Fresh Fish 8/FreshFishVol8-CD1.bin/useful/dev/c/cmanual/system/hardware/hardware.doc

Text File | 1993-10-12 | 19KB | 510 lines

1    AMIGA HARDWARE

1.1  INTRODUCTION

This chapter is intended to give you a brief introduction
of the Amiga and its hardware.



1.2  AMIGA MODELS

The first Amiga model was released in the middle of 1985 and
caused much publicity. It was the first "home" computer with
a so called "multi media architecture" (it can combine raw
data with astonishing graphics and stereo sound) and it was
using a new operating system with true multi-tasking (several
programs/tasks can run at the same time).

Although it was far superior to other available computers on
the marked, it did not sell as good as could be expected. The
main problem was, as with all new computers, that there did
not exist any software that used the special features which
the Amiga offered. The Amiga was expensive (although just a
fraction of a similar computer would cost), and most software
was simply "ported" from other computers and were therefore
extremely bad. (Who wants to work with an Amiga which feels
like an Atari or PC?)

However, slowly more and more programs were written specially
for the Amiga and people started to realize what the Amiga
really could do (and what other computers could not do). Two
new models (A2000 and A500) were released with even more
features and with a more attractive price tag.

Now everything started to accelerate. More people bought an
Amiga and therefore more programmers started to write software
for it, which encouraged even more people to buy it and so
on... During 1989 and 1990 the Amiga community grew so fast
that it became the best selling home computer.

The success has continued since then, despite what all so called
"professional" programmers have said. The Amiga has constantly
been looked down on by the rest of the computer world, accusing
it for being a game machine. The problem is that they do not
understand that a computer that can play stunning games with
stereo sound and fantastic graphics must have a computer power
far beyond other so called "professional" computers which hardly
could handle graphics not to mention sound.

The attitude towards sound and graphics have luckily slowly
changed, and now these so called "professional" people start
to dream about operating system which offers good graphics, and
maybe even some sound. I do not think we shall tell them that
this already existed 1985, with true multi-tasking, on a machine
which in their opinion "only" could play games...



1.2.1  AMIGA 1000

The Amiga 1000 was the first Amiga model, and was released
in the middle of 1985. The very first models were sold with
only 256 KB of memory, but this was soon changed to 512 KB.
At that time, this amount of memory was considered to be a
lot, but most people using the Amiga realized that more,
actually a lot more, could sometimes be needed.

The Amiga 1000 consists of a main box (a bit smaller that
the box of the A200) with a separate keyboard. It uses
a 7 MHz Motorola 68000 processor (see below for more
information), and came with DOS V1.0 and V1.1 (some are
even using V1.2 and V1.3). This model is still used by some
people, but more and more are switching over to newer models,
or changing the mother board so it becomes very similar to an
Amiga 2000. Most new programs does not support this model any
more.



1.2.2  AMIGA 2000

Two new models of the Amiga were released 1987/88 - Amiga 2000
and Amiga 500. The A2000 was intended for the more professional
part of the Amiga community. The main box contains five large
slots (100 pins) and two smaller ones (intended for IBM PC
cards), in total seven slots. To each slot you may connect
external devices like hard disks, extra memory, internal
modems, etc...

Both the A2000 and A500 were released together with DOS V1.2,
and was later upgraded to V1.3. It is now also possible to buy
the new chips for V2.0.

Both computers are sold with 512 KB of memory (so called "chip
memory"). When upgraded the next 512 KB of memory is called
"slow memory" and the rest (up to 8 MB) is called "fast".
The Amiga's special chips (see below) can only reach the "chip
memory", hence the name, while the main processor (the 68000)
can reach all 9 MB. The 512 KB above the "chip memory" is called
"slow memory" since the main processor may be interrupted by
the custom chips while working with this memory type, and this
memory is therefore not always as fast as the rest.

The later models of the Amiga 2000 are sometimes called
"2000C". This is because they have 1 MB of chip memory instead
of only 512 KB as previous models.



1.2.3  AMIGA 500

The smaller model is almost identical to its big brother A2000,
but does not have any internal expansion slots. The keyboard
and the computer are built together. It has only one (external)
expansion slot on the left side and a small internal expansion
slot for 512 KB of extra memory. This model is much cheaper than
the A2000 and was intended to become a home computer for the
family, which it one year later became.

Many people thinks that the A2000 is far superior to the small
A500, but this is actually not true. As said above, the only
difference between these two models are that it is easier to
expand (add on extra devices) an A2000, and that it has a
separate keyboard. The rest is identical.



1.2.4  AMIGA 3000

The Amiga 3000 is currently the most powerful model. It comes
with a Motorola 68030 processor which is boasted with a 16 or
25 MHz mathematical coprocessor. All Amiga 3000s are sold with
an internal hard disk of various sizes. This model comes with
the latest version of the operating system V2.0 (explained
below).

This model comes with the new "Enhanced Chip Set" (ECS) and
can address up to 2 MB of chip memory. On the mother board
can up to 16 MB be installed, and if using one of the slots
up to 1 Gigabyte can be used. This is a mean machine!



1.2.5  AMIGA 500+

This is a new version of the Amiga 500. It comes also with the
new "Enhanced Chip Set" (ECS) and can address up to 2 MB of
chip memory. This model is also sold with the new V2.0 operating
system.

It still uses the old and trusted 68000 processor, but is still
a nice update from the Amiga 500.



1.2.6  AMIGA 600

The latest model is the Amiga 600. This machine comes in a much
smaller box than the Amiga 500, and does not have any numeric
key pad. This will definitely cause some problems with programs
that are using these keys. However, this model is easier to
take to your friends, and will probably be cheaper in the end.

The Amiga 600 does not have the famous expansion slot on the
left side as the Amiga 500 and Amiga 500+ have. Instead there
is a new type of slot which is made for "electronic credit
cards". These small cards can contain programs, games, extra
memory up to 8 MB, and a lot of other useful stuff like sound
samplers and video digitizers.

Since there is no expansion bus on this model you can not
connect existing hardwares like hard disk, and memory
expansion slots to it. This is sad, but since the Amiga 600
can use an internal hard disk I do not think this cause any
problems.

This model will definitely be called a "game machine", and will
will undoubtedly appeal to many families who previously used
game consoles.



1.2.7  FUTURE MODELS

Everything is changing these days, and so is the Amiga. It is
impossible to say what is coming next, but I would not mind
an Amiga "4000" with 68040 processor, 1 Gigabyte hard disk, 16-
bit stereo sound channels and a 24-bit graphics cards with
built in genlock... One thing is sure at least, the Amiga will
continue to live, more than ever.



1.3  PROCESSORS AND SPECIAL CHIPS

The main processor on the Amiga is not specially strong or
powerful, but together with several coprocessors (extra
processors) which are specialized in doing certain things very
fast, the Amiga can do things other computers can not.

The main processor on the Amiga is a Motorola 680x0. The famous
coprocessors are called ("Fat") Agnus, Paula, and Denise. These
chips are close linked to each other and can only work with
"chip memory" (explained below). These coprocessors are often
referred as the "custom chips".



1.3.1  MOTOROLA MC680X0 PROCESSORS

The main processor on all Amiga