Roland's TR-909 drum machine has been emulated countless times in software, so it was only a matter of time before a version was released for the iPhone. And that time is now: the IR-909 is ready to be purchased from the Apple App Store.
The emulation looks pretty basic, but the essentials seem to be in place. There are eight slots for the drum samples, four patterns and a 16-step sequencer. Each sample can be tweaked with pitch, attack and length controls.
Pleasingly, it's not just 909-style sounds that are included - users are also supplied with TR-808, TR-707 and TR-606 drum sets. Two further kits are labelled Tech House and Kärv.
Priced at just $5/£3, the IR-909 is certainly affordable, though it does have its limitations. You can't export or import audio, for example, and according to a reader on Create Digital Music, patterns can't be saved and the tempo adjustment is a bit crude. Furthermore, a reviewer on the App Store has commented that the step sequencer is fiddly to use.
If you want to find out more, you can watch a video of the IR-909 in action.