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Skype on iPhone–iChat next?

VoIP on iPhone. Find free Skype for iPhone on the App Store.

It works–Skype calls over WiFi–and the quality seems better than Fring or TruPhone.

Why hasn't Apple got an iPhone version of iChat yet–or Gizmo5 to give us a free SIP phone?


USB Ethernet "not connected"?

Oh, yes it is!

"Oh, no it isn't," says System Preferences.

Physically it is connected. The ethernet works fine when I try it with another laptop. But my MacBook Air has no network connection.


Not sure what causes this, but it seems to arise when moving from one network to another — work to home. Until Apple fix their bug, one workaround is as follows:

  • Open System Preferences >> Network
  • Select USB Ethernet in the ports list.
  • Click the - sign at the bottom of the ports list to delete your existing USB Ethernet port
  • Click the + sign, to add a new one; select the new one click Apply.

If you're lucky (it's worked for me a couple of times already) you will find that, after a short pause, the USB Ethernet n port you just created now works as normal.

If the option to create a USB Ethernet port doesn't appear, check that you have the ethernet adapter dongle plugged in. This seems to be neccessary.

If it still doesn't appear (sometimes it doesn't), restart and try again. This has always worked for me (so far).


Wireless again

As long-time readers of this blog will know, I have an extended wireless network. It now includes two daisy-chains and one spur: a daisy-chain on 802.11n (5GHz) with a TimeCapsule (which has internet connection from my ADSL modem/router) and two Extremes; a daisy-chain on 802.11g (2.5GHz) with older kit — two Extremes (one connected by ethernet to the remote end of the 802.11n chain) and three Expresses.

Autoconfigure was a welcome feature of the 802.11n Express. It was great — when it worked — but it was always flakey.

With the 7.4.1 firmware update my setup became completely unstable. In particular, whenever Time Machine started a backup the network would auto-reconfigure, and break. I had to use an ethernet connection direct to the Time Capsule to make a backup. I've now reverted to a manual setup of the WDS with explicit MAC numbers. All appears stable, my iPhone is back on WiFi and backup over wireless is working again.

If you're having problems with an autoconfigured wireless network, try going back to manually configured WDS. Use Airport Utility. First make a note of the Airport ID (MAC number) for each of your devices. Then, one-by-one switch from Create a Wireless Network or Extend a Wireless Network to Participate in a WDS Network. A WDS tab will appear. Under this tab you can see (and manually adjust) the autoconfigured setup. In my case I found that two Extremes were trying to act as WDS main.

As usual, be careful to update the various access points in an order that doesn't leave you unable to access some device over wireless. If you do get into that sorry state, a direct ethernet connection can be used to reconfigure the lost device.


Google Base encoding woes

Google Base lets you upload descriptions of goods, services, publications—or whatever—to enable the world to find your stuff.

You can do this item-by-item, using a web form, or in bulk by submitting an RSS or Atom feed as an xml file.

So far, so good ...

But ...

If you want to use extended character sets (eg. characters, ξ € я þ ø æ œ and accents, å ç ê ñ ü ) you will naturally use utf-8 or unicode encoding.

So, I set up the feed for utf-8 encoding, and uploaded the xml using Direct Upload via Google Base, Google's file upload interface ...

Once my feed was processed, Google said, Your data feed contains an invalid character for the current encoding setting.

I tried File Transfer Protocol, uploading via ftp to Google still didn't get the right encoding (I think Google was at fault here).

I tried Automatic upload via scheduling. This probably failed because my ISP's server insists on sending a content header saying it is serving everything in ascii—Google did the "right thing" and believed this travesty.

So, nothing worked: Your data feed contains an invalid character for the current encoding setting.

Solution: use xsl:output to encode your feed in ascii

Here is a simple xsl transform to copy an xml file and change its encoding. The important line is the attribute encoding="us-ascii", in the xsl:output element.


<?xml version="1.0" encoding="utf-8"?>
<xsl:transform version="1.0"

  <xsl:template match="/">
    <xsl:apply-templates />



<?xml version="1.0" encoding="utf-8"?>
  characters, ξ € я þ ø æ œ 
  and  accents, å ç ê ñ ü

Executing the command

xsltproc -o ascii.xml toascii.xsl utf8.xml
produces an ascii-encoded version:


<?xml version="1.0" encoding="us-ascii"?>
  characters, &#958; &#8364; &#1103; &#254; &#248; &#230; &#339; 
  and  accents, &#229; &#231; &#234; &#241; &#252;

If you are already using xsl to produce your feed, just add encoding="us-ascii" to the xsl:output element. If you have it by some other means you can use the identity transform given above.


Adjust brightness for 24 inch LED Cinema Display?

I think that the F1/F2 keys on my MacBook Air used to adjust brightness of the primary display. In any event, they certainly don't now (10.5.6) allow me to adjust the brightness of my 24" LED display—they adjust the brightness of the MacBook Air screen, whichever display is selected as Primary.

However, the Display tabs of the Display panels of System Preferences allow you to adjust the brightness of each display independently.