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Category: computers

Shattered Hard Drive Platter

To collect neodymium magnets for rebuilding the not-currently-great drip tray to kegerator / kegged beer cooler I started disassembling more old hard drives, attempting to salvage the magnets. When disassembling one drive I decided it’d be fun to bend the platter, but I (stupidly) didn’t pay attention to the platter material before doing so. The result? Tiny bits of broken glass and amazingly thin foil spraying all over the basement floor. Whoops.

At least it was easy to clean up.

I had little luck collecting useful magnets from the drives because some were too small, some drives only had one, and many of them shattered as I removed them. Instead I’ll just buy a bunch of tiny ones on eBay or Amazon and epoxy them on instead. It’ll be a lot easier.

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iPod Battery Replaced

Roughly six years after buying my black fifth generation iPod I finally replaced the battery. After years of working well it was starting to fail, providing me with only a few hours of music listening while at work, way down from the original 10-15 that I was getting when it was new.

The replacement battery was part number BIPOD550MV30 from OWC, a very reliable online Apple reseller who has been around for years, and cost just over $20 shipped. While I could have purchased a cheaper battery via eBayI wanted to be sure to get one from a reliable place, so if I had problems with it there wouldn’t be an issue returning it.

The battery is now installed and charging, so hopefully by morning it’ll be full and ready to go.

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MS12-006 and HTTP 408 Errors

I recently worked on an issue where a new Microsoft patch for a security bulletin, MS12-006, was correlated to a web-based application occasionally returning errors. Specifically, while using a web-based version of a reporting package off of a version of Sun (Oracle) Java Web Server the browser would occasionally return a Times New Roman-font “Request Timeout” message when users clicked report-generating links. The folks who support the server working on the issue initially had spent time uninstalling recent patches and found that removing KB2585542 (the patch for MS12-006 on Windows 7 clients) from the client machine would stop the issue from occurring. They then thought it might be a Windows client issue, which is where I got involved.

After some investigation it turns out that the problem was actually with the web server not handling split (fragmented) SSL/TLS records properly. The installation of the patch for MS12-006 causes IE to, in some cases, split SSL/TLS records into multiple requests. Since the server couldn’t appropriately handle these requests it thought the client closed the connection before sending a complete request and returned an 408 Request Timeout message.

This was illustrated by the HTTP logs on the server which show incomplete requests being returned 408 messages, similar to what follows. The bold line illustrates a request that correlates with the issue:

IP       | Username | Date                 | Request Header              | Status | Content | Length
---------+----------+----------------------+-----------------------------+--------+---------+--------

10.0.0.2 | -        | 17/Feb/2012:10:03:25 | "P"                         | 408    |         | 148

10.0.0.2 | -        | 17/Feb/2012:10:01:13 | "POST /TestApplet HTTP/1.1" | 200    |         | 13056

After the installation of the patch for MS12-006 there is a setting which allows this new feature to specifically be used only when called for (“optin mode”, the default), all the time (“enabled for all”), or never (“disabled for all”). Setting the option to “disabled for all” kept the issue from being reproduced, and when set to “enabled for all” it always occurred. (See the Registry Information section of 2643584 for more information on these options and how to set them.) By this I showed that it was this SSL/TLS feature causing the issue communicating with the server. Since this appeared to be an issue only with this particular server the team supporting it is now looking into potential solutions on that side.

While it may be tempting to simply disable this feature on clients, this would handicap one of the security enhancements brought along with the MS12-006 patch. Since this issue isn’t likely to be widespread (else lots of HTTPS sessions would be failing) I believe that the servers should be fixed to be compatible with the client’s standard behavior. Specifically, I believe the issue to actually be with the server not having an RFC2246-compliant TLS implementation and thus it should be fixed.

Hopefully this information will be useful to others who run into such an issue. It’s a bit opaque at first, since it looks to the users like the server is having a problem, but to server like the client is occasionally failing to send proper HTTP requests. Trying to troubleshoot this with Fiddler didn’t help either, because the HTTPS proxying would recreate the request, apparently no longer splitting the SSL/TLS record, which kept the error from appearing.

Here’s a few links which are helpful in understanding this issue, in order of usefulness:

· MS12-006: Vulnerability in SSL/TLS could allow information disclosure: January 10, 2012
· SSL/TLS Record Fragmentation Support – Microsoft blog article describing the issue in reverse, from a few years ago when SChannel didn’t support SSL/TLS Record Fragmentation.
· Microsoft Security Bulletin MS12-006 – Important, Vulnerability in SSL/TLS Could Allow Information Disclosure (2643584)
· HTTP Status Code 408 Documentation
· RFC2246 – See section 6.2.1.

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Burroughs Mainframe Cards

Years ago I got the chance to help empty out a friend’s neighbor’s basement after they passed away. This basement was stuffed with old computers and electronics, and I acquired a number of interesting items from there, many of which are now displayed around the house. (Core memory, old test equipment, notebooks, etc.)

The photos from this excursion can be found here, if you’re interested.

One of the items I’d acquired was a milk crate full of old cards from a Burroughs mainframe. Each is a bunch of discrete components built into what’s essentially a logical unit, designed to perform some function. These days a small integrated circuit would be used to perform the same (or multiple) functions.

I’ve given many of these items away, as in my excitement I ended up with many more items than needed. Everything from large boxes of valves to old, uncalibrated oscilloscopes have found homes with friends who had a better use for them than I did. A little while back I was contacted by a guy named William Donzelli who was interested in the history of the Burroughs mainframe and the cards from it. I didn’t know much about it and couldn’t answer many questions, so a couple days back I sent off this box containing the cards to him. Hopefully he’ll find them enlightening.

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Crucial m4 SSD for Data Processing

I’ve been processing some relatively large sets of data at work lately, and I’m running into disk IO issues after kicking off some of the data processing tasks. As an easy way to alleviate this I picked up a 64GB Crucial m4 SSD and stuffed it into my laptop’s optical drive bay via a $20 Nimitz-branded SATA hard drive adapter acquired from eBay. The drive itself was $99.99 from Micro Center, and since I purchased it myself once I’m done working with it I’ll be able to repurpose it in a personal machine of some sort.

While not a panacea nor excuse for my poor habits of bolting together VBScript and GNU command line utilities, it has helped quite a bit. One typical script (immediately post-reboot, with an empty disk cache) takes ~120.234 seconds to run a task from the hard drive and ~28.400 seconds from the SSD. I’ve seen similar speed improvements across the board, and this really helps when I’m prototyping things and wanting feedback as quickly as possible.

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Vector Symbols for Maps

Ever been drawing a map and found yourself needing vector copies of symbols? Well, thanks to the great state of Minnesota there is a font containing most of these symbols freely available. On the state’s page Recreation Symbols Extension for ArcView one can download recreate.ttf, a 126-character TrueType font containing indicators for everything from XC ski trail difficulty to lighthouse locations and from winter camping sites to RV dump locations.

To make using this font easier I’ve created a spreadsheet-based key listing each of the symbols next to their corresponding Unicode character. This can be found here: Minnesota DNR Recreation Symbol True Type Font Key.xlsx

There’s a few other nifty things that Minnesota has provided to the general GIS community, including Road Symbols. The rest can be found here.

UPDATE: Here is another set of symbols provided by the National Park Service (NPS). These are much more up to date and provided as both PDF and .AI files.

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Plastic Bottles, Foil, Visine, and a Shoe

Oh, the things that one finds when looking for a route for some new trail. There were three or four of these, an empty bottle of Visine, and one shoe are all laying within 15′ of each other next to a hiker / game trail leading from some apartments to the main two track. If I’m able to route a trail as hoped then another piece of return trail will pass through this area and make for a small segment ending directly across from the current trail start.

I came across this while looking over a place for a new segment of trail after finishing up some tweaking of the newest segment of trail in the park. There were a few poorly designed corners to sort out, some overhanging brush to trim, and some weirdly rough/lumpy trail surface to smooth. It was a fun 3.5 hours of work on a very nice autumn afternoon. Now, to ride it and see what else needs adjusting.

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Why Intuit? Why?

Dear Intuit, why is this option in Quicken 2012 necessary? I would have hoped that a modern application would be able to detect a date change and handle this itself without needing a restart.

UPDATE: Here are two posts that Nick found where Quicken support folks explain the issue away as “…this would have required extensive reworking of Quicken, and possible other bugs while working it all out” and “The “Quicken Restart” process is like a mini reboot of the program, to make sure that all services are properly dated/timed/synchronized.”. Isn’t sorting those things out what the sales of Quicken are supposed to pay for?

I suspect that Quicken reads the date on startup, that gets used a bunch of places, and it’s presumed by most of the app to be static. I imagine this option is because they aren’t interested in doing the heavy lifting to have the date-consuming pieces of the app handle being notified of a date change. Or something. Either way, needing to restart an app just because a date changes smacks of incompetence.

Having been a regular Quicken user for more than ten years now, I’ve noticed that Intuit seems to have little interest in moving the app forward. I wonder if this is because they are hoping to get most people over to mint.com or something and let Quicken die.

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Keyboard Cleaning Time

A visible build-up of finger gunk on the flat surface and laser-etched numbers on most-used keys shows that it’s time to clean my keyboard. To do this I first use Simple Green All Purpose Cleaner at full strength, then a generic glass cleaner to remove the Simple Green residue, then 99% isopropyl alcohol to remove any remaining residue. Each is applied to a clean paper towel and used to carefully scrub both the keys and gaps between. Being one of the (excellent) modern, flat, metal-body Apple keyboards it’s particularly easy to clean, and after I’m done the keyboard feels like new.

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Microsoft Excel Date Munging: 1900 vs. 1904 Date System

While working on migrating data for the upcoming MMBA Chapter Transition one of my tasks was to export membership data, split it into chapters, then sent it off to IMBA for import into their membership system. After getting the information out of the database I used my Mac to create one large spreadsheet with all the requisite fields covering the entire state (including a chapter column) and sent it around to all interested parties for confirmation that it looked fine. The next step was to break it out into per-chapter data so this time I sat down at my PC, opened the file, filtered on each chapter, selected everything displayed, copied the data, created a new file, pasted the data, saved the now per-chapter data, and sent it off to IMBA.

A couple weeks later, once the files had been pulled into IMBA’s systems, I received a few notes questioning the data as some chapters listed only single-digit counts of active members whereas they were known to have exponentially more. Checking over my data I found that the per-chapter spreadsheets were wrong, and that the date columns had been decremented by a good deal rendering most active memberships expired. For example, on my personal row the expiration date of 6/29/2012 became 6/28/2008.

After a bit of investigation I learned about the toggle shown above to set Excel documents to use the 1904 Date System, and this turned out to be a big key to figuring out the problem. As documented here in Microsoft KB article 180162, when I’d first created the spreadsheet on Mac the file was set to use the Office for Mac default of 1904 Date System and the populated with the accurate data. Opening the file on PC retained this 1904 setting and displayed the data correctly, but when the new file was created with the PC default the 1900 Date System and data pasted into it became offset by roughly four years. I’d presumed that the copy/pasted data would be the same and with the first few columns in each sheet looking correct I didn’t check the rest, and files with incorrect expiration data were thus sent off to IMBA.

The real reason for this goes a bit deeper and involves how Excel stores dates. Specifically, dates are stored as a numerical offset (called a serial number in Excel) from a starting point in time (an epoch). Toggling between the 1900 Date System and 1904 Date System changes the epoch, but as date fields copied and pasted between sheets are copied as their serial number, if the epoch changes the displayed date will be different. The data behind the scenes doesn’t change, but the information presented to the user does. See Microsoft KB article 180162 for a more detailed explanation of why this occurs.

I understand all of the reasons why this works as it does (legacy compatibility with Mac vs. PC, the use of a serial number + epoch so that all international date formats are easily handled, etc) but in some edge cases (such as what I ran into) the result for the end user is maddening.

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