The Jargon File (version 4.4.7, 29 Dec 2003):

Amiga
 n

    A series of personal computer models originally sold by Commodore, based on
    680x0 processors, custom support chips and an operating system that
    combined some of the best features of Macintosh and Unix with compatibility
    with neither.

    The Amiga was released just as the personal computing world standardized on
    IBM-PC clones. This prevented it from gaining serious market share, despite
    the fact that the first Amigas had a substantial technological lead on the
    IBM XTs of the time. Instead, it acquired a small but zealous population of
    enthusiastic hackers who dreamt of one day unseating the clones (see Amiga
    Persecution Complex). The traits of this culture are both spoofed and
    illuminated in The BLAZE Humor Viewer. The strength of the Amiga platform
    seeded a small industry of companies building software and hardware for the
    platform, especially in graphics and video applications (see video toaster
    ).

    Due to spectacular mismanagement, Commodore did hardly any R&D, allowing
    the competition to close Amiga's technological lead. After Commodore went
    bankrupt in 1994 the technology passed through several hands, none of whom
    did much with it. However, the Amiga is still being produced in Europe
    under license and has a substantial number of fans, which will probably
    extend the platform's life considerably.


The Free On-line Dictionary of Computing (30 December 2018):

Amiga

    A range of home computers first released by
   Commodore Business Machines in early 1985 (though they did
   not design the original - see below).  Amigas were popular for
   games, video processing, and multimedia.  One notable
   feature is a hardware blitter for speeding up graphics
   operations on whole areas of the screen.

   The Amiga was originally called the Lorraine, and was
   developed by a company named "Amiga" or "Amiga, Inc.", funded
   by some doctors to produce a killer game machine.  After the
   US game machine market collapsed, the Amiga company sold some
   joysticks but no Lorraines or any other computer.  They
   eventually floundered and looked for a buyer.

   Commodore at that time bought the (mostly complete) Amiga
   machine, infused some money, and pushed it through the final
   stages of development in a hurry.  Commodore released it
   sometime[?] in 1985.

   Most components within the machine were known by nicknames.
   The coprocessor commonly called the "Copper" is in fact the
   "Video Timing Coprocessor" and is split between two chips:
   the instruction fetch and execute units are in the "Agnus"
   chip, and the pixel timing circuits are in the "Denise" chip
   (A for address, D for data).

   "Agnus" and "Denise" were responsible for effects timed to the
   real-time position of the video scan, such as midscreen
   palette changes, sprite multiplying, and resolution
   changes.  Different versions (in order) were: "Agnus" (could
   only address 512K of video RAM), "Fat Agnus" (in a PLCC
   package, could access 1MB of video RAM), "Super Agnus"
   (slightly upgraded "Fat Agnus").  "Agnus" and "Fat Agnus" came
   in PAL and NTSC versions, "Super Agnus" came in one
   version, jumper selectable for PAL or NTSC.  "Agnus" was
   replaced by "Alice" in the A4000 and A1200, which allowed for
   more DMA channels and higher bus bandwidth.

   "Denise" outputs binary video data (3*4 bits) to the "Vidiot".
   The "Vidiot" is a hybrid that combines and amplifies the
   12-bit video data from "Denise" into RGB to the monitor.

   Other chips were "Amber" (a "flicker fixer", used in the A3000
   and Commodore display enhancer for the A2000), "Gary" (I/O,
   addressing, G for glue logic), "Buster" (the bus
   controller, which replaced "Gary" in the A2000), "Buster II"
   (for handling the Zorro II/III cards in the A3000, which meant
   that "Gary" was back again), "Ramsey" (The RAM controller),
   "DMAC" (The DMA controller chip for the WD33C93 SCSI adaptor
   used in the A3000 and on the A2091/A2092 SCSI adaptor card for
   the A2000; and to control the CD-ROM in the CDTV), and
   "Paula" (Peripheral, Audio, UART, interrupt Lines, and
   bus Arbiter).

   There were several Amiga chipsets: the "Old Chipset" (OCS),
   the "Enhanced Chipset" (ECS), and AGA.  OCS included
   "Paula", "Gary", "Denise", and "Agnus".

   ECS had the same "Paula", "Gary", "Agnus" (could address 2MB
   of Chip RAM), "Super Denise" (upgraded to support "Agnus" so
   that a few new screen modes were available).  With the
   introduction of the Amiga A600 "Gary" was replaced with
   "Gayle" (though the chipset was still called ECS).  "Gayle"
   provided a number of improvments but the main one was support
   for the A600's PCMCIA port.

   The AGA chipset had "Agnus" with twice the speed and a 24-bit
   palette, maximum displayable: 8 bits (256 colours), although
   the famous "HAM" (Hold And Modify) trick allows pictures of
   256,000 colours to be displayed.  AGA's "Paula" and "Gayle"
   were unchanged but AGA "Denise" supported AGA "Agnus"'s new
   screen modes.  Unfortunately, even AGA "Paula" did not support
   High Density floppy disk drives.  (The Amiga 4000, though,
   did support high density drives.)  In order to use a high
   density disk drive Amiga HD floppy drives spin at half the
   rotational speed thus halving the data rate to "Paula".

   Commodore Business Machines went bankrupt on 1994-04-29,
   the German company Escom AG bought the rights to the Amiga
   on 1995-04-21 and the Commodore Amiga became the Escom
   Amiga.  In April 1996 Escom were reported to be making the
   Amiga range again but they too fell on hard times and
   Gateway 2000 (now called Gateway) bought the Amiga brand
   on 1997-05-15.

   Gateway licensed the Amiga operating system to a German
   hardware company called Phase 5 on 1998-03-09.  The
   following day, Phase 5 announced the introduction of a
   four-processor PowerPC based Amiga clone called the
   "pre\box".  Since then, it has been announced that the
   new operating system will be a version of QNX.

   On 1998-06-25, a company called Access Innovations Ltd
   announced plans (http://micktinker.co.uk/aaplus.html) to
   build a new Amiga chip set, the AA+, based partly on the AGA
   chips but with new fully 32-bit functional core and 16-bit AGA
   hardware register emulation for backward compatibility.
   The new core promised improved memory access and video display
   DMA.

   By the end of 2000, Amiga development was under the control of
   a [new?] company called Amiga, Inc..  As well as continuing
   development of AmigaOS (version 3.9 released in December
   2000), their "Digital Environment" is a virtual machine for
   multiple platforms conforming to the ZICO specification.
   As of 2000, it ran on MIPS, ARM, PPC, and x86
   processors.

   (http://amiga.com/).

   Amiga Web Directory (http://cucug.org/amiga.html).

   amiCrawler (http://amicrawler.com/).

   Newsgroups: news:comp.binaries.amiga,
   news:comp.sources.amiga, news:comp.sys.amiga,
   news:comp.sys.amiga.advocacy,
   news:comp.sys.amiga.announce,
   news:comp.sys.amiga.applications,
   news:comp.sys.amiga.audio, news:comp.sys.amiga.datacomm,
   news:comp.sys.amiga.emulations, news:comp.sys.amiga.games,
   news:comp.sys.amiga.graphics,
   news:comp.sys.amiga.hardware,
   news:comp.sys.amiga.introduction,
   news:comp.sys.amiga.marketplace, news:comp.sys.amiga.misc,
   news:comp.sys.amiga.multimedia,
   news:comp.sys.amiga.programmer,
   news:comp.sys.amiga.reviews, news:comp.sys.amiga.tech,
   news:comp.sys.amiga.telecomm, news:comp.Unix.amiga.

   See aminet, Amoeba, bomb, exec, gronk, guru
   meditation, Intuition, sidecar, slap on the side,
   Vulcan nerve pinch.

   (2003-07-05)