XP Home (which I'm sure this would be) is around $90 for a single copy at places like newegg.com.
I think my college's volume licensing agreement is around $25/CPU.
AOL is big enough that they probably make the H/W manufacturers (and Sun for StarOffice) take part of their revenue from the monthly fees, rather than up-front.
Let's face it, the typical AOL customer isn't aware of the alternatives.
Chris H. wasn't the only SCO employee to make significant contributions to Linux. The "members only" area at Groklaw contains an "article in progress", which will demonstrate that another SCO employee made *significant* contributions to the effort of developing the SMP kernel.
Without a kernel debugger, developing an SMP kernel becomes increasingly difficult. Register at Groklaw, or wait till the article is published for all the nitty-gritty details.
I can't imagine the hours that Pamela has put into this, and from all I've seen, she's not into the tech aspects at all, she was and is a paralegal.
Now, how long before ThinkGeek comes out with "Go Pamela, you go Grrl" T-shirts.???
Re:Not applicable! Think about it!
on
Real Security?
·
· Score: 1
But the security of the password file is a system security issue, not a username-password issue.
What surprises me is how many ISPs gloss over the fact that the account username (for login purposes) need not match the username for email purposes.
For probably 95%+ of users, their username is the same as their account name, so a large part of their security is compromised from the start.
Assume a six character (alpha-numeric) username and a six character password, also alpha-numeric.
If I know the username, and only have to brute-force the password, the probability of guessing the password in any one trial is (1/62)^6, = 1.76E-11
But if I have to brute-force both the username and password, the probability for a single guess becomes (1/62)^12, or 3.1E-22. (This is not twice as long, but 100 billion times as long.)
Most consumer ISPs allow multiple email accounts, but I bet most of us use the primary account as our "everyday" account, instead of treating that primary account as "root", and using another username for everyday email.
Re:I use good passwords, and here's how
on
Real Security?
·
· Score: 1
That works, provided you can remember your "secret phrase". I have a friend who literally has to have her daughters pick her passwords for her... so they'll remember! PINs, passwords, phone numbers, etc., just are not easily remembered by some people.
I suspect most/.-ers have a favorite pattern, which probably yields at least semi-secure passwords. I use the full names of three people that I won't forget, mix the first letters of those nine names in a particular order, throw in a few digits that I'm likely to remember, and then alternate upper and lower case in a specific pattern.
Re:Common Sense
on
Real Security?
·
· Score: 4, Interesting
"Security training is useless if the user ignores it."
I had a similar experience at the Community College where I teach. After the Sobig, Blaster, etc. attacks of a few months ago, they (Information Technology) installed a McAfee program called "Stinger", which runs every time a user logs into the network, and (apparently) scans the hard drive for virus infected files.
Takes 10-12 minutes to run.
Classes are 50 minutes long.
Stinger responds to the STOP button
---> Illusion of Security!!!
Re: Son of Concorde
on
Son of Concorde
·
· Score: 5, Informative
It appears the Beeb has confused peak
speed with average speed.
According to the US Department
of Agriculture, the Great Circle distance from Paris to Tokyo is 6033
miles. Let's round that to 6000 mi. The speed of sound varies
with temperature, but using 750mph makes the math easy (at aircraft altitudes,
the speed of sound is closer to 700mph).
If it could hold the fuel, the Concorde at Mach 2 (1500mph) could do 6000
miles in four hours. If the EADS jet achieves Mach 4 (3000mph), it could
do 6000 miles in two hours. If the entire distance were covered at cruising
speed.
My impression (purely from being a passenger) is that it takes half an hour
or so for a typical commercial airliner on a 1000 mile flight to reach cruising
speed and altitude; the plane will then be at cruising speed for about 60
minutes, and then another 30 minutes is spent in deceleration. Of the 2 hours
spent in the air, only half of the time is actually spent at crusing speed.
How long would it take for the EADS-SS to reach Mach 4? And how long would
it take it to slow down from that speed to the typical 150mph (+/-) landing
speed that current runways are designed for? I doubt the typical passenger
is prepared for Michael Schumacher / John Force g-forces on takeoff and landing.
Let's say the EADS-SS takes 45 minutes to reach Mach 4, and another 45 minutes
to drop back to landing speeds. Assuming linear acceleration and deceleration,
that's an hour and a half spent at an average speed of 1500mph. So 2250 miles
of the trip takes 1.5 hours. Transiting the remaining 3750 miles at Mach
4 (3000mph) would take another 1.25 hours, for a total trip of 2.75 hours.
[Ignoring any ground taxi times or other delays.]
I would think, fuel-wise (which is basically the only marginal cost of airplane
flight), that going from Mach 2 to Mach 4 is more expensive than going from
Mach 1 to Mach 2. On the other hand, Mach 1 -> 2 is done in denser air
than Mach 2 -> 4, so maybe not.
This could be a great question for a final exam in Engineering Analysis and
Synthesis.
Take your son or daughter to your college, and show him/her your dorm room when you first ventured into the "real world", back in the Peace and Love, Hell No We Won't Go days.
Two or three times a year, I drive from Western Pennsylvania to
West-Central Florida.
Using the same start and ending addresses, I get:
1056 miles and 16Hr 14Min using maps.yahoo.com
1031 miles and 17Hr, 38Min using mapquest.
For the most part, the routings are in agreement; I would judge the
mapquest time estimate as slightly more realistic, especially if you
must accomodate the needs of other family members. (I did this trip
solo in 17 hours flat, but the only stops were at gas stations for
fuel.)
On this particular route, Yahoo seems to choose the most direct "as the
crow flies" routing, while mapquest makes more intelligent decisions.
In this case, it was in choosing to go "out of the way" to bypass
Morgantown WV to the east, and then take I-68 back west to pick up I-79
south.. Mapquest did that, maps.yahoo did not. Another example is in
northern Florida... Mapquest routes you west to US301 (if you're headed
to Tampa) and south on I-75, avoiding the Jacksonville - Daytona -
Orlando mess along I-95 and I-4.
To its credit, maps.yahoo displays its "Trip-Tik" in a larger format
than Mapquest (easier to read when navigating solo), but neither give
en-route confirmations. That is, once you turn onto a route, it would
be nice to know that you're going to be on it for the next 4 hours...
20:
Stay straight to go onto I-64
E/ I-77 S. Continue to follow I-77 S (Portions toll).
310.64 miles
This single Mapquest instruction, while "correct", takes you from
Beckley WV to Wytheville VA, then north on I-81N/I-77S, then south on
I-77 through Virginia, North Carolina, and all the way to Colombia SC.
Both services could offer a larger map format, ideally something that
would just fill an 8.5 x 11 page.
IIRC, Lisa ran about $10-12K, depending on options. As you note, a real dud in the market.
Probably a year or two before its time, too focused on secretarial tasks. It took the IBM PC and Lotus 1-2-3 to open up the business market, to make the very idea of a small computer legitimate.
At a really fundamental level, how different is transparently running a plug-in on a web page different from a program written in C or C++ causing a DLL written in Assembler to execute?
Are printer (and other device) drivers all that different than plug-ins?
When I click the Print icon, aren't I in effect asking the operating system to transparently execute a separate ("plug-in") program, the printer driver, to perform a task for me?
AFAIK, the prototypical GUI windowing system was the Xerox Star office automation system, ca 1981. As I recall, it's said that Jobs and Woz saw a demo at Xerox PARC, cost cut the design from a $25K office system to a $5K personal system, and begat the Macintosh of 1984.
And yes, as far as low-power, high s/n signaling goes, CW is very nice. The thing is, I could whip up from scratch a microcontroler-based decoder that displays on an LCD in about 30 minutes of work and $10 in parts ($6 of which go to the LCD itself). There is no need for human transcoding anymore; simple hardware does a more reliable job cheaper and faster.
[I think MG meant to write low S/N signaling.]
I really have to challenge this assertion. Not to the cost, but to the accuracy.
In the real world, Morse is not sent with letter perfect 3:1 dash-dot ratios thru frequency-synthesized transmitters.
It's sent from Jose, who just learned Morse code from a book, and is using a 40 year old Heath DX-40 with a hand ground crystal in a loose case to make it resonate on the "ham bands", which is the only place his signal can be heard.
It's sent from Alberto, whose village in Italy has just been wiped out by an earthquake. Alberto is making his dots and dashes by holding two ends of a wire together.
Leonid in Stalingrad sends his messages using a "bug", and since he is quite old, his signal has quite a 'swing" to it. Hams around the world recognize his "swing", computers around the world are simply confused.
It's sent by Anna in Prague. Slowly, hesitantly, as she translates the letters into dots and dashes... she speeds up, she slows down, she halts for a few moments.
I'll trust MG that his $10 in parts will decode perfect Morse correctly. But I challenge MG to establish a communications node (without notice) anywhere within 100 miles of his location, that can communicate messages anywhere else in the world. Amateur Radio can do that today.
Better be careful hanging on to your partner. Apparently,/. thinks anyone who knows CW is an ignorant old fart. And once we old farts lose ham radio for our CW fix, where will we turn?
I guess I'm an old fart, since I regard Morse ability as one of the essential characteristics of being an amateur radio operator. At one level, it's an anachronism, like the parallel parking test to get your driving license in this day of malls and shopping centers. But at another level, I think it's a way of distinguising those with a combination of technical knowledge and operational skills, and I think one of the essential operational skills is using CW to communicate.
For the/.-ers not familiar with amateur radio, there are a number of license classes, with increasing levels of operating privileges. Currently, not all amateur radio licenses require knowledge of Morse Code, although that was true 30+ years ago. Also, transmissions sent using Morse code are referred to as CW (Continuous Wave) because while the key is closed, in theory a pure sinusoidal wave is continuously transmitted.
But in order to send Morse code, that continuous wave must be interrupted (to make the dots and dashes). That interruption creates small sideband signals, and so CW signals do not occupy a single frequency, but rather a small bandwidth (~300hz) about the carrier frequency.
Knowing the Hollerith code might be useless today, but knowing Morse is not, for an amateur operator. A significant portion of amateur communications today are still conducted using CW, for a variety of reasons (simpler equipment, better S/N, limited vocabulary = less language problems).
Granted, translating sounds into words (only beginners translate into letters) may be difficult to some. I imagine that some aspiring pilots might not react quickly enough when the instructor says to add left rudder and lower the right flap... or when the driving instructor says turn right at the next intersection. Should the licensing requirements be lowered for pilots and drivers?
There are just some things that are good for you to know, and IMHO, amateur radio won't really be the same if the CW (Morse) requirement is dropped.
*nix geeks need to know vi, Windows admins need to know batch files and xcopy, and I think any mid- to high-level amateur needs to know Morse.
Morse really isn't a code, it's a language, and those who learn it well hear not dots and dashes, not di's and dah's, not even letters, but words and phrases.
Only a few hobbies require licensing, amateur radio is one of them. Being a private pilot is another... should we allow beginning pilots to jump directly into jet airplanes, because propeller-powered aircraft are so 1900's?
Is it a barrier to entry into the hobby? Certainly. But note that it's required for a license only for those frequencies that can communicate internationally (e.g., the High Frequency portion of the spectrum, up to 30MHz).
Obtaining a license and operating an amateur radio station is a privilege, not a right. One earns that privilege by demonstrating knowledge of the "radio arts", which includes not just technical expertise, but rules and regulations, good radio engineering practice, and operational ability.
What needs to be thought about is how to integrate the WiFi System into the Amateur Radio Emergency System and the ARRL National Traffic System.
While this seems cool today, how will WiFi enthusiasts maintain interest day in and day out, year in and year out? Amateur radio does this by making Field Day (in part) a contest (how many stations can you contact in how many different parts of the country/world, your score is the product of the two).
Separate categories are established to measure the degree of emergency preparedness... Being battery powered in a remote location is separate from using a generator at your house, for example.
There's a lot of overlap between the amateur radio community and the slashdot community. For example, I believe both Phil Karn and Kevin Mitnick were amateurs, and a number of/. articles recently have dealt with amateur radio, most notably those concerning interference to the HF and low VHF bands caused by Broadband Power Line experiments.
Forget about how AND is defined for binary, just think about how AND is defined in logic:
AND[1,1,1] -> 1
AND[ Any of the other possibilities] -> 0
OR[0,0,0] -> 0
OR[ Any of the other possibilities] -> 1
NOR[ anything ] -> ~ OR [Anything]
NAND [anything] -> ~ AND [Anything]
XOR [1,0,0] -> 1
XOR [0,1,0] -> 1
XOR [0,0,1] -> 1
XOR [Anything else] -> 0
Basic logic is not limited to boolean logic. It will take a time to adapt to it, but if it proves to be the way to improve performance, we'll do it.
I suspect, 60 or 70 years ago, Turing and Atasanoff and Eckert and Mauchley and Perlis had to struggle a bit when they had to think in binary instead of decimal.
IF trinary becomes common, those engineers real close to the hardware will have to worry about it. For the rest of us, it's bascially a non-issue.
I don't know enough about how CD's work to intelligently comment on your question, but I will anyway, in the true/. tradition.
My understanding of optical disks is that they use the amount of reflectivity to determine the 1's and 0's. [I could be wrong about that.]
I could envision a CD system where some baseline reflectivity value is determined to represent 0... less than that would mean -1 and greater than that +1, thus giving us our trinary system.
Backwards compatibility could even be maintained in Trinary-CD drives by have the drive scan the disk upon loading, and take a "guess" as to its type.
Lets assume that reflectivity ranges from 0 to 1000. A drive could scan the disk upon loading... if if sees primarily 0 and 1000 reflectivity values, it assumes it's a binary CD/DVD... if it sees roughly equal 0-500-1000 reflectivity values, it assumes the disk is a tri-value CD/DVD.
And the intelligent drive of the future would allow the user to override the automatic detection, if she knew the disk was of a specific type.
Which then becomes a design issue... at the current State of the Art, which is better?
At the future state of the art, which will be better?
Binary became dominant from the early days of computing, because it was easy to slam a lot of current into the grid of a vacuum tube, and cause the plate circuit to saturate (conduct maximum current). The plate voltage would drop to near zero, and we'll arbitrarily call this Logic 0 (False).
If we inject no electrons into the grid of the vacuum tube, no current will be conducted in the plate circuit, and the plate voltage will be near the power supply level. We'll call this Logic 1 (True)
This, basically, is how Marconi's trans-Oceanic transmitter worked in 1903 (or was 1903 when the Wright Brothers flew?), and it's bascially how digital circuitry works today.
With todays technology, maybe it's true that a 3-state CPU might only achieve the performance of 10, 15, or 20 years ago.
Just remember that the first IBM PC of 30 years ago came with 16KB (that's Kilobytes) of memory.
But the noise margin of a 3-state [-1.5, 0, +1.5] volt system is the same as a 2-state [0, +1.5] system. The hardware cost in the P/S would be minimal, vanishing to zero over time.
We would need to change nothing about the way we code; at the highest, the changes would occur at compiler output level.
Hardware designers, on the other hand, would be in for a whole new world.
Representing trinary digits on magnetic or optical media, OTOH, might be quite a challenge.
Here's why (I think) the minimum of m*n is considered optimal:
Each additional "base" value takes more complex circuitry (base 2 being the simplest).
But for small values of the base, we need more "bits" to represent a given value. A single hex value can represent the same number as four binary values.
Those of us old enough to remember using octal notation probably remember wishing that getting to 7 as a largest value was getting close, but not quite, to 9.
Binary (base 2) was adopted in the early days of computers because (1) electronically it was very easy to design circuits that either were saturated (max current) or cut-off (zero current), and (2) Boolean algebra had been around for 200 or so years, making the transition straightforward (although not easy).
It's been a long time since I took a semiconductor course, but I would think that a tri-state logic circuit (using -1.5V, 0V, and +1.5V, for example) should be fairly straightforward today.
Yes, truth-tables and such would become much more complicated, and de-Morgan's theorem would be relegated to the scrap heap, but it would seem to be a way to continue to increase processing power once Moore's Law begins to poop out as feature sizes become sub-atomic.
Moore's Law itself could continue, just taking advantage of better technology to move to quad-bit, penta-bit, and so forth, computing.
In deference to those who might be easily offended, I have abstained from using the obvious acronym for a 3-state digit.
Slashdot Mirror
I think my college's volume licensing agreement is around $25/CPU.
AOL is big enough that they probably make the H/W manufacturers (and Sun for StarOffice) take part of their revenue from the monthly fees, rather than up-front.
Let's face it, the typical AOL customer isn't aware of the alternatives.
Without a kernel debugger, developing an SMP kernel becomes increasingly difficult. Register at Groklaw, or wait till the article is published for all the nitty-gritty details.
I can't imagine the hours that Pamela has put into this, and from all I've seen, she's not into the tech aspects at all, she was and is a paralegal.
Now, how long before ThinkGeek comes out with "Go Pamela, you go Grrl" T-shirts.???
What surprises me is how many ISPs gloss over the fact that the account username (for login purposes) need not match the username for email purposes.
For probably 95%+ of users, their username is the same as their account name, so a large part of their security is compromised from the start.
Assume a six character (alpha-numeric) username and a six character password, also alpha-numeric.
If I know the username, and only have to brute-force the password, the probability of guessing the password in any one trial is (1/62)^6, = 1.76E-11
But if I have to brute-force both the username and password, the probability for a single guess becomes (1/62)^12, or 3.1E-22. (This is not twice as long, but 100 billion times as long.)
Most consumer ISPs allow multiple email accounts, but I bet most of us use the primary account as our "everyday" account, instead of treating that primary account as "root", and using another username for everyday email.
I suspect most /.-ers have a favorite pattern, which probably yields at least semi-secure passwords. I use the full names of three people that I won't forget, mix the first letters of those nine names in a particular order, throw in a few digits that I'm likely to remember, and then alternate upper and lower case in a specific pattern.
I had a similar experience at the Community College where I teach. After the Sobig, Blaster, etc. attacks of a few months ago, they (Information Technology) installed a McAfee program called "Stinger", which runs every time a user logs into the network, and (apparently) scans the hard drive for virus infected files.
Takes 10-12 minutes to run.
Classes are 50 minutes long.
Stinger responds to the STOP button
---> Illusion of Security!!!
It appears the Beeb has confused peak speed with average speed.
According to the US Department of Agriculture, the Great Circle distance from Paris to Tokyo is 6033 miles. Let's round that to 6000 mi. The speed of sound varies with temperature, but using 750mph makes the math easy (at aircraft altitudes, the speed of sound is closer to 700mph).
If it could hold the fuel, the Concorde at Mach 2 (1500mph) could do 6000 miles in four hours. If the EADS jet achieves Mach 4 (3000mph), it could do 6000 miles in two hours. If the entire distance were covered at cruising speed.
My impression (purely from being a passenger) is that it takes half an hour or so for a typical commercial airliner on a 1000 mile flight to reach cruising speed and altitude; the plane will then be at cruising speed for about 60 minutes, and then another 30 minutes is spent in deceleration. Of the 2 hours spent in the air, only half of the time is actually spent at crusing speed.
How long would it take for the EADS-SS to reach Mach 4? And how long would it take it to slow down from that speed to the typical 150mph (+/-) landing speed that current runways are designed for? I doubt the typical passenger is prepared for Michael Schumacher / John Force g-forces on takeoff and landing.
Let's say the EADS-SS takes 45 minutes to reach Mach 4, and another 45 minutes to drop back to landing speeds. Assuming linear acceleration and deceleration, that's an hour and a half spent at an average speed of 1500mph. So 2250 miles of the trip takes 1.5 hours. Transiting the remaining 3750 miles at Mach 4 (3000mph) would take another 1.25 hours, for a total trip of 2.75 hours. [Ignoring any ground taxi times or other delays.]
I would think, fuel-wise (which is basically the only marginal cost of airplane flight), that going from Mach 2 to Mach 4 is more expensive than going from Mach 1 to Mach 2. On the other hand, Mach 1 -> 2 is done in denser air than Mach 2 -> 4, so maybe not.
This could be a great question for a final exam in Engineering Analysis and Synthesis.
Take your son or daughter to your college, and show him/her your dorm room when you first ventured into the "real world", back in the Peace and Love, Hell No We Won't Go days.
"Dad, just show me where the ATM machine is..."
Using the same start and ending addresses, I get:
- 1056 miles and 16Hr 14Min using maps.yahoo.com
- 1031 miles and 17Hr, 38Min using mapquest.
For the most part, the routings are in agreement; I would judge the mapquest time estimate as slightly more realistic, especially if you must accomodate the needs of other family members. (I did this trip solo in 17 hours flat, but the only stops were at gas stations for fuel.)On this particular route, Yahoo seems to choose the most direct "as the crow flies" routing, while mapquest makes more intelligent decisions. In this case, it was in choosing to go "out of the way" to bypass Morgantown WV to the east, and then take I-68 back west to pick up I-79 south.. Mapquest did that, maps.yahoo did not. Another example is in northern Florida... Mapquest routes you west to US301 (if you're headed to Tampa) and south on I-75, avoiding the Jacksonville - Daytona - Orlando mess along I-95 and I-4.
To its credit, maps.yahoo displays its "Trip-Tik" in a larger format than Mapquest (easier to read when navigating solo), but neither give en-route confirmations. That is, once you turn onto a route, it would be nice to know that you're going to be on it for the next 4 hours...
20: Stay straight to go onto I-64 E/ I-77 S. Continue to follow I-77 S (Portions toll).
310.64 miles
This single Mapquest instruction, while "correct", takes you from Beckley WV to Wytheville VA, then north on I-81N/I-77S, then south on I-77 through Virginia, North Carolina, and all the way to Colombia SC.
Both services could offer a larger map format, ideally something that would just fill an 8.5 x 11 page.
Sorry, I had forgot about Lisa.
IIRC, Lisa ran about $10-12K, depending on options. As you note, a real dud in the market.
Probably a year or two before its time, too focused on secretarial tasks. It took the IBM PC and Lotus 1-2-3 to open up the business market, to make the very idea of a small computer legitimate.
At a really fundamental level, how different is transparently running a plug-in on a web page different from a program written in C or C++ causing a DLL written in Assembler to execute?
Are printer (and other device) drivers all that different than plug-ins?
When I click the Print icon, aren't I in effect asking the operating system to transparently execute a separate ("plug-in") program, the printer driver, to perform a task for me?
Or am I missing the point here?
AFAIK, the prototypical GUI windowing system was the Xerox Star office automation system, ca 1981. As I recall, it's said that Jobs and Woz saw a demo at Xerox PARC, cost cut the design from a $25K office system to a $5K personal system, and begat the Macintosh of 1984.
And yes, as far as low-power, high s/n signaling goes, CW is very nice. The thing is, I could whip up from scratch a microcontroler-based decoder that displays on an LCD in about 30 minutes of work and $10 in parts ($6 of which go to the LCD itself). There is no need for human transcoding anymore; simple hardware does a more reliable job cheaper and faster.
[I think MG meant to write low S/N signaling.]
I really have to challenge this assertion. Not to the cost, but to the accuracy.
In the real world, Morse is not sent with letter perfect 3:1 dash-dot ratios thru frequency-synthesized transmitters.
It's sent from Jose, who just learned Morse code from a book, and is using a 40 year old Heath DX-40 with a hand ground crystal in a loose case to make it resonate on the "ham bands", which is the only place his signal can be heard.
It's sent from Alberto, whose village in Italy has just been wiped out by an earthquake. Alberto is making his dots and dashes by holding two ends of a wire together.
Leonid in Stalingrad sends his messages using a "bug", and since he is quite old, his signal has quite a 'swing" to it. Hams around the world recognize his "swing", computers around the world are simply confused.
It's sent by Anna in Prague. Slowly, hesitantly, as she translates the letters into dots and dashes... she speeds up, she slows down, she halts for a few moments.
I'll trust MG that his $10 in parts will decode perfect Morse correctly. But I challenge MG to establish a communications node (without notice) anywhere within 100 miles of his location, that can communicate messages anywhere else in the world. Amateur Radio can do that today.
Better be careful hanging on to your partner. Apparently, /. thinks anyone who knows CW is an ignorant old fart. And once we old farts lose ham radio for our CW fix, where will we turn?
CWIRQ!
I guess I'm an old fart, since I regard Morse ability as one of the essential characteristics of being an amateur radio operator. At one level, it's an anachronism, like the parallel parking test to get your driving license in this day of malls and shopping centers. But at another level, I think it's a way of distinguising those with a combination of technical knowledge and operational skills, and I think one of the essential operational skills is using CW to communicate.
/.-ers not familiar with amateur radio, there are a number of license classes, with increasing levels of operating privileges. Currently, not all amateur radio licenses require knowledge of Morse Code, although that was true 30+ years ago. Also, transmissions sent using Morse code are referred to as CW (Continuous Wave) because while the key is closed, in theory a pure sinusoidal wave is continuously transmitted.
For the
But in order to send Morse code, that continuous wave must be interrupted (to make the dots and dashes). That interruption creates small sideband signals, and so CW signals do not occupy a single frequency, but rather a small bandwidth (~300hz) about the carrier frequency.
Knowing the Hollerith code might be useless today, but knowing Morse is not, for an amateur operator. A significant portion of amateur communications today are still conducted using CW, for a variety of reasons (simpler equipment, better S/N, limited vocabulary = less language problems).
Granted, translating sounds into words (only beginners translate into letters) may be difficult to some. I imagine that some aspiring pilots might not react quickly enough when the instructor says to add left rudder and lower the right flap... or when the driving instructor says turn right at the next intersection. Should the licensing requirements be lowered for pilots and drivers?
I guess this only goes to prove that everyone, even Bruce Perens, has a fatal flaw.
There are just some things that are good for you to know, and IMHO, amateur radio won't really be the same if the CW (Morse) requirement is dropped.
*nix geeks need to know vi, Windows admins need to know batch files and xcopy, and I think any mid- to high-level amateur needs to know Morse.
Morse really isn't a code, it's a language, and those who learn it well hear not dots and dashes, not di's and dah's, not even letters, but words and phrases.
Only a few hobbies require licensing, amateur radio is one of them. Being a private pilot is another... should we allow beginning pilots to jump directly into jet airplanes, because propeller-powered aircraft are so 1900's?
Is it a barrier to entry into the hobby? Certainly. But note that it's required for a license only for those frequencies that can communicate internationally (e.g., the High Frequency portion of the spectrum, up to 30MHz).
Obtaining a license and operating an amateur radio station is a privilege, not a right. One earns that privilege by demonstrating knowledge of the "radio arts", which includes not just technical expertise, but rules and regulations, good radio engineering practice, and operational ability.
Da-da-di-di-dit Di-di-di-da-dah.
What needs to be thought about is how to integrate the WiFi System into the Amateur Radio Emergency System and the ARRL National Traffic System.
/. articles recently have dealt with amateur radio, most notably those concerning interference to the HF and low VHF bands caused by Broadband Power Line experiments.
While this seems cool today, how will WiFi enthusiasts maintain interest day in and day out, year in and year out? Amateur radio does this by making Field Day (in part) a contest (how many stations can you contact in how many different parts of the country/world, your score is the product of the two).
Separate categories are established to measure the degree of emergency preparedness... Being battery powered in a remote location is separate from using a generator at your house, for example.
There's a lot of overlap between the amateur radio community and the slashdot community. For example, I believe both Phil Karn and Kevin Mitnick were amateurs, and a number of
But if the logic is set up to be complementary, [-1.5V, 0v, +1.5V] won't, on average, the + and - current paths balance thenselves out?
Why not?
AFAIK, Exclusive OR means that the result is true, if one and only one of the arguments to XOR is true.
That scales from any number of arguments, from 2 to N.
Forget about how AND is defined for binary, just think about how AND is defined in logic:
AND[1,1,1] -> 1
AND[ Any of the other possibilities] -> 0
OR[0,0,0] -> 0
OR[ Any of the other possibilities] -> 1
NOR[ anything ] -> ~ OR [Anything]
NAND [anything] -> ~ AND [Anything]
XOR [1,0,0] -> 1
XOR [0,1,0] -> 1
XOR [0,0,1] -> 1
XOR [Anything else] -> 0
Basic logic is not limited to boolean logic. It will take a time to adapt to it, but if it proves to be the way to improve performance, we'll do it.
I suspect, 60 or 70 years ago, Turing and Atasanoff and Eckert and Mauchley and Perlis had to struggle a bit when they had to think in binary instead of decimal. IF trinary becomes common, those engineers real close to the hardware will have to worry about it. For the rest of us, it's bascially a non-issue.
I don't know enough about how CD's work to intelligently comment on your question, but I will anyway, in the true /. tradition.
My understanding of optical disks is that they use the amount of reflectivity to determine the 1's and 0's. [I could be wrong about that.]
I could envision a CD system where some baseline reflectivity value is determined to represent 0... less than that would mean -1 and greater than that +1, thus giving us our trinary system.
Backwards compatibility could even be maintained in Trinary-CD drives by have the drive scan the disk upon loading, and take a "guess" as to its type.
Lets assume that reflectivity ranges from 0 to 1000. A drive could scan the disk upon loading... if if sees primarily 0 and 1000 reflectivity values, it assumes it's a binary CD/DVD... if it sees roughly equal 0-500-1000 reflectivity values, it assumes the disk is a tri-value CD/DVD.
And the intelligent drive of the future would allow the user to override the automatic detection, if she knew the disk was of a specific type.
Which then becomes a design issue... at the current State of the Art, which is better?
At the future state of the art, which will be better?
Binary became dominant from the early days of computing, because it was easy to slam a lot of current into the grid of a vacuum tube, and cause the plate circuit to saturate (conduct maximum current). The plate voltage would drop to near zero, and we'll arbitrarily call this Logic 0 (False).
If we inject no electrons into the grid of the vacuum tube, no current will be conducted in the plate circuit, and the plate voltage will be near the power supply level. We'll call this Logic 1 (True)
This, basically, is how Marconi's trans-Oceanic transmitter worked in 1903 (or was 1903 when the Wright Brothers flew?), and it's bascially how digital circuitry works today.
With todays technology, maybe it's true that a 3-state CPU might only achieve the performance of 10, 15, or 20 years ago.
Just remember that the first IBM PC of 30 years ago came with 16KB (that's Kilobytes) of memory.
But the noise margin of a 3-state [-1.5, 0, +1.5] volt system is the same as a 2-state [0, +1.5] system. The hardware cost in the P/S would be minimal, vanishing to zero over time.
We would need to change nothing about the way we code; at the highest, the changes would occur at compiler output level.
Hardware designers, on the other hand, would be in for a whole new world.
Representing trinary digits on magnetic or optical media, OTOH, might be quite a challenge.
Here's why (I think) the minimum of m*n is considered optimal:
Each additional "base" value takes more complex circuitry (base 2 being the simplest).
But for small values of the base, we need more "bits" to represent a given value. A single hex value can represent the same number as four binary values.
Those of us old enough to remember using octal notation probably remember wishing that getting to 7 as a largest value was getting close, but not quite, to 9.
Binary (base 2) was adopted in the early days of computers because (1) electronically it was very easy to design circuits that either were saturated (max current) or cut-off (zero current), and (2) Boolean algebra had been around for 200 or so years, making the transition straightforward (although not easy).
It's been a long time since I took a semiconductor course, but I would think that a tri-state logic circuit (using -1.5V, 0V, and +1.5V, for example) should be fairly straightforward today.
Yes, truth-tables and such would become much more complicated, and de-Morgan's theorem would be relegated to the scrap heap, but it would seem to be a way to continue to increase processing power once Moore's Law begins to poop out as feature sizes become sub-atomic.
Moore's Law itself could continue, just taking advantage of better technology to move to quad-bit, penta-bit, and so forth, computing.
In deference to those who might be easily offended, I have abstained from using the obvious acronym for a 3-state digit.