Slashdot Mirror


User: PeterBrett

PeterBrett's activity in the archive.

Stories
0
Comments
824
First seen
Last seen
Profile
(view on slashdot.org)

Comments · 824

  1. Re:easy on Ask Slashdot: How To Stay Fit In the Office? · · Score: 1

    This is the right answer!

    I've always cycled to work, sometimes as far as 25km each way. It's a great way to stay in shape, it's fun (even when the weather's bad), and you get to see and hear lots of interesting things you'd miss sitting in a car or on a bus. Also, it can often be faster than driving or taking public transport, especially if the roads where you are tend to get congested at rush hour.

  2. Re:Wait. on 2013 Will Be a Big Year For Private Spaceflight · · Score: 3, Informative

    That's out of date. Dragon's C&C software has been Linux (not even RT-Linux) since the first flight that docked with the space station.

  3. Re:Wait. on 2013 Will Be a Big Year For Private Spaceflight · · Score: 4, Interesting

    Some guys down the corridor from me are literally using a Makerbot to fabricate flight components for prototype satellite plasma thrusters.

  4. Re:US Law Everywhere on Amazon and Google Barred From UK Government Cloud · · Score: 1

    Last time I checked, a maximum of a two-year custodial sentence is not a life sentence.

    Just look at cases where an English judge asks a defendant 20-30 times for a key, and each refusal is three more years in the slammer.

    Yeah, that didn't happen.

    But your unnecessary hyperbole aside, I entirely agree that RIPA is utter rubbish, and I wish it would go die in a fire.

  5. Re:hearts and minds on Alan Cox to NVIDIA: You Can't Use DMA-BUF · · Score: 3, Insightful

    "Please comply with the very permissive licence that we chose to licence our code under" does not amount to a religious argument.

  6. Re:And this is why on Alan Cox to NVIDIA: You Can't Use DMA-BUF · · Score: 5, Informative

    I thought Oracle v. Google said APIs weren't copyrightable. As such, GPL-only APIs make no sense because the API can't be copyrighted to begin with.

    You're wrong.

    It is fine for someone to go and make a new, compatible implementation of the DMA-BUF API, with the same calling conventions etc., and license it however they wish. That is what the Oracle vs Google judgement said.

    It is not okay to link your code into the GPL version of the DMA-BUF API unless your code is also GPL'd. That is something different.

  7. Re:Reshuffles on The UK's New Minister For Magic · · Score: 1

    Do any of these people have any actual experience or qualification in the departments they get dumped on?

    Sometimes, albeit rarely.

  8. Re:He might not think it works, but IS a politicia on The UK's New Minister For Magic · · Score: 1

    It doesn't really matter what treatments Hunt wants the NHS to pay for; NICE is not under political control, and approves treatments based only on measurements of cost-effectiveness. BTW, this makes NICE extremely unpopular.

  9. Re:News Flash on Study Shows Marijuana Use In Teens Correlates To Decreasing IQ · · Score: 1

    There are some things for which just about any amount is overdoing it (e.g. cyanide).

    My bag of almonds begs to disagree.

  10. Re:please remind me the religion of Germany + Russ on Nobel Laureate Wiped From Pakistan's Textbooks As Heretic · · Score: 1

    Um. Actually, Germany = Lutheran, for the most part.

  11. Gaisler VHDL style on Ask Slashdot: Sources For Firmware and Hardware Books? · · Score: 4, Interesting

    It's not a book, but this book chapter is more-or-less compulsory reading for someone planning to get into HDL programming:

    A structured VHDL design method

  12. Re:Breakup on Billionaires and Polymaths Expected To Unveil a Plan To Mine Asteroids · · Score: 1

    The NASA study mentioned in the summary, which makes very worthwhile reading, recommends using a C-type asteroid rather than an M-type asteroid, explicitly because C-type asteroids explode and burn up very high in the atmosphere. And M-type asteroids of the size discussed hit the Earth multiple times every year anyway.

  13. Re:A bad idea that "sounds good". on Billionaires and Polymaths Expected To Unveil a Plan To Mine Asteroids · · Score: 1

    And when the mission makes a mistake and an asteroid goes plummiting into a major city it will cause trillions of dollars in damage and massive loss of life and potentially create a cloud of dust that will cause an ice age.

    Objects bigger than the size they're proposing to catch enter Earth's atmosphere several times every year. I think you've been watching too many movies. Did yo think the LHC was going to make a black hole and destroy the Earth, too?

  14. Re:Highway lights??? on UK To Dim Highway Lights To Save Money · · Score: 1

    You want to save electricity? Ban clothes dryers, electric heaters, dishwashers and electric kettles. At least you'd cost less lives than this insanity.

    Actually, dishwashers usually use less energy and less water than washing up by hand, if you run them with a full load. And it's quite common in the UK to have electric hobs in the kitchen; boiling water in an electric kettle is always more energy efficient than boiling it in a conventional kettle on an electric hob.

    Furthermore, the examples you provide are unambiguously uses of the energy to do something useful. Using huge amounts of power to light a completely deserted stretch of road at 3 am in the morning is unambiguously not useful.

  15. Re:Loss of Service is more annoying on EFF Seeking Information of Legal Users of Megaupload · · Score: 1

    What about OwnCloud?

  16. Re:Undercosting much? on Spanish Extremadura Moving 40,000 Desktops To Linux · · Score: 4, Informative

    "And of course, it needs to be free. Because our budget for this plan is of zero euros."

    Yep.

    Can't see this blowing up in anyones face. (See: the ongoing ordeal and budget overruns of the Munich conversion)

    Um, last time I checked (which was a couple of weeks ago) the Munich project was going extremely well.

  17. Re:The problem with our railways is not speed on UK Green Lights HS2 High Speed Rail Line · · Score: 1

    Well, I live in Surrey, and regularly travel between Woking, Guildford, London, Oxford and Cambridge (I don't have a car). And I literally can't remember the last time a train I wanted to travel on was cancelled, or sufficiently late that I missed a connection or important connection.

    Although in fairness I must point out that, despite running on time, First Capital Connect trains from Kings Cross to Cambridge are incredibly shitty and crowded.

    Don't forget, folks: the plural of "anecdote" is not "data"!

  18. Re:Yes lots, also lots of rich city types on UK Green Lights HS2 High Speed Rail Line · · Score: 2

    Confirming that the "environmental concerns" are really concerns over property prices on the part of people rich enough to own country homes in the Chiltern Hills...

  19. Re:The problem with our railways is not speed on UK Green Lights HS2 High Speed Rail Line · · Score: 2

    Note that the biggest problem with that route is the section between Cardiff and Swansea, where the terrain is so hilly that the only way to speed up the existing tortuous train route would be to rebuild it entirely with lots of tunnels. Note that the main reason that the government recently decided not to electrify that section was that the increased speed benefits of lighter, faster electric trains would not be realised on that section of line.

    Once the trains get past Bristol, they do get up to full speed. Also, note that the three hours on that route includes several stops, which bring down the overall average speed quite severely! London to Brussels only stops at Ebbsfleet, Calais, and Lille on the way, and runs on very high speed lines all the way.

    I don't think it's really fair to compare those two routes, TBH. When you think about it, the Swansea-London trains are actually doing pretty well...

  20. Re:The problem with our railways is not speed on UK Green Lights HS2 High Speed Rail Line · · Score: 1

    They are building the line to the European loading gauge. The line is designed to be fully compatible with European very-high-speed lines, as DB and SNCF have expressed an interest in running through trains from European cities to Birmingham through the Channel Tunnel once the Eurotunnel monopoly expires. Additionally, the line is being built to serve very long trains (up to 12 European-length carriages).

    All-in-all, the wider/taller loading gauge (which provides the option for double-decker carriages) and the long platforms will mean that HS2 will provide enormous numbers of seats between London and Birmingham.

    It's not practical to upgrade most UK lines to the larger gauge, because it would mean rebuilding every station, raising every platform, re-laying every piece of track with wider separation (displacing hundreds of thousands of homes and businesses near train lines), widening every cutting and embankment, rebuilding every bridge, and reboring every tunnel. It would be possible, but not politically viable (imagine the voter response to being told that there will be no train service between London and Bristol for the next five years due to regauging, and oh by the way, we're taking half your back garden).

  21. Re:I thought this was a crypto/cypher challange on GCHQ Challenge Solution Explained · · Score: 2

    This sounds like they are more interested in recruiting people to analyze stuff like Stuxnet

    Yes, that's probably exactly what they're after.

  22. Re:Not so packed on Raspberry Pi PCB Layout Revealed · · Score: 1

    It's a pretty trivial board. I'd quote at most a day's work (8-10 hours) for a board of that complexity, even assuming I was handrouting the whole thing...

  23. Re:Complicated? on Raspberry Pi PCB Layout Revealed · · Score: 1

    Xilinx has some good info on bypass caps and how they can be placed in their Spartan 6 docs.

    Xilinx Application Note 623 is an excellent introductory guide to PDS design.

    Just to expand on your points: the main thing to bear in mind is that the higher the frequency you're running it, the smaller the cap values you need and the more important it is to keep loop inductance low. There are two cases in which I place my decoupling caps on the reverse side inside the package footprint (usually BGAs have an area free of pins in the centre of the die). Firstly, when I'm running at very high frequencies (> 100 MHz) and it's essential to use really tiny capacitors. Secondly, when I have a very restricted number of layers and putting the caps inside the footprint simplifies my fanout.

  24. Re:It'd be nice if ... on The IOCCC Competition Is Back · · Score: 1

    Thank you for confirming that Java sucks for anything that needs to be slightly performant.

    In contrast, C# has value types (structures), so it can pack the "value" reference and the "stamp" into either 2 pointers, or 1.5 if you mix 64-bit pointers and 32-bit ints. In C#, arrays of value types are packed, so the total size is... 1.5-2 pointers per entry, just like in C.

    I don't know of any architectures that can do unaligned compare-and-swap of a element with a non-power of two extent, so you need to use either a 64-bit (CMPXCHG8B) or 128-bit (CMPXCHG16B) combined value.

    My issue with .NET is its lack of portability and extremely dubious legal status. I have no opinion on the language's technical aspects.

  25. Re:It'd be nice if ... on The IOCCC Competition Is Back · · Score: 2

    java.util.concurrent.atomic is a perfect example of why Java is not a viable choice for the work I'm doing. One of the tasks I currently have to handle is multiprocess disjoint set construction (using the wait-free union-find algorithm), on a very large corpus. This algorithm requires each disjoint set tree node to contain two fields: a reference to its superset, and a rank counter. In Java, the only choice I have is to use an array of AtomicStampedReference<V>, which will always occupy at least two platform words. Because I know the exact size of the corpus, in C I can easily do some trivial pointer arithmetic to halve the amount of storage required on 64-bit platforms. Not only does this allow me to process larger datasets on my workstation without suffering from memory exhaustion, but because the computation turns out to be memory bandwidth-limited, it allows me to process it faster as well.

    Oh, and .NET can DIAF.