Palm OS PDA/Phone combo devices use the same operating
system as PDA devices but include additional software to
utilize the cell phone functions of the device.
Palm OS 5.0 is the latest version of the Palm operating system
developed by PalmSource and introduced on PDA devices. Version 5 utilizes the ARM processor
architecture while still supporting applications developed for
previous version of the Palm OS. Version 5 turns Palm OS devices
into more powerful mobile computers then ever before. Devices
with a non-version 5 Palm OS cannot be upgraded to Palm OS version 5.