Category: computers

Microsoft: Dump Switch Support for Windows

Published December 18, 2008

Schematic from Microsoft's article Dump Switch Support for Windows.

Known mostly as a software company, it surprised me a bit when I came across the article Dump Switch Support for Windows at Microsoft’s site a few years ago. This site has a schematic (which appears to have been done in Paint, detailing a PCI device for generating an NMI to force a machine to bugcheck and dump.

Many servers have NMI switches built in, but it’s quite nice to be able to add one to a PCI slot bearing device of your choice. I think it’d be nice to know how to do this on PCI Express, but it’d take me a little time to figure out how. It’s probably not as easy as this implementation.

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NGROUPS_MAX to 64 under FreeBSD 7.0-RELEASE on banstyle.nuxx.net

Published December 8, 2008

Just so everyone knows, I’m changing NGROUPS_MAX on banstyle.nuxx.net to 64 shortly, which will require rebooting the box. Everything should come back up okay after this.

This change is being made so that a user can be a member of more than 15 groups, which will allow me to add far more local web hosting users under the lighttpd / PHP privilege separation model which I prefer. Due to some incoming sites this is needed in order to best host them. As far as I can currently tell this will only break NFS, which I don’t use.

I’ll update this post once the reboot is complete.

UPDATE: Well, that seemed to have gone as expected. Per usual, please let me know about any problems you are having with the server.

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Bad Mood

Published December 7, 2008

After failing to get my grandparents iMac G5 working again and with an overwhelming feeling like I haven’t been accomplishing anything, I started to get in a bad mood this afternoon. Fast forward to this evening and I’m feeling downright awful. I think I’m just acting cold, not very talkative, and extremely pessimistic all while feeling like little matters and I can’t fix the problems I’ve created. I wish I knew how I could make myself be in a better mood, but absolutely nothing sounds like it’ll help.

Maybe I just need some better food and a good night sleep. The bowl of potato chips in front of me do not qualify as good food, so I’ll have to eat something else soon.

On a related note, I think the only realistic solution to my screwing up my Grandparents’ computer is to build them a PC out of spare parts, locate a (working) monitor, and get that to them. It’s not as elegant as an iMac and likely won’t be as easy to use, but at least it should work. I’ll then part out the iMac and sell the pieces on eBay. I know the display, RAM and various small cables work properly.

This means more work for me. Hopefully I won’t screw this up somehow too.

(No, I didn’t get it working, even after attempting to reflow some of the connections, checking for any solder droplets or wire pieces on the board, ensuring all cables are right, etc.)

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iMac G5: Worse Than Before

Published December 6, 2008

Image of the machine in Open Firmware showing video glitches present after recapping. I suspect that there are cold solder joints and the video card isn't getting proper power.

Well, I managed to get all the capacitors I previously complained about desoldered and the new parts fitted. However, the iMac G5 now displays video glitches while POSTing, and it never boots past a plain blue screen with an artifacted cursor. As can be seen above, video glitches are also present in Open Firmware.

Looking at this photo (large size here) and seeing what may be some cold solder joints I suspect that some of the caps — specifically those for the video controller / memory — aren’t doing what they are supposed to. This means that I’m going to be taking the machine back apart tonight or tomorrow and attempting to reflow those joints.

I’m disappointed. It really frustrates me when I screw something up.

UPDATE: I think I should probably take a look at the display cable and its connector as well.

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I Fail At Desoldering

Published December 6, 2008

Another view of the domed caps, after some of the dried electrolite had fallen off.

My grandparents computer is an older iMac G5. When installing an Airport card in it last weekend I noticed that a number of the capacitors were domed, and some were leaking electrolyte, a sure sign of failing capacitors, possibly because of the capacitor plague. After digging around through Digi-Key, Mouser, et al I found that the cheapest way to get a set of replacement caps is to order them from The Cap King. He sells a set of the 25 needed caps for $16 shipped, and the set arrived earlier this week.

After sorting the caps, tearing down the iMac, and removing the logic board I identified which caps needed to be replaced, marked them by type, then set about desoldering two of the most accessible ones. This is where I began to have problems.

Normally I’m pretty decent at soldering, but getting these first two caps out was difficult. The first one left a lead sitting in the board, and the other three holes still contain solder. I presume its because of the number of layers in the board and the giant planes of copper near them, but I cannot seem to get enough heat on the board to melt the solder all the way through and wick it out.

Here are two photos of where things currently stand: 1 · 2. I think the next thing I’ll try is pre-heating the board with a hair dryer, then leaving the hot air flowing over it while attempting the desoldering. Hopefully that’ll help.

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Oil Slick and Other Images

Published December 2, 2008

I do not like seeing oil slicks like this in a parking lot. This is from the snow plow / salt spreading people.

Here, have some moblog images:

· I do not like seeing oil slicks like this in a parking lot. This is from the snow plow / salt spreading people.
· Car with YOU SUCK @ PARKING written in paint marker on the side window.
· Engrish on a model helicopter box at Microcenter. (Click to read more.)
· Deatheater standing near the console at IPM.
· It’s December 1st, time to start on the advent calendar my mom gave me.
· DBAN having just finished running on my old D610.
· Bye bye, D610. Time for me to begin using another laptop at work.
· The bathroom at work has a shiny new air freshener installed.

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ObeXplorer Feeds My Moblog

Published December 2, 2008

ObeXplorer running on my work machine under Vista browsing Push Upstairs, my Nokia E51.

I’m now running Vista on my work laptop, and while I had no problem finding Bluetooth drivers for it, I didn’t like the default Bluetooth OBEX program which only allowed one file at a time to be exchanged. Looking around online I came across ObeXplorer, a free OBEX tool written by Giorgi Dalakishvili. It provides exactly the basic browsing and copying functionality that I wanted, and now whenever I’m using a PC I use this to pull files off of my phone for upload to my moblog. On OS X I still use Bluetooth File Exchange.

If you’d like a copy of it, please visit Giorgi’s post about it, or download it from my mirror here: 2008_10_ObeXplorer.zip

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Sanyo “The Claw” CD/DVD Media Destroyer

Published December 1, 2008

Not long ago John pointed me to a sale at Woot for a device which destroys CDs or DVDs. Having a huge stack of discs to dispose of and costing only $4.99 (+$5 shipping) I decided to order one. Today my Sanyo “The Claw” CD/DVD Media Destroyer arrived.

Yes, that’s exactly what it says on the box, not far from the part which shows that it is Compact Disc and DVD compatible. Too bad it doesn’t do Blu-ray.

After eating some dinner I set to work processing discs, and with a ~2 second cycle time per disc I was able to get through 163 discs (one after another) before The Claw stopped working, with a FreeBSD 3.2 CD stuck in the drive. Thankfully it was just a thermal shutdown, and after allowing it to rest in the garage for half an hour I was able to continue processing the discs, chewing through the remaining 70 or so in no time flat.

The Claw works by pinching the media between two spiked rollers, which put a bunch of small indentations all over both sides of the disc while at the same time somewhat deforming the plastic so that the disc isn’t really flat nor round. A test audio CD made a bunch of horrible noises when placed in a top load radio, so I can only imagine what putting one of these discs in a normal reader would do.

Here is a detailed image of what The Claw did to a NT 5.0 beta CD and here’s similar damage to a CD-R, including delamination of the foil. Here is a 600dpi scan of a processed CD-R showing the typical damage pattern.

Now that I’m done processing that giant stack of discs I’m not sure what to do with it. I could relabel it as a DVD cleaner and drop it off a the Salvation Army, but that’d just be mean.

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Founders’ Backwoods Bastard

Published November 30, 2008

Tonight I’m sipping a snifter of Founders‘ Backwoods Bastard while trying to figure out a Time Machine problem I’m having. Thankfully, the need to let the beer warm up to a bit below room temperature for drinking tied in well with time spent working on the backup.

This beer is interesting, and tastes quite a bit like their Curmudgeon, but with lots of oak. It’s nifty and worth drinking, if you like potent, strongly flavored beers.

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NXE Xbox LIVE with pf and miniupnpd on OpenBSD 4.2

Published November 24, 2008

New Xbox Experience (NXE) showing a successful Xbox Live test via NAT and UPnP on OpenBSD 4.3 with pf and miniupnpd.

(UPDATE: This issue has been worked around / resolved. Please see Xbox Live Open NAT Using pf on OpenBSD.)

I rather enjoy turn-based artillery games like Worms, Scorched Earth (and Scorch 2000 and Scorched 3D), and GORILLA.BAS, so when I found out that Worms for Xbox Live Arcade was available, I purchased it.

A few months ago, before Microsoft released NXE, or the New Xbox Experience, I had no problems playing Worms online when using my Trashwall set up with the Microsoft proscribed forwards of 88/udp, 3074/udp, and 3074/tcp. However, after NXE was released it seemed to stop working. The Xbox LIVE test would consistently tell me that I have “Strict” NAT settings and that some things won’t work. I was unable to host private or public games. Xbox LIVE supposedly works best with either a direct internet connection or a firewall which implements UPnP, so I set to implementing UPnP on my pf-based firewall.

In order to do so I compiled and set up miniupnpd per the directions, but I ran into a whole bunch of weirdness along the way. I eventually got it working, getting an occasional successful Xbox LIVE test (as seen above) which indicates “Open” NAT, and I was able to play a private game against , but things don’t seem right.

Below the cut I’ll document what I’m been seeing.

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