Amiga Inc.
operating systems and software development company with headquarters in Washington (USA)
<
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 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.
Home.
Amiga Web Directory.
amiCrawler.
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)
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