python_regious

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About python_regious

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  1. best version of linux

    I generally use Debian, however it can occasionally be a total bitch to setup. Ubuntu is good if you want something that will "just work".
  2. Looking for a good file source control/backup utility

    We use (a custom modified) PRCS at work, and it's pretty good. I've had much better experiences with it than Subversion or CVS, though I've no idea whether it uses an SQL backend or not...
  3. For those that use eclipse

    The only non-commercial plugins I use/have used are JUnit and CDT. I use all sorts of commercial ones at the moment, most notably Cantata++ and Wind River Workbench.
  4. How a CPU Works? The Nitty Gritty

    Quote:Original post by hplus0603 You're not alive until you've written microcode using toggle switches for an ALU implemented in discrete 74-series logic :-) I think it's useful, because it gives you an understanding of subjects such as write hazards, race conditions, instruction latencies, etc. :-( I've only input microcode into the instruction cache of some god awful 8 bit CPU with hex switches. You may find actual IC design interesting too (I know I did), though I can't recommend any books on it, as I can't find mine. Though, I suppose it all depends on whether you're interested in the layouts of circuit elements (no, that nice circuit diagram you have doesn't translate directly to what's on an IC), deep sub-micron effects and so on.
  5. A thought occured to me [political]

    Quote:Original post by trzy You Europeans would be in a better position to argue against US military spending if you had self-sufficient militaries of your own. I realize European nations have capable and advanced military forces but during the Cold War (which has been most of the time since WWII), the US was largely responsible for putting up any real defense of Europe against the Soviets. I wonder whether your social programs would be as expansive had you been solely responsible for your own defense. The amount of military spending to accomplish this would have been enormous. A trade-off between military and social service spending is not unique to the US. The Chinese have recently increased their military spending (which, as a percentage of their national budget, is still far behind the US) while their veterans complain about inadequate pension payments. I've also heard that Britain may be significantly reducing the size of their naval fleet soon. Britian is rather upgrading it's naval fleet rather than reducing it, though the number of ships may eventually decrease slightly, it's capability will not. We've just launched the first of a new series of attack subs, and our 45 series destroyers are due to start to be launched later in the year I believe. (This is of course ignoring the whole developmenet of new nuclear subs and aircraft carriers planned for the next 10-25 years). As for Europe not doing anything, the primary reason Britain is designing a new class of aircraft carrier is because of the role the current class is designed to make. During the cold war, Britain was essentially responsible for the defence of Soviet Union submarines, hence all it's carrier fleet is designed with submarine warfare in mind. Because this isn't relavent anymore, a new generation is being designed. The US was responsible for a significant proportion of the brunt of force granted, however the "little things" like making sure subs don't get through and so on were left to us to handle, and our militaries evolved accordingly. As for "the US was largely responsible for putting up any real defense of Europe against the Soviets", something you may not know is that the independant strategic nuclear deterrent from Britain to the Soviet Union was based on proportionate damage. Such that, any attack from the SU onto GB would result in significant civilian casualties even if only military installations were targetted, due in no small cost to the size of Britain and the proximity of these installations to civilian centres. Because of this, the entirity of Britains nuclear deterrent was targetted at Soviet Union civilian centres, rather than military targets, to provide a proportional cost of destruction and to assure MAD. We may "only" have had 1000 or so nuclear weapons at our disposal during the cold war (This has since been cut to 100-200 or so), but they were to be used in such a way as to assure a realistic deterrent. Anyway.
  6. Death of a dream?

    I've pretty much accepted that all of the projects I had going a year ago will no longer be finished, and will not have anything more done with them. It's a bit of a shame (I had a sweet ass engine going too), but then that's life I suppose. The thing that did it for me was actually getting a job where I'm coding, or doing coding related things 90% of the time. The last thing I want to see when I get home is more code. This is also probably one of the major reasons I've been pretty much abscent from the technical fora for the past year or so. Still, life changes, you get on with it I suppose.
  7. What does English sound like?

    Quote:Original post by Fiddler unless he went into Welsh territory that is (which as far as I'm concerned doesn't sound like English - or any other language - at all). Well, if he was actually speaking Welsh, I can see why that wouldn't sound anything like English, because it's well, not. I don't find the Welsh accent hard to understand, though that maybe because I'm Welsh myself (minus any significant accent however).
  8. Beginning Electronics

    Quote:Original post by daviangel I guess everyone has their own opinion of what beginning is and obviously yours is way different than mine. In all fairness, that's quite likely. It wouldn't suprise me that my version of "beginner" is way skewed, when it comes to electrical engineering that is anyway. Quote: For the most part, it's analog design that requires the more advanced math. The Apple had to be made mostly of digital components, like a microprocessor chip, chips for RAM and/or ROM, and maybe some other chips to help interface the chips together. Maybe some analog design was needed for the video output since an NTSC signal is an analog signal (I think you could hook it up to a tv). I'd bet it's accurate when Woz says he didn't need much more than basic math to build the Apple I. Agreed on the analog front, probably why I used to prefer digital stuff when I did my degree. However, designing a high-speed circuit can be quite tricky and maths intensive. Though, I've no idea how fast the Apple I actually went.
  9. Beginning Electronics

    Quote:Original post by daviangel "Everything is covered in a lot of detail, and is rather mathematical (you AT LEAST need to be very comfortable with calculus). You'll also learn quite a bit of semiconductor chemistry with this book." How can you consider this a beginner book? Because everything is covered, right from the beginning. Yes, it assumes you have some standing knowledge of mathematics, but it's no less a beginner book on the subject of electronic devices.
  10. Beginning Electronics

    A big second for "The Art Of Electronics" here. Granted, it only covers the very very basics in one, skimmed over chapter (stuff like Ohms law, the Kirchoff ones, and so on), however you don't really need more than that IMO. After that, it really does explain things in easy-to-understand terms, and actually gives you practical advice, rather than just theoretical knowledge. I'd also highly recommend "Electronics : Circuits and Devices". It's a fabulous book, the first chapter centred on basic circuit elements, and values, and exactly what they mean (mathematically). It then goes onto teaching you the fundementals of transistors, and eventually goes on to Op-Amps, amplifier circuits, and so on. Everything is covered in a lot of detail, and is rather mathematical (you AT LEAST need to be very comfortable with calculus). You'll also learn quite a bit of semiconductor chemistry with this book. That's all I can think of really books wise (certainly the only two on my shelf that are suitable for beginners). One thing I have noticed though, is that there really aren't any online references that are even remotely any good, which is a shame.
  11. iPhone you?

    Meh, I'll stick with my HTC Universal thank you very much.
  12. Division by 0 problem solved - apparently

    Quote: Nope, I'm with the École normale supérieure, which provides the Astrée static analysis tool used by Airbus. Most dynamic tests used on airplanes are integrated into the on-board control system. I don't know the specific details of this, but I'm pretty sure that every time the electronic system of a plane is turned on, it runs diagnostic tests to check that both software and hardware act correctly. Cool. Well, I know Boeing use unit testing techniques on their software (using AdaTEST95), however I should bloody well hope that they have an onboard diagnostic system!
  13. Division by 0 problem solved - apparently

    Quote:Original post by ToohrVyk Quote:Original post by python_regious Fair enough, though I believe Airbus are using Ada for at least part of their software. I hear it's used for the command interface. Quote: Well, testing is really the only method to be able to prove that the software under test is actually doing what it should (and just as importantly not doing what it shouldn't). Developing a good testing strategy (unit, integration and functional) is paramount. The approach used by Airbus is different: they sprinkle their code with assertions, add several common sense constraints (no divide-by-zero, no writing outside arrays, no calling sqrt on a negative number), and then run the entire code through a static analysis program (Astrée). The static analysis program then lists possible errors, which are corrected, until it is proven that no assertions or constraints are violated anymore. EDIT: this isn't to say that they don't also use tests, simply that the soundness of their programs is proven instead of just tested. Unlike tests (where there is always a possibility that an untested case is buggy), static analysis proves that no runtime errors happen. Of course, asserting conditions and constraints is a little bit like writing unit tests, but you can be a lot more expressive with it (in static analysis, assert(x > 0) means x is always positive, in testing it means x is positive in all tested cases). I see. Well, you can't verify code integrity with static analysis alone (though, it's good for enforcing coding standards, and the like). You have to drive the SUT with some sort of dynamic test and gather results from that (in the form of code coverage - D0-178B Level A MC/DC for instance - a military condition on software and general checks). When dynamically testing software you need some sort of test harness that can gather coverage information on the SUT - such that you know what bits of code have been tested, and which have not, and so you can verify values in and out of the SUT, can verify call sequences and so forth. Do you guys (I presume you work for Airbus) not use any sort of test harness then? (for example, IBM's Rational, IPL's Cantata(++) and AdaTEST95 [smile], etc?) Yeah... I work with this sorta thing... [smile]
  14. Division by 0 problem solved - apparently

    Quote:Original post by ToohrVyk Quote:Original post by python_regious Erm, not really. Ada is used in most safety critial applications that I can think of. The code for most aircraft, all space craft, signalling systems for trains, and a lot of military applications is written in Ada. That's possible. However, the primary flight system on the A340 was written in C, and I doubt that they would move away from Ada if they had used in previous versions. Fair enough, though I believe Airbus are using Ada for at least part of their software. Quote: Quote:Besides, the best programming language in the world is useless unless you have a decent test harness and testing strategy. True. Unexpected arithmetic errors aren't due to a lack of exceptions. In the end, you still have to prove (or test, but that's less convincing) that the critical system behaves as expected. Well, testing is really the only method to be able to prove that the software under test is actually doing what it should (and just as importantly not doing what it shouldn't). Developing a good testing strategy (unit, integration and functional) is paramount. Anyway, I digress from the topic [smile].