AmigaOS
AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early versions of AmigaOS required the Motorola 68000 series of 16-bit and 32-bit microprocessors. Later versions were developed by Haage & Partner (AmigaOS 3.5 and 3.9) and then Hyperion Entertainment (AmigaOS 4.0-4.1). A PowerPC microprocessor is required for the most recent release, AmigaOS 4.
Developer
Amiga
Current
July 23, 1985
4.1 Final Edition Update 2 / January 12, 2021
AmigaOS is a single-user operating system based on a preemptive multitasking kernel, called Exec.[1]
It includes an abstraction of the Amiga's hardware, a disk operating system called AmigaDOS, a windowing system API called Intuition, and a desktop environment[2] and file manager called Workbench.
The Amiga intellectual property is fragmented between Amiga Inc., Cloanto, and Hyperion Entertainment. The copyrights for works created up to 1993 are owned by Cloanto.[3][4] In 2001, Amiga Inc. contracted AmigaOS 4 development to Hyperion Entertainment, and in 2009 they granted Hyperion an exclusive, perpetual, worldwide license to AmigaOS 3.1 in order to develop and market AmigaOS 4 and subsequent versions.[5]
On December 29, 2015, the AmigaOS 3.1 source code leaked to the web; this was confirmed by the licensee, Hyperion Entertainment.[6][7]
Features[edit]
Graphics[edit]
Until the release of version 3, AmigaOS only natively supported the native Amiga graphics chipset, via graphics.library, which provides an API for geometric primitives, raster graphic operations and handling of sprites. As this API could be bypassed, some developers chose to avoid OS functionality for rendering and directly program the underlying hardware for gains in efficiency.
Third-party graphics cards were initially supported via proprietary unofficial solutions. A later solution where AmigaOS could directly support any graphics system, was termed retargetable graphics (RTG).[13] With AmigaOS 3.5, some RTG systems were bundled with the OS, allowing the use of common hardware cards other than the native Amiga chipsets. The main RTG systems are CyberGraphX, Picasso 96 and EGS. Some vector graphic libraries, like Cairo and Anti-Grain Geometry, are also available. Modern systems can use cross-platform SDL (simple DirectMedia Layer) engine for games and other multimedia programs.
The Amiga did not have any inbuilt 3D graphics capability, and so had no standard 3D graphics API. Later, graphics card manufacturers and third-party developers provided their own standards, which included MiniGL, Warp3D, StormMesa (agl.library) and CyberGL.
The Amiga was launched at a time when there was little support for 3D graphics libraries to enhance desktop GUIs and computer rendering capabilities. However, the Amiga became one of the first widespread 3D development platforms. VideoScape 3D was one of the earliest 3D rendering and animation systems, and Silver/TurboSilver was one of the first ray-tracing 3D programs. Then Amiga boasted many influential applications in 3D software, such as Imagine, maxon's Cinema 4D, Realsoft 3D, VistaPro, Aladdin 4D and NewTek's Lightwave (used to render movies and television shows like Babylon 5).
Likewise, while the Amiga is well known for its ability to easily genlock with video, it has no built-in video capture interface. The Amiga supported a vast number of third-party interfaces for video capture from American and European manufacturers. There were internal and external hardware solutions, called frame-grabbers, for capturing individual or sequences of video frames, including: Newtronic Videon, Newtek DigiView,[14] Graffiti external 24-bit framebuffer, the Digilab, the Videocruncher, Firecracker 24, Vidi Amiga 12, Vidi Amiga 24-bit and 24RT (Real Time), Newtek Video Toaster, GVP Impact Vision IV24, MacroSystem VLab Motion and VLab PAR, DPS PAR (Personal Animation Recorder), VHI (Video Hardware Interface) by IOSPIRIT GmbH, DVE-10, etc. Some solutions were hardware plug-ins for Amiga graphics cards like the Merlin XCalibur module, or the DV module built for the Amiga clone Draco from the German firm Macrosystem. Modern PCI bus TV expansion cards and their capture interfaces are supported through tv.library by Elbox Computer and tvcard.library by Guido Mersmann.
Following modern trends in evolution of graphical interfaces, AmigaOS 4.1 uses the 3D hardware-accelerated Porter-Duff image composition engine.
Audio[edit]
Prior to version 3.5, AmigaOS only officially supported the Amiga's native sound chip, via audio.device. This facilitates playback of sound samples on four DMA-driven 8-bit PCM sound channels. The only supported hardware sample format is signed linear 8-bit two's complement.
Support for third-party audio cards was vendor-dependent, until the creation and adoption of AHI[15] as a de facto standard. AHI offers improved functionality, such as seamless audio playback from a user-selected audio device, standardized functionality for audio recording and efficient software mixing routines for combining multiple sound channels, thus overcoming the four-channel hardware limit of the original Amiga chipset. AHI can be installed separately on AmigaOS v2.0 and later.[16]
AmigaOS itself did not support MIDI until version 3.1, when Roger Dannenberg's camd.library was adapted as the standard MIDI API. Commodore's version of camd.library also included a built-in driver for the serial port. The later open source version of camd.library by Kjetil Matheussen did not provide a built-in driver for the serial port, but provided an external driver instead.
