dict.org

The DICT Development Group


Search for:
Search type:
Database:

Database copyright information
Server information


1 definition found
 for amiga
From 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 http://micktinker.co.uk/aaplus.html)">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/)">(http://amiga.com/).
  
     http://cucug.org/amiga.html)">Amiga Web Directory (http://cucug.org/amiga.html).
  
     http://amicrawler.com/)">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)
  

Contact=webmaster@dict.org Specification=RFC 2229