Issue #212: Add XOR doc to the audio secton of the VERA #213
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| For PCM playback, VERA contains a 4kB FIFO buffer. This buffer needs to be filled in a timely fashion by the CPU. To facilitate this an **AFLOW** (Audio FIFO low) interrupt can be generated when the FIFO is less than 1/4 filled. | ||
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| ### Audio registers | ||
| #### Audio registers |
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Heading hierarchy seems a bit off. If "Audio registers" is made h4, the respective register headings should be h5, and "Audio data formats" also h4 (since they also relate to PCM).
That does feel like some very deep nesting into the hierarchy, but I think that's a symptom of most of the VERA stuff being on the one page, an issue for another day.
| The **Left** and **Right** bits control to which output channels the sound should be output. | ||
| **Volume** controls the volume of the sound with a logarithmic curve; 0 is silent, 63 ($3F) | ||
| is the loudest. The **Left** and **Right** bits control to which output channels the sound | ||
| should be output. |
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I know you haven't changed this sentence but the first "output" (line 925) seems redundant.
| give a 50% duty cycle or square wave, 0 will give a very narrow pulse. | ||
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| When the triangle or saw waveform is selected, the value influences an XOR calculation | ||
| the changes the resulting waveform. This is most noticeable with the triangle waveform. |
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Smells like a typo, possibly intended as "an XOR calculation that changes"?
| It can be used to provide an NES-like fuzzy triangle as well as an overdriven saw sound | ||
| (similar to the VRC6 NES chip) among several other varieties of sounds. | ||
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| When used with the saw, the result is more substle. It adds some overtones to |
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Since I want to close this PR out, I tried to remedy these changes, but the PR was not opened to allow edits back into the source branch. I'm going to merge these then apply the fixes in the next PR |
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Changes applied in #218 |
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