Users of handhelds do not expect to stare at an hourglass waiting for the next screen to appear. Batteries are relatively small on a handheld, yet one of the keys to the success of the platform is the outstanding battery life of the device, which in many cases exceeds a month. In this way, a handheld is much more like a good cell phone then a laptop. Users depend on being able to use their device without needing to worry about whether or not it is charged up. Consider your actions carefully before performing tasks that consume a lot of power, such as serial or IR communications, sound, extended animation, or other tasks that use the CPU for long periods.
Optimization is critical.
Optimize for heap space first, speed second, and code size third. A database is analogous to a file, but the breaking down of a database into records allows the data to be stored in non-contiguous chunks of memory. To save space, you edit data in the storage heap in place rather than creating or buffering it in RAM and later writing it to the storage heap. Backward compatibility is a key component of the Palm OS because users are not expected to upgrade their operating system as much as they would on a desktop computer. You can always use the latest version of the SDK, even if you want to create programs that run on older handhelds such as Palm Professionals.