegasus handles some of these things well. It supports multiple identities very well, has a good filter system w/ color highlighting and such... The current version works fairly well, and there's a major new version due out later this year...
Best of it, it's free (as in beer, not speech).
My thinkpad A20m works great in Linux...
It's got 3 mouse buttons, and the internal modem works fine with the ltmodem driver from linmodems.org. I didn't opt for the internal ethernet, instead I use a Netgear FA510 10/100 PCMCIA card.
The built in sound originally required the ALSA drivers from www.alsa-project.org, but I think the later kernels have support for it.
If you pick the right model thinkpad, you can even get Linux preinstalled on it.
Even APM works, including suspend and hibernate.
I'm not too worried about the LCD backlight wearing out... Not for a few years, after which I'll probably need a new computer with a bigger drive to accommodate my files ever increasing size and entrophy.
Re:Only turn the fan on while needed?
on
Quiet Laptop Fan?
·
· Score: 2
Here's a place with power supplies with variable speed fans (and other cooling devices).
http://www.pcpowercooling.com/
I've had great experiences with IBM hard drives. The ones I've had have been extremely quiet. (Even the 7200rpm ones)
Mozilla 0.8 has the ability to let you block popup windows, cookies, and images on a per domain basis. It doesn't have a nice front end for editing the popup windows, but see the release notes at: http://www.mozilla.org/releases/mozilla0.8/
for how to set them.
As for other features... The source is out there...
I believe that http://savannah.gnu.org/ is what you're thinking of.
It appears to be available for any registered GNU project...
(And it uses the sourceforge codebase)
If only it was that easy... At least for New York, zip codes aren't enough to identify the proper tax area. Even the mailing address city isn't enough. You have to check street names for some cities.
I wouldn't mind doing the work to handle collecting sales taxes for each state, if it was just 1 rate per state. But it's much more complicated than that. California for example, has some locations that have 4 separate components to the sales tax: State, County, City, and Special district. Each of these gets reported on a different line on the CA sales tax form.
And then, some states, shipping and handling is taxed (NY for example), others it's not.
Oh, you mean like PICS ratings?
See:
http://www.w3.org/PICS/
http://www.rsac.org/
http://home.netscape.com/comprod/products/commun ic ator/netwatch/
http://www.microsoft.com/windows/Ie/Features/Con te ntAdv/default.asp
I've worked with code that has provoked an emotional response... (and screaming "WTF? What was he thinking?")
Art wasn't usually the word that came to mind...
I agree, getting the cost for radio tags down to less than a penny opens up lots of possibilities... It's a whole lot easier to read a RF tag than getting a barcode lined up the right way to scan on an assembly line...
Or if they're really light combine them with a streamer and some triangulating stations to measure air currents inside of a tornado/storm
Although, I don't think I'd want to be the one tracking the tornado if the reader only works within 5 meters...
The main drawback I see to running 12V DC around the house, is you need to run big cables to keep the voltage drop from being a problem over longer distances...
(Re: police demanding id)
Years ago, a friend of mine was landing her hot air balloon near the highway, and as we're trying to get it packed up, a cop comes up, and DEMANDS that she produce her drivers license...
She tried to convince him that she didn't need a drivers license to fly a balloon... just a pilots license...
The neural net would allow one to almost directly map the human musculature to the airplane control surface...
Why did I suddenly picture the pilot running around, holding his arms straight out to the side "flying"?
Here in the U.S. (specifically metropolitan Southern California), you pay an extra $5 for the extra channels, and then (if available) an extra $5 for the digital tier (which, if you have premium channels, greatly increases the number of available channels).
Lets see, here in SE Michigan, in wonderful TimeWarner cable land:
Standard cable: $33.57 (plus taxes)
Plus $9.50 for 2 premium channels, or $19.95/8
Or $10.95-$34.95 (Plus the $33.57 for standard) for various digital cable packages...
Standard includes 71 channels (counting 2 shopping, and 11 public access/messageboards)
And for (coming soon for the last 2 years!)
Cable modem: $39.95
If only I was in one of the cities around here where Ameritech is a competitive cable supplier...
Long ago, I remember people using special statically linked SCO binaries of WP and the iBCS support in Linux to run WP under Linux... I seem to remember someone figuring out that they sold more copies of WP for SCO to be used under Linux, than they sold to use under SCO...
Slashdot Mirror
Here's the answer I found in the telecom digest FAQ:
i ve s/new-readers/frequent-ask-questions-97
Q: Why use a negative charge (-48 volts) for Ring instead of a positive charge (such as +48 volts)?
A: The reason for doing this is galvanic corrosion protection. A conductor with a negative charge will repel chlorine ions, as Cl (chlorine) ions are negative also. If the line were to have a positive charge, Cl ions would be attracted.
This form of corrosion protection is called cathodic protection. It is often used for pipelines, bridges, etc. Such protection was very important in the days of open wire transmission lines.
From:
http://mirror.lcs.mit.edu/telecom-archives/arch
(Take out the spaces)
If I remember right, it has to do with protecting
the phone lines. It helps prevent corrosion. (Alot like anodic protection for ships and such)
You could use the -48V DC computer power supplies that are common in telephone applications.
(Since most of the telephone switch equipment runs on -48V DC...)
They're a bit more expensive than the normal ones...
Then just use a big 110VAC to -48VDC converter, tie in a bank of batteries, and you've got the UPS end of it handled as well.
Pegasus handles some of these things well. It supports multiple identities very well, has a good filter system w/ color highlighting and such... The current version works fairly well, and there's a major new version due out later this year...
Best of it, it's free (as in beer, not speech).
See http://www.pmail.com/
Hey, I only visit playboy.com for the linux article....m l
See: http://slashdot.org/articles/00/01/04/2134245.sht
My thinkpad A20m works great in Linux...
It's got 3 mouse buttons, and the internal modem works fine with the ltmodem driver from linmodems.org. I didn't opt for the internal ethernet, instead I use a Netgear FA510 10/100 PCMCIA card.
The built in sound originally required the ALSA drivers from www.alsa-project.org, but I think the later kernels have support for it.
If you pick the right model thinkpad, you can even get Linux preinstalled on it.
Even APM works, including suspend and hibernate.
I'm not too worried about the LCD backlight wearing out... Not for a few years, after which I'll probably need a new computer with a bigger drive to accommodate my files ever increasing size and entrophy.
Here's a place with power supplies with variable speed fans (and other cooling devices).
http://www.pcpowercooling.com/
I've had great experiences with IBM hard drives. The ones I've had have been extremely quiet. (Even the 7200rpm ones)
Mozilla 0.8 has the ability to let you block popup windows, cookies, and images on a per domain basis. It doesn't have a nice front end for editing the popup windows, but see the release notes at: http://www.mozilla.org/releases/mozilla0.8/
for how to set them.
As for other features... The source is out there...
I believe that http://savannah.gnu.org/ is what you're thinking of.
It appears to be available for any registered GNU project...
(And it uses the sourceforge codebase)
If only it was that easy... At least for New York, zip codes aren't enough to identify the proper tax area. Even the mailing address city isn't enough. You have to check street names for some cities.
I wouldn't mind doing the work to handle collecting sales taxes for each state, if it was just 1 rate per state. But it's much more complicated than that. California for example, has some locations that have 4 separate components to the sales tax: State, County, City, and Special district. Each of these gets reported on a different line on the CA sales tax form.
And then, some states, shipping and handling is taxed (NY for example), others it's not.
Anyone want to write a Business::SalesTax module?
So, I'll just run it in vmware, with an undoable partition... It deletes it, I revert the partition back to it's prior status...
If you control the hardware, you can control the software.
It's also small enough that it wouldn't cost much to run it as part of an ad in a newspaper...
Except some of those emergency phone systems actually use the cellular phone system. :)
Oh, you mean like PICS ratings?n ic ator/netwatch/
n te ntAdv/default.asp
See:
http://www.w3.org/PICS/
http://www.rsac.org/
http://home.netscape.com/comprod/products/commu
http://www.microsoft.com/windows/Ie/Features/Co
I've worked with code that has provoked an emotional response... (and screaming "WTF? What was he thinking?")
Art wasn't usually the word that came to mind...
I agree, getting the cost for radio tags down to less than a penny opens up lots of possibilities... It's a whole lot easier to read a RF tag than getting a barcode lined up the right way to scan on an assembly line...
Or if they're really light combine them with a streamer and some triangulating stations to measure air currents inside of a tornado/storm
Although, I don't think I'd want to be the one tracking the tornado if the reader only works within 5 meters...
The main drawback I see to running 12V DC around the house, is you need to run big cables to keep the voltage drop from being a problem over longer distances...
(Re: police demanding id)
Years ago, a friend of mine was landing her hot air balloon near the highway, and as we're trying to get it packed up, a cop comes up, and DEMANDS that she produce her drivers license...
She tried to convince him that she didn't need a drivers license to fly a balloon... just a pilots license...
Wait'll they start using strong encryption and hiding messages in images/chat sites to plot their attacks... Oh wait, that was Tuesday's story...
A quick search turned up this:h p
http://www.php.net/manual/en/features.http-auth.p
Which shows how to get browsers to forget, by sending a 401 status at them...
Hopefully this helps someone...
The neural net would allow one to almost directly map the human musculature to the airplane control surface...
Why did I suddenly picture the pilot running around, holding his arms straight out to the side "flying"?
Use ftp://updates.redhat.com for patches, then you don't have to fight with everyone grabbing ISO's.
Here in the U.S. (specifically metropolitan Southern California), you pay an extra $5 for the extra channels, and then (if available) an extra $5 for the digital tier (which, if you have premium channels, greatly increases the number of available channels).
Lets see, here in SE Michigan, in wonderful TimeWarner cable land:
Standard cable: $33.57 (plus taxes)
Plus $9.50 for 2 premium channels, or $19.95/8
Or $10.95-$34.95 (Plus the $33.57 for standard) for various digital cable packages...
Standard includes 71 channels (counting 2 shopping, and 11 public access/messageboards)
And for (coming soon for the last 2 years!) Cable modem: $39.95
If only I was in one of the cities around here where Ameritech is a competitive cable supplier...
Long ago, I remember people using special statically linked SCO binaries of WP and the iBCS support in Linux to run WP under Linux... I seem to remember someone figuring out that they sold more copies of WP for SCO to be used under Linux, than they sold to use under SCO...
Hopefully this device will have an American tourist mode:
Tourist: Where is the bathroom?
Translator: WHERE...IS...THE...BATH...ROOOOM???