#qi-hardware IRC log for Tuesday, 2012-09-25

whitequarkhttp://whitequark.org/blog/2012/09/25/why-raspberry-pi-is-unsuitable-for-education/04:23
Action: pabs3 submits that to slashdot04:43
Action: whitequark checks if the server could handle the load04:44
whitequarkthanks, btw.04:44
pabs3lwn and #debian-arm too, since there are some ARM employees in the latter :)04:46
pabs3whitequark:  seems you are missing some info? "except for the graphics processor, see more on that below" but that is the 2nd last paragraph04:49
pabs3maybe s/below/above/04:50
whitequarkyeah, should be above.04:50
pabs3whitequark: some feedback:04:59
pabs3<p2-mate> mips is not royalty free :P05:00
pabs3<p2-mate> and mips inc does hold some patents on the mips architecture05:00
whitequarkpabs3: any chances to discuss that?05:00
pabs3jump on #debian-arm on irc.oftc.net05:01
pabs3wikipedia and http://www.mips.com/company/about-us/patent-portfolio/ seem to confirm the patent part05:01
pabs3LM32 would probably have been a better example05:02
whitequarkyeah, I'll add a paragraph there05:09
rz2kdamn it, why we have two "opensource"-oriented irc networks?05:16
whitequarkthe same reason we have qt&gtk05:17
whitequarkoss&alsa05:17
whitequarketc.05:17
pabs3hysterical raisins05:22
Action: rz2k nearly said u mean one is bogus like hell and second one is barely usable?05:23
rz2kI should stop using kvirc, it eats my quotation marks.05:24
whitequarkpabs3: _raisins_?05:24
whitequarkthat is, the berries?05:24
rz2kbro, that was a language-based joke.05:26
pabs3http://www.catb.org/jargon/html/H/hysterical-reasons.html05:26
whitequarkheh05:33
Action: pabs3 prefers OFTC because Freenode have /mode +i by default05:46
lekernelwhitequark: nice rant. now I can point everyone asking me about rpi to it.09:18
lindi-I'd concentrate on the non-free GPU code that you need to boot it09:40
whitequarklindi-: technically, every Cortex-* chip has proprietary bootrom in some form or another09:48
whitequarkI'd say that practically any chip nowadays does09:48
whitequarkbut yeah, the scheme that rpi has is off limits.09:48
whitequarklekernel: you're welcome.09:48
Action: xiangfu tweeted. whitequark's rpi post.09:55
LunaVoraxHi!10:08
pabs3whitequark: how does LM32 boot?10:22
whitequarkpabs3: there is no silicon LM32 implementations10:27
lindi-indeed10:42
lekernelwhitequark: there are, but they aren't public11:41
lekernel(lm32 license isn't gpl-style)11:41
whitequarklekernel: then I doubt that bootrom would be public either11:43
Fallenouwell the bootrom is not a big problem is it ?11:54
Fallenouas long as it is documented11:54
Fallenouyou cannot change it anyway11:54
whitequarkI agree. I was replying to lindi- 11:57
viricrpi was a lot meant to beat in price, isn't t?12:13
viricit12:13
larscprimarily it is a marketing campaign, I guess12:15
virica marketing campaing with a product, though12:18
kyakand why exactly would education need a "white box"?12:20
larscwell I guess that always depends on what you want to teach. If you want to teach how to use and program a black-box SoC the rpi is probably not too bad12:24
larscif you want to teach how a modern SoC works from top to bottom, the rpi is probably not so good12:25
viricI agree12:26
virica cheap blackbox soc, with enough degrees of freedom for many CS students12:26
viric(and a huge effort marketing it)12:27
kyakthen we agree that rpi is good for teaching how to work with SoC, and bad for teaching how SoC works.12:28
kyaknoone in his mind will use rpi to teach to SoC works, so rpi IS suitable for education12:29
kyaks/to/how12:29
kyakhehe12:29
whitequarkto everyone about black boxes.12:29
whitequarkyou see, the RPi isn't the cheapest or most accessible one.12:30
kyakwhat is a cheaper alternative?12:30
whitequarkyou have plenty of Allwinner boxes in very different form factors which have cases and accessories and still just a little bit more expensive12:30
whitequarkthe link in the beginning mentions one.12:30
whitequarkI'm absolutely sure that an RPi won't survive a day without a case in a school environment.12:30
whitequarkand you need either WiFi (which isn't there), or wired Ethernet infrastructure (which isn't there either, or otherwise you won't need RPis), etc.12:31
whitequarkthe TCO for RPi is far higher than the board cost.12:31
whitequarkso yeah, it's kinda usable in that sense, but what's the point12:32
kyakso feel free to just say that rpi is shit due to technical flaws12:32
kyakbut your main point is about opennnes12:32
whitequarkfor me, the whole "for education" point was about teaching computing from ground up, see also comparison to BBC Micro.12:32
viricthe old bbc micro?12:33
whitequarkbecause otherwise I don't see which problem does it solve at all.12:33
viricwhat is a TCO?12:33
whitequarkif you need a cheap computer for schools, there are _plenty_ of options, you hardly need another crappy broadcom board12:33
whitequarkTCO = total cost of ownership12:33
viricok12:33
paul_boddiewhitequark: Nice article! :-)13:17
paul_boddieI agree with you about the relative openness of the BBC Micro, although there were proprietary bits in that, too. But at least they published the schematics.13:19
whitequarkraspberry pi schematics are public13:21
whitequarkboard layout isn't13:21
viricI didn't know the bbc micro was any open13:21
paul_boddieOK, I'm not sure the board layout was public for the BBC Micro, but they at least published a lot of technical details including the BOM in the manual, I think.13:22
whitequarkviric: it wasn't, but it was distributed with schematics and BOM13:22
viricok13:22
viricwell, many televisors were distribted with schematics, no? :)13:22
whitequarkand given the complexity of computers in that age, it was enough to figure out the rest13:22
virictelevisions?13:23
whitequarkso the goal of having even the lower layer accessible was achieved13:23
viricat the valve time, a lot came with schematics :)13:23
paul_boddieI think the ULAs were all proprietary, which was probably less of an inconvenience on the BBC than it was on the Acorn Electron.13:23
whitequarkULA?13:24
paul_boddieUncommitted Logic Array. The forerunner to FPGA technology.13:24
paul_boddieThere's a project and a book about reverse-engineering the ULA in the ZX Spectrum.13:25
wpwrakthe war cry of the martians in "war of the worlds" :)13:26
whitequarkah. well, you could use a good microscope13:26
whitequarkgiven that it's OTP13:26
paul_boddieYes, that's what they did, I think. http://www.zxdesign.info/book/theZXSpectrumULA.shtml13:27
paul_boddieThe Electron's ULA takes the essentials from various discrete ICs and combines them into a single component. Acorn did actually document that in a vague "block diagram" kind of way, and the registers were all documented, of course, but replicating it is left as an exercise for the reader. :-)13:29
paul_boddieBut I guess that just comparing the amount of technical information in the manuals for those old computers to what you get with the Raspberry Pi shows that they are leagues apart.13:37
paul_boddieSome more material for whitequark's article: http://www.wired.com/opinion/2012/09/raspberry-pi-insider-exclusive-sellout-to-sell-out/15:49
whitequark>How could we enable hacking while preventing cloning?15:53
whitequarklolwhat15:53
whitequarklike if you *actually* need 7 years to make an rpi.15:54
whitequarkor that absence of gerbers prevents cloning.15:54
larscI thought you couldn't source the brcms on the rpi anyway?15:56
whitequarklarsc: maybe a chinese company wishing to clone them could16:57
whitequarkthey probably won't anyway, but that's another thing16:57
viricwhitequark: they were afraid of qi-hw17:06
GNUtoo-desktopwho? tuxbrain?17:07
GNUtoo-desktophi btw17:07
viricrpi people17:08
GNUtoo-desktopok17:08
GNUtoo-desktopif rpi is the raspery py they can't be QI because of how their device is made:17:09
GNUtoo-desktop*rasberry17:09
GNUtoo-desktopThey need a GPU "firmware" to boot the machine17:09
GNUtoo-desktopwhich is proprietary....17:10
paul_boddieYes, whitequark's article sums it all up pretty comprehensively.17:14
viricIs the nanonote opus-ready? :)17:51
viric(quite an unfortunate name, here)17:52
lekernelhaha they had problems with BGA routing18:19
lekernelI guess wired reportards are now discovering what BGA means ...18:19
larscthe article was written by one rpi founders18:23
whitequarkviric: define "afraid"?18:53
whitequarkfor what reason?18:53
viricqi-hw cloning rpi :)18:53
viricee hackers18:54
viricI was just kidding18:54
whitequarkah18:55
whitequarklekernel: is wired that bad?19:01
Action: whitequark finds gigaom pretty competent19:01
lekernelah, gigaom... "The solar kit charges at a rate of 4 watts per hour and can hold 16 watts in its battery"19:24
lekernelhttp://gigaom.com/cleantech/a-social-energy-network-turns-to-solar-chargers-shopping/19:24
lekernelauthor is specialist of "renewable energy"19:25
virichold 16 watts?19:25
lekernelthat's my point :)19:26
viric:)19:26
Fallenou21:02 < whitequark> lekernel: is wired that bad? < does it contain anything else than advertisment pages ?19:31
whitequarklekernel: LOL19:33
whitequarkwatts per hour19:34
whitequarkreminds me of how utility companies here measure energy in kW*h, which is technically correct, but quite fucked up.19:35
wpwrakhow so ?19:36
whitequarkwpwrak: correct or FU?19:36
whitequarkif latter, I just find it weird19:37
whitequarkprobably because my physics class was before I ever needed to track grid energy usage19:37
viricI'm fine with kW*h19:38
whitequarkwell I always need to include 3600 coefficient, that drives me mad19:39
viricfor what? That translates easily to money :)19:39
whitequarkbecause I tend to calculate everything else in SI units19:41
whitequarkand if you run a 20A device for 80s, then how much kWh will it be?.19:42
whitequark*?..19:42
whitequarkwell disregard that, it's just my pet peeve19:42
larscyou could calculate the amount of money you have to pay per joule once and use that ;)19:45
viricdo you use m^3 for milk?19:45
viric:)19:45
whitequarkif only the price of electricity was constant...19:45
whitequarkviric: liters are translated to cubic meters with a 1e6 coefficient, that's way easier than dividing by 3.6.19:46
viricI agree.19:46
whitequarkand have you ever seen milk sold by liter, not by package?19:47
wpwrakmaybe if you ask nicely, they'll send you your bill in MWs, and charge you for 1 MWs the same as for one 1 kWh ;-)19:50
wpwrakactually, you should pay more, since it's a whole million !19:51
whitequarkMJs you mean?19:51
whitequarkah, MW*s19:52
whitequarklol19:52
whitequarkI'd send that idea to putin19:52
whitequarkwho'll be our dicta^Wpresident for the next 18 years19:52
viricwhitequark: milk sold by liter? sure19:53
whitequarkviric: yeah I understand what you mean, through I'm probably somewhat young and lived mostly in urban areas19:54
viric:)19:54
virichere we have trendy milk service machines, where you insert coins, and a tap gives milk.19:55
whitequarkcool19:55
whitequarkI won't really trust such a machine to provide non-rotten milk here, through19:55
larsci suppose they throw away whats left over every evening19:59
viricI'm not a milk master20:00
viricThey change it every day20:00
viricbut I doubt they 'throw it away'20:00
viricthere are plenty of good things to do with milk.20:00
whitequarklarsc: that implies you actually care about it and do some maintenance.20:00
virichttp://translate.google.com/translate?sl=ca&tl=en&js=n&prev=_t&hl=ca&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.lletllet.com%2Fhigiene-seguretat.html20:01
larscwhitequark: that's a big problem in russia isn't it, nobody cares about anything20:01
whitequarklarsc: exactly20:02
viricor care on very particular things, and nothing else. 20:02
viricIt's just a matter of finding what does every russian care about20:02
whitequarkviric: looking at people around, I suppose it is "not giving a fuck about anything". so...20:03
viric:)20:03
whitequarkwell you could definitely distract people enough to strip they from the ability of not giving a fuck. you'd need a second WWII. I doubt you actually want it.20:04
larscbut why is that, is everything so fucked up, that people gave up to care?20:04
viricIt could be bad feedback. People not caring on anything because other people don't care on anything.20:05
whitequarkyup, positive feedback plays a great role20:05
larsctragedy of the commons extreme20:06
whitequarklarsc: kind of. gave up, yeah20:06
whitequarkactually I won't really oppose some country dropping a thermonuclear bomb on moscow, even considering that I'm there20:10
whitequarkbecause I'm absolutely sick of it20:10
whitequarkeverything around20:10
larscand no chance of leaving it behind?20:17
whitequarksometimes you can't actually believe that there is a good world out there20:21
wpwrakstep 1: find a country that has low immigration barriers. step 2: learn the language. step 3: make enough money for the trip and whatever you need to get started. step 4: escape into the adventure :)20:22
larscwhitequark: that's what you did?20:23
larscwpwrak: 20:23
wpwrakwell, it looks a bit like that from the outside :) with less desperation, though20:24
whitequarkwpwrak: 1. australia 2. done 3. in progress 4. I won't leave some people behind. I'm trapped here for at least 2 yrs, and who knows what next.20:24
whitequarkdesperation might be caused by the fact that I'm a bit drunk atm. might. or different causes.20:26
wpwrakah well, people have endured worse :)20:26
wpwrakof course, 4 adds baggage20:26
wpwrakgrmbl. brain still not working well enough to write a brute-forcer for finding an algorithm that picks the k-th (sorted) value from an unsorted n-vector :-(20:30
larscare you trying to find something that does it in less than n log n?20:32
wpwrakyup20:33
larsci don't think that's possible20:34
wpwrakand with very little overhead. has to run a lot of times in an avr.20:34
wpwrakhere's an example for n = 3, k = 2nd element (i.e., the median): http://pastebin.ca/220766020:35
larscand you use n * log n compare operations20:37
wpwrakthe brute-forcer idea is to try all sequences of comparisons and pick one that yields the decision tree with the lowest depth. should still be doable up to at least n = 5.20:38
wpwrak(compares) yes20:38
larscbut?20:39
wpwrakoh, just need to wrap my hay-feverish brain around it, that's all20:39
larscso n and k are fixed?20:43
larscand you just want the code like above?20:43
wpwrakyes20:52
wpwrakk and n are build-time values20:52
wpwrak(well, the idea is to make it possible to generate variants with different k and n values. as opposed to manually cooking up such a function, as in my example)20:53
mthwhitequark: is your server melting yet?22:08
Fallenoua lot of moronic comments22:10
Fallenouthey don't even understand why it is so chip22:11
Fallenoucheap*22:11
FallenouI bet they got the main chip for almost nothing22:11
Fallenouthey work there god damn it22:11
Fallenouit's almost a project of the company making the chip22:11
Fallenouand so far they were right to invest on this project22:12
Fallenouso much advertisement22:12
Fallenoublog posts, tweets, facebook posts, conferences22:12
FallenouI wonder how much it would have cost to pay such a huge advertisement campaign22:13
mthit depends on what kind of education you're looking for: if you want to teach people application programming, R-Pi is fine, but if you want to teach them low-level programming or hardware design, it has serious problems22:33
mthand if it's just about application programming, then the board should have been sold boxed, imo22:34
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