Writing ... or Just Practicing?

Random Disconnected Diatribes of a p&p Documentation Engineer

  • Writing ... or Just Practicing?

    Currently Overloaded...

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    You don't normally expect zonking amounts of current to be flying around inside a computer (unless you've packed it solid with extra disk drives), so tagging a couple of skinny wires to one end of the circuit board is probably an eminently sensible approach. Those five DC volts will eventually find their way along the copper tracks and wander into the odd chip when required, and it's fairly unlikely you'll get flash-over between the connector pins or a nasty smell as several amps of current rumble uncontrolled through the resistors and capacitors.

    In fact, the working bits inside a chip are now so small and close together that we worry about quantum effects (and if all the dead cats will interfere with calculations). I mean, what if an odd electron decided to go walkabout one day and debit your account at the bank instead of crediting it? If the nice man at Intel happened to sneeze when they were making the chip for your machine, it could mean that all of your spreadsheets are calculating the wrong answer.

    See, this is the thing. We're so focused on digital stuff, miniaturized electronics, and tiny voltages squirming their way through the ever-increasing complexity of modern machines that we tend to forget that real electricity doesn't behave anything like this. It needs big chunky wires, and often involves several real amperes rather than those wimpy milliamp things - as I discovered when I went to see if I could help a friend sort out a problem with his model railway (railroad) layout last week.

    When I was younger, and a practitioner in the art of miniaturized transport modeling, the only way you could get the locos to move was to shove lots of DC current through the track, accompanied (in the later period as electronics began to blossom into the modeling world) with a high frequency pulsed current that zapped the bits of dust and cat hair that might impede the flow of amps into the tiny electric motors. It you put two locos on the same track, they went round together and the speed controller box got hotter and hotter until the reset button popped out. Unless, of course, you'd wired them different so they went opposite ways. Then the head-on collision usually occurred before the reset button had time to react.

    I remember reading, just at the end of my modeling days, about the new electronics that were coming to the hobby. Digital Command Control (DCC) was the upcoming thing. You just shove 15 volts AC into all of the track all of the time, and the individual control modules in each loco, turnout motor, and accessory allow you to individually control each one. Up to 99 separate channels, and superbly fine speed control as well because the chip can fire pulsed bursts of current into the electric motor, rather than just feeding it a constant voltage. And, from what I've seen in working layouts recently, it really does make everything easier and better. Another first for technology. It even uses wireless now so that the "driver" can wander around getting the best viewpoint without being constrained by (or tripping over) trailing cables.

    However, the trouble with my friend's layout was that the fine control only worked for about 30 seconds before the control box decided all was not well and turned off the power. We initially suspected a short circuit, but my multi-meter could find no sign of one. We tested several different locomotives with no effect. Finally, we started measuring track voltages and current consumption in multiple places around the layout.

    And, yes, even with DCC and the magic of electronics, model railway locos still do absorb quite a lot of power. The voltage drop as each one started was quite noticeable and it soon became clear that the controller was cutting out not when there were too many amps coming out of it, but when it detected that the voltage in the track had dropped below some predefined limit. Yet it took 30 seconds or so for this to occur.

    Finally, after investigating the wiring layout, it became clear why. My friend had made the same assumption that computer system builders do - that you just need to tag on some skinny wires at one end, and the volts will meander through to where they're needed. In fact, this system used skinny wires to carry the track power all the way from the remote power unit to one end of a long and remote siding so that the whole layout (containing a very large four-track main line loop) dragged these volts through several very thin connectors, and lots of fishplates between track sections that (although soldered together) would move around with changes in humidity and movement of the baseboards and the floor underneath.

    One of these joints was probably not as good as it could have been, and was increasingly resisting the not inconsiderable amount of current flowing through it. My suggestion was to go back to the principles of the electrician. Run couple of bus bars made of thick single-strand copper wire all the way from the power unit, continuing underneath the whole layout, and tag the track and everything else into it at regular intervals.

    I suspect that it's not a solution you could apply to a recalcitrant server, though another friend did have lots of problems with a disk array that kept failing when he was driving it off an old 200 Watt power supply, so maybe there's correlation there. Amazingly, this friend uses speaker cable for his extra-high hi-fi stuff that could comfortably carry the output of a small power station. Mind you, at ten pounds (in money) per metre, it's probably a bit expensive for wiring up a model railway.

  • Writing ... or Just Practicing?

    I Need a Wii...

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    According to Nintendo, the name of their family games console expresses their direction to break down the wall that separates video game players from everybody else, puts people more in touch with their games, and with each other. The two letter "i"s emphasize both the unique controllers and the image of people gathering to play, and the pronunciation "we" emphasizes that this console is for everyone. But I think they only called it this so people in England could make up silly jokes.

    Anyway, having got past the obvious hilarity when my wife told me the other week that she "really, really, really wanted a wii", we've taken the plunge and acquired our first games console. She managed to convince me that it would make us both fit as we while away the evenings playing tennis and ten-pin bowling, contour our upper-body through regular boxing exercise, and master relaxation by standing on one leg on an electronic wobble-board. I can't say I was totally convinced, but—at my stage of middle age and corresponding spread—anything is worth a try.

    Of course, there's pretty much no way it will connect up with our aging TV that's driven by Media Center, or any more room (or sockets) in the lounge. And it seems we need to replace the TV in the office upstairs because it doesn't work with the aerial in the attic now they've built more houses behind us, and it only gets five channels anyway. Besides, how would I watch the educational programs I enjoy, such as racing anything with wheels or any of the myriad Poirot repeats, while my wife is electronically toning her body and mind?

    Ah, but have you tried to buy a stand for a TV that's more than three feet high lately? If you're going to be posing on a wobble-board and leaping around playing badminton, you probably want the TV positioned a bit higher than that. Yes, you can spend four hundred pounds (or six hundred dollars) buying a fancy wall mounted arrangement to hold the TV if, like me, you have a flimsy plasterboard wall to mount it on, but that seems a bit steep; so my wife helpfully suggested I build a nice shelf unit to hold everything. And in a nice wood that matches the rest of the furniture.

    So, after wandering around the Bank Holiday sales at a selection of electronic retailers and DIY stores, we came home with a new flat screen TV package (complete with the incredible assortment of paraphernalia that seems to be standard with these things), a Wii everything, and a truck full of timber and ironmongery. Last time I bought a TV, you only had to plug it into an aerial and an electric socket and it all just worked. This time, it's taken me three days to get to the point where we can watch a DVD, and I've still got to figure out how on earth the twenty or so incomprehensible components of a Wii fit together (I haven't worked out yet how get the back off the controllers to put the batteries in). And I reckon I got my month's exercise just building the wall frame and assembling everything.

    It seems that nobody has just "a TV" any more. Now you have to have a "Home Cinema System". In fact, the box that it came in was bigger than the TV. Do I really need "five plus one" speakers just to hear Louise Redknapp telling me how to stand on one leg on my wobble-board? OK, so the office already looks like a power station with all the wires my computers and the associated junk require, so a couple of furlongs of extra speaker cable will probably meld in quite well. Maybe I should copy the setup a friend has—two big sofas arranged on platforms like in a cinema with the bass woofer underneath them. Makes you really appreciate films with lots of explosions.

    And it shows how out of touch I am with this brave new world of entertainment technology when I discovered that I needed an optical audio cable (obviously wire is old-fashioned now) to connect the bits together. Worse still, I struggled for ages trying to plug it in until I finally discovered that you have to remove the squidgy clear plastic protector caps from the ends first. Well it didn't say anything about that on the packet, and the instruction books for the rest of the kit just contain vague pictures that might apply to any of a selection of products from the manufacturer's range.

    Still, at least we got there in the end. OK, so I ended up having to repaint the wall and relay the carpet afterwards, but—as my wife likes to point out—jobs I tackle never seem to be as easy as it says on the box. All we need to do now is get the TV hooked up to some receiving hardware on the roof so as it actually works. As the TV has a satellite decoder built in, we might as well go that way so I talked to somebody who is brave enough to climb a tall ladder and knows where to point the dish.

    It seems, however, that (according to my brave ladder-climbing man) satellite signals are "very sensitive to trees". Ah, I thought, obviously they have to comply with some government environmental directive, or exhibit corporate "green" credentials. In fact, he tells me, it means that we won't get a signal if there are any tall trees nearby. And there was me thinking that the dish pointed up into the sky. I live in the countryside, where there are lots of tall trees, so I'm still awaiting with baited breath to see if we're in what he calls a "reception-capable area".

    Mind you, when we turned the TV on the first time, it asked for our full postal code so it could ensure that we received "programs optimized for our viewing area". Maybe there is a satellite up there that just transmits programs suitable for our small patch of Derbyshire. Lots of documentaries about sheep and coal-mining, perhaps...

  • Writing ... or Just Practicing?

    Windows 2008 Hyper-V and Service Pack 2

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    A quick note to Hyper-V users. When I installed Windows Server 2008 Service Pack 2, it installed fine with no errors, but after a while I was getting NetBT errors in Event Log saying there was a duplicate name on the network, and other issues finding machines on the network.

    Turns out that the service pack had re-enabled all of the network connections in the base O/S running Hyper-V. As two of these need to be disabled (see http://blogs.msdn.com/alexhomer/archive/2009/02/08/Hyper_2D00_Ventilation_2C00_-Act-III.aspx for an explanation), this meant the base O/S had two connections to the internal network, one of which was obtaining a new IP address through DHCP and registering itself in DNS. 

    After disabling these connections again, everything returned to normal. Maybe I should have deleted the connections in the first place instead of just disabling them... any advice from an expert in this area would be very welcome.

    Update: In Windows Server 2008 R2 you can untick the Allow management operating system to share this network adapter option in Virtual Network Manager to remove these duplicated connections from the base O/S so that updates and patches applied in the future do not re-enable them.

  • Writing ... or Just Practicing?

    Boeing, Boeing, Gone to Seattle

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    Travel, they say, broadens your mind and narrows your arteries. Now back home in wonderfully green and Springing England after a couple of weeks in downtown Redmond, it looks like I survived the combined effects of altitude sickness, jet lag, and airport aggravation. Perhaps I'm becoming a "seasoned traveler". Especially as the dictionary definitions of "seasoned" include "hardened", "tested", and "weathered". I probably fit into all of those categories; and probably "soaked in alcohol" as well, though probably not "rubbed with herbs".

    Perhaps it's also the reason that my weekly rants regularly seem to include airports. Mind you, I am rapidly becoming a fan of Schipol airport in Amsterdam (which, I'm reliably informed, is the is the only international airport located below sea level. That must be scary for pilots when their altimeter starts to go negative...). Unlike most airports, Schipol seems to have been designed especially so that people can use it to get on and off 'planes; without having to take a train or bus trip, or go through three security barriers.

    Talking of airports, I really like the quote from Terry Pratchett who says "It's no coincidence that in no known language does the phrase 'As pretty as an airport' appear." Likewise the comments I heard from one of our local comedians this week. He asked why we say "I'm going to the airport", like there is actually only one. He pointed out that this would make traveling somewhat boring. The only flights available would start and end in the same place, but they'd probably still be able to lose your luggage.

    However, what I really wanted to talk about this week was not airports, but airplanes (see how I cover a broad range of topics each week). When I was growing up, we lived on air bases all around the world and so I'm a long time fanatic of all things connected with planes, especially military ones. Therefore, two of the highlights of my recent trip to Seattle, other than a visit to Archie McPhee as described last week, were visits to the Boeing Museum of Flight and the Boeing Factory Tour.

    The Museum of Flight is quite amazing. As well as loads of planes (including an SR-71 Blackbird hanging from the ceiling in the main hall), they have displays and memorabilia commemorating space flights, and whole halls devoted to WWI and WWII planes and events. Outside, you can wander through the cabins of Concorde and an old "Air Force One" 707 from 1959. I liked the way that there are little signs pointing out the features of the presidential airliner, including one in front of the mass of extremely ancient communication gear that says "The fact that it never worked very well was only revealed after the aircraft was decommissioned". That could have been a little worrying. Imagine if, when deciding whether to start a nuclear war, all that Eisenhower or Kennedy could hear was whistling noises and odd chunks of broken speech... There is also a little label on the president's desk pointing to a hole in the table that says "Cup-holder". Shows you how old the plane must be if it only has one cup-holder. I've seen baby buggies fitted with two.

    Saturday morning was the trip to the Boeing Factory. This tour, called the Future of Flight takes you round the factory where they build the 747, 767, 777, and the new 787. After a half-mile walk through a tunnel full of pipes and cables that reminds you of some futuristic science fiction movie, you pop out onto a balcony overlooking a production floor so large that I didn't actually notice a Jumbo jet parked in one corner (probably back for its annual service and oil change) until the guide pointed it out. I wonder if they get delivery pilots wandering around asking if anyone had seen their 747? "Hmmm, I'm sure I left it over by that pile of tail fins..."

    But it really is stunning to see six airliners lined up in a row still under construction. You almost can't appreciate how big the place is. Even if you are not wildly passionate about aircraft, it's worth going just to marvel at the size and the technology. Best of all is the facility where they're assembling the new all-plastic 787 "Dreamliner". It seems that they make the parts all over the world, and fly them in using a fleet of strangely modified 747s that look like they're pregnant (they call these "Dreamlifters"). Then they just have to glue all the bits together in the main hall, and nail on the engines and wheels. It all sounds like those model airplane kits I used to build when I was a kid. Except they seem to make a lot neater job of painting theirs.

    There's also some nice displays of associated technologies. I especially enjoyed seeing the Rolls Royce Trent 1000 engines they offer as an optional extra when you order a new 'plane. They make these engines in a factory only a few miles from where I live. One of my friends who works there likes to tell everyone about how they test them by firing fresh chickens into them with a special compressed air cannon while the engine is running at full speed. I wonder who gets the job of cleaning them afterwards - I can't see Boeing being terribly pleased if they drip blood all over their nice clean factory floor when they unpack them.

  • Writing ... or Just Practicing?

    Five Go To The Library

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    Our little documentation department here at p&p occasionally gets some odd requests. I've done the "write some fictitious stories about corporations that don't exist" bit in the past (as content for a sample application, in case you were wondering), and the "write a technical article about cloud computing but don't mention any products or technologies" thing (it was a very short article). Combine this with an emerging policy of rewriting everything four times when people keep changing their minds about what they want, and you can see why I'm usually quite busy.

    However, now that I've at last escaped from nearly a year of working on the updated Application Architecture Guide (more news of that it a couple of weeks time), I'm free to devote my full resources to the upcoming version 5.0 of Enterprise Library. This is one of my favorite projects, and I've worked on several releases in the past. In fact, I suspect that it was working as a contractor on EntLib (as we insiders like to call it) for three releases that persuaded Microsoft to give me a proper full-time job. Perhaps everyone else is frightened off when they see the 900 pages of source Word documents that make up the documentation for it.

    If you've been keeping up with the news on the community site (http://www.codeplex.com/entlib) you'll have seen that the team finally got bored with holidaying on foreign beaches and basking in the glow of version 4.1. They decided that they need to make it even better by building a whole new version for release early next year. There's lots of new goodness planned, based on feedback from a survey undertaken a couple of months ago. This includes closer integration with the Unity dependency injection mechanism, better opportunities to decouple your crosscutting concerns from your "actually does stuff" code, and plenty of other minor but useful improvements across many of the application blocks. You can read about the results of the survey and the new release plans on Grigori's blog, and even see a 1920s-style sepia-tinted photo of the miscellaneous collection of miscreants who are charged with achieving all this.

    One of the main thrusts of the version 5.0 release is "learnability" (yes, it's a made-up word, but not one of mine - blame Grigori for this one). So I've been asked to create a series of printed guides that "provide a friendly and conversational introduction to working with EntLib". I'm not convinced that my previous efforts at guidance were aloof, detached, or unsociable; but I get that the plan is to try and write stuff that is entertaining and well as educational. And I'm not sure if they intend to have someone sit next to me and crack me over the knuckles with a stick every time I type "functionally implementable versionability" or "demonstrably compartmental manageability capabilities". I did suggest we include a joke from every country from which members of the developer team originate, and then have a quiz at the back of the book to see if anyone can guess the correct country for each one. But I'm not sure I could get that past our legal department.

    So, anyway, the long-term plan is to have a printed guide for developers, one for architects, and one for administrators. We may even do one that concentrates solely on the principle of dependency inversion, though maybe I could just send everyone an attribute and have this book injected automatically at runtime. Of course, it's kind of hard to write all these while the dev guys are still "exploring concepts" (an activity I've christened "white-board rafting") and playing with early code spikes. But, amazingly, we do have a preview of the developer guide available now! I don't know how I do it. And, even better, you can get a chance of a free copy when it's finally released in "real paper and ink" format by downloading the preview and submitting your opinions through our online feedback and survey. Go to the preview page, grab the PDF, and tell us what you think.

    But please be gentle with me... they made me learn about lambda expressions this week, and I'm still recovering.

  • Writing ... or Just Practicing?

    How Much Configuration Do You Need?

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    I endured a severe culture shock this week. And that was without meeting new people from countries afar, or travelling to distant lands. And it didn't involve a trip to some foreign eatery (such as our local Indian restaurant or Greek fish 'n' chip shop) either. No, all I did was respond to a change in the company security policy by replacing the existing well-known virus protection software with the new Forefront Client Security application. All I need to do now is work out how to configure it.

    You see, I'm used to virus scanners (and most other software) that provides oodles of configuration options. I mean, the one we just abandoned has about ten pages of check boxes, option buttons, lists, and text boxes where you can play happily for hours messing up the configuration, then click the Reset button to put it all back to where you started. Ah, the many happy hours spent trying to decide whether to scan zip file contents on disk, or just when the files inside them are opened (and the additional hours spent trying to remember where I found that option the last time).

    But, all of a sudden, I've got almost no configuration options. Forefront Client is one of those applications where they could have fitted all of the UI into a window about one inch square. It only has one page plus a link to open the Help file. And I thought Windows Defender was extravagant with screen estate. OK, so there is a link you can open to look at all the nasty malware that it captured, and one that has a few options to specify the type of scan to perform and the frequency. They even included some options to specify files, locations, and processes you don't want to scan. But you can't help thinking that it all looks a bit sparse, like they have only built half of it so far. I mean, when you flip open one of the tab-bar things, all you get is one line of text telling you that the feature is turned on or off, or is up to date, and no buttons to do anything about it.

    And then, after you install it and run it for a while, you discover that it added a new Event Log named Operations Manager with a size of about 15 MB, and is proceeding to fill it up with error messages that it can't find a management server to connect to (although that may be because I installed our "corporate" version). Obviously the name of the log gives the game away - it's meant to be administered remotely from some Windows System Server management console. Probably that's why the interface is so sparse and lacking in stuff to play with. No problem, I thought, I'll just install the Forefront Server Security Management Console (FSSMC) so there's something for my local machines that aren't joined to the corporate big iron to talk to.

    Maybe you'll remember (if you have a habit of wasting your time reading my weekly disconnected ramblings) that I recently went through the Hyper Ventilation experience and upgraded all my server infrastructure to Windows Server 2008 and Hyper-V hosted machine instances. But the FSSMC will only install (at least in the current incarnation) on Windows 2003 32-bit systems. OK, so I've got such a box running ISA 2006, but I'm not convinced that's a prime location for an admin tool that manages internal network security. Especially as you have to allow DCOM through all your internal firewalls. I did find a link to a page named "Forefront Server Security Products Next Generation", and - since I'm working on Enterprise Library at the moment - it seemed for a while that 2009 might be my Star Trek year. But no such luck, the next generation products don't yet include a Windows 2008-compatible 64-bit version.

    Mind you, there is the Client Security Enterprise Manager, but the reams of installation instructions frightened me off that - at least for the time being. It's probably overkill for managing six machines anyway. And it looks like it all hooks into System Center Operations Manager in a big way, so I reckon that's a "wait and see" job. I'd love to have all that working, but I can't face the effort at the moment. Maybe after I've managed to get a life, and there is some spare left over.

    Meanwhile, at least it seems to be doing stuff. The Event Log says is did a scan when it should, and that it is happily downloading and installing the new definitions every day from my WSUS server. Interestingly, on Vista, I still have Windows Defender running as well. I removed if from the XP boxes, but as its part of the O/S in Vista I didn't know whether to remove it (or how to) and the helpful support guy I spoke to said I should just leave it running alongside. I suppose, when I do pick up some malware infection, they'll have a fight over who gets to quarantine it.

    And what's the best part of all? The Forefront Client UI is plastered all over with the word "Antimalware" which, when you glance at it, always seems to read "Animalware". Every time I decide to check my security status, I end up with visions of horse blankets, fur coats for dogs, and those photos you see on the Web where people dress up their family moggy in some ridiculous outfit.

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