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Atari coding BBS
| Re: YM dumping & soundchip effects |
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Posted by: Mr.Styckx
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Mar,08.2011-00:48
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Hello
dumping register is rather simple : call the music replay and then read register 0 to 13 in $ff8800.
Then, you will need to handle special case for register 13 : writing to this register will reset the envelope position, so you should not write to reg 13 on every VBL. This means you need to analyze each replay and determine when it wrote to reg 13 to dump it only in that case.
Regarding MFP timers (sample, sid voice, sync buzzer), you will need also to understand the specific music replay to determine what it tries to do. In the end, you should get a timer freq and a modulation method : playing samples, alternating volume between 0 and another value for sid voice (or even use a kind of SIN wave to modulate volume).
Note that SID voice is not really digidrum, it's more a way to emulate a volume modulation using a square wave (ym only support "triangle" wave). SID effect will for example alternate volume 0 and 10, while digidrum / samples will really use all possible volume between 0 and 15 to get a low quality sample replay on one voice.
So, there's no magic and no universal tool : simple replay (without timers) can be easily dumped (with special case for reg 13), others replays will usually require some custom analysis.
Nicolas
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Date
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YM dumping & soundchip effects
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shazz
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Mar,06.2011-11:37
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Re: YM dumping & soundchip effects
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AdamK
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Mar,07.2011-20:24
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Re: YM dumping & soundchip effects
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Mr.Styckx
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Mar,08.2011-00:48
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Re: YM dumping & soundchip effects
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shazz
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Mar,08.2011-10:19
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Re: YM dumping & soundchip effects
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Mr.Styckx
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Mar,10.2011-14:51
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Re: YM dumping & soundchip effects
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defjam
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Mar,10.2011-14:57
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Re: YM dumping & soundchip effects
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Dma-Sc
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Mar,11.2011-17:39
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Re: YM dumping & soundchip effects
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evil
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Mar,11.2011-18:05
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Re: YM dumping & soundchip effects
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shazz
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Mar,12.2011-14:18
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Re: YM dumping & soundchip effects
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Leonard
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Apr,03.2011-16:53
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What's the anti-troll code?
That's your personal code to be able to add comments and messages on the dhs.nu site.
Don't have a code or forgot it? Fix it here.
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