amiga

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.
    

Amiga

   <computer> 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)