| Chase H.Q. | Routines |
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Writes the complete set of AY audio registers, final register first.
Lives at $8096 when relocated. Used by the routine at play_siren_sfx_128k.
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| write_audio_registers_128k | F2A2 | LD HL,$A21E | Load address of final AY register value | |
| F2A5 | LD A,$0B | Select AY-3-8912 sound chip register 11: envelope fine duration | ||
| F2A7 | LD C,$FD | Load constant for port writes | ||
| wr_loop | F2A9 | LD B,$FF | Writing to port $FFFD | |
| F2AB | OUT (C),A | Select register A | ||
| F2AD | LD B,$BF | Writing to port $BFFD | ||
| F2AF | OUTD | Write to the register from (HL), then decrement B and HL | ||
| F2B1 | DEC A | Advance to next register down | ||
| F2B2 | JP P,$809D | Loop to wr_loop while +ve | ||
| F2B5 | RET | Return | ||
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