I purchased this book before it was published and promptly read it from cover to cover when I received it. Using that knowledge, I was able to help an out-of-state friend fix his system. At the time, he could connect his scanner or his CD-RW drive, but not both at the same time. The problem turned out to be that the scanner had a single-ended, 25-pin Mac-style connector and was messing up the rest of the system. Once we configured his host adapter correctly, and got the scanner connected to the end of the bus with a short cable and appropriate terminators, his problems were fixed.
The path of SCSI standards is convoluted. And this book does an extremely good job of sorting though it all and presenting it in an understandable manner.
It sounds simple, but keep in mind that there are multiple *types* of termination, and different versions of the SCSI standard require different types of termination. It's easy to get confused, and I found the quick-reference table to be invaluable.
1) GPS data is transmitted as pseudo-random noise. If you were to look at a GPS signal, it would look just like noise. In fact, it is typically "buried" in noise. Finding a GPS "signal" is not like homing in on a carrier wave. A typical GPS receiver goes through a lengthy process to find and extract the GPS signal from the noise.
2) Most GPS receivers use a 2nd-order tracking loop. This type of loop can handle constant velocity differences between the transmitter and receiver, but will fail in the presence of acceleration. So the missiles would require a 3rd-order loop at a minimum. Given the high velocities and accelerations of two missiles, I would be doubtful that GPS could be used in this situation.
3) Part of the GPS tracking system must have knowledge of the Doppler shift of the carrier frequency. For the 2-missile scenario, the Doppler would be extreme -- well outside of normal parameters. Thus making the acquisition process take a very long time. Also, if the Doppler changes rapidly (which it most likely will), then we would lose tracking. And once that happens, we lose the GPS signal.
In essence, there are quite a few technical problems with using a GPS "beacon". It would be much, much simpler to just use a standard beacon that doesn't have all the overhead of GPS. I find this article to be highly improbable.
If you've ever worked with classified computer systems, you understand the following:
A computer system containing any classified information can
NEVER legally be connected to an unclassified computer system (e.g. the internet). Of course, sometimes this rule is broken by people like our former CIA director.
Thus, I very seriously doubt that someone was able to secure "top secret" information over the internet.
If you don't already know about it, go to the Gibson Research Center. He has a program, Shields Up!, that tells you if your NetBIOS (and other) ports are vulnerable. He also includes detailed steps on how to configure Windows to make the NetBIOS ports inaccessible from the internet. Even if you don't have shares, the NetBIOS ports will give out information about the configuration of your computer.
I personally used to remember every single one of my appointments. I got tired of doing it and began to write everything down. Now I make no effort to remember, but instead check my calendar every day. Does this mean I can't remember? No. It just means that I freed my brain up to work on other things.
Another observation is that this article appears to be somewhat misrepresented here at "/.". The article presents 2 different possible causes for memory loss. The first is that young people have relied too much on technology and have not exercised (my word) their brains enough. Thus, they lose their memory abilities due to the brain's equivalent of obesity. The second is that there is so very much information in today's computerized society that the brain gets overloaded and loses its ability to distinguish between what is important and what is not. Thus, people lose their memory abilites due to the brain chucking away important things and remembering unimportant things.
I agree that the article is somewhat optimistic about the security of the beam. The bounced signal widens into a 30km by 15km ellipse. While that's better than broadcasting with an omnidirectional antennae, it doesn't quite add up to the pinpoint precision you could get with lasers. If you were within that ellipse, then you could easily listen to one side of the message traffic, and you might be able to mess with the communications by responding to the "probe" signal. Good crypto, however, would get rid of these problems.
The article also mentions that they handle the case where multiple remote sites reply to the base station's "probe" signal. Thus, while the system works best with a large, sparse network, they can have some level of density.
Donald Knuth's web site is here. Information about the reward for TeX bugs (currently $327.68) can be found here under the section titled "Rewards".
It says: "If you do succeed in finding a previously undiscovered bug in the programs for either TeX or METAFONT, I shall gladly pay you a reward of $327.68. Corrections to errors in The TeXbook or The METAFONTbook are worth $2.56, as in all my other books."
I've used a lot of pornography in my lifetime, but even I steer away from child porn. Deep down I feared that I'd like it too much. It's a slippery road, and if I start down it I'm not sure I could stop. It may be legal, but virtual child porn is dangerous.
An applicable joke from the rec.humor.funny archives is here.
I wish it would work that way in real life.
Junkbusters works well getting rid of junk mail
on
Spammer Gets Spammed
·
· Score: 2
Junkbusters has a comprehensive list of mass snail-mailers. You enter your information, it composes the letters, and you print them out and mail them (addresses included, so no envelopes necessary). I did this and was amazed at the reduction in the amount of mail that I received.
...so I can downgrade of some of these messages. Egads! Today we will get to see just exactly how many posts complain and/or use profanity in regards to the JVC/QVC error.
Check this link on CNN.
Apparently the sponsors were contracted to pay for his internet purchases, which they did. In addition, he formed a company (DotComGuy, Inc.) that would pay him the $100,000. The tone of the article indicates the company was supposed to make money independent of the sponsors, but at the end of the year the company hadn't made enough to both pay his "bonus" and stay in business. Thus, he decided to keep the company afloat and forgo the $100K.
I don't like Anonymous Coward's tone, but I agree that Cliff will be in for a rude awakening when he leaves college and goes to work as a programmer.
I once took a class where the professor required us to use rcs and troff/nroff as part of the project. (To the uninitiated, rcs is a generic UNIX version control system, and troff/nroff is a bare-bones UNIX text formatting system.) He insisted upon the use of troff/nroff, despite the fact that WordPerfect and MS Word were much easier to use. He frankly admitted these were oddball requirements. His goal was to show us a slice of real-life. As any experienced programmer knows, specifications often requires us to do something in a non-optimal (or non-preferential) manner.
The funny part of all this is that my professor must have been prescient. In my current company, we were using rcs up until a couple years ago. The reason? It was free.
Knowing that/. is a Linux haven, I still disagree that some of these items are myths. Particularly in the "Installation" portion of the Linux myth dispeller.
I contend that the Linux experts have forgotten how difficult Linux can be when you're new to it. In the case I present below, this was my very first fresh installation of a UNIX/Linux system, although I'm familiar with UNIX and have been a system admin for several years now (small network).
I have set up a single Linux machine as my firewall/masqerade and mail server, and I can say the following:
While installing Linux as a workstation may be possible for the average computer user (one who could install Windows), I do not believe it to be easy. It would certainly take more than the hour or so mentioned in the myth dispeller. And unless you have significant experience as a UNIX developer and/or system admin, I am absolutely sure that you will not be able to install Linux as a server in an hour or two.
I had more difficulty installing and configuring the utilities than I did installing and configuring the OS. But without the utilities, the system was pretty much useless to me. By "utilities", I mean ipchains, qpopper (a POP3 server), mail, and ftpd. And, of course, once I got into this stuff I had to do kernel recompiles.
Without the linuxconf utility (provided with Red Hat 6.2) I would have been completely lost. Even so, linuxconf contained an error (or a confusion) concerning the configuration of multiple NE2000-compatible network cards. Fortunately, I found on-line help (which I believe to be one of the TRUE advantages of Linux).
Even Jerry Pournelle, computer god extraordinaire, had to call an expert (see this link). And even he admits that it's easier to configure WinNT as a server than Linux (see this link).
The first thing the Red Hat installation program did was ask me for a driver disk. Huh? I had no idea what it wanted. After some experimentation, I realized I could just hit cancel and continue with the installation.
To summarize, I disagree with a good portion of the installation myths. Now that I've done it a few times, sure, I can install Linux in an hour or so with only one kernel recompile. But that first time was tough, and the second wasn't super-easy either. And while I may not be a kernel programmer or a "guru" who knows the source inside and out, I am a UNIX systems administrator and I have been a C/Assembler developer for over 10 years.
Here are my counters to the myths:
Linux is difficult to install if you have not done it before, especially if you wish to use it as anything other than a workstation. It does, however, come with some utilities that make it easier to install than other UNIX flavors.
If you are installing a Linux system for the first time, make sure you have access to a UNIX/Linux expert. It will save you a lot of time and frustration.
Even though Linux is open-source, there is a higher likelihood of errors (or confusions) in the installation/configuration utilities (I ran into some, as I mentioned above). The reason for this is that the open source community doesn't put as much money and effort into testing (or into ease of use) as is done by a company like Microsoft or Apple. Also while the open source community may be a massive code review resource, I don't see the installation/configuration utilities getting as much scrutiny as they would at a large company.
Installation/configuration program errors (or confusing instruction) have a smaller chance of being fixed than similar errors would on Windows/MacOS, because:
Someone has to notice the errors, find out who to report them to, and actually report them.
Some programmer, somewhere, has to decide that he/she wants to fix this in his/her spare time. And we all know how exciting it is to work on installation/configuration programs.
Slashdot Mirror
I purchased this book before it was published and promptly read it from cover to cover when I received it. Using that knowledge, I was able to help an out-of-state friend fix his system. At the time, he could connect his scanner or his CD-RW drive, but not both at the same time. The problem turned out to be that the scanner had a single-ended, 25-pin Mac-style connector and was messing up the rest of the system. Once we configured his host adapter correctly, and got the scanner connected to the end of the bus with a short cable and appropriate terminators, his problems were fixed.
The path of SCSI standards is convoluted. And this book does an extremely good job of sorting though it all and presenting it in an understandable manner.
Highly recommended.
-- Chad
It sounds simple, but keep in mind that there are multiple *types* of termination, and different versions of the SCSI standard require different types of termination. It's easy to get confused, and I found the quick-reference table to be invaluable.
2) Most GPS receivers use a 2nd-order tracking loop. This type of loop can handle constant velocity differences between the transmitter and receiver, but will fail in the presence of acceleration. So the missiles would require a 3rd-order loop at a minimum. Given the high velocities and accelerations of two missiles, I would be doubtful that GPS could be used in this situation.
3) Part of the GPS tracking system must have knowledge of the Doppler shift of the carrier frequency. For the 2-missile scenario, the Doppler would be extreme -- well outside of normal parameters. Thus making the acquisition process take a very long time. Also, if the Doppler changes rapidly (which it most likely will), then we would lose tracking. And once that happens, we lose the GPS signal.
In essence, there are quite a few technical problems with using a GPS "beacon". It would be much, much simpler to just use a standard beacon that doesn't have all the overhead of GPS. I find this article to be highly improbable.
It's the Digital Millennium Copyright Act (DMCA). Note the apparent dyslexia. Here is one of the top google.com search results
http://www.educause.edu/issues/dmca.html
- A computer system containing any classified information can
- NEVER legally be connected to an unclassified computer system (e.g. the internet). Of course, sometimes this rule is broken by people like our former CIA director.
Thus, I very seriously doubt that someone was able to secure "top secret" information over the internet.If you don't already know about it, go to the Gibson Research Center. He has a program, Shields Up!, that tells you if your NetBIOS (and other) ports are vulnerable. He also includes detailed steps on how to configure Windows to make the NetBIOS ports inaccessible from the internet. Even if you don't have shares, the NetBIOS ports will give out information about the configuration of your computer.
I personally used to remember every single one of my appointments. I got tired of doing it and began to write everything down. Now I make no effort to remember, but instead check my calendar every day. Does this mean I can't remember? No. It just means that I freed my brain up to work on other things.
Another observation is that this article appears to be somewhat misrepresented here at "/.". The article presents 2 different possible causes for memory loss. The first is that young people have relied too much on technology and have not exercised (my word) their brains enough. Thus, they lose their memory abilities due to the brain's equivalent of obesity. The second is that there is so very much information in today's computerized society that the brain gets overloaded and loses its ability to distinguish between what is important and what is not. Thus, people lose their memory abilites due to the brain chucking away important things and remembering unimportant things.
I agree that the article is somewhat optimistic about the security of the beam. The bounced signal widens into a 30km by 15km ellipse. While that's better than broadcasting with an omnidirectional antennae, it doesn't quite add up to the pinpoint precision you could get with lasers. If you were within that ellipse, then you could easily listen to one side of the message traffic, and you might be able to mess with the communications by responding to the "probe" signal. Good crypto, however, would get rid of these problems.
The article also mentions that they handle the case where multiple remote sites reply to the base station's "probe" signal. Thus, while the system works best with a large, sparse network, they can have some level of density.
Donald Knuth's web site is here. Information about the reward for TeX bugs (currently $327.68) can be found here under the section titled "Rewards".
It says: "If you do succeed in finding a previously undiscovered bug in the programs for either TeX or METAFONT, I shall gladly pay you a reward of $327.68. Corrections to errors in The TeXbook or The METAFONTbook are worth $2.56, as in all my other books."
I've used a lot of pornography in my lifetime, but even I steer away from child porn. Deep down I feared that I'd like it too much. It's a slippery road, and if I start down it I'm not sure I could stop. It may be legal, but virtual child porn is dangerous.
I wish it would work that way in real life.
Junkbusters has a comprehensive list of mass snail-mailers. You enter your information, it composes the letters, and you print them out and mail them (addresses included, so no envelopes necessary). I did this and was amazed at the reduction in the amount of mail that I received.
...so I can downgrade of some of these messages. Egads! Today we will get to see just exactly how many posts complain and/or use profanity in regards to the JVC/QVC error.
Check this link on CNN. Apparently the sponsors were contracted to pay for his internet purchases, which they did. In addition, he formed a company (DotComGuy, Inc.) that would pay him the $100,000. The tone of the article indicates the company was supposed to make money independent of the sponsors, but at the end of the year the company hadn't made enough to both pay his "bonus" and stay in business. Thus, he decided to keep the company afloat and forgo the $100K.
I don't like Anonymous Coward's tone, but I agree that Cliff will be in for a rude awakening when he leaves college and goes to work as a programmer.
I once took a class where the professor required us to use rcs and troff/nroff as part of the project. (To the uninitiated, rcs is a generic UNIX version control system, and troff/nroff is a bare-bones UNIX text formatting system.) He insisted upon the use of troff/nroff, despite the fact that WordPerfect and MS Word were much easier to use. He frankly admitted these were oddball requirements. His goal was to show us a slice of real-life. As any experienced programmer knows, specifications often requires us to do something in a non-optimal (or non-preferential) manner.
The funny part of all this is that my professor must have been prescient. In my current company, we were using rcs up until a couple years ago. The reason? It was free.
Knowing that /. is a Linux haven, I still disagree that some of these items are myths. Particularly in the "Installation" portion of the Linux myth dispeller.
I contend that the Linux experts have forgotten how difficult Linux can be when you're new to it. In the case I present below, this was my very first fresh installation of a UNIX/Linux system, although I'm familiar with UNIX and have been a system admin for several years now (small network).
I have set up a single Linux machine as my firewall/masqerade and mail server, and I can say the following:
- While installing Linux as a workstation may be possible for the average computer user (one who could install Windows), I do not believe it to be easy. It would certainly take more than the hour or so mentioned in the myth dispeller. And unless you have significant experience as a UNIX developer and/or system admin, I am absolutely sure that you will not be able to install Linux as a server in an hour or two.
- I had more difficulty installing and configuring the utilities than I did installing and configuring the OS. But without the utilities, the system was pretty much useless to me. By "utilities", I mean ipchains, qpopper (a POP3 server), mail, and ftpd. And, of course, once I got into this stuff I had to do kernel recompiles.
- Without the linuxconf utility (provided with Red Hat 6.2) I would have been completely lost. Even so, linuxconf contained an error (or a confusion) concerning the configuration of multiple NE2000-compatible network cards. Fortunately, I found on-line help (which I believe to be one of the TRUE advantages of Linux).
- Even Jerry Pournelle, computer god extraordinaire, had to call an expert (see this link). And even he admits that it's easier to configure WinNT as a server than Linux (see this link).
- The first thing the Red Hat installation program did was ask me for a driver disk. Huh? I had no idea what it wanted. After some experimentation, I realized I could just hit cancel and continue with the installation.
To summarize, I disagree with a good portion of the installation myths. Now that I've done it a few times, sure, I can install Linux in an hour or so with only one kernel recompile. But that first time was tough, and the second wasn't super-easy either. And while I may not be a kernel programmer or a "guru" who knows the source inside and out, I am a UNIX systems administrator and I have been a C/Assembler developer for over 10 years.Here are my counters to the myths: