| Routines

6DA3: Check whether a location is on the assembly hall stage

Used by the routine at 63D2. Returns to the caller of 63D2 with the carry flag reset if the location is on the stage. Returns to 63D2 otherwise.
Input
D | y-coordinate
E | x-coordinate
6DA3 | LD BC,$B63B | B=0xB6, C=0x3B
6DA6 | LD A,D | A=y-coordinate of the location
6DA7 | CP $0E | The assembly hall stage's y-coordinate is 14
6DA9 | RET NZ | Return to 63D2 if the location is not there
6DAA | LD A,E | A=x-coordinate of the location
6DAB | CP $5A | Return to 63D2 unless 74<=A<90 (the rough vicinity of the stage)
6DAD | RET NC
6DAE | CP $4A
6DB0 | RET C
6DB1 | POP BC | Drop the return address from the stack
6DB2 | LD A,$C0 | A=0xC0: region identifier for the assembly hall stage (see 63D2)
6DB4 | RET | Return with the carry flag reset (indicating that the location is not on a staircase) to the caller of 63D2