Ο Dave Haynie (Commodore senior engineer) είχε δώσει αρκετές ενδιαφέρουσες πληροφορίες για το AAA chipset. Παραθέτω λίγο κείμενο και για περισσότερα δείτε εδώ
http://www.amigareport.com/ar210/p1-3.html
Ο Dave ήταν σίγουρος πως η Α5000 θα κόστιζε μερικές χιλιάδες δολλάρια και το έβρισκε αυτό απόλυτα λογικό (και ας πουλούσε ο ανταγωνισμός φτηνότερα). Αφού όπως φένεται καθαρά διαβάζοντας το πλήρες κείμενο, σχεδόν θεοποιούσε την Α5000 που φορούσε το ΑΑΑ chipset και επέμενε πως ήταν το πιο δυνατό και ολοκληρωμένο computer. Εντύπωση προκαλεί η άποψη του Dave για την δικαιολογημένη καθυστέρηση του chipset στην αγορά. Αλλά μάλλον έτσι μας αποκαλύπτεται και η τότε φιλοσοφία της Commodore για την άποψή της για την τότε αγορά πληροφορικής.
AAA Chipset:
AAA consists of four custom CMOS chips, with a total of approximately one million
transistors. It's a totaly new design, not an upgrade from AGA, thus it has none
of the limitations of AGA.
The four chips are called Andrea, Monica, Linda and Mary.
They are all full 32 bit chips, with the "exception" of Linda and Monica
which also have 64 bit modes. They are not limited by the 14Mhz
clock of AGA, or the hardware-fixed DMA slots (see the hardware reference manual).
There are 40 DMA channels, with dynamic allocation of bandwidth.
That means that each channel can be as fast as it needs to be (up to the limit
of total bandwidth in the system).
DMA:
DMA is used for everything, from the blitter and copper, to sprites,
the audio voices, video display, floppy disk I/O and serial ports.
These DMA channels are the heart of AAA and part of what sets the Amiga
apart from other computers. It's part of what gives the Amiga its
performance. The OS is fully capable of taking advantage of DMA and
hardware coprocessing, due to it's multitasking nature.
When one task is waiting for some DMA or other hardware processing to
finish, another task can switch on and use the processor. This is
something that other computers have a hard time with (for instance, the
Mac, which doesn't have the pre-emptive multitasking required for this.
The Mac IIfx had DMA channels that couldn't be used by the Mac's OS!
Only UNIX on the Mac could use this hardware).
The blitter and the copper:
In AGA, the blitter and copper becamevery outdated.
They are slow by modern standards, very slow, although there is still
nothing that quite duplicates the functionality of thecopper.
In AAA, these two important components become greatly enhanced.
The blitter is basicly just some DMA channels that feed data (graphics)
into a processor and then write it back out to RAM. The blitter can
easily do all the necessary bit shifting, modulo counting, and bit
masking required to move 2D images around in a raster/bitmap; in addition
to doing things like combining more than one image based on a logic
operation. These calculations are quite a bit more time consuming when
done by a general purpose CPU.
The AAA blitter can blit 24 blit images "significantly faster" than AGA
can blit 8 bit images (according to Dave Haynie, who built a prototype!).
I've seen Mac's manipulating 24 bit graphics, and you can visualy see the
windows "slosh" ("shear", "squish", etc) when they are moved (you can see
the graphics get redrawn slowly from top to bottom). AAA will move such
windows instantly (just like back in 1985, when comparing a colour Amiga
to a B/W Mac -- the Mac windows moved very slowly).
The Amiga's "Copper" is also a DMA channel. It feeds a stream of
instructions into a very simple processor (one could almost call it a
RISC CPU). It's capable of doing almost anything the CPU can do; loading
chipset registers, jumping, looping and waiting. It can be used to
control *everything* in the chipset, independant of the CPU. It lets the
Amiga have dragable screens, giant scrolling screen bitmaps, and many
other things characteristic and unique to the Amiga.
Video:
First of all, AAA just simply runs faster, due to its high speed CMOS
chip design. Everything is at least 32 bits, further increasing
bandwidth. Memory can now be accessed in "burst mode", which allows you
to read four successive locations in memory very quickly. And finaly,
VRAM!
What's VRAM? It stands for "Video RAM". In order to get the high
transfer rates (bandwidth) required for hi-res displays, VRAM was
invented. It has two "ports" (and is hence also called "dual ported"
RAM), one exclusively for video and one for accessing and changing the
bitmaps. That effectively doubles the speed.
With VRAM, there will be no more "video contention". Ever notice how
slow your Amiga gets when you open up the largest, most colourfull screen
(640 x 400 x 16c for ECS or 640 x 400 x 256c for AGA)? That's because
those modes need so much bandwidth, that there is almost none left for
the CPU and blitter to use.
In the AAA chipset, using VRAM, this won't be a problem anymore! The
video DMA only uses one of the ports on the VRAM (in fact, this port is
designed specificaly for video, and the VRAM has a built in shift
register for this purpose). You can open the largest most colourfull
screen you can, and the blitter and copper etc won't slow down! Of
course, they'll have more graphics to chew on..
You can also use normal everyday DRAM, which will be slower, but
cheaper. VRAM costs about twice as much. Luckily, you can combine both!
VRAM is good just for the display, DRAM is good for everything else. So
as long as you have enough VRAM to open your screens, you're OK. This
flexibility is a great advantage. You can have upto 16MB divided between
DRAM and VRAM.
So, what kind of resolutions are we talking about? The maximum
resolution, NON-INTERLACED, should be around 1280 x 1024 (at 8 or 16
bits). That's quite a far cry from 640 x 480 x 8 in AGA. It should be
able to do 1024 x 768 x 24 bits as well. And it'll be FAST in these
modes.
We'll also have our choice of chunky or bitplane modes. Chunky will be
2, 4, 8 or 16 bits. Bitplane mode will allow up to 16 planes. The types
can be combined. For a 24 bit mode, for instance, you would have three
bitplanes, each of which is an 8 bit chunky bitmap.
There is also some kind of new compressed display mode (in addition to
HAM which is also technicaly compressed). Of course, there's HAM and
HAM8, which at a resolution of 1280 x 1024 will be very nice, and there
is likely to be a HAM10 mode, giving 24 bit graphics with only 10 bits
per pixel!
Sound:
Another hallmark trait of the Amiga is its built in sound ability.
Most computers do not have good built in sound (the exceptions being the
Apple IIgs and the Atari Falcon, both of which failed despite being
decent machines), most even have none standard.
The Amiga's old 4 voice, 8 bit sound has been quite sufficient for a
number of years and remains better than average for a PC. But AAA takes
this to new levels: it now has 8 independant voices, each with 16 bit
accuracy, and 64Khz sampling rates (compared to 30Khz for AGA). That
puts each channel well beyond a CD player in technical accuracy, and far
beyond what the human ear can hear. It's also far beyond typical sound
boards on other computers.
Amiga sound samples are fed by DMA channels, thus relieving the CPU
from 99% of the work normaly involved.
Why the A5000 is still a good idea?
And now, the point to this article. The primary feature of the A5000
will be the level of integration of the *system*. All the parts will
cooperate smoothly, complementing each other, and giving the system an
overall feel and power that is greater than the sum of its parts.
Look at the A5000 and look at what the competition will have then.
Sure, there may be individual areas where other machines will beat it.
Particularly, IBM clones will still be cheaper. But as an overall
system, the A5000 will win for many applications.
The A5000 will have very respectable graphics. How many people will
have 1280 x 1024 graphics? Such monitors are very expensive.
How many will have 8 voice 16 bit sound? Cards that do that alone are
expensive.
Will QuadDensity floppies be standard by then? Probably not.
Will there be a system that has all these things, and more, in a
perfectly balanced system?
Will there be an OS for it that uses all these features, and lets
applications take full advantage of them?
The A5000 system is built right, from the ground up. With a high speed
64 bit local bus at its core, a fast 32 bit CPU, a fast 32/64 bit custom
highly integrated multipurpose chip set, SCSI-II, DSP, and PCI slots, its
a formidable system.
And running on this hardware, you have an OS that already knows how to
use all this power. A very fast, multitasking kernel. All the basic
multimedia extensions, built in.
The Amiga, and especialy the A5000 (or whatever they call it), is a
perfect multimedia system. It can go full blast doing sound, graphics,
communications, number crunching, multitasking, disk I/O, networking, etc
all at once with ease.
I've heard altogether too many stories about Macs that just barf when
trying to multitask with serial or network transfers going on, slow
animation, mega expensive video hardware and software, and just plain
being slow no matter what you're doing.
I don't think the A5000 or AAA is too little, too late. Sure, I think
Commodore could have created this machine two years ago (which would have
been mind blowing), but that's the way it goes.
).