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Routines |
| Prev: 655B | Up: Map | Next: 6622 |
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Called from the main loop at 6229.
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| 65A1 | LD A,($7C79) | Pick up the tunnel timer. | ||
| 65A4 | AND A | Is Horace in a tunnel? | ||
| 65A5 | RET NZ | Return if so. | ||
| 65A6 | LD HL,($7C6D) | Pick up Horace's new location. | ||
| 65A9 | CALL $6C20 | Check the attribute bytes at this location. | ||
| 65AC | RET Z | Return if there's nothing to eat there. | ||
| 65AD | CP $3C | Has Horace run into a flower? | ||
| 65AF | JR NZ,$65BD | Jump if not. | ||
| 65B1 | LD HL,($7C73) | Add 10 to the score (Horace has eaten a flower). | ||
| 65B4 | LD BC,$000A | |||
| 65B7 | ADD HL,BC | |||
| 65B8 | LD ($7C73),HL | |||
| 65BB | JR $65C7 | |||
| 65BD | LD HL,($7C73) | Add 50 to the score (Horace has eaten a cherry or strawberry). | ||
| 65C0 | LD BC,$0032 | |||
| 65C3 | ADD HL,BC | |||
| 65C4 | LD ($7C73),HL | |||
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This entry point is used by the routines at 6000 (when initialising a maze), 66A4 (when Horace has thrown the guards out of the park) and 686A (when Horace has sounded the alarm).
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| 65C7 | LD DE,$4000 | Set DE to the display file address for the score (in a roundabout way). | ||
| 65CA | EX DE,HL | |||
| 65CB | LD BC,$000F | |||
| 65CE | ADD HL,BC | |||
| 65CF | EX DE,HL | |||
| 65D0 | CALL $6B21 | Print the score. | ||
| 65D3 | LD HL,($7C73) | Pick up the current score. | ||
| 65D6 | XOR A | Clear the carry flag and set A=0. | ||
| 65D7 | LD BC,$2710 | Perform trial subtractions of 10000 from the score. | ||
| 65DA | INC A | |||
| 65DB | SBC HL,BC | |||
| 65DD | JR NC,$65DA | |||
| 65DF | INC A | This should be DEC A. | ||
| 65E0 | LD B,A | Now B=INT(Score/10000)+2. | ||
| 65E1 | LD A,($7C77) | Pick up the extra life indicator. | ||
| 65E4 | CP B | Is it time to award an extra life? | ||
| 65E5 | JR Z,$6601 | Jump if not. | ||
| 65E7 | LD A,B | Update the extra life indicator. | ||
| 65E8 | LD ($7C77),A | |||
| 65EB | LD A,($7C78) | Increment the number of lives. | ||
| 65EE | INC A | |||
| 65EF | LD ($7C78),A | |||
| 65F2 | LD HL,$4007 | This is the display file address for the number of lives. | ||
| 65F5 | CALL $6C0F | Set HL' to the corresponding attribute file address (unnecessarily). | ||
| 65F8 | LD A,($7C78) | Pick up the number of lives remaining. | ||
| 65FB | ADD A,"0" | Convert it into an ASCII code. This does not work if there are 10 or more lives remaining, which is a bug. | ||
| 65FD | EX DE,HL | Transfer the display file address to DE. | ||
| 65FE | CALL $6B4F | Print the number of lives remaining. | ||
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Now make a sound effect.
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| 6601 | LD HL,$7C69 | Pick up the sound on/off indicator. | ||
| 6604 | LD C,$10 | Initialise C for the loop that follows. | ||
| 6606 | PUSH BC | Save the loop counter (unnecessarily). | ||
| 6607 | LD B,C | Set B equal to 8*C. This value determines the pitch. | ||
| 6608 | SLA B | |||
| 660A | SLA B | |||
| 660C | SLA B | |||
| 660E | PUSH BC | Save the pitch parameter briefly. | ||
| 660F | LD A,$1F | Flip the speaker off if the sound on/off indicator is on, or on otherwise. | ||
| 6611 | AND (HL) | |||
| 6612 | OUT ($FE),A | |||
| 6614 | DJNZ $6614 | Produce a short delay. | ||
| 6616 | LD A,$07 | Flip the speaker on. | ||
| 6618 | OUT ($FE),A | |||
| 661A | POP BC | Restore the pitch parameter to B. | ||
| 661B | DJNZ $661B | Produce another short delay. | ||
| 661D | POP BC | Restore the loop counter to C (unnecessarily). | ||
| 661E | DEC C | Finished yet? | ||
| 661F | JR NZ,$6606 | Jump back if not. | ||
| 6621 | RET | |||
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