Apple Computer has updated the software for some of its iPod digital media players so that songs bought from RealNetworks won't play.
The change affects Apple's new iPod Photo, which was introduced in late October and lets users store and display their digital image collections, in addition to digital music, on the iPod.
Apple's action comes several months after it accused Real of adopting "the tactics and ethics of a hacker to break into the iPod." Real in July announced a technology called Harmony that allows consumers to download songs they can play on a wide variety of portable digital media players, including Apple's iPod devices.
"As we stated in July, we strongly caution Real and their customers that when we update our iPod software from time to time it is highly likely that Real's Harmony technology will cease to work with current and future iPods," an Apple spokeswoman said Wednesday. She declined to comment further.
Real is keen to provide music to iPod Photo users as well, a company spokeswoman said. "We remain fully committed to providing consumers with the freedom to use the music they purchase from us on different portable audio devices, both now and in the future, including the iPod Photo," she said.
Apple's iTunes is the most popular online music store and the iPod is a very popular digital music player. Apple is protecting its turf by not allowing others to sell music that can be transferred to and played on the iPod.