THE AMIGA 4000
In September 1991 at the European Developers Conference in Milan,
developers were treated to a first look at the new Amiga graphics shipset,
then known as the AA Chipset (AA standing for Advanced Amiga). Now,
just over a year later, the first machines featuring that new chipset have
arrived: the Amiga 1200 (see elsewhere) and Amiga 4000.
by Eddy Carroll, October 1992
For some months, I had been trying to figure out a way to convince myself
that I needed a 68040 card for my A3000 to give it a speed boost. Now, for
little more than the price of one of those cards, I could get a brand
new computer. I was sold. Two other CUGI members, Leon Hurst and Rocco
Matassa also fell under the A4000's spell and we placed the three orders
together. The machines arrived on 13 October.
Let's Get Physical
Physically, the A4000 is somewhere between the sleek lines of the A3000
and the ugly utility of the A2000. Its dimensions are a compact
15" x 15" x 5" and it is enclosed in a metal
case capable of supporting a monitor. Inside are a 5.25" drive
bay and four low-profile 3.5" bays. Two of the latter are already
occupied with a high-density 1.76 Mb floppy drive and 120 Mb IDE Seagate
hard drive. A vertically mounted backplane provides four Zorro III 32 bit
slots, which are in line with three IBM AT slots and an enhanced video
All these slots are fully backwards compatible with those found in
the A2000 and A3000, making it easy to move cards across from an older
system. In my case, I had an A2386 Bridgeboard and PC VGA card from
my A3000, and I had also purchased an A2091 SCSI controller
and A2320 Display Enhancer (for reasons that will become apparent). The
other device I had was a 520 Mb 3.5" Fujitsu SCSI drive,
and for the time being, I elected to mount this in the 5.25" bay.
The only glitch that arose with all this hardware was that the A2091 needed
a ROM upgrade, since it didn't understand 32 bit memory and would hang the
system while booting. Once I had obtained the necessary chips, the system
So much for my personal setup. What does the A4000 offer over, say, an
A3000? The differences can be summed up as follows:
- 25 MHz 68040 CPU instead of 68030
- 4 megs of fast RAM, 2 megs of CHIP ram
- AGA Advanced Graphics Architecture (previously AA) chipset
- Kickstart 3.0 and Workbench 3.0 as standard
- 1.76 Mb floppy drive instead of 880K drive
- IDE hard disk interface instead of SCSI
- Three IBM AT slots instead of two
- CPU on a removable daughter card for easy upgrades
- Memory can be upgraded to 18 Mb using SIMM modules instead of ZIPs
- 5.25" bay allows CD-ROM or tape drive to be installed
- Keyboard lock on the front of the case
- Keyboard uses a slimline connector
- New, contoured mouse to fit the hand more comfortably
- Mouse ports on the left side of the case
- No 15 pin VGA video connector (though a 23 pin to 15 pin
converter plug is included)
- No display enhancer (AGA makes it mostly redundant)
By now, much has been written about the AGA chipset, but it's worth
mentioning the main features once more. It supports resolutions up to
1280 x 512 at 50 Hz interlaced, including 640 x 480 at 72 Hz and
800 x 600 at 72 Hz interlace (which flickers much less than the
standard Amiga interlace). All resolutions now support 256
colours from a palette of 16 million, and all modes now support the new
extended HAM8 mode which allows over 256,000 simultaneous colours from
HAM8 is nothing short of stunning, especially at the higher resolutions,
and for most people will be indistinguishable from true 24 bit graphics.
Since HAM8 only uses the the same bandwidth as a 256 colour screen, it
will be very useful for animation.
Other AGA features include enhanced sprites, which can now be up to 64
pixels wide and be displayed in lowres, highres or super-highres
resolution, regardless of the screen mode and a new scan-doubling feature
to make it easy to display lowres screens on a VGA monitor (similar to
the A2320 Display Enhancer). And finally, all AGA modes take up only
1/4 of the video bandwidth of the equivalent ECS modes, which
means that previously CPU-hungry modes like 640 x 512 in 16 colours
now zip along.
So, if this last point is true and the display enhancer is now redundant,
why then did I feel it necessary to spend £100 on an A2320? Well,
my A3000 monitor was a very nice Hitachi SuperScan multisync which
unfortunately can't sync down to 15 kHz, the scanrate used by most Amigas.
On the A3000, this wasn't a problem since the built-in display enhancer
ensured that the output was always 31 kHz, regardless of screen mode.
While Kickstart 3.0 on the A4000 can do the same thing, it only works
for programs that use the operating system; games and demos that take
over the machine will still operate at 15 kHz mode. In addition, Guru
Meditation errors and the new Kickstart 3.0 Boot Menu are displayed at
On a Commodore 1960 or similar multisync, none of this would be
a problem, since they can quite happily display 15 kHz. However, since
I like to play the occasional game, I decided the display enhancer would
be a good investment. The only disadvantage of the display enhancer is that
it can only output 4096 colours instead of 16 million, but it is quite happy
to do this at 640 x 480 non-interlace, and the results are really
very impressive. And of course, the original output is also there if I
The other card I purchased was the A2091 SCSI disk controller, which I
needed because the A4000 has no SCSI controller as standard (a major oversight
in the view of most people; IDE is cheaper, but significantly less
flexible). Commodore have said that they will have a Zorro III-based SCSI II
controller available some time around January which I intend to upgrade to
immediately; I view the A2091 as merely an interim step.
Apart from AGA, the most noticeable difference with the A4000 is Kickstart 3.0.
This fully supports all the features of AGA, and large parts of the low-level
graphics.library have been rewritten to increase speed and add
features. It incorporates all the features of Workbench 2.1 (soon to be
released for existing owners), such as localisation support, built-in
CrossDos for accessing 720K and 1.44 Mb PC disks, more flexible
device handling, and a PostScript printer driver.
Workbench 3.0 also
includes a new multimedia file viewer called MultiView which can
handle a variety of file types, including IFF images, sounds,
AmigaGuide help files, ASCII text, and so on. The best thing about
MultiView is that it is extensible -- it makes use of one of the
new features of Kickstart 3.0, the datatypes.library,
which allows additional data types to be defined and added by third
parties. Any application program can use datatypes.library, and
will then automatically gain access to future formats.
As a simple example of the kind of thing this implies, imagine a paint
program that uses the picture type in datatypes.library. Initially,
sub-types IFF and GIF might be defined, so the program could automatically
read and write images of those types. Later on, you might add JPEG, BMP
and TIFF files; with no changes to the code, the paint program would now
be able to handle those filetypes as well. The same applies to sound,
text, animations, and so on. The possibilities are endless.
The new Workbench 3.0 palette preferences screen
Another nice feature of Workbench 3.0 is the new Palette preferences
This now features a colour wheel to allow colour selection as well as
the more familiar RGB sliders. In addition, the colour of each screen element
(menu bar, menu highlight, window border, etc) can now be chosen individually.
Also improved is the Workbench pattern editor, which now offers the
capability to install a picture of your choice as a backdrop to your
Workbench. If Workbench has fewer colours than your picture, it will be
automatically dithered to display a good approximation. Even the mouse
pointer has been beefed up, and can now appear in high resolution, removing
that chunky look that has so identified it in the past.
Other changes are more subtle. The layers.library that handles
overlapping windows has been greatly optimised, removing almost all
the delays that used to occur if you had a lot of windows on the screen.
All bitmaps are now interleaved where possible, a technique borrowed from
the games world which can greatly enhance graphics performance (since the
blitter can do in one operation what used to take two or three).
All in all, Workbench 3.0 is a very nice upgrade indeed.
All this is very nice, you say, but what about speed? This is, of
course, the jewel in the crown of the A4000; it is awesomely fast. Overall,
it rates about three times the speed of my A3000 on most tasks, which makes it
about 20 times faster than your average A500 or A2000. For floating point
work, the gains are even more impressive: one benchmark (a ray-traced
beach ball, from LaMonte Koop's AIBB benchmark suite) runs
a stunning 550 times faster than an A500!
Leon, who uses his A4000 for ray-tracing with Imagine, reports that
some of his pictures are generated over 200 times faster, and the output
in HAM8 is a huge improvement over HAM.
So is this finally the perfect Amiga? Well, no. It has a lot of great
features, but also some significant ommissions: no DSP and no onboard SCSI.
Commodore has said it's aware of both these failings and is actively
working to provide solutions in each area within a few months. A better
solution for users with non-15 kHz monitors is also required, since those
monitors are now becoming very cheap in comparison to other displays.
Overall though, this is the Amiga you've always dreamed off.
The only thing to marr this otherwise perfect picture is that there seems
to be a reliability problem. Out of the three that arrived in Ireland,
Rocco's had a faulty CHIP RAM SIMM module (he managed to do a swap at the
Developers Conference that weekend, which was handy), and mine stopped
working completely after about two weeks. I'm currently waiting for it
to be collected by Commodore and replaced, but no sign of anything yet.
I am typing this review on an Amiga 1500 which, more than anything, is
giving me a good impression of how fast the Amiga 4000 really is!
Last updated 26 November 2000. Comments to firstname.lastname@example.org.