Routines
Prev: 54504 Up: Map Next: 54619
54540: Routine at D50C
Used by the routine at FindScene.
54540 OR A Set zero flag based on A.
54541 SLA A Shift A left (with carry).
54543 LD L,A Store the result in L.
54544 RLA Rotate A left (bit 7 is moved to bit 0).
54545 AND %00000001 Keep only bit 0.
54547 LD H,A H=A.
54548 LD DE,50944 DE=50944.
54551 ADD HL,DE HL+=DE.
54552 EX DE,HL Exchange the DE and HL registers.
54553 LD BC,32 BC=0032.
54556 LD HL,24896 HL=24896.
54559 PUSH HL Stash HL and DE on the stack.
54560 PUSH DE
54561 LD A,(DE) A=*DE.
54562 DEC A Decrease A by one.
54563 INC DE Increment DE by one.
54564 OR A Set the bits from A.
54565 LD (HL),1 Write 1 to *HL.
54567 SBC HL,BC HL-=BC.
54569 DEC A Decrease A by one.
54570 JR NZ,54565 Jump to 54565 until A is zero.
54572 LD A,(DE) Jump to 54608 if *DE is zero.
54573 AND A
54574 JR Z,54608
54576 PUSH HL Stash HL on the stack.
54577 LD HL,51200 HL=51200.
54580 LD E,A E=A.
54581 LD A,(HL) A=*HL.
54582 INC HL Increment HL by one.
54583 CP 128 Jump to 54581 if A is lower than 128.
54585 JP C,54581
54588 DEC E Decrease E by one.
54589 JP NZ,54581 Jump to 54581 until E is zero.
54592 EX DE,HL Exchange the DE and HL registers.
54593 POP HL Restore HL from the stack.
54594 LD A,(DE) A=*DE.
54595 AND %01111111 Keep only bits 0-6.
54597 LD (HL),A Write A to *HL.
54598 LD A,(DE) A=*DE.
54599 BIT 7,A Jump to 54608 if bit 7 of A is set.
54601 JR NZ,54608
54603 SBC HL,BC HL-=BC.
54605 INC DE Increment DE by one.
54606 JR 54594 Jump to 54594.
54608 POP DE Restore DE and HL from the stack.
54609 POP HL
54610 INC HL Increment HL by one.
54611 INC DE Increment DE by two.
54612 INC DE
54613 LD A,L Jump to 54559 if L is not equal to 96.
54614 CP 96
54616 JR NZ,54559
54618 RET Return.
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