The hardware of the
When it was first introduced, in 1984, the Amiga was nearly a decade
ahead of its time. Although the rest of the industry has largely succeeded
in matching or even exceeding the Amiga's hardware advantages, many
will argue that the Amiga continues to hold true to a goal of elegance
in computing even as the rest of the industry has become mired in
a swamp of inefficiencies that require more and more hardware to make
it work at all.
The Amiga was introduced with a 7.16MHz Motorola 68000 CPU. Working
in tandem with the main CPU are several other chips (CPUs almost in
their own right, and equipped with cute names, too): Agnus, Denise,
These peripheral CPUs (PPUs?) handled various input/output (I/O)
tasks: memory access, sound generation, floppy disk I/O, display generation,
special graphics tricks, etc.
These peripheral chips allowed the main CPU to concentrate on other
tasks (such as user interaction, decoding sound, etc.) without any slowdown
due to graphic objects bouncing around on the screen, or data coming
off the floppy disks, or thundering stereo sound pouring out of the
Yes, it's true: the Amiga has always been a kind of multiprocessing
Flexible Memory Architecture
The Amiga was introduced with 512K of ``Chip'' RAM and up to 8MB
RAM. Chip RAM is the memory addressable by the display chips (for those
of you familiar with the Intel machines, this is the equivalent of the
Monochrome or Color display memory area at B8000 or B0000, and more
recently the dedicated memory on graphics cards.)
By 1990, the Amiga's ``Chip'' RAM address space had grown to 2MB
and it could have up to 256MB of memory on the motherboard.
The Amiga's Chip RAM is not for graphics displays only, however.
``Chip'' RAM is named so because the Amiga's peripheral CPUs (chips)
all access that region of memory. But unlike with other computers you
can, in fact, run programs in Chip RAM if your main memory is exhausted.
The operating system manages such a case all on its own, of course.
When the main CPU and the peripheral chips all want access to ``Chip''
RAM, a bit of a ``traffic jam'' occurs. When there is no contest for
that special memory area, however, both the main CPU and the peripheral
CPUs can access their respective memory independently of each other
and without hurting each other's performance. This architecture gave
the Amiga the ability to play 4096 color full-screen animations along
with four-channel stereo sound in 1985, over ten years before any other
personal computer had any hope of getting anywhere near that kind of
The Amiga's peripheral CPUs are able to generate video compatible
signals, meaning that their output is compatible with televisions and
VCRs. Every Amiga can generate NTSC and PAL signals at will.
A company named NewTek created for the Amiga the Video Toaster,
a device that plugs into the Amiga's video slot and provides it with
the ability to generate live video effects, such as flipping, bending
and twisting images in real time, rolling a video signal up or down
as if it was on a roll of paper, etc. The Video Toaster put the
Amiga into many television studios and made possible the special effects
on shows such as Startrek, SeaQuest, and Babylon 5.
To this day, the Amiga is unequaled in the video field.
Even equipped with today's comparatively slow 680x0 series CPUs (68000,
68020, 68030, 68040, and 68060) the Amiga's highly efficient operating
system is able to hide many of the limitations of the aging hardware
and provide Amiga users with relatively modern computers that are often
as responsive as entry-level Pentiums.
The Amiga is now poised to enter the age of the Motorola PowerPC
RISC CPU, providing Amiga users with computing power that is one or
two orders of magnitude above their current machines, and exceeds the
power of high-end Pentium computers, especially in the realm of floating-point
operations. Combined with the elegance and efficiency of the Amiga's
high-performance multimedia operating system, this promises to be a