Amiga Operating System

      Kevin Marinak
      Holly Medeiros
       John Feehan
        Jon Bradley
       Nimish Patel
             Amiga History
• Three dentists and 7 million dollars
• Amiga computer gaming system
• Debut - 1985: Commodore Amiga 1000
  – Amiga OS 1.0 for Motorola MC68000 processor
• Competed with and overtook Atari
• Financial disaster by 1994
  – Commodore  Escom  Gateway
• Amiga Research Operating System
  – Devoted following
         Technically Amazing
• Several state-of-the-art features
  –   Preemptive multitasking
  –   Color GUI (Before Apple)
  –   Multiple screens with different resolutions
  –   Fast graphic subsystem (ECS)
  –   Television connectivity (Digital to Analog Converter)
  –   Autoconfig
       • Microsoft purchased rights (now plug-and-play)
• Lost marketing battle between Sega / Nintendo
  & Microsoft / Apple
         File Management
• File system
  – Original File System (OFS)
  – Amiga Fast File System (AFFS)
• Workbench and AmigaDOS
  – Drawers and tools
• Naming conventions
  – Files and directories: 30 characters long /
    not case sensitive
        AmigaOS memory
• Chip RAM
  – Main CPU
  – Peripheral processors
  – Processes that share information
  – Locking needs to happen
  – Can be used by programs if Main memory
    is used up
   AmigaOS memory (cont.)
• Fast RAM
  – CPU exclusive access
  – This RAM is much larger
  – Requested RAM is reserved exclusively for
    that program
  – Locking not used
  – Seems faster than Chip RAM
   AmigaOS memory (cont.)
• No partitioning of memory
• Write protection in Chip RAM
• Programs are responsible for memory
• Free memory lists
  – Looks for equal/greater size space…if
    greater returns extra to list
  – Used memory not on list
• Fragmentation
    Processor configurations
• Mainly used in a Uniprocessor environment
• Amiga has always utilized processors in
  addition to the CPU
• Symmetrical Multi-Processing
  – Partially Implemented (Release 4.0)
  – Further implementation planned
• Process states
  – Runnable (Ready Resident)
  – Running
  – Blocked (Waiting Resident)
• Pre-emptive Multitasking
• Advantages
  – Lower priority background applications
• Disadvantages
  – Overwrite or corrupt
• No deadlock prevention

• No deadlock avoidance

• No deadlock detection and resolution
       A Look into the Future
•   Amiga OS 3.X
•   Amiga OS 4.X
    – History
    – Features
        • Move the 68K OS3.9 to a native PPC OS, enhancing and where necessary re-
          implementing the OS to take advantage of the PPC CPU
        • Add new functionality to improve the functionality and performance of
        • Allow for full backwards computability via the Eyetech AmigaOne (with a
                   classic Amiga attached) or retargetable application compatibility via
                   any AmigaOne
        • Move the community to new, state of the art hardware
        • Provide an attractive computing environment to non Amigans so as to
                   encourage growth of the Amiga community
        • Integrate the AmigaDE into the AmigaOS
        • Provide a foundation for the development of AmigaOS
    – Improvements
• Amiga OS5
  – Improved Performance
  – Features
     • Brand new services model providing
          –   Virtual Memory
          –   Memory Protection
          –   Symmetric and Asymmetric modes
          –   Contract QoS
          –   64 bit
          –   Fully distributed
     • AmigaOS4 sandbox
     • PDP sensory processing system - PDP stands for Physical to Digital to
              Physical and provides a scalable system that provides for capture,
              conversion, representation, manipulation and presentation of sense
              delimited observation and interaction
     • Orthogonal Persistence - all content is persistent, instead of having to be
              saved to and loaded from storage.
     • Safe and Unsafe environments - separate memory spaces in which
              developers can continue to use unsafe languages or develop using
              the new SafeC language and environment.
     • Semantic Context - an environment is which the user can layer any number
              of associations, relationships and meaning to their environment and
              content, and use that semantic information to organize and query.

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