Routines
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6BED: Process control state flags and trigger sound effects
Sound processing dispatcher called from interrupt handler. Reads state_controls control flags and calls appropriate sound routines. Multiple sounds can trigger simultaneously (e.g., fire + low fuel).
Bit Flag Sound Handler
0 FIRE_SOUND do_fire (fire)
1 SPEED_NOT_FAST beep_engine_normal (normal speed)
2 SPEED_CHANGED beep_engine_fast (fast speed)
1+2 Both speed bits beep_engine_slow (slow speed)
3 LOW_FUEL do_low_fuel (warning)
4 BONUS_LIFE do_bonus_life (jingle)
5 EXPLODING beep_explosion (explosion)
Flags are set by game logic (input handlers, collision, fuel system) and cleared by sound routines when complete.
handle_controls 6BED LD A,($5C08) Skip if LAST_K is 'h'.
6BF0 CP $68
6BF2 JP Z,int_return
6BF5 LD HL,$6BB0 Check FIRE_SOUND → do_fire.
6BF8 BIT 0,(HL)
6BFA CALL NZ,do_fire
6BFD BIT 4,(HL) Check BONUS_LIFE → do_bonus_life.
6BFF CALL NZ,do_bonus_life
6C02 LD HL,$6BB0
6C05 BIT 5,(HL) Check EXPLODING → beep_explosion.
6C07 CALL NZ,beep_explosion
6C0A LD HL,$6BB0
6C0D BIT 3,(HL) Check LOW_FUEL → do_low_fuel.
6C0F JP NZ,do_low_fuel
6C12 LD A,(HL)
6C13 AND $06 Mask speed bits.
6C15 CP $02 Normal speed → beep_engine_normal.
6C17 JP Z,beep_engine_normal
6C1A CP $04 Fast speed → beep_engine_fast.
6C1C JP Z,beep_engine_fast
6C1F CP $06 Slow speed → beep_engine_slow.
6C21 JP Z,beep_engine_slow
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