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Routines |
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Continues from F51E. Checks whether ERIC has jumped up to the safe or a shield, and makes it flash or unflash as appropriate.
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| F726 | LD A,($7FEA) | Pick up the game mode indicator from 7FEA | ||||||
| F729 | CP $02 | Are all the shields flashing? | ||||||
| F72B | JP NZ,$6DE2 | Jump if not (to check whether ERIC touched a shield) | ||||||
| F72E | LD A,D | A=y-coordinate of ERIC's hand | ||||||
| F72F | CP $A1 | This is the y-coordinate of the spot just under the safe in the staff room | ||||||
| F731 | RET NZ | Return if ERIC is not on the middle floor | ||||||
| F732 | LD A,E | A=x-coordinate of ERIC's hand | ||||||
| F733 | CP $0A | Has ERIC jumped up to the safe? | ||||||
| F735 | RET NZ | Return if not | ||||||
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ERIC has jumped up to the safe. Can he open it?
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| F736 | LD HL,$7FED | 7FED holds the number of the character who last wrote on the Reading Room blackboard | ||||||
| F739 | LD DE,$7FA8 | 7FA8=Reading Room blackboard contents buffer | ||||||
| F73C | LD C,$03 | There are 3 blackboards | ||||||
| F73E | LD A,(HL) | A=number of the character who last wrote on this board | ||||||
| F73F | INC HL | Move HL along to the next blackboard | ||||||
| F740 | INC HL | |||||||
| F741 | CP $AC | Did ERIC write on this blackboard? | ||||||
| F743 | JR NZ,$F75A | Jump if not | ||||||
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ERIC wrote on this blackboard. Check whether he wrote the safe combination code.
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| F745 | PUSH HL | |||||||
| F746 | LD L,$9F | HL=7F9F (which holds the safe combination code) | ||||||
| F748 | LD B,$04 | There are 4 characters in the safe combination code | ||||||
| F74A | PUSH DE | Save the pointer to the blackboard contents buffer | ||||||
| F74B | LD A,(DE) | A=character written on the blackboard by ERIC | ||||||
| F74C | AND $5F | Convert to upper case | ||||||
| F74E | INC E | Move DE along to the next character on the blackboard | ||||||
| F74F | CP (HL) | Does the character on the blackboard match a safe combination letter? | ||||||
| F750 | JR NZ,$F756 | Jump if not | ||||||
| F752 | INC L | Move to the next letter of the safe combination code | ||||||
| F753 | DJNZ $F74B | Jump back until all four letters have been checked | ||||||
| F755 | XOR A | Set the zero flag to indicate a match | ||||||
| F756 | POP DE | Restore the blackboard contents buffer pointer to DE | ||||||
| F757 | POP HL | |||||||
| F758 | JR Z,$F762 | Jump if ERIC got the right combination | ||||||
| F75A | LD A,E | Point DE at the next blackboard contents buffer (7FAE or 7FB4) | ||||||
| F75B | ADD A,$06 | |||||||
| F75D | LD E,A | |||||||
| F75E | DEC C | Decrease the blackboard counter | ||||||
| F75F | JR NZ,$F73E | Jump back until all three blackboards have been checked | ||||||
| F761 | RET | |||||||
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ERIC got the right combination.
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| F762 | CALL $F8B4 | Add 1000 to the score and play a celebratory tune | ||||||
| F765 | LD HL,$A18A | Point HL at the attribute byte for the safe | ||||||
| F768 | SET 7,(HL) | Alter the attribute byte of the safe in the skool attribute data to make it flash | ||||||
| F76A | EX DE,HL | Point DE at the attribute byte for the safe | ||||||
| F76B | CALL $F4D2 | Get the attribute file address of the safe in HL | ||||||
| F76E | RET C | Return if the safe is off-screen (unlikely!) | ||||||
| F76F | SET 7,(HL) | Adjust the on-screen attribute byte of the safe to make it flash | ||||||
| F771 | RET | |||||||
| Prev: F70A | Up: Map | Next: F772 |