Palm Operating System

Features

• Hand-held computer operating system
• Written in C
• Graphical user-interface
• Pre-emptive multi-tasking
• Display and serial drivers
• User Interface toolbox
• Graffiti Power Writing Technology
• No secondary storage
• No file system
• Memory is organized in variable-length chunks which are movable or immovable
• Memory consists of dynamic heap and storage heap
• Memory manager allocates memory in dynamic heap
• For handling chunks, Memory manager uses locks and Master Pointer Table
• Database management system used to store and retrieve information on storage heap
• 2 separate database types :
  • resource databases used to store read-only data
  • record databases used to store appointments , application data and provides tools for synchronization
• Provides no protection for dynamic heap
• Services are used through managers
• Consists of only one library, which contains managers

Goals

• Related hand-held side
  • Speed and efficiency - nearly instantaneous response to user
  • Low-cost and low-power
  • Small form-factor devices - fast efficient data entry without the use of a keyboard
  • Integrate PC connectivity
  • Standard application development
• Related PC side
  • Efficient synchronization - without user intervention
  • Extendability - conduits provides synchronization between hand-held applications and desktops
  • Communication independence - conduits are developed independent of communication protocols

Hardware Requirements and Features

• Microprocessor Motorola 68328
• Physical buttons for navigation
• System Memory - 32K system memory ( 64K if the system has Net Library installed ) plus data storage ( RAM storage )
• System ROM - usually 512K
• Memory is provided on memory cards
• Data bus is only 16 bits wide
• PalmOS devices uses 32-bit address

Questions

• What is the difference between PalmOS and a traditional desktop operating system ?
• If the system has multiple dynamic heaps ( has more than one memory card ) it uses only one dynamic heap and ignores all other potential dynamic heaps. Why ?