Transcript Amiga-by-Kevin-Marinak-Jon-Bradley-Holly-Medeiros-John

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
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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
allocation
• 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)
Scheduling
• Pre-emptive Multitasking
• Advantages
– Lower priority background applications
• Disadvantages
– Overwrite or corrupt
Deadlock
• No deadlock prevention
• No deadlock avoidance
• No deadlock detection and resolution
A Look into the Future
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Amiga OS 3.X
Amiga OS 4.X
– History
– Features
• Move the 68K OS3.9 to a native PPC OS, enhancing and where necessary reimplementing the OS to take advantage of the PPC CPU
• Add new functionality to improve the functionality and performance of
AmigaOS
• 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
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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.