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Kernel. Expanded version of Kodak’s AMX kernel Features Uses Preemptive Priority Scheduling Multithreading Multitasking. Final Report: Palm OS. Thad Cox Gerald Irish Duo Lei Chip Seymour. Typical architecture layers of a PDA. Palm OS Specs. CPU speed ranges from 16MHz to 33MHz

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Kernel
Kernel

  • Expanded version of Kodak’s AMX kernel

  • Features

    • Uses Preemptive Priority Scheduling

    • Multithreading

    • Multitasking


Final report palm os

Final Report: Palm OS

Thad CoxGerald IrishDuo LeiChip Seymour



Palm os specs
Palm OS Specs

  • CPU speed ranges from 16MHz to 33MHz

  • Random Access Memory (RAM) ranges from 128k to 8MB

  • Dynamic heap ranges from 32K to 256K


Devices
Devices

  • Handspring

  • HandEra

  • Sony

  • Palm Inc.

  • Kyocera/QUALCOMM

  • Symbol Technologies


Palm os 5 0 multimedia
Palm OS 5.0 - Multimedia

  • support for high-resolution 320x320 pixel screens -four times the resolution of most current generation products

  • high-fidelity sound recording and playback


Palm os 5 0 wireless connectivity
Palm OS 5.0 - Wireless Connectivity

  • support for Bluetooth and 802.11b wireless networking standards

  • capable of connecting and communicating with networks and other devices like never before


Palm os 5 0 security compatibility
Palm OS 5.0 - Security & Compatibility

  • 128-bit data encryption based on the RC4 algorithm and Secure Socket Layer (SSL) support for Internet email, web browsing, and commercial transactions.

  • backwardly compatible with most existing Palm OS applications


Palm handheld and issues concerning software applications
Palm Handheld and Issues concerning Software Applications

  • Screen Size

  • Quick Turnaround expected

  • PC Connectivity

  • Input Method

  • Power

  • Memory

  • Backward Compatibility


Continue
Continue…

  • Programming Concepts

    • PilotMain

    • Event Loop

    • Predefined UI and Custom define UI

    • Managers


Memory
Memory

  • Broken into three Heaps

    • Dynamic

    • Storage

    • ROM

  • Each heap (except ROM)

    • Header

    • Master Pointer Table

    • Chunks

    • Terminator


Memory cont
Memory Cont.

  • Dynamic Heap is Palm’s RAM

    • global variables and data objects, user interface components, buffers, application data, and an application stack

    • variable size chunks are allocated

    • two types, movable, and unmovable

  • Movable memory is referenced by ‘handles’

    • handles reference master pointers which point to the beginning of each memory chunk

    • handles must be locked before memory access

    • a lock counter keeps track of how many locks are on a particular chunk. Chunks can only move when locks = 0


Memory1
Memory

  • Compaction

    • compaction is automatically performed whenever there is not enough memory for an allocation

      • the OS does not keep track of when it performed last compaction

      • if after compaction the memory allocation fails again, the system will continue to try which may lead to a system crash


Memory cont1
Memory Cont.

  • Storage Heap

    • where user data and applications reside

    • data is divided into records in either a resource or record database, logical constructs

    • multiple databases within memory

    • records can be accessed by index or searched by one of its attribute fields

    • each record must be <64K, thus applications should be <64K, however Palm OS supports segmenting


Conclusion
Conclusion

  • Palm’s success comes from its minimalism

  • solutions to design constraints are sometimes suboptimal from a logical standpoint but work well given the application

  • future releases will gain some of the capabilities of desktop machines as PDA hardware advances


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