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@@ -90,6 +90,7 @@ void SN76496Write(int data)
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case 4: /* tone 2 : frequency */
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R->Period[c] = R->UpdateStep * data;
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if (R->Period[c] == 0) R->Period[c] = R->UpdateStep;
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+ if (R->Count[c] > R->Period[c]) R->Count[c] = R->Period[c];
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if (r == 4)
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{
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/* update noise shift frequency */
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@@ -155,8 +156,9 @@ void SN76496Update(short *buffer, int length, int stereo)
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/* and vol[i] incremented only if the exit status of the square */
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/* wave is 1. */
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if (R->Count[i] < -2*R->Period[i] || R->Volume[i] == 0) {
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- /* Cut of anything above the Nyquist freqency */
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- /* It will only create aliasing anyway */
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+ /* Cut off anything above the Nyquist frequency. */
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+ /* It will only create aliasing anyway. This is actually an */
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+ /* ideal lowpass filter with Nyquist corner frequency. */
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vol[i] += STEP/2; // mean value
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R->Count[i] = R->Output[i] = 0;
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}
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