> But it also says that documentation on the ARM architecture is not freely > available, and that indeed could be a problem. Did the author of that > article even try to do a basic search of the documentation or is he trying > to make his point by obfuscating the facts?Here's is the full Technical > Reference Manual, including the programmer's model (for those inclined to > roll their own assembly code), for the ARM11 core used in the R-Pi. You can > download the full PDF (all 728 pages) if you wish peruse it offline. > http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0360f/index.html > In general, I'm not sure I care much what CPU/SoC a system uses as long as > we have a gcc port that can compile to that platform. What I'm really > interested in is what kind applications/tools can we build to make these > systems actually reach the target (education) market. Or even better, > intuitive tools for kids to use to build their own applications. -Nilanjan > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf > Of Tom Metro > Sent: Saturday, October 06, 2012 1:35 PM > To: [email protected] > Subject: [HH] Raspberry Pi stuff: enclosure, Pi NAS, closed source not good > for education > > Thanks to Stephen Adler for filming and posting his Raspberry Pi > Video/Tutorial: > http://www.mail-archive.com/[email protected]/msg00487.html > > (I haven't viewed it, but will take a look when/if I get a Raspberry Pi.) > > > Here's a fairly introductory Raspberry Pi tutorial that end with how to use a > Raspberry Pi as a NAS: > http://www.techradar.com/news/computing/pc/raspberry-pi-tutorial-how-to-do-more-1095946 > > > adafruit is promoting a colorful new Pi enclosure that is made of a rainbow > assortment of laser cut acrylic that stacks up and is sandwiched between a > top and bottom layer of clear acrylic: > http://www.adafruit.com/blog/2012/09/20/in-stock-pibow-enclosure-for-raspberry-pi-computers/ > > > Why One Person Thinks Raspberry Pi Is Unsuitable For Education > http://hardware.slashdot.org/story/12/09/25/2056240/why-one-person-thinks-raspberry-pi-is-unsuitable-for-education?utm_source=rss1.0mainlinkanon&utm_medium=feed > > (Quoting Slashdot, which quotes the original article, > http://whitequark.org/blog/2012/09/25/why-raspberry-pi-is-unsuitable-for-education/) > > "Raspberry Pi was designed for education. As any popular product is > bound to, Raspberry Pi has been criticized a lot for things like lack > of a box, absence of supplied charger or even WiFi. Raspberry Pi has a > much more fundamental flaw, which directly conflicts with its original > goal: it is a black box tightly sealed with patents and protected by > corporations. It isn't even remotely an open platform." > > The "proprietary GPU blob needed to boot" is mentioned, which has been > discussed here before. The article also touches on the ARM being patented, > which I don't have a problem with. But it also says that documentation on the > ARM architecture is not freely available, and that indeed could be a problem. > > It goes on to list some completely open source CPU cores, as well as pointing > out other proprietary vendors, like Atmel, have freely shared their > documentation without onerous licensing restrictions. > > The author recommends the more open Beagle Board or Samsung ODROID-X as a > Raspberry Pi alternative. He also recommends the fully open hardware > Milkymist One, but it costs $800 and thus isn't a practical alternative. > I guess he wasn't aware of some of the other open hardware boards that are in > the same league as the Pi and still fairly cheap. > > Rhombus Tech (http://rhombus-tech.net/), a company creating an open hardware > platform, was mentioned in the Slashdot comments. (Not terribly unique. I > posted about another Raspberry Pi-class device recently > (OLinuXino-Micro) that was open.) The Rhombus Tech products will use a > PCMCIA-like metal-enclosed card design, and their first model will use an > Allwinner A10 CPU. > > The full article is worth a read. > > The Slashdot blurb also references: > > Raspberry Pi's Secret: 'Sell Out a Little to Sell a Lot' > http://www.wired.com/opinion/2012/09/raspberry-pi-insider-exclusive-sellout-to-sell-out > > ...if other manufacturers copied the design, our partners would lose > their investment, which was approaching several million dollars. > > How could we enable hacking while preventing cloning? Holding back the > schematics altogether troubled us. Not being open would impede > people's ability to interface and hack the hardware - defeating the > very goals we had set out to accomplish with Raspberry Pi in the first > place. > > So we decided to publish the schematics, but hold back the detailed > Bill of Materials (BOM) and physical PCB design or "Gerbers" for a > limited amount of time. After all, hardware is just one part of our > overall plans. The schematics alone don't provide enough information > to clone the Pi without expending considerable effort re-laying the > PCB and figuring out the exact part used in each location. > > Ummm...if Broadcom is one of the partners, and the product depends on the > Broadcom SoC that in turn requires a proprietary software blob, it would seem > they already had two hard to bypass barriers to cloning: > Broadcom could refuse to sell the SoC, or it could shut down the clones for > copyright violation. Was Broadcom not cooperative? > > Here's an interesting bit on the board fabrication: > > ...we had 253 connections to bring out (the BGA escape) in an area > much smaller than the size of a dime. And while there are special > high-density interconnect (HDI) techniques for densely layered PCBs, > those would just reduce yield and increase processing steps not to > mention the costs. ... What if we could steal the idea of "blind micro > vias" from high-density interconnects, but apply it cheaply enough for > the Pi design? > > Instead of going through all the PCB layers, we made human-hair sized > holes (micro vias) that go through only the first couple of layers > (blind) - saving just enough space on the other layers for wiring up > the other PCB components. At high volumes, these holes could be made > quickly and efficiently with a laser. And it only cost a few cents > extra. Making these tradeoffs resulted in a relatively simple > six-layer board that didn't compromise power distribution. And it > enabled manufacturing at scale. > > Seems like another good way to ward off clones, unless this technique is > widely known. > > -Tom
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