Operating system
From TreoCentral
Native Operating Systems
An Operating System is the core software that runs the main functions of the Treo, controlling access to resources such as processor time, memory, and storage. It includes the nitty-gritty code that makes the phone work. The built-in applications that are included with the Treo, are included on the firmware, but are not part of the Operating System.
Most Treos run off the Palm OS, though the Treo 700w/wx is based on Windows Mobile. Operating systems cannot be upgraded, except for small bug fixes, but the built-in applications can, by flashing the firmware. A Palm OS Treo cannot be switched to a Windows Mobile Treo nor vice versa. A CDMA Treo cannot be changed to GSM, nor vice-versa.
Furthermore, upgrading the built in applications involves a less than complicated process called flashing to update the firmware in the non-volatile memory. Essentially, the built in applications are stored in the non-volatile memory, which is specially allocated memory designed to keep the device functional in the aftermath of a loss of data. These applications and low level software components are updated in the aforementioned process.
Platforms
Although it is not an Operating System, Java Micro Edition (JME or J2ME) is also an environment in which applications run. JME applications (usually midlets) can run under Palm OS, Windows Mobile, Symbian OS or desktop operating systems, after the appropriate Java runtime and libraries have been installed. See midlets for more info.
Emulators
Software written for a different operating system can be run (much more slowly) if an emulator is available. Emulators running under Palm OS have been written for the Apple II (Appalm), Amiga OS (MyUAE), Atari ST (CaSTaway), Gameboy (Liberty}, the Multiple Arcade Machine Emulator (PalmMAME), and NES (NesEm), among others.
StyleTap is a Palm OS emulator that runs under Windows Mobile.
POSE (Palm OS Emulator) emulates Palm OS 4 and earlier, and runs under Windows, Mac OS X, Linux and Unix.
