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Category: computers

iTunes 10.4.1 UI Bug

Published August 27, 2011

There is a UI bug in iTunes 10.4.1 which causes the rewind (<<) button to become highlighted when switching to the Mini Player. This causes unexpected behavior when one Cmd-Tabs to iTunes and presses space intending to pause the music. To replicate this issue do the following: - Bring the normal iTunes window to the foreground. - Note that the Play / Pause button is highlighted. If it's not, press Tab to move the highlight to it. - Double-click a track to begin it playing. - Click the + or press Shift+Cmd+M to switch to Mini Player. - Note that the rewind (<<) button is now highlighted instead of the Play / Pause button. This was tested with iTunes 10.4.1 on OS X 10.7.1. UPDATE: This appears to finally have been fixed in iTunes 10.5.3.

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16GB of RAM in my iMac

Published August 15, 2011

Along with the SSD I also upgraded the RAM in my iMac to a full 16GB. It’s amazing to me, but a full 8GB (2x 1333 MHz SO-DIMMs) is only US$59.99 from Crucial. It wasn’t long ago that an 8GB flash card cost this much.

Sure, I don’t need this much RAM very often, but I did find that with 8GB and a bunch of design programs open (such as when doing PCB or mapping work) the machine would occasionally page. At today’s prices I don’t mind buying a bit more ram so that swap is almost never used.

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Shell Variables Not Expanding in %PATH% on Windows 7 Non-Administrator Command Prompt

Published August 15, 2011

I recently ran into an interesting issue on Windows 7. Users running a non-Administrative Command Prompt on Windows 7 would find that Windows’ programs which are supposed to be in their %PATH% (eg: ipconfig.exe, xcopy.exe, etc) weren’t. Checking the path showed that shell variables inside of the PATH variable weren’t being expanded:

Path=%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\Wbem;%SYSTEMROOT\System32\WindowsPowerShell\v1.0\;C:\Program Files\Microsoft Windows Performance Toolkit\

However, if Command Prompt is run as an Administrator (Start → Right Click Command Prompt → Run as administrator) %PATH% will be set correctly:

Path=C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\Wbem;%SYSTEMROOT\System32\WindowsPowerShell\v1.0\;C:\Program Files\Microsoft Windows Performance Toolkit\

Thanks to a coworker, online research, and the helpful folks over at serverfault the cause of this was found to be an incorrect value type in the registry (discussion here). Specifically, the Path value in HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment must be set to REG_EXPAND_SZ so that it’ll expand shell variables that it contains. If (incorrectly) set to REG_SZ the symptom above will be seen because the variables aren’t expanded.

What doesn’t (yet) make sense to me is why this issue is only visible with the incorrect type in a non-administrative Command Prompt.

For reference, per this MSDN article entitled Registry Value Types the difference between REG_SZ and REG_EXPAND_SZ is that the latter will expand shell variables that it contains; literally “A null-terminated string that contains unexpanded references to environment variables”. The former (REG_SZ) is just a string.

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SSD Installation in a Mid-2010 27″ iMac

Published August 14, 2011

This weekend I fitted my 27″ iMac with an SSD and I now have that running as the boot and OS drive, with large-stuff-storage on the internal 1TB drive. I’ve been considering an SSD for a while, and with prices finally becoming reasonable (~$225 for 120GB) it was time to give it a go. Due to Apple’s screwup last year I ended up with a mid-2010 iMac; a model which could have been ordered with an SSD from the factory. While this 27″ iMac didn’t come with an SSD, thanks to this post by Tobias Müller I found that it was possible to buy the plastics and cabling and add one with a factory-type fit. So, I did.

After receiving the parts and reading through Tobias’ post and the Apple factory service manual I set about fitting the drive. I won’t go into details of the install here, but it would easily rate 4 out of 5 for difficulty of non-custom computer work that I’ve done. Because the SSD sits in a carrier behind the logic board I had to remove the display, power supply, LCD power supply, Airport card, a blower, hard drive, optical drive, logic board, and an IR receiver to get the job done. The SSD, mounted in the pressure wall / plastic carrier and connected with a new wiring harness, settled nicely into the case and everything went back in.

Beyond the SSD, if you’d like to try this modification yourself you’ll need the following Apple parts:

922-9531: Power Cable / Wiring Harness
922-9485: Pressure Wall
922-9538: SATA Cable

I purchased all of these new from Usedmac for a total of $84.24 shipped and installed them along with a 120GB Intel 320-series SSD. These parts, with the SSD attached, can be seen here. If you don’t want to pay ~$20 for an Apple-specific SATA cable, a 10″ cable with a right angle connector on one end (only) which bends towards the top of the drive will suffice.

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Download Maps via QR Codes

Published June 1, 2011

While working up some revisions to the River Bends trail map for the trail head kiosk and I realized that having a QR code on it which links solely to a PDF of the same map might be a good idea. This would allow one to scan the code and download the map to a phone and keep an offline copy; exactly how one would want an electronic copy while out and about.

I think this would nicely augment the standard large map placed at the trail head and the typical paper map distribution box. One would just have to ensure that the link stays live for the life of the map. It might be a better idea to have the QR code on a separate smaller poster that just says “Scan Me to Download The Trail Map”, as it’d be cheaper / easier to update should the need arise.

This is probably the first productive use I’ve had for a QR code.

(The image above is a draft / mockup and links here to the current [but soon to be out of date] version of the map. Final implementation will definitely need more polish.)

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Historic Case Badges

Published May 25, 2011

This evening while cleaning out an old tool bag I found these two old computer case badges for Data Premium and Pack In Tell brand computers. These were two house brands from Computer Warehouse, a retail computer outlet in Troy and Madison Heights where I worked from late 1996 until early 1999. These shops were later known as Thomas Computer Warehouse and then Computer Builders Warehouse. During this time the Computer Warehouse stores worked closely with Inca Computer Company; so much so that I essentially transfered from CW to Inca to work in their R&D department. Once Inca closed up shop (it was basically a brick and mortar chain with grandiose plans opening right in the middle of the dot-com bubble) under I returned to Computer Warehouse for a few months before moving on to the world of corporate IT.

I think I’ve got an Inca badge or two around here somewhere as well.

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RSS Graffiti Test Post

Published May 16, 2011

For years I’ve been hesitant to use Facebook too much, instead opting to post everything to nuxx.net, with article-length content going in a wiki, photos going in the photo gallery, and blog posts going here at the blog. Since Facebook has picked up steam, is going to be around for a while, and is the de facto non-geek online identify, I figure I should start using it more.

To continue centrally publishing content but allowing it to be available in Facebook I’ve enabled the RSS Graffiti application, set it to pick up nuxx.net blog‘s RSS feed, and let it do its thing. This is my first post after enabling this and thus a joint test / welcome-to-me-actually-posting-stuff-on-Facebook.

UPDATE: I’ve opted to not use RSS Graffiti and instead allow Facebook’s Notes application to import RSS feeds. Hopefully this will work better.

UPDATE 2: Damn you for being broken, Facebook! Notes consistently returns an error saying that it’s failed saying that there is a problem which is being worked on.

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MultiTech MultiModem II (5600 Series) Teardown

Published March 7, 2011

I recently had a chance to play with one of the last bastions of high-quality analog modem technology, a MultiTech MultiModem II, 5600 series. It’s an extremely high quality device which can do things such as automatically dialing a stored number when DTR goes high. These are quite useful as diagnostic backup devices and are often found connected to enterprise-class equipment to allow tech support another channel in or to allow the device to send emergency error messages.

Since I had access to this I decided to open it up and look inside, since tech like this isn’t too common these days. Photos of the MultiTech MultiModem II (5600 Series) disassembly (such as the one above) can be seen here in this gallery.

In the two photos showing the two sides of the PCB (top · bottom) here’s the components I found most interesting:

· Conexant SM56D / CX06833-44: This is the heart of the device; the modem itself.
· Atmel ATF1502ASV: EEPROM CPLD (Electronically Erasable Programmable Read-Only Memory Complex Programmable Logic Device); likely where the front panel controls run and how the modem chip is controlled.
· LM7805 (x3): Three linear voltage regulators which seems to me like an old but very reliable method for getting smooth power.
· Intersil ICL3207ECBZ (x2): RS232 transmitters / receivers.
· Atmel 26C16AN: 16K serial EEPROM.
· Atmel AT49BV040A: 4-megabit (512K x 8) Flash Memory. (Hidden in photo by front panel bracket.)
· Fairchild Semiconductor 74LVX4245: Dual Supply Translating Transceiver. Converts between 3.3v and 5v busses; used to drive 5v logic in LCD display module. (Hidden in photo by front panel bracket.)
· LM386: Audio amplifier for modem speaker.
· Cypress Semiconductor CYIFS781BSXC: Spread spectrum clock generator designed to reduce EMI.
· 28.224 MHz Crystal: Connected to clock generator.

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Chest Freezer First Steps

Published February 28, 2011

Now that I’m brewing beer again and kegging it (1 · 2 · 3 · 4), the approach of warm weather means that I have to find a way to keep the kegs cool so that I may serve them. To do this I purchased a chest freezer and am in the process of adapting it to use a more precise temperature control system so that I may try and keep the kegs at a consistant 40°F.

After receiving a Johnson Controls A419ABC-1C temperature control I opened up the 7.0 ft3 Holiday-brand chest freezer acquired from Lowes (item number 0073849) and set to understanding it’s temperature control system. It turns out that this chest freezer just has a basic on/off control that switches mains on and off for the compressor based on a temperature probe fed into the wall of the freezer. This should make it very easy to replace the controller with the A419.

Part of converting a chest freezer to beer keg holding requires one to drill holes for both CO2 and the temperature control, which is a very risky task because hitting the refrigerant lines will vent the freezer’s cooling system rendering it useless. To try and understand where the coils are I started the freezer, let it run for a bit, then placed 1L of boiling water in it with the lid closed. The result was this, a nicely frosted freezer showing that almost all of the bottom part contains coils. Knowing this I’m going to attempt to drill the gas/probe holes by first carefully removing some of the lining metal then picking away at the foam to be sure that I’m not going to hit a line when widening the hole. I will start in the corner in the upper right of this picture, as this will allow for both easy gas and temperature probe access once everything is assembled. Hopefully that’ll go well.

If you’re interested, my first photos from this project can be found here.

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Friends Don’t Let Friends Buy eMachines

Published February 4, 2011

Danielle’s dad’s computer has been having a bunch of problems, and as some of them seem malware-related I am planning on wiping the computer and reinstalling Windows XP. Unfortunately when attempting to back up data it keeps rebooting unexpectedly, so I’ll have to pull the disk to recover data. I suspect the power supply may be going, which may cost a non-trivial amount if it’s even worth replacing.

Worse than that, when dusting out the machine I decided to pull the CPU heatsink / fan assembly as it was pretty well caked with dust. When I did this the CPU popped out along with the heatsink because the CPU was not latched in place. The downward pressure of the heatsink retention mechanism must have been allowing it to make enough contact to work. (For those that don’t know, CPUs normally sit in sockets with large latching levers which actuate contacts to ensure that all pins make contact. This wasn’t set in the socket, just on it. Here is a diagram.)

I hate working on eMachines. The cost saved up front bites you in frustration and parts later.

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