Alien (BUGFIX 1.7): Routine at 34684

Reads the keyboard and moves the corridor cursor. Calls the key-scanner at 34636, which packs five keys into 33682 (set bit = pressed): bit 0 = key 8, bit 1 = key 5, bit 2 = key 7, bit 3 = key 6, bit 4 = key 0 (action).

While the action key is held the border flashes yellow/black; on RELEASE control jumps to 34840, which dispatches through RoomDispatchTable on the current room mode (31252) — this is how a room's action handler / menu is opened.

Otherwise: key 6 -> 34743 (advance the cursor along the corridor), key 7 -> 34788 (retreat), and keys 8/5 move between rows when the room view has more than one row (mode != 0).

Used by the routine at 36457.

Reads the keyboard and moves the corridor cursor. Calls the key-scanner at 34636, which packs five keys into 33682 (set bit = pressed): bit 0 = key 8, bit 1 = key 5, bit 2 = key 7, bit 3 = key 6, bit 4 = key 0 (action). While the action key is held the border flashes yellow/black; on RELEASE control jumps to 34840, which dispatches through RoomDispatchTable on the current room mode (31252) — this is how a room's action handler / menu is opened. Otherwise: key 6 -> 34743 (advance the cursor along the corridor), key 7 -> 34788 (retreat), and keys 8/5 move between rows when the room view has more than one row (mode != 0). Used by the routine at 36457.
34684	CALL 34636	scan keyboard → 33642 bitmask
34687	LD A,(33682)	A = key bitmask (33642)
34690	AND A	any key pressed?
34691	RET Z	no: return immediately
34692	BIT 4,A	action/fire key held?
34694	JR Z,34716	no: check directional keys
34696	XOR A	A = 0 (border black)
34697	EX AF,AF'	save border colour to A'
34698	CALL 34636	re-scan keyboard (wait for release)
34701	LD A,(33682)	read updated key state
34704	BIT 4,A	action key still held?
34706	JP Z,34840	released: open the room-action dispatch
34709	EX AF,AF'	restore A' border colour
34710	XOR 6	toggle between 0 (black) and 6 (yellow)
34712	OUT (254),A	flash border
34714	JR 34697	repeat until key released
34716	BIT 3,A	key 6 (advance)?
34718	JR NZ,34743	yes: advance cursor along the corridor
34720	BIT 2,A	key 7 (retreat)?
34722	JR NZ,34788	yes: retreat cursor along the corridor
34724	AND 3	key 5 or key 8 (row movement)?
34726	RET Z	no directional key: return
34727	LD A,(31252)	A = room mode (31252)
34730	AND A	mode 0 = single-row corridor (no up/down)
34731	RET Z	in single-row mode: up/down keys ignored
34732	LD A,(33685)	A = cell value under the cursor ($8395)
34735	CP 61	column 61 = leftmost valid position
34737	RET Z	at left wall: cannot move
34738	CALL 34743	move one step (shares forward-move code)
34741	JR 34732	keep moving while at edge