IntroductionThe Palm Operating System

• In 1996, a product called the PalmPilot was released by US Robotics. The Palm Pilot ran on an operating system made especially for that device, called the Palm OS.

• The Palm Operating System (Palm OS) is the current leader in the PDA market, accounting for 70% of the market share. The Palm Pilot (now known as just Palm), became one of the fastest growing computer platforms in history, reaching the million-sold mark faster than the IBM PC or Apple Macintosh.

• Today, the Palm line has grown to include a variety of models. In addition, a number of other companies such as IBM, Qualcomm, and Symbol Technologies released their own Palm OS PDA models, with Sony's version hitting the market later this year.

Definition Palm OS

• Palm OS is the most popular operating system that runs on Personal Digital

Assistants,also known as PDA’s. • It can be found running on PDA’s produced by Palm, Sony, IBM, Samsung, and a few cell

phones. Palm OS offers a variety of ways for the

user to interact with it, with a user interface that fits most users needs allowing for ease

of use.

Palm Operating System Objectives

Flexibility

• To protect Palm’s investment in older software, OS 5 supports the Application Programming Interface (API)

• All Palm Operating systems were 16-bit and used a processor.

• The Palm OS 5 now uses the ARM processor because of its superior speed and architectural improvements

• Even though the Palm OS 5 has upgraded to 32-bit, there's such a speed improvement (2 to 20 times faster) that it has the ability to run.

Ease of Use

The two biggest differences between a desktop-based computer and a Palm

OS based computer is the size and theI/O devices.

Functionality is extremely important when designing an Operating system on a device with such a small display. The amount of information displayed

at any one time is greatly limited.

Mobility

Mobility is another important objective of thePalm Operating System.

Palm OS is intended for handheld portable devices. If the handheld is just a little too heavy or large, it

stays in a drawer and never gets used. The Palm operating system software was designed

exclusively for mobile devices. It uses memory and battery power very efficiently,

enabling Palm Powered hardware makers to engineer extremely small and lightweight systems

Power Management

• To minimize power consumption, the Palm OS dynamically switches between three different states:

• sleep mode• doze mode• running mode• The system manager controls transitions between different power modes and

provides an API for controlling some aspects of the power management. • Sleep mode:-The Palm OS will enter into sleep mode when the power is turned

off or after a few minutes without any user input.• Run mode:-In this mode the display and the main clock shut down while the real

time clock and interrupt generator continue to run.• Doze mode:-While in doze mode the operating system stands by but the CPU

does not perform any operations.• Using this power management system, the Palm OS can run up to two weeks on a

single charge lithium batteries.

Data and File Management

Palm devices do not have hard disks or floppy drives.

Therefore, the Palm OS does not implement the traditional concept of a file system. Because there is no file system, no flash

RAM support, and no secondary storage, the data is stored and organized in storage

heaps in the devices memory (which will be explained in the Memory Management

section).

Memory ManagementMemory for the palm OS comes in the form of a removable

card. The card can contain both ROM and RAM.

The Palm OS is capable of supporting up to 256 different memory cards at one time, but to date all Palm products

only support a single card. ROM is actually implemented as Flash memory and is

somewhat editable as a result. The memory card’s ROM size varies anywhere from 512K

to 2MB. ROM is non-volatile, and as a result is where critical

information is stored including the operating system and standard applications.

Palm OS Memory

Process ManagementThe Palm OS utilizes a single process mode

kernel. This is similar to the original DOS in that one

process is allowed to run at a time. That process will run until it has completed or it receives a stop event from the Event Manager.

All applications that run within the OS are single threaded processes.

User created threads are not allowed. However, the kernel does have the

functionality to handle multiple kernel threads and does in fact run multiple threads at a time.

Security

The Palm OS provides various methods that help keep the users data safe. The first is the use of a password

protection scheme much like what is seen in other operating system.

The user has to enter their password to be able to log onto the system or use

certain features. Data contained in the Palm OS is

encrypted.

Conclusion

The Palm OS is very popular right now because of the large developer base and the ease of creating new

applications.As more and more devices become wirelessly

connected to the internet, I see handhelds devices becoming more important for everyone in the future. There are some things that handheld devices can’t do

that a normal machine can do, but the goal of this revolution is to move away from the desktop .

To a smaller computer, or maybe just using home computer for backup and recovery purposes, either

way, Palm is leading us into the future.