ARM based controllers are a common choice for robots these days and there's a new Open Source ARM simulator you can use for development and debugging. Freshmeat carried a release notice for Skyeye v0.2.8 today. Skyeye runs under Linux or Windows. It provides simulations of the ARM720T (including support for MMU Cache), the AT91x40 board based on ARM7TDMI CPU core, the Atmel AT91 board based on the ARM7TDMI CPU, and the Clps7110 board based on the ARM720T CPU. Other hardware included in the simulated environment includes the Timer, UART, and NE2k compatable 8019AS. You can run ucLinux and ARM Linux in the simulated environment. SkyEye is Free Software licensed under the GNU GPL.