Back of the envelope for battery life
on
Portable Linux Box
·
· Score: 4
The SONY Glasstron glasses (the cheap TV version without the VGA) have an SVHS in, which is sweet, 'cause it just happens this little bugger has a matching SVHS out... The power draw is a bear though.
Their power supply output is 15v DC @ 3A (45W).
Now, Sealed Lead Acid batteries (the best power per volume i have been able to find for my wearable) run about 13 Watt Hours per Pound. Now i figure the average draw of the machine is probably slightly less than half the supply rating, (although we still want to source the peak current when needed i'm more concerned with average when figureing out how long the batteries will last), so to be save we call it 20 W. So we need just under 2Lb of battery per hour of battery life. That's something to think about. Right now if i carry all 8 pounds of my wearable battery bank, i get 12 hours out of it (WITH DISPLAY!), wheras here we're talking 4 hours, not even counting that we'll need another 18w according to SONY's specs, so call that 2 hours with display carrying 8 pounds of battery. That sucks.
Now for plan B. We go for high capacity Li-ion batteries, more expensive, larger, but bettwer power-weight. Okay, now we get 34h/battery, and i can't find the weight spec, but i think they are a little more than a pound, but they cost $114/each so 8 pounds gets us 4 hours or so with these, but that's probably over $1500 in batteries. No good =:-( Doh!
I remember writing scripts for Telix (an old dos comm program) in it's mini implementation of C, which it called SALT (which stood for something, goodness knows what...) to go back and forth between my planets and Sol to get more colonists... It was fun.
A project i was working on at work needed to make calls (through Corba) to this big hairy fangs and claws having library from a third party that was written in Java. Now the neat thing, is that they didn't use any of that vendor-specific crap, so they actually shipped the same library for NT, Linux, Slowlaris, Tru64, and whatever else...
It was actually pretty impressive, and it worked too =:-)
Now that being said, i sure as hell wouldn't want my standard libraries to be in Java, 'cause it'd be slow as hell.
The day after i watched that movie, i was at work and some stupid program crashed on the stupid NT machine, and the error message it gave said the memory could not be "read" and i laughed my ass off =:-)
I am curious if anybody knows how hobbyist friendly this field is. It looks like the physical hardware needed to pick up these signals isn't much, but i can imagine you need some _REALLY SPIFFY_ (read expensive, large, current-hungry, heat dissipating...) amplifiers to make this sort of thing work, and then some really spiffy algorythms on the computer side to filter out noise that gets picked up, plus whatever low-level chatter is happening on that nerve...
So here is my question: Does anybody that knows something in this field know of a source of information on this? Is the technology patented by somebody? How complex are the electronics, and are the algorythms for extracting the data public?
The reason i ask is because i've always wanted to be able to do this, now i don't want to land jets, or play quake, i have a much more modest application in mind, i'd like to be able to get several (as few as four would still kick ass, although up to 10 would be nice...) reproducable (you don't have to be able to reproduce them from memory, there will be a visual feedback mechanism, so you know what you are inputting now, and you can watch it change as you "move"). I don't really have a practical use for this, and i'm sure i'll _always_ be able to type faster than i can use this method, but i still think it's very cool.
So i guess if it's something i could concievable do for under $1000 assumming i already had microcontroller tools, a scope, prototyping tools, etc... (so i'm talking only parts, books, software that must be purchased, and oddball tools...)
Thanks, and i really hope i hear from somebody, because this has sort of been a dream of mine since i was about 12 years old =:-)
All the nerds at my school (me included) were gathered at the school library to watch it take off, and then it blew up and everybody freaked out. Then later on i was sort of desensitised to the whole thing since they played the footage on the news on every station every hour for a week or so. Talk about shameless exploitation of mayhem...
X-Com is a good turn-based strategy game, it wasn't too popular when it came out (c. 1994?) but it was _very good_. You had to direct the actions of a team of scientists, police, firemen, and military personell to contain and cover up an alien invasion...
I always see a lot of people saying "this is all just common sense" or "this is nothing new" or whatever, but if people followed this set of guidelines, there would be a lot fewer bugs out there irritating computer users.
A similar strategy is set forth in some of the newer computer programming books i've seen including "The Practice of Programming" and "The Pragmatic Programmer", both of which aim to develop habits in programmers that cause them to produce cleaner saner code in a practical and intuitive way.
I think this is important because it is a practical alternative to the people who say "all programmers should be licenced and regulated, they should all have degrees, and all their code should be mathematically proven and group audited" while this will produce space-shuttle or medical-instrument grade applications, it will also produce space-shuttle grade costs. When you have to pay $125,000 per seat to use your word processor, but it's bug free, it's just not worth it.
These common sense practical approaces are more efficent than standard high pressure, low quality, commercial software development in terms of man-hours spent developing the same software, and as an added bonus, the software works better, and when it does have bugs, they are easier to track down.
So, no it's not new, it's the advice from older programmers who have been doing this since _way_ before i was born, so i should listen to it, not ignore it because it's not new....
Cool =:-) I'm just starting to experiment with FreeBSD. Of the UNIX systems i've had a machine running, it is the nicest. I've had Linux machines (still do infact), and i've also had a System V.r3 machine (boy was _that_ one a pain...) Yeah. It was an old 3B2/310. In any case, thanks for helping my UNIX knowledge...
These are neat features, just when i was thinking of replacing my linux masq box with a FreeBSD box to use it's spiffier NAT support and all that good stuff, this looks like it takes care of that. I may still do it for security though...
Now: Does anybody here know offhand if the packet filtering support in FreeBSD supports these features? (stateful ftp support, DNS probe rejection, etc...?) i know it has rate-limiting to make DOS attacks not work as well...
I know a while ago they were working on a system where they'd bind something (usually a bad-ass toxin) to a specific antibody and they could use that to go find cancer cells and kick their asses... Something like that may be useful here...
I've got a FreeBSD box that i want to bolt down and harden. It's a Dual PIII 800, and i want to use it for development and testing of a server program i'm writing. The server runs as nobody, so i'm not worried about that.
I've closed stuff off such that an nmap from localhost, tcp, syn, and udp shows only sshd, dhcpc, and syslog. I'm currently running the verson of openssh that comes with FreeBSD 4.2.
I'm planning on installing tripwire on the machine at some point as well. I also plan to write something that will mail me a diff of the setuid log between the current day and the previous day, as well as a similar thing for the password file. Any other suggestions?
Here is to the end of the cold war. The whole reason we have this huge national debt is because of off-the-wall military spending, etc...
It's good to see some of this gear that the government pissed away so much money on to fight the commies getting recycled for a peaceful, useful, civilian purpose. I wish i had that compound, it would be my dream home =:-)
The trick is that if somebody views the spam, as a convenience the browser loads the images specified in the tags, and most web bugs are 1x1 pixel images that the user doesn't notice, but still generate a get request, often with a cookie sent along with it. The average user is not oging to find browsing/etc... with "auto load images" turned off a tolerable functional browsing experience.
my solution is not to run an HTML-aware mail program. I delete anything that is not text/plain unless i'm _very_ sure of the source...
Having recently upgraded to a dual CPU system (dual Pentium III/800 Running FreeBSD) for the first time in my life, it's a real treat. I'd have a hard time going back. I can basiclt dedicate one processor to some evil large computing job, and still edit/compile/test code with no real lag. It's cool. I'd like to see more affordable SMP systems out there. I got mine dirt-cheap on ebay, but for the most part, dual and quad systems are out of reach of the average user, and that's a bummer...
I see how joe dumb user doesn't get too much use from it if they are just playing games, but hell, anybody doing any programming, content creation, etc... could get good use out of one. I think that is really the way to go... It's getting harder and harder to get more clocks out of the same piece of silicon, and nowadays that most serious processor hog apps are either threaded or distributed across processes, there is no good reason not to go SMP for everything if it can be made affordable.
I'm working on (or more accurately about to start) a very math intensive client server system, where the server has to do a metric ass-load of calculations mostly on 64-bit signed integers on behalf of client machines. The data are all going to be in ram, and multi-cpu support is a good thing.
Would you recommend a PPC machine over a x86 machine for a task like this? I guess this is mainly a chipset/etc... question, but i have been unable to find that sort of information elsewhere, and i figure who better to ask, 'cause you probably have a decent gut-feeling for how the architecture works in practice on real-world data =:-)
Disclaimer: I'm talking out my ass, because i personally don't believe in a sentient god.
It's quite possible that he believes in god, but not creationism. You don't have to take the bible literally to believe in god. I've heared some people go so far as to say that god knows/controls the outcome of interactions in the universe that we would call non-deterministic, and so he/she/it could set up an inital state and let it run and watch it go... Whatever you can imagine... I'll hazard a guess that this guy is not a creationist...
Is it just me or is the thing about the study of the brain's mechanism for suppressing agressive responses to negative emotions a little scary? Don't get me wrong, i don't think there is anything wrong with brain research (or dna research or computer research or about any other research... It's what keeps our civilization going...), but the potential applications of this, espescially in the current fear-driven medication-crazy culture are really scary. Clockwork Orange, andybody?
They even mention screening people based on the activity of this neural pathway for their likelyhood to commit violent acts. This is really going to be a can o' worms...
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The SONY Glasstron glasses (the cheap TV version without the VGA) have an SVHS in, which is sweet, 'cause it just happens this little bugger has a matching SVHS out... The power draw is a bear though.
Their power supply output is 15v DC @ 3A (45W).
Now, Sealed Lead Acid batteries (the best power per volume i have been able to find for my wearable) run about 13 Watt Hours per Pound. Now i figure the average draw of the machine is probably slightly less than half the supply rating, (although we still want to source the peak current when needed i'm more concerned with average when figureing out how long the batteries will last), so to be save we call it 20 W. So we need just under 2Lb of battery per hour of battery life. That's something to think about. Right now if i carry all 8 pounds of my wearable battery bank, i get 12 hours out of it (WITH DISPLAY!), wheras here we're talking 4 hours, not even counting that we'll need another 18w according to SONY's specs, so call that 2 hours with display carrying 8 pounds of battery. That sucks.
Now for plan B. We go for high capacity Li-ion batteries, more expensive, larger, but bettwer power-weight. Okay, now we get 34h/battery, and i can't find the weight spec, but i think they are a little more than a pound, but they cost $114/each so 8 pounds gets us 4 hours or so with these, but that's probably over $1500 in batteries. No good =:-( Doh!
Yeah, you're right, but the sector was called sol (a guess belonging to our sun...) so that's what stuck in my mind =:-) Man i miss that game...
I remember writing scripts for Telix (an old dos comm program) in it's mini implementation of C, which it called SALT (which stood for something, goodness knows what...) to go back and forth between my planets and Sol to get more colonists... It was fun.
A project i was working on at work needed to make calls (through Corba) to this big hairy fangs and claws having library from a third party that was written in Java. Now the neat thing, is that they didn't use any of that vendor-specific crap, so they actually shipped the same library for NT, Linux, Slowlaris, Tru64, and whatever else...
It was actually pretty impressive, and it worked too =:-)
Now that being said, i sure as hell wouldn't want my standard libraries to be in Java, 'cause it'd be slow as hell.
Maybe we should put up a similar website BonsaiSpook.com with FBI agents crammed into jars =:-)
I used to play that with a bunch of other geeks in High School. It was cool =:-)
The day after i watched that movie, i was at work and some stupid program crashed on the stupid NT machine, and the error message it gave said the memory could not be "read" and i laughed my ass off =:-)
I am curious if anybody knows how hobbyist friendly this field is. It looks like the physical hardware needed to pick up these signals isn't much, but i can imagine you need some _REALLY SPIFFY_ (read expensive, large, current-hungry, heat dissipating...) amplifiers to make this sort of thing work, and then some really spiffy algorythms on the computer side to filter out noise that gets picked up, plus whatever low-level chatter is happening on that nerve...
So here is my question: Does anybody that knows something in this field know of a source of information on this? Is the technology patented by somebody? How complex are the electronics, and are the algorythms for extracting the data public?
The reason i ask is because i've always wanted to be able to do this, now i don't want to land jets, or play quake, i have a much more modest application in mind, i'd like to be able to get several (as few as four would still kick ass, although up to 10 would be nice...) reproducable (you don't have to be able to reproduce them from memory, there will be a visual feedback mechanism, so you know what you are inputting now, and you can watch it change as you "move"). I don't really have a practical use for this, and i'm sure i'll _always_ be able to type faster than i can use this method, but i still think it's very cool.
So i guess if it's something i could concievable do for under $1000 assumming i already had microcontroller tools, a scope, prototyping tools, etc... (so i'm talking only parts, books, software that must be purchased, and oddball tools...)
Thanks, and i really hope i hear from somebody, because this has sort of been a dream of mine since i was about 12 years old =:-)
All the nerds at my school (me included) were gathered at the school library to watch it take off, and then it blew up and everybody freaked out. Then later on i was sort of desensitised to the whole thing since they played the footage on the news on every station every hour for a week or so. Talk about shameless exploitation of mayhem...
X-Com is a good turn-based strategy game, it wasn't too popular when it came out (c. 1994?) but it was _very good_. You had to direct the actions of a team of scientists, police, firemen, and military personell to contain and cover up an alien invasion...
I always see a lot of people saying "this is all just common sense" or "this is nothing new" or whatever, but if people followed this set of guidelines, there would be a lot fewer bugs out there irritating computer users.
A similar strategy is set forth in some of the newer computer programming books i've seen including "The Practice of Programming" and "The Pragmatic Programmer", both of which aim to develop habits in programmers that cause them to produce cleaner saner code in a practical and intuitive way.
I think this is important because it is a practical alternative to the people who say "all programmers should be licenced and regulated, they should all have degrees, and all their code should be mathematically proven and group audited" while this will produce space-shuttle or medical-instrument grade applications, it will also produce space-shuttle grade costs. When you have to pay $125,000 per seat to use your word processor, but it's bug free, it's just not worth it.
These common sense practical approaces are more efficent than standard high pressure, low quality, commercial software development in terms of man-hours spent developing the same software, and as an added bonus, the software works better, and when it does have bugs, they are easier to track down.
So, no it's not new, it's the advice from older programmers who have been doing this since _way_ before i was born, so i should listen to it, not ignore it because it's not new....
Cool =:-) I'm just starting to experiment with FreeBSD. Of the UNIX systems i've had a machine running, it is the nicest. I've had Linux machines (still do infact), and i've also had a System V.r3 machine (boy was _that_ one a pain...) Yeah. It was an old 3B2/310. In any case, thanks for helping my UNIX knowledge...
These are neat features, just when i was thinking of replacing my linux masq box with a FreeBSD box to use it's spiffier NAT support and all that good stuff, this looks like it takes care of that. I may still do it for security though...
Now: Does anybody here know offhand if the packet filtering support in FreeBSD supports these features? (stateful ftp support, DNS probe rejection, etc...?) i know it has rate-limiting to make DOS attacks not work as well...
Thanks
Hehheheh =:-) I prefer the _time honored_ method of exchanging genetic material =:-) [sorry, couldn't resist...]
I know a while ago they were working on a system where they'd bind something (usually a bad-ass toxin) to a specific antibody and they could use that to go find cancer cells and kick their asses... Something like that may be useful here...
I've got a FreeBSD box that i want to bolt down and harden. It's a Dual PIII 800, and i want to use it for development and testing of a server program i'm writing. The server runs as nobody, so i'm not worried about that.
I've closed stuff off such that an nmap from localhost, tcp, syn, and udp shows only sshd, dhcpc, and syslog. I'm currently running the verson of openssh that comes with FreeBSD 4.2.
I'm planning on installing tripwire on the machine at some point as well. I also plan to write something that will mail me a diff of the setuid log between the current day and the previous day, as well as a similar thing for the password file. Any other suggestions?
Here is to the end of the cold war. The whole reason we have this huge national debt is because of off-the-wall military spending, etc...
It's good to see some of this gear that the government pissed away so much money on to fight the commies getting recycled for a peaceful, useful, civilian purpose. I wish i had that compound, it would be my dream home =:-)
The trick is that if somebody views the spam, as a convenience the browser loads the images specified in the tags, and most web bugs are 1x1 pixel images that the user doesn't notice, but still generate a get request, often with a cookie sent along with it. The average user is not oging to find browsing/etc... with "auto load images" turned off a tolerable functional browsing experience.
my solution is not to run an HTML-aware mail program. I delete anything that is not text/plain unless i'm _very_ sure of the source...
Having recently upgraded to a dual CPU system (dual Pentium III/800 Running FreeBSD) for the first time in my life, it's a real treat. I'd have a hard time going back. I can basiclt dedicate one processor to some evil large computing job, and still edit/compile/test code with no real lag. It's cool. I'd like to see more affordable SMP systems out there. I got mine dirt-cheap on ebay, but for the most part, dual and quad systems are out of reach of the average user, and that's a bummer...
I see how joe dumb user doesn't get too much use from it if they are just playing games, but hell, anybody doing any programming, content creation, etc... could get good use out of one. I think that is really the way to go... It's getting harder and harder to get more clocks out of the same piece of silicon, and nowadays that most serious processor hog apps are either threaded or distributed across processes, there is no good reason not to go SMP for everything if it can be made affordable.
Thanks. My current two test-bed machines are an Athlon 750 and a Dual Pentium III 800. I can't wait for the dual athlons to come out =:-)
I'm working on (or more accurately about to start) a very math intensive client server system, where the server has to do a metric ass-load of calculations mostly on 64-bit signed integers on behalf of client machines. The data are all going to be in ram, and multi-cpu support is a good thing.
Would you recommend a PPC machine over a x86 machine for a task like this? I guess this is mainly a chipset/etc... question, but i have been unable to find that sort of information elsewhere, and i figure who better to ask, 'cause you probably have a decent gut-feeling for how the architecture works in practice on real-world data =:-)
I guess "Thpppt" is better than "Ack!" which is the other famous Bill the Cat sound...
Let me get this straight! Solar winds "sound" like "whales in ecstasy?" That's fucking ridiculous... Hehehe
Disclaimer: I'm talking out my ass, because i personally don't believe in a sentient god.
It's quite possible that he believes in god, but not creationism. You don't have to take the bible literally to believe in god. I've heared some people go so far as to say that god knows/controls the outcome of interactions in the universe that we would call non-deterministic, and so he/she/it could set up an inital state and let it run and watch it go... Whatever you can imagine... I'll hazard a guess that this guy is not a creationist...
Is it just me or is the thing about the study of the brain's mechanism for suppressing agressive responses to negative emotions a little scary? Don't get me wrong, i don't think there is anything wrong with brain research (or dna research or computer research or about any other research... It's what keeps our civilization going...), but the potential applications of this, espescially in the current fear-driven medication-crazy culture are really scary. Clockwork Orange, andybody?
They even mention screening people based on the activity of this neural pathway for their likelyhood to commit violent acts. This is really going to be a can o' worms...