Routines
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9DBD: Index ID Table
Used by the routines at Start, Drawing, DisplayLocHlpMsg, Action_Dir, Action_Examine, 9A85, 9B81, LocateObject and ActionClimbOut.
Input
A Key ID
IX Address of table data
Output
IX The address in the table which matches the key ID
Searches through what is essentially key value data to find a key match.
IndexIdTable 9DBD EXX Exchange registers.
9DBE PUSH IX HL=IX (using the stack to do so).
9DC0 POP HL
9DC1 LD B,A B=key ID
9DC2 LD E,$03 DE=$0003 as each record is 3 bytes of data.
9DC4 LD D,$00
Begin searching the table.
IndexIdTable_Loop 9DC6 LD A,(HL) Grab the next ID.
9DC7 CP B If the key ID is the one we want, jump to IndexIdTable_Found.
9DC8 JR Z,IndexIdTable_Found
9DCA CP $FF If we've reached the termination character (key ID not found), jump to IndexIdTable_Found.
9DCC JR Z,IndexIdTable_Found
9DCE ADD HL,DE Add DE to HL to check the next row, and jump back to IndexIdTable_Loop to continue checking.
9DCF JP IndexIdTable_Loop
Handle the output.
IndexIdTable_Found 9DD2 PUSH HL IX=HL (using the stack to do so).
9DD3 POP IX
9DD5 CP $FF Set flags (checking if the key ID was not found).
9DD7 EXX Exchange registers.
9DD8 RET Return.
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