Downgrading AirPort Extreme to 7.6.1

I made a mistake last Thursday evening: upgraded my AirPort Extreme base station’s firmware to 7.6.3. Until Sunday afternoon WAN routing stopped three times (for which I first blamed our ISP), but when WiFi is also stopped last afternoon I decided to go back to the very well behaving 7.6.1.

But, to rephrase what Mr. Scott said: downgrading is easy, finding the file – that’s hard. Apple’s respective firmware page is an insult: it contains no link to the firmware update itself. Google turned up nothing, so I decided to go after a solution myself.

Note that I’m still using AirPort Utility 5.6. I consider 6.0 a huge step backward.

AirPort Utility stores the firmware files under the ~/Library/Application Support/Apple/AirPort/Firmware folder. You have a numbered subfolder for each model. My 4th generation AirPort Extreme’s number is 114. Here I found just one file: 7.6.3.basebinary.

So I knew that I had to look for 7.6.1.basebinary and put it into that folder. I also found a file named version.xml under the Firmware folder. Opening it quickly revealed that it contains actual download links for firmware images under the firmwareUpdates key (it’s actually an array of dictionaries, with each element corresponding to a firmware file). To find your file look for a dictionary containing your product number under the productID key, 7.6.1 under the version key, and you’ll get the download link in the location key, as you can see below:

<dict>
    <key>location</key>
    <string>http://apsu.apple.com/data/114/041-3395.20120130.Ka1Br/
        7.6.1.basebinary</string>
    <key>productID</key>
    <string>114</string>
    <key>version</key>
    <string>7.6.1</string>
    <key>sourceVersion</key>
    <string>76100.4</string>
    <key>sizeInBytes</key>
    <integer>6364116</integer>
</dict>

Also note that I had to download the firmware directly attaching the ADSL modem to my Mac, as at the end routing was so hectic that I was not able to do it via the AirPort Extreme. Having downloaded the file the actual downgrade procedure was seamless: put the file in the aforementioned folder and choose “Upload Firmware…” from the “Base Station” menu in AirPort Utility 5.6.

I also noticed a strange thing: while on 7.6.3 the Upload Firmware dialog only allowed me to upload 7.6.3 and nothing else. Now that I’m back on 7.6.1, it allows me to choose between 7.5.2, 7.6, 7.6.1 and 7.6.3.

All is well since then.

Update 8/14/2013

Just installed 7.6.4. I’ll report after a week or so how it works.

Sleepless External Display on a Mac

The original frustrating issue: my other half’s 13″ retina Macbook Pro was unable to put the external display into sleep. Video signal was off, but something kept the display always on (it’s a Samsung SyncMaster 213T – which isn’t a young one, but still a very capable monitor). So I tried a crazy idea: swapped my Mini Displayport to DVI adapter with hers.

And the result was – to my biggest surprise – proper display sleep. I was curious whether it is a faulty adapter or what, so tried the non-sleeping adapter with my EIZO CG241W. The result? Proper sleep behavior again.

The only difference between the two MiniDP to DVI adapters is that mine is almost three years old, while hers is from last December. They look exactly the same, have the exact same part number, etc.

Conclusion: if you encounter display sleep issues, the culprit might be compatibility between your adapter and monitor. Try to get an older Apple adapter or try an aftermarket one.

Year-End Server Upgrades

At the end of every year I take some time to upgrade server hardware (if necessary and if it brings any benefit to the business) and to bring all software on it to the latest level. We are trusting our small business to FreeBSD for the second year – since 8.1. And I’m really happy with the OS. There are two business-critical services on it: Perforce and AFP file services (Netatalk).

On the hardware side this upgrade moved the boot/system partitions to SSD. The speed increase is dramatic. The machine feels much faster. Some tasks, like portsclean -D, which previously took considerable amount of time are completed in seconds. FreeBSD also supports TRIM, just don’t forget to specify -t for newfs when you create file systems. Now I’m investigating whether our ZFS pool would benefit from adding an SSD for L2ARC. Here I would like to note how much I love to use my ancient DLT VS tape drive to do backups and restores. Just dump, replace the disks, partition/create file systems, and finally restore. A truly easy and seamless experience!

FreeBSD 9.1 was officially released yesterday. The upgrade went smoothly, as usual. I also brought Perforce and Netatalk to the latest binaries. In case of Netatalk this means 3.0.1. This version puts AFP metadata into a database and does not trash your folders with AppleDouble directories. Just make sure that your /var filesystem has enough free space for it. In my case the CNID database occupies about 200MB (for 2.5TB of shared files).

Speaking of Perforce: the latest P4 Visual Client (2012.3) brings partial retina display support! Partial means that while text is high resolution, all graphical elements are just pixel-doubled. The majority of the UI is text, so image aren’t a big deal.

iPad mini First Impressions

Owning a small software company that produces iOS apps has a huge benefit: I have access to all the latest and greatest devices Apple makes. Actually it is a necessity: we have to measure their cameras on our optical bench for Viewfinder. And most of them will remain here after that as a test device.

We have an iPad 4th generation for weeks, it works as expected, but nothing to write home about (except that I had to send the first one back because its display had an ugly green cast in the upper left corner).

The mini is a completely different story, though. When I got the package earlier today, I was really surprised by the weight. I knew that it’s light, just expected a heavier package. Back in the office I told Agnes: “Two words: mine and want are invalid, so don’t say them”. She looked at the device and quickly replied: “no dinner – how about these two?”

Joking aside (the ownership of the mini is still undecided, however – and we are after the dinner), here’s a quick rundown of my initial impressions.

  • This is the ideal size for me as a content consumption device. Reading books, websites, Flipboard-ing, things like these. The classic iPad is way too heavy to hold for extended periods of time and tends to punch a hole in my left palm in the position I usually hold it. I spent the last two hours reading Kindle books on it and really enjoyed the experience. Way more than on the classic iPad (retina or not). I suspect that I’ll read more books in the coming weeks than I usually do.
  • Performance is great, but even the iPad 2’s perf was OK for me. I don’t play OpenGL-heavy games on the iPad, so can’t talk about that part (XPlane 9 is fast enough).
  • The screen – well, it’s lacking. In my usual reading distance it’s pretty good, but way worse than anything retina. On the retina iPad I can read pretty small type without strain – the mini’s screen is not so easy on my eyes. I find myself zooming in more often than with the retina iPad. Actually it’s the same thing I experienced with the iPad 2. Reading Kindle books is more than OK, however.

All in all, I love the mini. For reading PDFs and anything high resolution I still reach for the retina iPad. Every other aspect of my iPad usage is a better fit for the mini. And I have some rather ambitious plans with the device…