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AuthorTopic: The astonishing unpopularity of "dynamic-highres"  (Read 5797 times)

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Offline ChaosLord

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #30 on: July 29, 2013, 03:46:12 PM »
Quote from: mr_a500;266981

So I'm wondering - why wasn't it popular? Why weren't there more paint programs or image converters to use dynamic-highres? AGA didn't come out until 1993 and dynamic-highres was around since 1990. It's unbelievable that for 3 years before AGA, there was the possibility to display 4096 colours in highres using software-only, but very few people were interested.

AGA came out in 1992.
"Dynamic Hires" has been around since 1985.  IIRC There are at least 3 different popular public versions of it.  And who knows how many private versions.


Quote

Was it the "dynamic-highres streaking" that turned people off? Digi-Paint allowed you to paint in HAM while minimizing HAM fringing, so it shouldn't have been hard to make a dynamic-highres paint program which minimized streaking. If you search Aminet now, there are a very small number of programs supporting dynamic-highres, SHAM or PCHG. Yes, AGA killed the need for dynamic-highres, but it had a whole 3 years to get popular and failed. Why?


It didn't fail.  Ppl still use it.

And you can do AGA Dynamic Hires better than you can do OCS Dynamic Hires since when you do it on AGA you get to easily have 256 colors on every scanline.  More than 256 colors per scanline with extra effort.

Using the simple method: 256 colors per scanline beats 16 colors per scanline every time.

You can also do Dynamic HAM mode but it is limited to 320x512 resolution  with 4096 colors on OCS.  But on AGA, Dynamic HAM can be 1280x512 with 16,777,216 colors.
Wanna try a wonderfull strategy game with lots of handdrawn anims,
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Offline Hattig

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #31 on: July 29, 2013, 03:54:25 PM »
This type of method of enhancing still images was popular amongst a lot of the 80s home computers, at least on an app-by-app basis. The problem with the Amiga implementation was that nobody defined a definitive specification that all the applications could parse, understand and display consistently.

In addition, at the time, the Amiga was so far ahead that people weren't thinking about improving it even further!
 

Offline ChaosLord

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #32 on: July 29, 2013, 04:21:40 PM »
Quote from: Hattig;742942
This type of method of enhancing still images was popular amongst a lot of the 80s home computers, at least on an app-by-app basis.


Yep!  I used the same type of method "rasterline interrupt color changes" on my C64 in 1983.

And it was very VERY useful on the Atari 800/400 computers which had a palette of 256 colors!  And no HAM mode.  So every good coder did "dynamic hires" on Atari 8-bit computers.  These are the computers that competed against the C64 and Apple ][+

The Atari 400 and Atari 800 chipsets were designed by Jay Miner who then took the idea to the next level in the Amiga.
Wanna try a wonderfull strategy game with lots of handdrawn anims,
Magic Spells and Monsters, Incredible playability and lastability,
English speech, etc. Total Chaos AGA
 

Offline spirantho

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #33 on: July 29, 2013, 04:30:47 PM »
On the Atari VCS, you had to do this. It had no concept of a frame buffer, so you built the display up manually on each scanline.

Now that's hardcore. :)
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Offline bbond007

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #34 on: July 29, 2013, 04:56:08 PM »
If you are able to get NewTek Demo #3 to run you'll notice that the resolution of the music playing in the background drops way down when displaying the dynamic-highres image...

I think the reason its not used more commonly is because the copper is leaving the CHIP RAM bandwidth starved...
 

Offline ChaosLord

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #35 on: July 29, 2013, 05:07:44 PM »
Quote from: bbond007;742951
If you are able to get NewTek Demo #3 to run you'll notice that the resolution of the music playing in the background drops way down when displaying the dynamic-highres image...

That is either because you were using UAE or maybe they switched to lower res music because there wasn't enuff chipram laying around in the 512k chipram days.

Quote

I think the reason its not used more commonly is because the copper is leaving the CHIP RAM bandwidth starved...

Impossible on a real Amiga.

But I have seen and heard stuff like that happen lots of times on my WinUAE.
Wanna try a wonderfull strategy game with lots of handdrawn anims,
Magic Spells and Monsters, Incredible playability and lastability,
English speech, etc. Total Chaos AGA
 

Offline Pyromania

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #36 on: July 29, 2013, 06:06:49 PM »
Dynamic High-Res was a very cool NewTek thing. I think someone else did something similar called Sliced HAM.
 

Offline blakespot

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #37 on: July 29, 2013, 07:44:34 PM »
Quote from: spirantho;742947
On the Atari VCS, you had to do this. It had no concept of a frame buffer, so you built the display up manually on each scanline.

Now that's hardcore. :)


You were literally "Chasing the Beam..."


bp
:: http://www.bytecellar.com - The Vintage Computing Weblog
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Offline minator

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #38 on: July 29, 2013, 08:17:09 PM »
Quote from: spirantho;742947
On the Atari VCS, you had to do this. It had no concept of a frame buffer, so you built the display up manually on each scanline.


IIRC That was another chip designed by Jay Miner.
 

Offline number6

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #39 on: July 29, 2013, 09:36:29 PM »
Quote from: ChaosLord;742945
Yep!  I used the same type of method "rasterline interrupt color changes" on my C64 in 1983.

And it was very VERY useful on the Atari 800/400 computers which had a palette of 256 colors!  And no HAM mode.  So every good coder did "dynamic hires" on Atari 8-bit computers.  These are the computers that competed against the C64 and Apple ][+

The Atari 400 and Atari 800 chipsets were designed by Jay Miner who then took the idea to the next level in the Amiga.



Although strong vertical design was stressed, changing color registers at the end of each scan line during horizontal blank was not always the best method.
Page flipping 2 screens offered more colors without the overhead. Just 4 load and stores for color and 1 load and store for the page flip. That left plenty of VBI time for other routines.

#6
 

Offline psxphill

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #40 on: July 29, 2013, 09:53:07 PM »
Quote from: bbond007;742951
I think the reason its not used more commonly is because the copper is leaving the CHIP RAM bandwidth starved...

On OCS/ECS the 4 bitplane hires will use all of the bandwidth in the displayable area & the copper will use all of the bandwidth in the non displayable area. The blitter and cpu will only be able to access chip ram during vblank. If you have no true fast ram to run code from then the cpu will barely be able to run at all.
 
http://amigadev.elowar.com/read/ADCD_2.1/Hardware_Manual_guide/node012B.html
« Last Edit: July 29, 2013, 09:57:38 PM by psxphill »
 

Offline bbond007

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #41 on: July 30, 2013, 12:12:10 AM »
Quote from: ChaosLord;742952
That is either because you were using UAE or maybe they switched to lower res music because there wasn't enuff chipram laying around in the 512k chipram days.

Yes, real Amiga. quite certain the sample it plays during Bert's face is lower quality than the rest of the sample.

Hard to tell because it avoids playing any instruments other than drums if I recall...

NewTek demo reel #1 is the reason I bought my first A500, so those demos are very clear in my head :)

Quote from: psxphill;743004
On OCS/ECS the 4 bitplane hires will use all of the bandwidth in the displayable area & the copper will use all of the bandwidth in the non displayable area. The blitter and cpu will only be able to access chip ram during vblank. If you have no true fast ram to run code from then the cpu will barely be able to run at all.
 
http://amigadev.elowar.com/read/ADCD_2.1/Hardware_Manual_guide/node012B.html

And I would imagine the the PAULA has to share that as well?
 

Offline psxphill

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #42 on: July 30, 2013, 12:16:30 AM »
Quote from: bbond007;743020
And I would imagine the the PAULA has to share that as well?

If you look on the diagram on the page I linked, you'll see that paula's slots are fixed and are always available.
 

Offline ChaosLord

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #43 on: July 30, 2013, 12:26:15 AM »
Quote from: bbond007;743020

And I would imagine the the PAULA has to share that as well?


Paula has its own 4 DMA channels that are permanently reserved for itself.

There is no such thing on Amiga as "oh no!  The gfx are draining to much electronz!  Its suxx0rizing all the quality out of the audio!" :D

That is the pc/mac way of doing things.  Not the Amiga way.


If you heard degraded audio then it was either
A: Your opinion, which you are entitled to.  (No one can like all bits of music equally)


B: It was degraded on purpose by the coder of the demo to save memory because that part of the demo was using all the chipram.  It was probably doing some hardcore double buffering or triple buffering or preloading an anim that would be shown later or etc.  There are a lot of reasons why it would run low on chipram and need to start using samples at a lower resoution.

> But I have tons of ram so that can't be it!

But it wasn't coded for your machine.  It was coded exactly and specifically for the machines of the day and had to work on them 100% guaranteed.
I think it was coded to work on 1MB Amigas with only 0.5MB chipram.



C: It might all just be an accident where the coder accidentally turned on the audio filter.  The audio filter makes everything sound "dead".  This might be exactly what you are hearing.
Wanna try a wonderfull strategy game with lots of handdrawn anims,
Magic Spells and Monsters, Incredible playability and lastability,
English speech, etc. Total Chaos AGA
 

Offline bbond007

Re: The astonishing unpopularity of "dynamic-highres"
« Reply #44 on: July 30, 2013, 12:28:33 AM »
Quote from: psxphill;743021
If you look on the diagram on the page I linked, you'll see that paula's slots are fixed and are always available.


I guess its just a crappy sample :)

Sure sounds like it gets really muddy right then.