| Chase H.Q. | Routines |
| Prev: AAC6 | Up: Map | Next: AB9A |
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Used by the routine at main_loop.
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| helicopter | AB33 | LD A,($A224) | Return if helicopter_control is zero | |
| AB36 | AND A | |||
| AB37 | RET Z | |||
| AB38 | DEC A | Jump to hc_1 if helicopter_control is one | ||
| AB39 | JR Z,hc_1 | |||
| AB3B | DEC A | Jump to hc_pick_direction if helicopter_control >= 3 | ||
| AB3C | JR NZ,hc_pick_direction | |||
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Otherwise helicopter_control is 2.
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| AB3E | LD A,($AA96) | Read from 'LD BC' @ sub_AA94 | ||
| AB41 | AND A | Set flags | ||
| AB42 | RET Z | Return if zero | ||
| AB43 | XOR A | A = 0 -- NOP | ||
| AB44 | LD D,A | DE = 0 -- NOPs | ||
| AB45 | LD E,A | |||
| AB46 | EX AF,AF' | |||
| AB47 | XOR A | A = 0 | ||
| AB48 | JR hc_3 | Jump to hc_3 | ||
| hc_1 | AB4A | LD HL,$FFC8 | HL = $FFC8 | |
| AB4D | LD A,$02 | New value for helicopter_control is 2 | ||
| AB4F | JR hc_2 | Jump to hc_2 | ||
| hc_pick_direction | AB51 | DEC A | A-- | |
| AB52 | LD HL,$98A9 | Point HL at pilot "turn left" messages | ||
| AB55 | JR Z,hc_chatter | Jump to hc_chatter if A now zero (helicopter_control == 3) | ||
| AB57 | DEC A | A-- | ||
| AB58 | RET NZ | Return if A now non-zero | ||
| AB59 | LD HL,$98B3 | Point HL at pilot "turn right" messages (helicopter_control == 4) | ||
| hc_chatter | AB5C | LD DE,($A26C) | Self modify 'LD BC' @ AAF6 to load road_pos | |
| AB60 | LD ($AAF7),DE | |||
| AB64 | LD DE,$FFE8 | Self modify 'LD BC' @ sub_AA94 to load $FFE8 | ||
| AB67 | LD ($AA95),DE | |||
| AB6B | XOR A | Self modify 'LD A' @ AAD7 to load zero | ||
| AB6C | LD ($AAD8),A | |||
| AB6F | LD ($AAE9),A | Self modify 'ADD A' @ move_helicopter_1 to load zero | ||
| AB72 | INC A | Self modify 'LD A' @ AADF to load one | ||
| AB73 | LD ($AAE0),A | |||
| AB76 | LD A,$0F | Call chatter (priority 15) | ||
| AB78 | CALL chatter | |||
| AB7B | LD HL,$0070 | HL = $0070 | ||
| AB7E | LD A,$85 | Self modify 'LD A' @ AACB to load $85 | ||
| AB80 | LD ($AACC),A | |||
| AB83 | LD A,$05 | New value for helicopter_control is 5 | ||
| hc_2 | AB85 | EX AF,AF' | Preserve AF | |
| AB86 | LD ($AB07),HL | Self modify 'LD DE' @ AB06 to load $0070, or $FFC8 | ||
| AB89 | LD DE,$AA38 | Address of helicopter_stuff | ||
| AB8C | LD A,$CD | Opcode for CALL | ||
| hc_3 | AB8E | LD ($8FA4),A | Self modify 8FA4 to be CALL helicopter_stuff, or NOPs | |
| AB91 | LD ($8FA5),DE | |||
| AB95 | EX AF,AF' | Restore AF | ||
| AB96 | LD ($A224),A | helicopter_control = A | ||
| AB99 | RET | Return | ||
| Prev: AAC6 | Up: Map | Next: AB9A |