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41 lines
418 B
NASM
41 lines
418 B
NASM
Sine_e:: ; 8ac9 (2:4ac9)
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ld a, e
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and $3f
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cp $20
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jr nc, .negative
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call .GetSine
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ld a, h
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ret
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.negative
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and $1f
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call .GetSine
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ld a, h
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xor $ff
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inc a
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ret
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.GetSine: ; 8adf (2:4adf)
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ld e, a
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ld a, d
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ld d, $0
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ld hl, .SineWave
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add hl, de
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add hl, de
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ld e, [hl]
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inc hl
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ld d, [hl]
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ld hl, $0
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.loop
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srl a
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jr nc, .no_add
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add hl, de
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.no_add
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sla e
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rl d
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and a
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jr nz, .loop
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ret
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.SineWave:
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sine_wave $100
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