Demos using a GFX mode please !

[darkcoder]

If you like RTG demos, why don't you do them by yourself?
I find the subject a little bit aggressive. Demo coders do demos just for fun  not to impress people not having an Amiga showing them what Amiga can do. Usually it's much more fun to code AGA, or OCS than to use RTG. With RTG is too easy, you just use library functions.
There is also a more thoretical reason, connected with your last observation:
------------------------------------------------
But I think you can impress people by using design and new effects instead of "I made it fast on a slow machine" !
------------------------------------------------

If one wants to "impress people with design adn new effects" than one can use a gfx program, like Photoshop and create very easily wonderful effects. Then you can spend a lot of time using Photoshop to improve your effect. The same goes for 3D: why code it in assembler, when there exists Lightwave?
My answer is that demo-coding is a particular type of computer-graphics. it's computer graphics with a particular architecture. Otherwise it makes no sense. You don't need programming skill to produce impressive computer graphics, just use good rendering package and eventually an SGI workstation. But you need programming skill if you want to produce good effects WITH A PARTICULAR MACHINE. So demo coding, IMHO is: choose a platform and do stuff with THAT platform. Portability doesn't matter. What is the meaning of a masterpiece like "Arte" produced with a P4. You can appreciate the design, ok, but this is a matter of graphicians. You cound'say that "Arte" is a masterpiece of coding if it run on a P4. but "arte" is a masterpiece of coding because it runs on A500!
So why not to choose RTG as a platform? Because RTG is not a platform, it is a standard. Many different CFX cards use RTG, hopefully more in the future. But all these gfx card are different, they have different features and speed. How can a coder program "the best way"? There is no way which is best for each gfx card.
Ok, this is my opinion. Many coders have different opinions, so there are RTG demos around. But I think most coders have ideas similar to mine. That's why PC scene never became as great as the Amiga one. Nowadays many coders prefer to look at alternative platform, like Dreamcast, Xbox or even Gameboy Advance.

The Dark Coder

[darkcoder]

First of all I apologise for being a little bit though in my previous posting.

I agree with carls that coding is an art. What I wanted to specify is that, IMHO, coding is not "the art of producing beautyful effects", but rather "the art of producing beatyful effects BY PROGRAMMING". And because this extra requirment you introduce, you need to specify an hardware
which gives you some limits and you have to reach the limit of the hardware by coding. If you don't fix a limit to the hardware (and with RTG you have no limit) it's useless to use coding, just use gfx applications and an hardware powerfull enough.

@Karlos you gave a good point. However, I still don't see the sense of RTG demos for the following argument: with RTG you can use many differeent gfx boards having very different features (which IS a good thing for everything but demo-coding). If you want a demo running on all the gfx cards, you have to consider the slow ones and you don't use the most powerful features of the others. On the other hand, if you say "this demo requires ATI Radeon card" then you are forcing the use of a particular hardware.
Still anotherr issue is that modern gfx cards are TOO powerful. They implement many many effects in hardware. So IMHO, with these cards there's nothing left to code. For example, a 3d demo could be something like this (I am actually NOT a RTG coder so I invent function names)

 lea CyberGfx_base,a6
 move.l PoligonList,a2
 move NumberOfPolygons,d0
.loop
  move.l (a2)+,a0
  jsr RotateVertex(a6)
  jsr ComputeVisibleSurfaces(a6)
  jsr RenderTexturedSurfacesInPhongWithZBuffer(a6)
 dbra d0,.loop

where the subroutines are NOT pieces of code but just computation done by the hardware. So, where's the fun in coding such a stuff? You don't need any programming skills just learn how to use an assembler. Is similar to what AMOS was, except that AMOS was not powerful enough to produce good result, while these monster chips are. But if it's so easy to produce wonderfuleffects by programming, why use programming at all? Just use Photoshop and concentrate your efforts just on the aestetical aspect.

@mahen Well..first of all these are just my ideas. But maybe people will have fun coding just doing a sequence of library calls...
Anyway the scene is not only coding: there is also gfx, music, writing diskmag and for all these things RTG is a VERY good thing. I think the spirit will stay alive. But you are interested in optimized coding, IMHO, you better consider different platform: consoles or (very, very interesting IMHO, PDA devices). And use your Amiga or Pegasos for every other thing.

The Dark Coder

[darkcoder]

@carl
Yes that's also my opinion. The spirit won't die.
There are many interesting platform!
Optimizing for the 68k emulator can be a good idea. But one should have any insight on how the emulator works..and ..which emulator? the Pegasos one? the A1? the WinUAE?
Any way I really would like to do demos for some console.

[darkcoder]

@crumb & magicSN

First of all I don't understand why you (and also Elwood who started this post)
want to force people do what you want. I am sure that you are all nice guys but
you sound a little bit arrogant. A little like Bill Gates.
(oops..hope you won't be offended to be compared with him..just joking :-))

Everyone can code as he\she prefers, the only rule are those of the programming
language.
The question is not planar vs. chunky. As you know there are several technique to render
chunky gfx on OCS and AGA. Since magicSN seems consider me stupid, I state that I know the staff well since I
coded several c2p (and copperchunky screen) by myself (i.e. not using the latest routine found on aminet).
It is true that I never coded for RTG, but I used OpenGL, the Amiga graphics library and SDL, the multi
platform library ported on the Amiga by Gabriele Greco. SDL in particular is very similar to what you describe
(and I imagined) just a set of functions to open a screen and copy a block of memory into a frame buffer.
What you call "a simple copying of data into a screen" is crucial for the speed of the demo. And it
differs from one board to another. I don't think that you would obtain the same speed and the same visual
apperence from a PicassoIV and a Radeon 7000. What RTG is missing, is *a clear limit*. Without a clear limit
you cannot reach the limit.

Said that, I am not *against* RTG demos. If you like to do them, please do them. I will enjoy looking at it.
But for me it makes no sense and no fun to produce one, because I don't have a limit to reach. Please note, as
I already wrote in previous messages that I really think that RTG is a VERY good thing for the Amiga, which
could have helped a lot if it would be ready on 92 (C= started speaking of an RTG system but never did
anything). And if I wanted to program a game or a gfx application I would certenly use RTG, and propably I
would have fun using it. Because there the aim is different. But a demo for me makes sence only with a well
defined architecture. So I thank Steffan for his kind offer but I am not interested in having my demos run on
RTG. By the way, you know the programs Extreme and Supreme, by darkage Soft? You can do very nice demos using
them, 100% RTG compatible (I helped them a bit with Extreme's copperlists .

>And why should this not be possible on RTG, having fun with coding ? Remember - many people (me included) don't have the
>HARDWARE anymore to display OCS/ECS/AGA. So if a demo does not support RTG we cannot watch it !

I am sorry for you, but we are not speaking of sofware wich is necessary for using the computer.
If, for example, LHA required AGA, well it would be a real problem but I think you can survive without
watching a demo. BTW, UAE should run OCS and ECS stuff without any problem. And I think that latest
WinUAE versions support AGA, or at least try. And concerning the monitors problem there exist cheap
devices called scandoublers, you know?

>On the other hand they should go sure people can actually WATCH their demos. And with requiring
why should I go sure? As I said I code to have fun, not to "impress people with my coding skills".
Anyway let's talk about compatibility: MagicSN wrote:

> Most people will not be able to view a Demo without RTG Support



which people? If I am right since 1986 about 6*10^6 Amigas were sold. All of them can run OCS stuff.
I think at least 2*10^6 AGA Amigas exist. All these can run AGA stuff. So only A1 are left. How many did they
sell? (and there is UAE for A1 also)
I have many friends who used to have an Amiga. None of them has an Amiga anymore. hence they can't watch
my demos, RTG or not (well there is WinUAE but I think more or less it supports AGA..) Anyway when they come
to visit me, I show them some demos, including mine :-)

But most of all, how many people in the world own an Amiga? Unfortunately, very few.
So I won't say that your argument is stupid because I always respect other's opinion, dear Steffen,
but I do say that it is definitly not convincing. It could be a good argument for PC demo-coding.
If my primal concering was to have my production watched by many people, I would code them for the PC.
Even better I could code them using Java. Java scene exists. Or I could even code them using Mathematica
which is a very nice program for many platform, unfortunately not Amiga. You can very easily experiment
nice formulas with mathematica. Of cource the render is very slow, but I have seen used it on an SGI,
and it's acceptable. (no limit=> I can use an SGI.)

But for the same reason as for RTG, for me
demo coding on PC or using Java makes no sense. Demo coding on Xbox or PS2 or gameBoy advance, that
I find really interesting. I suspect that the most part of the great Amiga coders more or less
thinks like me. In fact, they went to PC...to produce games!!! :-)

@crumb (about the group Mankind). I met at Spoletium 4 a Mankind coder. We had a pizza together.
I think he is the coder of that c2p. Anyway he gave me sourcecode of his nice demo, which of cource
 run on RTG, so I should even have an internal version.

Ok, finished for today. I really apologise if I was a bit though but when someone "order" me to do something
against my will, I get a little bit upset.

Friendship RULEZ!
The Dark Coder

[darkcoder]

@crumb

>No one is forcing you with a gun to add support, we are expressing our opinions. In my opinion the effort needed to add RTG
support is so small that it is a pity that it's not included in most of demos. (that sounds better for you ummm? as english is not

Yes, that sounds a lot better. Thank you.

>well, now read again the first lines of your first post in this thread.

I know that my very first answer to Elwood was a very bad one, and I already
apologised in the end of the same posting (the first one). It was my very first
reaction to his post which sounded like an order, and in the beginning that was
the only thing I wanted to say. Then after 2 minutes, I changed my mind and I
thought that it was better discussing so I started the longest reply.
nevertheless I decided to keep also the very first answer because if someone
shouts at you, you first have to show that you too are able to shout, and then
you can start discussing.


>You say that demos are not made to impress. Well they are made for fun and to impress. Isn't impressive to see how much can
>be done with little resources? And one of many people all-time-favourites, State of the Art was designed to impress, not showing
>the machine limits but a great design. I think that SOTA only moves a little polys most of times and that a A500 can do that

While am coding an effect, my only concern is enjoy myself doing something
difficult and proving to myself that I can solve the problems. I don't think to
people's reaction when they see my demos. Sometimes the graphicians or the
designers come to me and suggest me to change something to increase
spectacularity, and if I find the thing interesting, I do.
SOTA is basically 2D morphing poligons. But there is great design work.
Maybe I have not explained what I mean when I say that when I don't do demos to
impress people. When I say that, I don't mean that I don't care about design or
gfx or nice music. I am always VERY happy when I can work with some good
graphician or designer (sometime I have to do design by myself, but I am not
good in that). What I mean is that I want to to a demo wich is fun and also
look good TO ME and my co-workers and the friends that are interested in my
work. I don't care about people using PC with emulators or A1s. If someone want
to watch my demos, I am happy. But if someone FREELY DECIDES not to watch my
demos, for me it's no problem. As I said, if I wanted my work to be seen by as
many people as possible, I would use a PC. I think that people who did SOTA
were thinking to do something looking great to themselves, not to have people
saying "ahhh unbelivable", like they were looking Michelle Pfeiffer.


>well, the little tests I've done run at more or less the same frame rates in every graphic card. I've tested with my program a 060
my Picasso4, a Voodoo5 and a CV64. The fastest of the three was the CV64 because it uses Zorro3 to the limit. But it was only

that "more or less"is not satisfactory to me. The "simple copying" of data is
often done using the gfx card blitter, wich is not accessible to the coder.
Different cards have different blitters. We are not only speaking about Zorro3
cards. A1 and Peggies and PC with emulators have PCI and AGP cards. I guess in
some months we will see programs (maybe demos) requiring DE FACTO AGP cards.
This is good for Amiga in general, but not for demo scene.
Moreover, the limit is not only speed. Is also screen resolution and video
refresh rate. With AGA I can decide wich resolution and which refresh rate I
want to use. Gfx board allows each different resolution and rates, hence I
cannot reach their limit.
Moreover, I heard (but maybe I am wrong) that there are 2 different RTG standrd,
the Picasso96 and the CyberGfx. So one should even support 2 different
standards?

But it is time to introduce another argument: in my last post I concentrate so
much in discussing the theoretical reason why I don't support RTG, that I forgot
there is a practical one!
Several posters wrote that "nowadays demos are only 3D stuff done by the CPU".
It is true that many coders do only stuff like that, but not me! GFX boards
usually have just 1 sprite and most of all, they don't have anything similar to
the Copper! To me, using sprites and Copper is much fun! You can change screen
resolution and depth in the middle of the screen (or in any other position of
cource). With sprites, you have a 4 colors 512 pixel wide or 16 colors 256 pixel
wide extra window which you can move around with 5-8 asm instructions! And there
is more. With Amiga chipset you can control how display DMA, audio DMA and CPU
compete to access the chip RAM. Hence (especially using copper) you have many
possibility of optimizing stuff. For example, in certain positions of the screen
you can lower screen depth, or make display window shorter to gain CPU speed
without a viewer noticing it. You have much more possibilities to obtain 100%
(maybe 99.9999%, since youcan never tell you reached 100%) optimization.
And this is very fun, to me.
So with AGA I can do BOTH CPU-only chunky effects AND chipset supported funny
tricks. And you can join these techniques together. (BTW, how many of these "new
generation coders" are able to proper initialize audio state machine to begin
audio output?) With RTG, instead I can only do one sort of effects. I think the
real progress is not the contraposition of old and new, but rather a ynthesis of
old (in this case coding techinques) and new.

So with AGA:

 more and fixed speed limit + more possibilities to invent solutions = more fun!

This reminds me that MagicSN stated in his post that it would be easy to make a demo like "Arte" RTG
compatible. I don't think so, since many "Arte" effects for example the
"rectangular" textured tunnel are copper based. Only the 3rd part (the 3D) is
cpu-only.

>I have fun coding RTG stuff, the only reason I'm adding AGA supportis for erm tradition, compatibility and well, because it's
easy and I can, and some people still don't have a gfx card and I found a bit arbitrary to stopping them from watching what I want

I can fully understand you, you do what you enjoy and you freely decide to also
support AGA users, for good reasons. Now I see it was not your intention, but I
suspect it was other intention to blame AGA coders to force them to do something
different to what they freely decided.

>to do. I mean that it's easy if you use a chunkybuffer and a c2p routine (like me) because sprites and bitplanes aren't used much
these days. If you do demos that use bitplanes etc... well that's harder than a gfx card for most of effects.

yes, somtimes it's harder, copperlists+sprites+ direct floppy disk access, with
that damned chip ram bus letting the CPU access sooo slowly..but..
...no problems, no fun! ;-)

See Ya!
The Dark Coder

[darkcoder]

@mdwh2

You gave good points

>others, either in terms of speed or features. I'm not sure what you mean by it being useless to use coding. And demos were
>popular back in the days when the Amiga's CPU speed was not fixed/limited.

With Amiga you have a fixed architechture. You can have CPU of different speeds
which gives rice to number of variants, because the speed of the rest is the
same. And not too much variants, you can control all the possibilities. That you
cannot do with  gfx cards, because there are many different boards with many
different features.

I admit that I haven't kept too up to date with graphics card features in the last couple of years, but I don't think they do
everything for you. Generally, they'll do things like the rasterisation for you, but other things such as hidden surface removal,
particle engines, realistic physics still require coding. In your example of code, there is no magic ComputeVisibleSurfaces

usually gfxcards have z-buffer, so you don't need hidden surface removal. Ok,
of cource t's better if you filter objects completely outside the picture.
Particle engines or realistic phisics, that's another story. I'll come back in a
moment.

>Well some people do do that, they're called artists;) But some people prefer coding - and some of those prefer working with 3D
>hardware and exploring programming of areas other than low level things like rasterisation.

That is a very good point. An artist can use "Supreme" and produce a nice demos
without even writing a single instruction. I think one has to choose the best
instrument with respect to what he want to do.
For me demo coding is "to reach the limit", i.e. try to do 100% (or 99.9%)
optimization. Yesterday I spent 4 hours on a new line clipping routine.
(there are more than 36 cases, so it's a rather heavy work). The new routine
(when finished) will perform 1 or 2 divisions (depending on the case) less than
the previous one (which I coded years ago). Apart from the fact that many gfx
board do line clipping in hardware, with a PPC or P4 2 divisions less is almost
nothing. With a 060 is something. But with a 000 (yes the routine is meant to
work on a A500) it is a lot! These are the things I can do with Amiga. Speaking
about code optimization, you may know that PPC and P4 do instruction
re-ordering. This mean that it is nonsense to work on the code triyng to reach
100% optimization, because you have not the complete control of the instruction
flow. It can happen that you reach 100% optimization, but it's not merit,
the machine did it for you! Again, for me is no sense to do demos with PPC or
P4.
In fact, many of the new generation coders and most of the PC coders use C and
only write in asm the critical parts. And with instruction re-ordering its very
hard to produce bettern code than that of the compiler, so the tendence is to
not use asm at all. So, using C and gfx board which you cannot fully control
you are no more doing 100% optimization but only 90% of it (which can even turn
out to be 100% because the machine does this for you...and to me there is no fun
in this). But there are people who are happy with 90% optimization (more on that
later).
Here comes back particle systems and realistic rendering. These are very
interesting things to do. However there are very complex algorithms and to code
them with 100% optimized asm code would require much strength and time.
Unfortunately I have already no times for coding a "simple" 3D engine, it would
be impossible for me to code a radiosity algorithm in 100% opt asm. And I
suspect that most of the people who program such nice things don't do 100%
optimization but only 90% (which is a lot, but not "the limit"). SAying that I
don't mean to blame them. Maybe there is someone who code such complex things
in 100% optimized code, he has all my admiration, but I really suspect the most
part do 90% only.
So now it should be clear: I want to do 100% optimization. I can do that with
the Amiga, I cannot do that with RTG PPC "new Amigas", hence I use AGA.

But now. Let's say I decide to do some 90% optimized code, for example to do a
radiosity algorithm. There I don't need a custom architecture, I could do that
with RTG. But I can do 90% opt code also with a PC. So way use RTG "new amiga"?
As magicSN wrote, you use the same basic techniques with Amiga RTG and PC.
Only that PCs are more powerful. So why use RTG amiga? I would certainly use a
PC for that! I like to choose the best tool according to the task I have to do.
I chose Amiga to do 100% optimization because it is the best tool do to that
stuff for the reason already explained (fixed architecture, funny custom chips).
You wrote that you do software rendering, I don't understand if you mean that
you code raytrace algotrithms or that you use software produced by others.
In either case I guess that I chose to do rendering with the Amiga because in
former times it was the best platform to do rendering. We all hope that it will
be the same again. But today, if you want to program 90% optimized code there is
no advantage in using a RTG "new amiga". So to me even doing 90% opt code is no
sense with amiga. But it is with a PC, so I can fully understand people that do
particle engines with PC, I will also do that when I had enough of doing 100%
opt code on AGA Amigas (but for the moment I have not enogh :-)

Anyway, the most importan thing is that everyone is free to do what he likes,
as long as Bill Gates and his italian friend Berlusconi don't suceed in ruling
the world.

See ya
The Dark Coder

PS. about monitors, I know the situation is not good. Multisync are difficult to
find, but not a used one. TV-monitors like 1084 are very common. Scandoublers
are not so expensive, I just seen 2 of them at 100euro on a website (ok, maybe
100 euro is not exactly cheap, but today almost everthing for Amiga is expensive
compared to the PC). But for me 15Khz output is worth the expence. First of all
for pixel's shape: pixel are not "squares" like on a VGA like card, but rather
round spot. This is very important for many demo effects, the appereance is
completely different.  Second, with 15Khz you can use so many games and demos...
:-)

[darkcoder]

@mdwh2

 ok, now I understand what you do and it is also funny and interesting things,
 I would also like to to "hi-level" 3D engines. Unfortunately we all have a
 limited free time, so we have to choose between interesting things, and I
 prefer "low-level" rasterization & tricky effects. So I can understand your fun
 in doing such things.
 
 I think we can agree also on another point. As you demonstrate by porting your
 windows programs to RTG Amiga systems, from a programmer point of view there is
 no difference between Amiga RTG and PC. The basic techniques are exactly the
 same. So there is nothing special in Amiga RTG. Amiga OS of course IS different
 and better than Win, but (please correct me if I am wrong) for "hi-level"
 graphics as well as for low level coding, the OS does not make any difference.
 
 So there is no technical reason to prefer Amiga RTG to PC. Then you say that
 you do this because there is "more room" on the Amiga for a new 3D engine, and
 this is some sort of "market" reason, although strange since you have to
 consider that there is a very little user base in the Amiga, and that you have fun in doing portings,
 which are worth respecting reason. (you really have fun doing portings?!?)
 
 I usually choose what system to use for technical reason, and I think many
 coders do the same.
 

[darkcoder]

@carls

>he "retro" sceners will probably stick to their old Amiga for scene activities much like you see Atari or C64 people doing today. They bring their old computer to the demo

this is probably what will happen. Anyway I am not saying that A1 or Peggy are not good machines!
I will stick with my Amiga for coding demos but that does not mean I will not use A1.

back in the old days, Amiga was the best because it had
1) best hardware perfect for games/gfx applications and demos (and still perfect NOW for demos)
2) the wonderful OS that we all know

the "new Amigas" have only the latter, the OS.
But as far as demos are concerned, the OS is not important so which are the reasons to do demos with RTG amiga? If you are interested in 3D only demos, do them on a PC! Much more people will look at them! There is no technical reason to do demos on the ERTG Amiga, while there are to do demos on AGA Amigas (copper, sprites and more).

And, please, be open minded and don't look only to 3D stuff. With AGA you can do BOTH 3D and special stuff.

[darkcoder]

@lempkee

 Hey, I am writing hundreds of text lines in this post to defend fixed platform against crappy RTG standards, and you don't say anything! :-)
 Kronos just wrote 1 post!! :-))

 please credit also me!! :-)))

the scene will continue in our hearts, at least!

BTW why don't you like PS2? I think it's great hardware, it's only very complex to master because it's different from anything else! But I think one could do great things with Emotion Engine!

[darkcoder]

You behaved right at Euskal party!
At Spoletium 4 I won the 4K compo. But I was the only one to compete! :-((
My intro was not bad, but I would have preferred to be 3rd out of 5 than 1st out of 1!
Anyway, coding the intro was fun, that's important!

>When you copy data from the fastram (or you write it directly to the gfx ram) you do it at maximum speed if you have coded it correctly. If I write a 32bit word to gfx ram
                                   that is going to run at the maximum speed regardless of if it is running in Zorro3/PCI/AGP.
                                   Ok I think there are some special transfermodes for AGPs but they are only used by the card to take textures from fastram when it has its memory full. That doesn't help if
                                   I'm writing pixels directly.

That sound a bit strange to me. The cards are connected with the system by means of the Zorro/PCI or AGP bus. Hence the speed at which you can write to them is that of the bus. But Zorro, PCI and AGP have diffrent speed. And also the card's memory are different both in size AND speed! So haw can you write always at the same speed? and which is the speed?

maybe there is something I don't understand...

Then as you said, coding RTG is like coding on a PC. Which is the advantage of using RTG instead of a PC?
Other point: please, don't do only 3D stuff! Today most demos are 3D only, but most of them are boring, as lempkey said! You can do beter things if you MIX 3D stuff with old 2D-copper stuff!
(and it's not only copper, there's sprites, hardware scrolling, etc.)
"new generation demos" have no problems with sound  because they use AHI or P61, which is a good replay routine. But the "new generation coders" don't know anything about DMA and hardware stuff. many of them know very little of asm and use C!
That's 90% optimization!

[darkcoder]

@crumb

Excuse me, how have you got these numbers?

Give a look here: http://list-archive.gin.cz/amiga/0010/msg00426.html

there are results of many speed tests. With AGA I think your numbers are wrong.
In fact the AGA bus runs at 7.19Mhz, which is a theoretical 28.8MBytes sec.
(with AGA 1 access=4 bytes, with OCS 2 bytes only hence you have to halve all
numbers).
Unfortunately the cpu is only allowed to acces half of these cycles, which lower
it to 14.2MB/sec. But sadly no CPU can do a write in chip for each cycle.
It depends a lot on what are DMA channels doing but with a standard 320*250*8
screen they don't interfere too much. Since the CPU have to syncronize its clock
with the 7.19Mhz clock more or less it write 1 every 2 cyvles, which is
7.1MB/sec. In practice, as these test show it's a little bit less, more or less
6.8MB/sec (for AGA machines). It's completely false that writing is 4 times
slower than reading, they have the same speed. Maybe you got confused thinking
to write 1 byte at the time, but good c2p as the Azure's on write 1 long at a
time.
Anyway these tests also show that on EACH AGA machine, regardless of the
CPU you have more or less a 6.8 MBsec writes to chipram. That is what I call
a *clear*, *fixed* limit.
With gfx boards things as you can see are different: the conclusions of the long
test are (I consider not-overclocked results):

 Card       Orginal        Overclocked

 CV3D      7.2 Mb/sec  ->  10.1 Mb/sec
 PIV       9.3 Mb/sec  ->  12.4 Mb/sec
 CV64     13.3 Mb/sec  ->  18.6 Mb/sec
 
well it seems to me that THERE IS a difference! And these are all ZIII boards!
Then there is CVPPC and Bvision which I think are different because they are
directly connected to the CPU with a custom bus (in fact they require CybPPC /
BlizzardPPC). And now, with A1 and Peggy, there are also PCI and AGP cards!
I guess there will be more differences.
So it is a complete mess, each card is different.
You say the bottelneck is the CPU. Maybe, it depends on the effect.
There the situation is less clear, but anyway I think with AGA you have
more stability. (BTW in this whole post with AGA Amiga I was speaking of
680x0 CPU. I only code 680x0, no PPC fo me).
It is true that also the (classic) Amiga can
have a wide range of CPU. But basically (with AGA machines) we only have:
1) 020 at 14Mhz (1200)
2) 030 at 50Mhz (many boards)
3) 030 at 25Mhz (4000/30, not many)
4) 040 at 25Mhz 4000/40
5) 040 at 40Mhz some boards but very rare
6) 060 at 50Mhz CybStorm

In practice, when you code a demo you choose one of these, usually 1) or 2)
and use it as the limit. And since the speed access to chipram is the same
regardless of the CPU (only very small differences, as you can check) many
effects look the same on all CPU. With RTG you have all these possibilities,
and since here the speed is not limited by the chipram, Practical differences
are BIGGER. Then you have 603, 603e, 604, 604e, G3 and G4 in many clock
variations. maybe in the future even more CPUs...

I think with RTG you can have 90% optimization, not more. With AGA 99.9%. :-)
But if you have fun doing 90% optimization, you are fine with RTG!

See Ya!
The Dark Coder

[darkcoder]

Ok men!! I think this has been a very good thread!
We had an interesting discussion, we exchanged different points of view. I learnt something in this discussion, and even though I will stick doing AGA only demos I can understand better the RTG coders point of view. I think this is my las post in the thread because in this days I wrote much text..but now it's time to write much code! :-)

 ... and I also have a to work, sometimes

Anyway I will continue to follow the discussion and if I will have something which I think it's important, I will do.
If someone wants to contact me in the future for exchanging news/ideas/production (especially those mixing old and new style) you can contact me privately, I would be happy.
Go on with this interesting discussion! :-)


Friendship RuleZ
The Dark Coder

[darkcoder]

So I decided to post again mainly to answer to lempkee.

But first @dagon:
you cannot say we are close-minded saying cliche, I think we gave good arguments for our positions, I wrote many long messages explaining why I don't like doing RTG demos and nobody said that you can't do demos on RTG. I only said that you can't do 100% optimization on RTG and I gave many arguments. You can fight my arguments like Crumb and others did and we had an interesting technical discussion but here everyone is speaking with his brain attached.

@lempkee
I agree with you that sadly scenein a sence *is* dieing since there are fewer and fewer parties and productions and people. But as Carls says in another sense is not dieing since as long as you have in your heart the spirit to do (or try) funny and nice and optimized work.
Anyway since you are good coder, may I ask you infos (if you want by email) about Aki's c2p code?

bye!

[darkcoder]

yes exactly. I am curious about diferences. I coded by myself a routine similar to that of Azure, after reading his tutorials on amycoders.
(but only after I did my routine I looked at his source code ;-). My routine seems to be a very little faster than the azure one (at least of the PUBLIC Azure code) on 060 but it's a little bit slower on 040.
But now I am curious about the Aki routine. Is the technique similar or different? Is the source code of Aki public?

[darkcoder]

@psyko
many thanks for your interesting comments about c2p!! I hope not to disturb you too much by asking some clarification

>For 1260 the best thing to do is to preload as much data as possible into the cache and then c2p and write to chipram (just write 4 longwords at a time,


I always tried to put as much c2p instructions as
possible between any two longwords write, i.e.

write 1 long
some instruction
write 1 lone
etc.

You say it's better to do:

write 4 long
some instrucions
write 4 long

??

>For 4060 it's totally different. Here a simple loop like: c2p'ing,read16, write16,c2p'ing, read16,write16 would work pretty well, and should

erm..what do you mean with read16 aand write16?
You mean using the MOVE16 instruction?!
I always thought that such instruction was not supported by Amiga architecture, so never used it!
If this is true shame on me and I think I change my nick to crappycoder!!
Does it works in both chip and fast ram?

>special one blueberry
this short one also does cache preloading?
Can you tell me how much bytes? :-)

I use a c2p who preloads 128 bytes, like Azure tutorial. I have almost the same speed as Azure on 060 but I am a little slower on 040. Do you have any hint?
It you will finish the article on this topic, where can I read it?? :-)))

thanks for you help and congratulations for your
wonderful work!