Palm OS overview

Palm OS is a compact operating systemthan on previous generation hardware. New
developed and licensed by PalmSource, Inc. forsoftware can take advantage of the ARM
personal digital assistants (PDAs) manufactured byprocessors with PNO (PACE Native objects), small
various licensees. It is designed to be easy-to-useunits of ARM code, these are also sometimes
and similar to desktop operating systems such asreferred to as 'ARMlets'. It was also around this
Microsoft Windows. Palm OS is combined with atime when Palm began to separate its hardware
suite of basic applications including an addressand OS efforts, eventually becoming two
book, clock, note pad, sync, memo viewer andcompanies, PalmSource, Inc. (OS) and palmOne
security software. Palm OS was originally released(hardware, now named Palm, Inc.). Further
in 1996.releases of Palm OS 5 have seen a standardised
Versions historyAPI for hi-res and dynamic input areas, along with
Palm OS was originally developed by Jeff Hawkinsa number of more minor improvements.
for use on the original Motorola DragonBall-basedPalm OS 5.2 and 4.1.2 (and later) also feature
Pilot PDA by U.S. Robotics. Palm OS 1.0 wasGraffiti 2. This is based on Jot by CIC.
present on the original Pilot 1000 and 5000.Palm OS 5.4 added the Non-Volatile File System,
Palm OS 2.0 was introduced with the PalmPilotand used Flash for storage instead of DRAM,
Personal and Professional.preventing data-loss in the event of battery drain.
Palm OS 3.0 was introduced, ith the launch of theHowever, this fundamentally changed the way
Palm III series. Incremental upgrades occurredprograms were executed from the
with the release of versions 3.1, 3.3, and 3.5,Execute-in-Place system that PalmOS traditionally
adding support for color, multiple expansion ports,used, and has been the source of many
new processors, and other various additions.compatibility problems, requiring many applications
Palm OS 4.0 was released with the m500 series,to have explicit NVFS support added for them to
and later made available as an upgrade for olderbe stable.
devices. This added a standard interface forIn December 2006, Palm (Hardware) paid $44
external filesystem access (such as SD cards)million to ACCESS for the rights to the source
and improved telephony libraries, security, and thecode for Palm OS (6.0) Garnet. With this
UI. Version 4.1 included a series of bug fixes.arrangement, a single company is again developing
Palm OS 5.0 was introduced in November 2002palm hardware and software. Palm can modify
with the Tungsten T and was the first versionthe licensed software as needed and it need not
released to support ARM devices. Described as apay royalties to ACCESS over future years.
stepping stone to full ARM support, DragonBallPalm OS 1.0 to 4.1 were based on top of a small
Palm apps are run in an emulated environmentkernel licensed from KADAK Products Ltd. While
called the Palm Application Compatibilitythese versions are technically capable of
Environment (PACE), making the device capablemultitasking, the "terms and conditions of that
of running software written for older versions.license specifically state that Palm may not
Even with the additional overhead of PACE, Palmexpose the API for creating/manipulating tasks
applications usually run faster on ARM deviceswithin the OS."