Curse of the SDL

[Khephren]

Your quite right, I'm afraid most of our native coders have moved on or don't have the time any more

And in reality the 040 is more like a 486, and the 060 is like a low end pentium.

[Khephren]

Talking about 68k apps and games, sound many time like it would be impossible to do anything to 68k amigas. Wich makes me wonder, how good they were, I mean those who made amaizing apps and games to amiga years ago?? Were they humans or some kind of super creatures with big brains and super natural skills??

The problem is that SDL is generic, and written in C. To get the most out of the Amiga, you would use assembler, and the tricks the Amiga provides to speed things up.

For example, in a web browser you could have a 64x640 'screen' with it's own palette for your navigation buttons (and could even run it at a different resolution to the webpage viewport itself). You could then run the actual viewport in a sliced mode for more colours etc. Such things would be difficult to add to a ported project.

[Khephren]

nother big problem is audio.old amiga games music have only samplerate of 7 khz and 4 channels.

but most games today use more than 4 channels and at least a sample rate of 22 khz but most 44 khz.

So you need all sounds convert to 7 khz and that sound is ok if only 4 channels are use.

Amiga sample playback is at 28khz. If you open and close a double scanned screen, that allows 56khz playback. Also, even the A500 is capable of channel mixing.There have been 8 channel MOD's since the late eighties. The problem as I have mentioned, is that ports from other platforms do not use Amiga tricks to increase the speed/quality of sound and graphics fidelity.

[Khephren]

try a old amiga game and a sample ripper.in winuae you can too rip samples-
you see sample rate is not often larger as 7 khz, because on A500 memory was low and memory need save

also transpose a sample with paula have very ugly sound quality.amiga have a 7 khz filter so it sound not so ugly as when disable the filter.

modern systems as sdlmixer use linear transpose this cost more CPU power but have good sound quality so you can get CD quality sound

so the first thing you can do, when you want play a sdl game on a slow amiga, is switch music and sound off.

 

Who's talking about the A500? who in their right mind would try running SDL on such a platform? Also, much of the OCS limitations came from lack of storage space, not bus throughput. I quite happily play 14bit multi channel ADPCM  music on my A1200/030, and it sounds brilliant. And the machine has plenty of bandwidth for other tasks.

The first thing you want to do if you play a game on Amiga is not use SDL, and use as many amiga hardware tricks as you can. Many Amiga demo's run in HAM modes and have 14bit sound. SDL would not allow this on such a limited platform, and I would it even allow you to reach such a low level? I doubt it.