computer A range of home computers first released by
not design the original - see below). Amigas were popular for
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
changes. Different versions (in order) were: "Agnus" (could
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
"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,
(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 adaptorused in the A3000 and on the A2091/A2092 SCSI adaptor card for
the A2000; and to control the
CD-ROM in the
CDTV), and
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
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
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
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
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
"
prebox". Since then, it has been announced that the
new operating system will be a version of
QNX.
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
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
processors.
(2003-07-05)