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andym00

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Posts posted by andym00

  7. Posted

    They will crash because it'll promptly generate 500+ blits over the poor NES sound driver..

     

    It's synthesising it all in software, just all as pulse waves.. I'm not really doing a triangle wave for voice 2, just a quieter square wave.. I'm not going to bother with the triangle since I've got other goals, I think..

     

    It's not meant to be a NES emulation, just a means to play around with this low overhead audio method.. But it's been a revelation in how few interrupts doing the pulse waves actually needs per frame..

     

    I just threw the Pokey in to do the noise channel, since it was annoying me it was missing, and generating noise with the pulse method is too expensive at the moment, though in the future maybe not so..

    ANTIC versions of previous.zip

    • Like 1

  11. Posted

    I'm not fussed about the antic features, nice as they are, just wanted to be sure that this was in fact the standard method of banking since it's not something I've paid much attention to so far..

     

    That separate ANTIC access stuff is all cool and dandy, but personally I'm hard pushed to actually find a proper use for it..

     

    Is there anything out there that actually does anything that really pushes the boat out using the separate ANTIC access ?

  12. Posted

    Another idea comes to my mind. As this is using "channel streaming", it must be possible to play random melodies aswell. Together with gr. 7 (or an even lower mode)an always changing visualizer could be possible. Charmode wouldn't fit well due to the high cycle stealing. It could result in an endless demo.

     

    That's not using any streaming in the versions there, I was thinking about doing it because the NSF player is so slow, but I haven't actually done that yet..

     

    RED = NSF Player + me shuffling the registers around to play the audio on my virtual channels..

    GREEN = Build volume tables

    BLUE = Synthesise stuff..

     

    Unless you meant something else ?

     

    I think this will work reasonably well in char modes actually.. There's a few possible issues, but I think it'll playback fine at 15.6k with a full screen on.. We shall see when I next play with it..

    • Like 1

  13. Posted

    You're all a bunch of filthy dirty scabs on the cock of a whores captains parrots cock :)

     

    Seriously guys, have some respect for peoples investments in this world..

     

    Yes, piracy is rife, but you don't have to press the super high button on your horses because you've no idea what he mad, or because you're feeling superior..

     

    Just let it lie..

     

    (null)

  17. Posted

    Just wait and see.. There's more to come with the stuff I'm playing with, one of which is to massively reduce the interrupt rate, I mean somewhere in the region of 8x, maybe more, but without sacrificing the underlying 15.6k rate.. So then you get the best of both worlds :)

    Who knows what next.. Maybe even 32k becomes possible ;)

     

    (null)

  18. Posted

    I guess because it's not really useful for a game or a demo.. I know in 64 land that half the challenge is to push the machine to the limits sound-wise with what's considered a normal player, actually seeing what weirdness lies under the bonnet that no-one has ever heard before and making it do things people haven't dreamt off..

     

    I mean as an example of this, listen to this.. A regular sound player, 50hz, no silly raster time (although you can't see it in the video, it is!)..

    And I don't mean get excited by the speech.. That's cool, but the bass is awesome, as is most of the damned song :)

     

    http://www.youtube.com/watch?v=XBLir3zTwkY

     

    It sounds astonishing to my ears for a plain old SID, for a 50hz, 20-30 rasters player.. And that's what I think people get a kick out of, pushing the hardware to its limits..

    But I suspect a lot of the Pokey world are the same :)

     

    If you want a tracker with some a few additional low-overhead voices then surely the answer is to just write it ? That's what I have to do when ever I want something doing..

     

    And just to balance out the thread a little ;)

    http://www.youtube.com/watch?v=in16hHDKPs4&feature=related

    http://www.youtube.com/watch?v=C3-YcpVowdA&feature=related

    Has to be done, after all, I'm a fully signed up member of the SID appreciation society ;)

  19. Posted

    Seeing the NES "emulation" .... the sound quality could be perfect. Always the same: Low notes played via software, high notes played via POKEY's generator: Remember, it has two 16 bit channels..... No quantization noise needed , even if using ANTIC ;)

     

    It was only a simple test because I was getting bogged down with writing a whole new music driver, and this allowed me to concentrate on what was important rather than implementing a bad music driver for now..

  20. Posted

    There's no bubbles being burst, just you want something different to me :)

     

    Anyway.. Here's a nicer sounding version.. You'll need a VBXE to see the display because right now trying to keep this thing working whilst the screen DMA is happening is a pain in the butt, so for now it's simpler to drive the display using VBXE..

     

    You can see the CPU time clearly.. The red region is the actual music player, green the volume table builder (actually doing 7 voices now, but there's nothing using it), and the blue the actual pulse builder.. Grey bit above that is free time..

     

    And this is playing back with a much higher bit depth now using Phaerons technique..

    main.xex

    • Like 2

  21. Posted

    It's not interesting to me I'm afraid.. It's only going to be 15.6Khz.. The aim is to be able to produce nice sound, not things aliased into oblivion :)

     

    But.. There's a lot more to the sound than meets the eye.. If you've figured out how the waveform generator works you'd realise that each of those channels is essentially a pulse stream, which means there's a huge amount of potential in those voices, and if you're familiar with *why* PWM samples work, then you know what I'm getting at.. But that's the next step, after making it drive 8 channels..

     

    Using much lower sample rates (well, not one constant one) is something I've been trying on the 64.. Using all 4 timers, each being a 'voice' then letting them generate IRQs/NMIs when they finish and toggling bits then whenever any one of them expires.. It means you only generate an IRQ for each voices waveform transition, which means it does in hardware what this does here, except I don't need a constant sample rate, and output is generated when it's actually needed, which is the big optimisation I'm talking about.. If I can do that on the A8, it means you'll be able to playback 15.6Khz output with maybe only few thousand IRQs per second..

    • Like 1

  22. Posted

    The best solution for a demo video was to syncronize both, but Altirra has simply speed problems with the sound ;)

     

    Anyone knows why A800 doesn't replay it?

     

    What do you mean with Altirra has speed problems with the sound ? It was written on Altirra and sounds exactly as it should..

     

    As for the CPU speed, it's variable.. Lower frequencies eat less CPU time, higher frequencies more CPU time..

    In that test, when all 6 voices are on, spread over a reasonable range of notes it's taking about 85% of the CPU time though the screen DMA is responsible for a lot of cycles going missing..

    If it runs with the screen off then the CPU load is about 70%..

    You can see this in Altirra if you use the profiler.. Although you don't have the symbols you can still see how much time is left for 'main'..

    There's many optimisations still possible, all while still keeping a 15.6K output rate, one of which is potentially a real game changer ;)

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