What exits or sprites to hide until key is acquired, detonator is triggered or if 5 staff pieces are collected.
Starts in ROM address 001d52, but some of them are scattered around.

Note, Exit in rooms EC, FB, E6 are always open from the other side, 
I guess the dev's figured out theres no need to hide them, 
as you cant access those rooms from the other side without hacking or cheating.

Four bytes
1. Room ID
2. What sprite opens it
3. Unknown, if 00 it hides exit/sprites, anything else it always shows items/exits regardless of anything
4. room side

01 = SW 
02 = SE 
04 = NE
08 = NW
Note: Other values doesn't seem to do anything.
Note: On detonators value 2. byte doesn't correspond to sprite, but something else? I dont know how it works exactly.
Note: On 5-staff piece reveal, other than the room ID I dont know what its other three bytes does.
---

add.	bit		What it is
------	--		-------------
001d52	B1		Room ID
001D53	D2		Key, sprite D2
001D54	00		unknown bit
001D55	08 		What exit to hide

001D56	B2		Room ID
001D57	D2		Key, sprite D2
001D58	00		unknown bit
001D59	02		What exit to hide

001D5a	A4		Room ID
001D5b	D4		Key, sprite D4
001D5c	00		unknown bit
001D5d	08		What exit to hide

001D5e	B0		Room ID
001D5f	D4 		Key, sprite D4
001D60	00		unknown bit
001D61	02		What exit to hide

001D62	A5		Room ID
001D63	D4		Key, sprite D4
001D64	00		unknown bit
001D65	08		What exit to hide

001D66	A6		Room ID
001D67	D4		Key, sprite D4
001D68	00		unknown bit
001D69	02		What exit to hide

001D6a	EB		Room ID
001D6b	D3		Key, sprite D3
001D6c	00		unknown bit
001D6d	01		What exit to hide

001D6e	D2		Room ID 
001D6f	FE		Sprite 29 (note, detonator)
001D70	00		Unknown bit
001D71	04		What exit to hide

001D72	45		Room ID 
001D73	FF		Sprite 2B (note, detonator)
001D74	00		Unknown bit
001D75	02		What exit to hide

001D76	47		Room ID 
001D77	FF		Sprite 2B (note, detonator)
001D78	00		Unknown bit
001D79	08		What exit to hide

001D7A	F7		Room ID 
001D7B	FD		Sprite 2D (note, detonator)
001D7C	00		Unknown bit
001D7D	04		What exit to hide

001def	0C		Room ID (note, unhides all sprites from the room)
001df0	D1		Key, sprite D1
001df1	00		Unknown bit
001df2	03		Unknown bit

001d91	E0		Room ID (Note, unhides all sprites until 5 staff pieces are collected)
001d91	D0		Unknown bit
001d92	0F		Unknown bit
001d93	AD		Unknown bit