The Hobbit (v1.0): Routine at 9B25

9B25: Get the address of an object record

Looks up object number A in the object index table at BF53 (using 9D12) and returns the address of its record in IX. Everything that can be manipulated - Bilbo himself (object 0), the other characters, doors, food, weapons, keys - is an 'object' with a record in C00B.

Input
A	Object number

Output
IX	Object record

9B25

LD IX,$BF53

IX = the start of the object index, the master list of every object and its record address

9B29

CALL $9D12

Search the index for object A

9B2C

PUSH HL

Save HL for a moment

9B2D

LD L,(IX+$01)

HL = the object's record address, read from the matching entry (low byte)...

9B30

LD H,(IX+$02)

...then the high byte

9B33

EX (SP),HL

Swap it onto the stack in place of the saved HL, so the address can be...

9B34

POP IX

...popped straight into IX, the register the rest of the game expects an object record in

9B36

RET