If you’ve ever had nightmares about falling from great heights, this is not the job for you.
Apparently a good example of how not to climb a tower, this guy gets 1,768 feet in the air with no safety lines.
Want vertigo? Play it fullscreen.
Archive for September, 2010
Well, here comes another year of university. It sort of feels like a piano hanging over my head, but it always feels like that after being out of the classroom for a while. Going into 3rd year, I’m accustomed to what the workload will be and the general structure of university courses. I know it won’t be nearly as bad as it feels like, certainly not as bad as the rapidly increasing locker dreams that happen around this time of year.
It’s just the general thought of all the work, attending classes, doing efficient time management to spread out the workload, trying to do well in all my courses, it takes up most of my cognitive capacity. It weighs on me so that little stuff like cleaning off a desk becomes a nigh impossible task, the motivation just isn’t there. Maybe it’s tied into my reluctance for multitasking. I’ve always preferred doing only one project at a time. 5 courses feels like 5 projects, plus any administrative stuff on top feels like another. I’m not terribly motivated either and am well versed in the art of procrastination. But fortunately I’m interested in my degree program (and if you aren’t, get out now. Being happy in your chosen career is much more important than whatever your salary will be).
I’m studying Cognitive Science, which is a multidisciplinary field of work that fits my need for variety. It can take you lots of places. A lot of my CogSci teachers are linguists or phoneticians, a lot are psychologists, a few are computer scientists, some work in the math department. From what I’ve heard, graduating with a multidisciplinary bachelor in Cognitive Science is pretty advantageous since you’re attractive to a greater number of employers. But whether that’s true or not is of little importance to me. My philosophy right from first year was to go where it looked interesting. I want my career to be something that’ll get me out of bed in the morning.
But even if it’s cool stuff, you still need to work to learn it. So I’ll read the books, attend the classes, and practice good time management so everything gets done. At least so I’m not doing my assignments the day before the deadline. Two days should be enough, right?
Don’t believe me? Well okay, it’ll probably take longer than that the first couple of times. But it really isn’t difficult to get the combination for a Dudley you’ve never seen before.
At first it seems like an impossible task. You’ve got 60 points on the dial and you need 3 turns to open the lock. That’s 60 x 60 x 60, or 216,000 possible combinations. Theoretically.
What helps us out here is that each and every number isn’t used, since the internal discs are not designed for 60 different positions. There are actually only 10 different positions the discs can assume, which is a good thing when you think about having to dial in numbers with millimeter accuracy when you’re trying to get into your locker.
So alright, how do we find these 10 positions? It doesn’t require any high-tech wizardry, all you need to do is pull up on the shackle while turning the dial. The dial will only move between a few numbers, and this is the key to finding the combination.
Sticking zones (in green) and buffers (in blue) for this particular lock.
Now you’ll be able to see the 10 positions behind the dial, and you’ll be able to find the 10 numbers the combination is picked from. Say you find that the dial sticks between 1 and 4. This is the first position of this lock, so take a number in the middle, let’s say 2. The next sticking point will be between 7 and 10. There will always be a two number buffer between the sticking points, representing the gap between indentations in each internal disc. The indentations are always 4 numbers wide, which makes it easy for us to figure out the rest of our combination numbers – just keep adding 6 to your first number.
So for this lock we have 2, 8, 14, 20, 26, 32, 38, 44, 50, and 56 for our possible combination numbers. Each lock will have different sticking zones so the numbers will vary, but there is always a 6 point spread between them. Hmm, this is starting to look possible!
Okay now we have 10 x 10 x 10, or 1000 possible combinations. Well you could sit down and run through 1000 combinations, mind numbing as that would be, but luckily it gets easier.
We actually only need the first two turns of the combination to open the lock, because on the third turn you can just spin the dial through each zone while pulling up on the shackle. This knocks our possible combinations down 90 percent. So really there are only 100 possibilities.
But in reality there aren’t even that many. For almost all Dudley locks out there, the second combination number is lower than the first. This may not hold true for all locks, but it’s been that way for every Dudley lock that I’ve seen. This means that our possibilities are reduced to 9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1. Which leaves us with a grand total of 45 combinations! The list is so small you can easily write it out.
These are the possible combinations of this particular lock, listing the first two numbers only. For the third number just spin through the sticking zones while pulling up on the lock until it clicks open.
8-2, 14-2, 20-2, 26-2, 32-2, 38-2, 44-2, 50-2, 56-2
14-8, 20-8, 26-8, 32-8, 38-8, 44-8, 50-8, 56-8
20-14, 26-14, 32-14, 38-14, 44-14, 50-14, 56-14
26-20, 32-20, 38-20, 44-20, 50-20, 56-20
32-26, 38-26, 44-26, 50-26, 56-26
38-32, 44-32, 50-32, 56-32
44-38, 50-38, 56-38
50-44, 56-44
56-50
I’ve followed this method for a few Dudley locks, and it’s taken me as little as 7 minutes to figure out the combination. Not really that secure is it? It’s a little scary when you think about the thousands of schools, universities, gyms, and other public places where combination locks are supposed to secure your personal stuff. With a little practice, it isn’t hard to imagine anyone being able to open your lock in 10 minutes when there are only 45 combinations to work through.
Say it takes you 30 seconds to find a sticking zone, count up the 10 possible numbers, and write them down. You don’t need to write down all the possible combinations, just start from the first number, keep the second number lower, and head clockwise. If you’re quick about it and can test one combination every 12 seconds (with a spin at the end), worst case scenario it will take around 10 minutes to crack that lock (12 x 45, + 30 seconds = 9 1/2 minutes). And even if you’re not that fast, the chances are only 1 in 45 locks you’ll need to test every possible combination.
Of course, this can also be useful for completely legitimate purposes, like finding a combination you’ve forgotten or removing an abandoned lock without bolt cutters. All padlock-style combination locks are designed pretty much the same, so even if it’s not a Dudley the method above should still be of some use.
**Take a look through the comments for updated info. Also, feel free to post your success stories with your lock letter and whether your first combination number was higher or lower than your second.**
**Update: My laptop has been repaired. See the info at the end of this post.
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Well, I thought it could never happen to me, but isn’t that the way we all feel when misfortune befalls others.
I’ve been the happy owner of a Dell XPS M1330 for two years and one month. Around the time that I bought it, I had seen rumblings about problems with the Nvidia 8400M GS that shipped inside the M1330. People were reporting that their machines were suddenly bluescreening, shutting down, and throwing out weird graphical errors. The video chip, plagued by inadequate cooling, would fry itself and render the computer unusable. Here is one of the threads where the GPU issue was first discovered.
I figured it was an isolated issue, and that these cases were within the normal failure rate. Well, apparently not – shortly after purchasing my M1330, Dell was forced to extend the warranties of computers with certain nVidia chips by a full year. Not so much an isolated issue.
My experience with the problem started about a week ago. While browsing around Google Earth, my laptop suddenly displayed a memory parity error like the one above, and I had to force a restart. When it booted back up, all seemed to be fine for a few hours. However, in the middle of a video I was playing it locked up again with the same error, and this time it refused to boot up again normally. The problem didn’t manifest itself until it actually booted into Windows, and I found that it worked alright in safe mode (although often with thin lines running across the screen).
During my attempts to find the source of the problem it eventually devolved into a rave-like display every time I started it outside of safe mode.
At this point it’s pretty clear that the video chip is the problem. Now it won’t get past the Windows welcome screen. It immediately starts displaying flashing colours and checkerboard patterns across the display. This video is pretty much what I’m getting, but without the aurora borealis-like stuff that happens at the end.
But at least in my case, the chip hasn’t failed completely (yet?). In safe mode I uninstalled the Nvidia drivers and had Windows fall back to the default VGA drivers. Now it will work starting up into Windows normally, although without hardware video acceleration. This seems to be working for the short term, until I can get it shipped back to Dell for repairs.
In retrospect, I had been getting a bunch of “The display driver nvlddmkm stopped responding and has recovered” messages in the days leading up to the final meltdown. I thought it was just driver issues with my version of 64 bit Windows 7, but I guess not.
Just doing some quick searching reveals a widespread problem with the M1330′s video chip. There are some possible “solutions” such as modifying the GPU’s heat sink or even underclocking the GPU, but it doesn’t really get to the issue, which seems to be bad design. The 8400M GS puts out a lot of heat and laptops aren’t that great at cooling hot components.
Unfortunately, the standard fix of replacing the motherboard + GPU doesn’t really fix the issue either, since the replacement parts are the same as the old ones. So really you’re just getting another few years before it might fail again.
In any case, I’ll be calling Dell to get the repairs done and I’ll update this post with the details.
**Update 1: After resuming my laptop from standby, I got pretty vertical lines like a lot of other people have had.
Here is someone who had the exact same symptoms that I did, almost 2 years ago – http://bindoo.blogspot.com/2008/11/dell-xps-m1330-nvidia-gpu-failure.html
**Update 2: I called Dell tech support. The technician I got had me do a few tests so he could confirm it was the video chip that failed. First he had me test the display by pressing D + the power button. I had run this test before, and it ran successfully again, so the laptop screen is fine. He then had me connect an external display via VGA to see if the same graphics problem showed up there. It managed to display the desktop, but there was significant corruption, exactly like the image below.
This was enough to convince him the GPU was at fault, and he said I would get a box within 2 business days to send the computer back to depot in. I also confirmed that my warranty was extended by a year (for GPU related problems only). When he said that the motherboard + GPU would be replaced with parts that shouldn’t fail again, I asked him what changes were made to the design. He said there was a problem with the thermal pad that sits between the GPU and the heatsink (for all M1330′s ever manufactured up to when Dell discovered the problem), causing the graphics chip to overheat.
**Update 3: I got my box, 2 business days later.
Inside the box: A sheet of paper where you can describe the problem, when it happens, etc., and the return postage sticker. Once you put your hardware in, you call Purolator and schedule a pickup.
**Update 4: Fixed! I just got my M1330 back via Purolator, 5 days after I had it picked up. I think that’s pretty quick, considering the 2 day transit time to and from the depot.
The motherboard + the gpu has been replaced. It looks like the original heatsink is still attached, which supports the technician’s comments about the faulty design of the thermal pad. The fan might be running more with the newer motherboard, but I won’t know for sure until I test it out for a while. It wouldn’t surprise me since that would keep everything a couple degrees cooler.
The hard drive was also replaced and the old one was sent back to me, even though there was nothing wrong with it. The reason might be that I had Windows 7 installed on the drive and the system is supposed to come with Vista. Replacing a motherboard isn’t always as simple as just dropping in a new one, often you need to reinstall the OS. So, since they would have had to nuke my Windows 7 install to put Vista back on, I guess it was easier for them to drop in a new drive with Vista on it. Dell returns the old one (you can only keep it for 10 days, then you have to send it back) so you can get any files you need off of it. I’m not complaining, I’ll take a newer drive over an older one any day.
All in all, it was a smooth process from calling tech support to when I got my computer back. I was only without it for 5 days in total. Yes, it’s too bad Dell shipped out computers with major defects that caused them to self destruct over time, but Dell’s support is good. If you have a problem it shouldn’t be difficult to get them to fix it in a reasonable amount of time. Whether the new parts are going to last longer than the replaced ones is anyone’s guess, but I sincerely hope Dell has gotten enough flack over the issue to make the GPU problem go away. Negative publicity just ain’t good for business.
**Update 5: Thanks to a class-action lawsuit, U.S. buyers of certain laptops with Nvidia GPUs may be entitled to financial compensation if they’ve had video problems. No love for Canada yet.
