mirror of
https://gitlab.com/camelot/kickc.git
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53 lines
1.3 KiB
C
53 lines
1.3 KiB
C
// NMI Sample Player using the SID volume register
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// Code by Scan of Desire (Richard-William Loerakker)
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// Sample from ART OF NOISE: MOMENTS IN LOVE
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#include <c64.h>
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const unsigned int SAMPLE_SIZE = 0x6100;
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char SAMPLE[SAMPLE_SIZE] = kickasm(resource "moments_sample.bin") {{ .import binary "moments_sample.bin" }};
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char* volatile sample = SAMPLE;
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void main() {
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// Boosting 8580 Digis
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// See https://gist.github.com/munshkr/30f35e39905e63876ff7 (line 909)
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asm {
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lda #$ff
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sta $d406
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sta $d40d
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sta $d414
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lda #$49
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sta $d404
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sta $d40b
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sta $d412
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}
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asm { sei }
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CIA2->INTERRUPT = CIA_INTERRUPT_CLEAR_ALL;
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*KERNEL_NMI = &nmi;
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CIA2->TIMER_A = 0x88; // speed
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CIA2->INTERRUPT = 0x81;
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CIA2->TIMER_A_CONTROL = 0x01;
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asm { cli }
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}
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__interrupt(hardware_clobber) void nmi() {
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(VICII->BORDER_COLOR)++;
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asm { lda CIA2_INTERRUPT }
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SID->VOLUME_FILTER_MODE = *sample & $0f;
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*KERNEL_NMI = &nmi2;
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(VICII->BORDER_COLOR)--;
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}
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__interrupt(hardware_clobber) void nmi2() {
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(VICII->BORDER_COLOR)++;
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asm { lda CIA2_INTERRUPT }
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SID->VOLUME_FILTER_MODE = *sample >> 4;
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sample++;
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if (BYTE1(sample) == BYTE1(SAMPLE+$6100)) {
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sample = SAMPLE;
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}
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*KERNEL_NMI = &nmi;
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(VICII->BORDER_COLOR)--;
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} |