ExpressPCB has a truly excellent MiniBoard service: 3 boards for $51 (aka $60 with shipping), 3.8"x2.5" (a convenient small-board size, really). They ship air mail the next business day. Other sizes get a little more expensive (<$100 in qty 2 until it gets large) as do features like 4-layer boards (though they only do internal power / ground planes, not traces) and solder mask / silk screen (either can be done for <$200). CNC-drilled mounting holes to match your box and line up the switches and LEDs and correct placement on things like heat sink posts adds a lot, and the plated-through holes and vias are a plus.
(No affiliation, but I've used their services many times, both as a hobbyist and professionally.)
I agree with almost everything you said. First, let me toss out a few part numbers. I know it can be annoying to try to figure out which silicon component to buy when they all look the same but are obviously slightly different.
Digikey is your friend. If they don't stock it, find a replacement they do stock. Buy a hundred each 2N3904 and 2N3906 for your bipolar transistors. At a couple cents each, you don't need to worry about letting the magic smoke out occasionally. 2N2222 makes a great slightly higher current NPN switch. At $0.36 each, the venerable 741 makes an excellent op amp to experiment with; by the time you can figure out what to do with a better op amp, you'll know what to look for. Buy a big assortment pack of 1/4W carbon film resistors; they're cheap, and not having the right value is annoying. For caps, you'll want a big stack of cheap 0.1uF ceramics for local power supply decoupling, some modest size (10-33uF) electrolytics, and some larger electrolytics (100-330uF) (I suggest the Panasonic FM series as inexpensive high quality caps, but there are lots of choices). Grab a few poly film caps in the 1nF - 0.1uF range; that should cover most other uses of caps for experimenting. You'll want some 1N4148 signal diodes, along with some 1N4004 rectifier diodes. Might as well add a few 1N5818 schottky diodes for power supply work. And, of course, the 555 timer you suggested. I don't happen to have part numbers to recommend for CMOS discretes. Add some random indicator LEDs and buttons, and a couple variable resistors. 7805 / 7812 make good fixed voltage regulators, and the LM317 should handle your adjustable needs. Anyway, if you can't build it with those parts, it's probably not a good early project. Eventually you'll get around to the 7400 / 4000 series logic chips.
If you're doing real analog work, get a real power supply. Failing that (they're expensive; no, the one from that old computer is not an acceptable substitute) get a cheap wall wart that just has a transformer and a bridge rectifier and a cap in it, and add a regulator. If you're doing it that way, get several -- you'll want multiple voltages around.
I have to disagree about making your own PCBs. It's educational, but it's also a pain. When you need an actual PCB, buy it from ExpressPCB. If you only need to work with surface mount parts, Digikey sells a number of handy prototyping boards that will convert surface mount things into through-hole things, and optionally have space for a couple surface mount passives to go next to them.
The guts of a 741 is both a good and a bad place to start learning about [bipolar] transistors. You certainly won't digest it all in one sitting. But it has most of the basic arrangements that are important, and they're relatively cleanly separated. It's got an emitter-follower push-pull output stage, a common-emitter gain stage, a long-tailed pair differential input stage, some current mirrors to set up biasing, and a Vbe multiplier to help bias the output stage; it's really not complicated if you take it in parts and don't feel any particular need to understand it in one sitting. That's true of any non-textbook circuit, though, really.
PICs are a great way to do interesting things, but if you really want to know why your PIC works quite well except when the moon is waxing gibbous, you're probably going to have to learn some analog stuff. You can go a long way without paying attention to the analog side, just as you can do an awful lot of programming without ever looking at compiler output -- but in either case, you're holding yourself back compared to what you could be doing.
Oh, and Jim's scope drawing is probably round because I believe he still uses that scope. Then again, his definition of a computer (page 12) is probably not the same as the poster's;)
Much as you can't learn to program well without looking at programs more complicated than you'll find in any textbook, you need to study real world circuits.
Whether you want to do digital stuff or analog, it's worth your time learning the analog stuff -- digital systems tend to break as a result of the underlying analog problem of circuit design.
For example, Wikipedia has the internal schematic for a 741 op amp along with a decent explanation. Once you understand the function of every one of those transistors, you'll be able to really understand why it has both a gain-bandwidth limit and a slew rate limit, and what the difference is.
The best source of real-world circuits I've found is the application notes and example circuits in data sheets published by manufacturers. Since they need the resultant circuits to work when engineers build them, they don't leave out the random extras that textbooks often do. Does that MOSFET need a gate resistor? A circuit in an app note will probably say, whereas an example diagram might well not.
If your goal is to learn more in general, as opposed to solving a specific problem, I'd pay more attention to the author than exactly what they're writing about. For example, I can't recommend Jim Williams' design notes highly enough -- he's both an excellent engineer and an excellent author. Making Shakespeare a citation is the sort of thing that keeps his writing lively and interesting. Or rating circuit complexity in baby bottles as a measure of how long it took him to design and debug it. And, of course, he often goes into great detail about the *practical* considerations involved in precise, high-speed analog work -- especially as it relates to working at the lab bench, rather than with professionally printed PCBs and the like.
I'm sure others will have excellent textbook recommendations. They're an important part, but only a part. Add some analysis of real-world circuits that you'll find in application notes, and a bunch of fussing around with actual silicon and a scope, and you'll be well on your way.
Wouldn't justice be better served if they have to pay the price of their bullying to the defendant? B-)
No. Pleasant as it might be to watch the RIAA get smacked down harder, justice is always best served by putting a stop to injustice at the first possible opportunity.
Re:Blizzard may be my favorite company, but please
on
Who Owns Software?
·
· Score: 1
So tetris isn't fun? Lots of people would disagree.
A game so simple a bot can play it does not necessarily mean it's fun. Bot-proof levels of complexity are neither necessary nor sufficient for fun. Depending on the type of game, the issues may be unrelated, correlated, or negatively correlated.
I have here a package of razor blades. "50 single edge #9 razor blades," it says in large print on the front. On the side, it reads "Warning: razor sharp blades."
TCP/IP provides data integrity guarantees. So, if your ISP wasn't mucking with your packets (and their checksums), either Apple was sending the wrong bits or your hardware or software was screwing with them. My vote is it's not Apple.
I suggest you diagnose your computer problems, rather than relying on BitTorrent to fix them for you.
Barney is not for 7 year olds. Many of them, if curious, are quite capable of understanding fairly complex topics. It's obvious you've never actually had a conversation with a smart, curious 7 year old.
WP should not be used as source material. That does not make it useless. The same is true for any encyclopedia.
WP is an excellent resource for several things. It provides a good overview of a subject. Often, if you're only somewhat knowledgeable on a subject, it can fill in some gaps in ways that are obviously not horribly wrong. For example, I've learned a lot of math on WP -- I can follow the derivations, and see their correctness independent of any other source, but I couldn't produce them on my own. This is, obviously, a limited case -- especially for a kid.
The best thing to use WP for, once you have a high-level grasp of a topic, is its bibliography. Nearly all articles contain at least a couple references; some contain quite extensive bibliographies. These are useful places to start your research. Need some data on global warming? I wouldn't get it from WP, but I would happily go to the WP page, find what appeared to be the data I wanted, find the citation for it, and then go read the referenced material.
What model? So far, for the majority of the work I do, 1mV/div is one of the few features I'd pay for. More bandwidth would also be nice, but I've been continually amazed at how much I can do on 650kHz. Of course, when you actually need the more bandwidth, you simply can't fake it -- but there are ways to deal with not enough sensitivity.
Got a reference? A peer-reviewed, relatively up to date one? That actually says anthropogenic CO2 is irrelevant, not just that some other study overstates the matter?
Of course, it's harder to troll if you have to post references, so I'm guessing you won't bother.
Really? CO2-caused climate change / warming won't have an impact on humans? Have you read the major studies, or any reasonable summary of them? Also, do you have a reference for your 0.28% number? Everything I've seen suggests you're off by nearly two orders of magnitude, depending on the accounting details.
Some of us define pollution as "anything that causes severe enough damage to our environment to make life difficult for us humans." And guess what, low-level ozone, ozone layer depleting compounds, acid rain precursors, CO2, volatile hydrocarbons, fertilizer runoff, and a variety of other things all count under that definition.
I can be really selfish and even somewhat short-sighted and still come to the conclusion that there is a problem on a massive scale. I have no particular need for us to not create any CO2, but it should be obvious to anyone who bothers to look at the data and the studies that we can't continue on our current pace.
I got my 561A for free, and I love it dearly. I don't mean to disparage it; lots of its features were state of the art at the time. Unless I'm mistaken, it introduced the ceramic strip construction techniques, producing much lower noise than its predecessors. The dual-trace alternating mode (3A72 amplifier) was certainly a selling point. But the features I mentioned -- properly compensated input, gain-selectable input amp, modest bandwidth -- were hardly new, unless I'm mistaken. The amplifier I have is actually only 650kHz, but I believe there were a variety of faster plugins available if you needed bandwidth.
I believe all the tubes are original. I've replaced some of the electrolytics and a couple pots. There are a couple switches that need replacing, along with something in the square wave generator -- or maybe the switch contacts just need cleaning; I haven't taken the time to debug it thoroughly yet. My favorite feature? The note, right next to the high voltage warning, cautioning the user to only use appropriate silver-bearing solder on the terminals, with accompanying roll of silver-bearing solder. Now *that* is a feature you won't find on any modern scope, no matter the price.
Have you actually implemented an oscilloscope in any meaningful sense, or is this just a low-performance data acquisition system? Nothing wrong with the latter (I'm in the process of designing and building a high-quality, modest performance data acquisition board myself), but it's not the same as a scope.
A scope needs, at a minimum, a decent sample rate (though for many purposes I'd settle for something as low as a 10MHz sample rate with 1MHz bandwidth, or even a bit less). It needs a properly compensated input (ie 1MOhm / 20pF or similar, and importantly specs on what that is). It needs an input amplifier with selectable gain, so that I can see down to at least 10mV/division (~100mV peak to peak full scale). It needs both an AC coupled and DC coupled mode. If it's implemented digitally, it needs 8 bits of noise-free resolution (10 would be nice, but often isn't required). If it's digital, it needs to specify timing jitter error (ideally specified as "negligible" though worse is fine as long as it's characterized). Ideally it should have multiple channels and some controls about triggers and such, but those aren't particularly required. Accuracy requirements are surprisingly loose: 2% is fine, 5% is usually acceptable for all or almost all parameters.
What you have looks like a handy first pass at a very simple data acquisition system. I don't mean to disparage that; it's a very useful tool. But, as an occasional analog engineer who would love to be able to recommend an inexpensive oscilloscope, this doesn't look like an oscilloscope at all, much less one worth recommending as such. The part that makes an oscilloscope hard to build is not the microcontroller code, but the analog front end. The 1960s vintage Tektronix tube scope I have does what I describe above, and most of that wasn't even state of the art at the time. The available tools have gotten better, but the fundamental requirements haven't changed. A data acquisition system is nice, but it's not really a tool for circuit analysis like a scope is.
Anyway, I'm done with my cranky analog engineer rant now. This looks like a very cool toy! I'll probably stick with my PICs out of habit, but I'll definitely take a look at this.
Are you sure? I've seen plenty with "polymer lead" in various forms, but that always seems to mean polymer-graphite composite. Are any of them nonconductive? Don't they still have issues with breaking?
Remember also that pencil technology has improved in the past 40 years. Whether there are or aren't pencils that would work today, I'd be surprised if there were pencils that would have worked 40 years ago.
We're talking about an overclocked CPU. He upped the voltage, and it draws more current now. What, you thought the cooling tower in the driveway was for show?
Please stop repeating that myth. Snopes says you're wrong.
For those too lazy to read the link: Fisher spent their own money on the development, and the results were far better than pencils. Pencil leads break off and create an electrical and fire hazard, not to mention making dust. These are real problems in free fall that aren't present on the ground. Sorry, but your intuition of what works well on the ground will not translate in any meaningful way to free fall.
10% of the light from a 30 meter telescope is the same amount of light as a regular 10 meter telescope. Hubble is a 2.4m telescope. I think it will have plenty of light.
Foil doesn't have to crinkle. Look at the center of a mylar balloon -- not exactly crinkly. Obviously if you want telescope-grade not-crinkly you'll have to spend a bit more, but that's not really a problem. This is also a bit more sophisticated than a pinhole camera -- those have trouble collecting much light.
You discovered the pinhole camera, aka tiny aperture = increased depth of field. This is different -- they actually have a large imaging aperture and still keep good focus.
It sounds to me like he's already out of the poverty cycle. Whether through his parent's sacrifice or other means, he's not in the lowest class. So, having accomplished that much, must the sacrificing continue? If so, is it to continue indefinitely? If so, what was it for in the first place?
Once the most basic goals are accomplished, happiness should be neither forgotten completely nor pursued to the exclusion of all else. Rather, it should be balanced against other needs.
Slashdot Mirror
ExpressPCB has a truly excellent MiniBoard service: 3 boards for $51 (aka $60 with shipping), 3.8"x2.5" (a convenient small-board size, really). They ship air mail the next business day. Other sizes get a little more expensive (<$100 in qty 2 until it gets large) as do features like 4-layer boards (though they only do internal power / ground planes, not traces) and solder mask / silk screen (either can be done for <$200). CNC-drilled mounting holes to match your box and line up the switches and LEDs and correct placement on things like heat sink posts adds a lot, and the plated-through holes and vias are a plus.
(No affiliation, but I've used their services many times, both as a hobbyist and professionally.)
I agree with almost everything you said. First, let me toss out a few part numbers. I know it can be annoying to try to figure out which silicon component to buy when they all look the same but are obviously slightly different.
Digikey is your friend. If they don't stock it, find a replacement they do stock. Buy a hundred each 2N3904 and 2N3906 for your bipolar transistors. At a couple cents each, you don't need to worry about letting the magic smoke out occasionally. 2N2222 makes a great slightly higher current NPN switch. At $0.36 each, the venerable 741 makes an excellent op amp to experiment with; by the time you can figure out what to do with a better op amp, you'll know what to look for. Buy a big assortment pack of 1/4W carbon film resistors; they're cheap, and not having the right value is annoying. For caps, you'll want a big stack of cheap 0.1uF ceramics for local power supply decoupling, some modest size (10-33uF) electrolytics, and some larger electrolytics (100-330uF) (I suggest the Panasonic FM series as inexpensive high quality caps, but there are lots of choices). Grab a few poly film caps in the 1nF - 0.1uF range; that should cover most other uses of caps for experimenting. You'll want some 1N4148 signal diodes, along with some 1N4004 rectifier diodes. Might as well add a few 1N5818 schottky diodes for power supply work. And, of course, the 555 timer you suggested. I don't happen to have part numbers to recommend for CMOS discretes. Add some random indicator LEDs and buttons, and a couple variable resistors. 7805 / 7812 make good fixed voltage regulators, and the LM317 should handle your adjustable needs. Anyway, if you can't build it with those parts, it's probably not a good early project. Eventually you'll get around to the 7400 / 4000 series logic chips.
If you're doing real analog work, get a real power supply. Failing that (they're expensive; no, the one from that old computer is not an acceptable substitute) get a cheap wall wart that just has a transformer and a bridge rectifier and a cap in it, and add a regulator. If you're doing it that way, get several -- you'll want multiple voltages around.
I have to disagree about making your own PCBs. It's educational, but it's also a pain. When you need an actual PCB, buy it from ExpressPCB. If you only need to work with surface mount parts, Digikey sells a number of handy prototyping boards that will convert surface mount things into through-hole things, and optionally have space for a couple surface mount passives to go next to them.
The guts of a 741 is both a good and a bad place to start learning about [bipolar] transistors. You certainly won't digest it all in one sitting. But it has most of the basic arrangements that are important, and they're relatively cleanly separated. It's got an emitter-follower push-pull output stage, a common-emitter gain stage, a long-tailed pair differential input stage, some current mirrors to set up biasing, and a Vbe multiplier to help bias the output stage; it's really not complicated if you take it in parts and don't feel any particular need to understand it in one sitting. That's true of any non-textbook circuit, though, really.
PICs are a great way to do interesting things, but if you really want to know why your PIC works quite well except when the moon is waxing gibbous, you're probably going to have to learn some analog stuff. You can go a long way without paying attention to the analog side, just as you can do an awful lot of programming without ever looking at compiler output -- but in either case, you're holding yourself back compared to what you could be doing.
Oh, and Jim's scope drawing is probably round because I believe he still uses that scope. Then again, his definition of a computer (page 12) is probably not the same as the poster's ;)
Much as you can't learn to program well without looking at programs more complicated than you'll find in any textbook, you need to study real world circuits.
Whether you want to do digital stuff or analog, it's worth your time learning the analog stuff -- digital systems tend to break as a result of the underlying analog problem of circuit design.
For example, Wikipedia has the internal schematic for a 741 op amp along with a decent explanation. Once you understand the function of every one of those transistors, you'll be able to really understand why it has both a gain-bandwidth limit and a slew rate limit, and what the difference is.
The best source of real-world circuits I've found is the application notes and example circuits in data sheets published by manufacturers. Since they need the resultant circuits to work when engineers build them, they don't leave out the random extras that textbooks often do. Does that MOSFET need a gate resistor? A circuit in an app note will probably say, whereas an example diagram might well not.
If your goal is to learn more in general, as opposed to solving a specific problem, I'd pay more attention to the author than exactly what they're writing about. For example, I can't recommend Jim Williams' design notes highly enough -- he's both an excellent engineer and an excellent author. Making Shakespeare a citation is the sort of thing that keeps his writing lively and interesting. Or rating circuit complexity in baby bottles as a measure of how long it took him to design and debug it. And, of course, he often goes into great detail about the *practical* considerations involved in precise, high-speed analog work -- especially as it relates to working at the lab bench, rather than with professionally printed PCBs and the like.
I'm sure others will have excellent textbook recommendations. They're an important part, but only a part. Add some analysis of real-world circuits that you'll find in application notes, and a bunch of fussing around with actual silicon and a scope, and you'll be well on your way.
No. Pleasant as it might be to watch the RIAA get smacked down harder, justice is always best served by putting a stop to injustice at the first possible opportunity.
So tetris isn't fun? Lots of people would disagree.
A game so simple a bot can play it does not necessarily mean it's fun. Bot-proof levels of complexity are neither necessary nor sufficient for fun. Depending on the type of game, the issues may be unrelated, correlated, or negatively correlated.
I have here a package of razor blades. "50 single edge #9 razor blades," it says in large print on the front. On the side, it reads "Warning: razor sharp blades."
I think warning labels have gotten excessive.
Such a shame, too, it only had one word in it...
TCP/IP provides data integrity guarantees. So, if your ISP wasn't mucking with your packets (and their checksums), either Apple was sending the wrong bits or your hardware or software was screwing with them. My vote is it's not Apple.
I suggest you diagnose your computer problems, rather than relying on BitTorrent to fix them for you.
Barney is not for 7 year olds. Many of them, if curious, are quite capable of understanding fairly complex topics. It's obvious you've never actually had a conversation with a smart, curious 7 year old.
WP should not be used as source material. That does not make it useless. The same is true for any encyclopedia.
WP is an excellent resource for several things. It provides a good overview of a subject. Often, if you're only somewhat knowledgeable on a subject, it can fill in some gaps in ways that are obviously not horribly wrong. For example, I've learned a lot of math on WP -- I can follow the derivations, and see their correctness independent of any other source, but I couldn't produce them on my own. This is, obviously, a limited case -- especially for a kid.
The best thing to use WP for, once you have a high-level grasp of a topic, is its bibliography. Nearly all articles contain at least a couple references; some contain quite extensive bibliographies. These are useful places to start your research. Need some data on global warming? I wouldn't get it from WP, but I would happily go to the WP page, find what appeared to be the data I wanted, find the citation for it, and then go read the referenced material.
What model? So far, for the majority of the work I do, 1mV/div is one of the few features I'd pay for. More bandwidth would also be nice, but I've been continually amazed at how much I can do on 650kHz. Of course, when you actually need the more bandwidth, you simply can't fake it -- but there are ways to deal with not enough sensitivity.
Got a reference? A peer-reviewed, relatively up to date one? That actually says anthropogenic CO2 is irrelevant, not just that some other study overstates the matter?
Of course, it's harder to troll if you have to post references, so I'm guessing you won't bother.
Really? CO2-caused climate change / warming won't have an impact on humans? Have you read the major studies, or any reasonable summary of them? Also, do you have a reference for your 0.28% number? Everything I've seen suggests you're off by nearly two orders of magnitude, depending on the accounting details.
Some of us define pollution as "anything that causes severe enough damage to our environment to make life difficult for us humans." And guess what, low-level ozone, ozone layer depleting compounds, acid rain precursors, CO2, volatile hydrocarbons, fertilizer runoff, and a variety of other things all count under that definition.
I can be really selfish and even somewhat short-sighted and still come to the conclusion that there is a problem on a massive scale. I have no particular need for us to not create any CO2, but it should be obvious to anyone who bothers to look at the data and the studies that we can't continue on our current pace.
I got my 561A for free, and I love it dearly. I don't mean to disparage it; lots of its features were state of the art at the time. Unless I'm mistaken, it introduced the ceramic strip construction techniques, producing much lower noise than its predecessors. The dual-trace alternating mode (3A72 amplifier) was certainly a selling point. But the features I mentioned -- properly compensated input, gain-selectable input amp, modest bandwidth -- were hardly new, unless I'm mistaken. The amplifier I have is actually only 650kHz, but I believe there were a variety of faster plugins available if you needed bandwidth.
I believe all the tubes are original. I've replaced some of the electrolytics and a couple pots. There are a couple switches that need replacing, along with something in the square wave generator -- or maybe the switch contacts just need cleaning; I haven't taken the time to debug it thoroughly yet. My favorite feature? The note, right next to the high voltage warning, cautioning the user to only use appropriate silver-bearing solder on the terminals, with accompanying roll of silver-bearing solder. Now *that* is a feature you won't find on any modern scope, no matter the price.
Have you actually implemented an oscilloscope in any meaningful sense, or is this just a low-performance data acquisition system? Nothing wrong with the latter (I'm in the process of designing and building a high-quality, modest performance data acquisition board myself), but it's not the same as a scope.
A scope needs, at a minimum, a decent sample rate (though for many purposes I'd settle for something as low as a 10MHz sample rate with 1MHz bandwidth, or even a bit less). It needs a properly compensated input (ie 1MOhm / 20pF or similar, and importantly specs on what that is). It needs an input amplifier with selectable gain, so that I can see down to at least 10mV/division (~100mV peak to peak full scale). It needs both an AC coupled and DC coupled mode. If it's implemented digitally, it needs 8 bits of noise-free resolution (10 would be nice, but often isn't required). If it's digital, it needs to specify timing jitter error (ideally specified as "negligible" though worse is fine as long as it's characterized). Ideally it should have multiple channels and some controls about triggers and such, but those aren't particularly required. Accuracy requirements are surprisingly loose: 2% is fine, 5% is usually acceptable for all or almost all parameters.
What you have looks like a handy first pass at a very simple data acquisition system. I don't mean to disparage that; it's a very useful tool. But, as an occasional analog engineer who would love to be able to recommend an inexpensive oscilloscope, this doesn't look like an oscilloscope at all, much less one worth recommending as such. The part that makes an oscilloscope hard to build is not the microcontroller code, but the analog front end. The 1960s vintage Tektronix tube scope I have does what I describe above, and most of that wasn't even state of the art at the time. The available tools have gotten better, but the fundamental requirements haven't changed. A data acquisition system is nice, but it's not really a tool for circuit analysis like a scope is.
Anyway, I'm done with my cranky analog engineer rant now. This looks like a very cool toy! I'll probably stick with my PICs out of habit, but I'll definitely take a look at this.
Are you sure? I've seen plenty with "polymer lead" in various forms, but that always seems to mean polymer-graphite composite. Are any of them nonconductive? Don't they still have issues with breaking?
Remember also that pencil technology has improved in the past 40 years. Whether there are or aren't pencils that would work today, I'd be surprised if there were pencils that would have worked 40 years ago.
We're talking about an overclocked CPU. He upped the voltage, and it draws more current now. What, you thought the cooling tower in the driveway was for show?
Please stop repeating that myth. Snopes says you're wrong.
For those too lazy to read the link: Fisher spent their own money on the development, and the results were far better than pencils. Pencil leads break off and create an electrical and fire hazard, not to mention making dust. These are real problems in free fall that aren't present on the ground. Sorry, but your intuition of what works well on the ground will not translate in any meaningful way to free fall.
10% of the light from a 30 meter telescope is the same amount of light as a regular 10 meter telescope. Hubble is a 2.4m telescope. I think it will have plenty of light.
Foil doesn't have to crinkle. Look at the center of a mylar balloon -- not exactly crinkly. Obviously if you want telescope-grade not-crinkly you'll have to spend a bit more, but that's not really a problem. This is also a bit more sophisticated than a pinhole camera -- those have trouble collecting much light.
You discovered the pinhole camera, aka tiny aperture = increased depth of field. This is different -- they actually have a large imaging aperture and still keep good focus.
Yes, but when the dev team decides to make the one choice be a bad one, and one that most users hate, there's cause for concern -- and even forking.
OrgName: SF Bay Packet Radio
NetRange: 134.17.0.0 - 134.17.255.255
CIDR: 134.17.0.0/16
What do you have against the SF Bay Packet Radio?
Their upstream providers shouldn't be routing it, but you shouldn't blackhole it either...
It sounds to me like he's already out of the poverty cycle. Whether through his parent's sacrifice or other means, he's not in the lowest class. So, having accomplished that much, must the sacrificing continue? If so, is it to continue indefinitely? If so, what was it for in the first place?
Once the most basic goals are accomplished, happiness should be neither forgotten completely nor pursued to the exclusion of all else. Rather, it should be balanced against other needs.