Chase H.Q.: Routine at FE7F

FE7F: Clears the options-menu screen area (attributes and bitmap)

Attribute memory from $5900 (511 bytes) and screen bitmap from $4800 and $4000, each via a self-filling LDIR pass ("LD (HL),L" seeds the first byte, then LDIR propagates it), servicing sound (run_title_tune) between passes. Falls through into run_title_tune at the end via a tail jump, not a RET. Used by the routines at run_title_screen, options_menu_driver and redefine_keys_screen.
clear_options_screen	FE7F	LD HL,$5900
	FE82	LD DE,$5901
	FE85	LD BC,$01FF
	FE88	LD (HL),L
	FE89	LDIR
	FE8B	CALL run_title_tune
	FE8E	LD HL,$4800
	FE91	LD DE,$4801
	FE94	LD (HL),L
	FE95	LD BC,$082F
	FE98	LDIR
	FE9A	PUSH DE
	FE9B	PUSH HL
	FE9C	CALL run_title_tune
	FE9F	POP HL
	FEA0	POP DE
	FEA1	LD BC,$07D0
	FEA4	LDIR
	FEA6	JP run_title_tune