I want to design a pocket computer from the scratch. i what to choose an appropriate microcontroller. i have arm and propeller on my mind. which way should i go?
I think you need to specify the functionality of the pocket computer. Once you have that with a list of IO devices you can determine what type of microcontroller you require, e.g. could you use a PIC24 or do you need to go to something like a PIC32 or an ARM?