Knight Lore: Routine at D0A9

D0A9: Cursor keys: the 6 to 0 half-row

Used by the routine at cursor. Part of cursor.
cursor_second_row	D0A9	LD A,$EF	half-row 0 to 6
	D0AB	CALL read_port
	D0AE	BIT 0,A	0 (fire): jump, bit 3
	D0B0	JR Z,cursor_up
	D0B2	SET 3,C