Observatory Credits Warp Steps

This is an exposition of the steps used in this video https://www.youtube.com/watch?v=El47iOS2fzQ to credits warp from the observatory (please see the video for anything I don't write out explicitly).  The file name used in that video is 8きぽヌピば0f (hex 08105970 A65000CA, https://lemon-sherbet.github.io/ootfname is a helpful tool to help identify the characters correctly) -- this name or a comparable one will be required for the ACE to work.

This route is designed for the N64 Japanese 1.0 version of the game.  In principle JP 1.1 would work as well, but the details of the setups would be different due to differences in memory addresses.  The Virtual Console version of the game cannot use the ACE in this trick due to its recompiler.

Here are some memory addresses which should be useful for practicing/learning these setups:
Link's rotation (vertical, 2 bytes) 803FFFE8
Link's rotation (horizontal, 2 bytes, (always?) equivalent to facing angle) 803FFFEA
Link's facing angle (2 bytes) 8040005E
Exit setter (doing the trick successfully will cause this to be set to 4DC0 while the pot draws) 803FF54A
Current room (for sets of loading planes where both rooms can be loaded simultaneously, as in observatory, will update when the next room loads & again when previous room unloads, 1 byte) 803FF3B0

The optimal version of this route would obtain bomb bag in first cycle, and then get at least three bomb drops from bushes in Termina Field.  A slower alternative that would make the route easier/more consistent for an rta player would be to deposit rupees during first cycle, then in second cycle withdraw and purchase bomb bag for a full 20 bombs.

One can use a recoil flip to clip through the Observatory fence instead of a hess.

In the steps listed below, the Observatory room (which you enter from TF) is room 1, and the tunnels section is room 0.  The pots in room 1 are, when looking at them from the middle of the room, in the order 1 2 0 (the numbers indicate the order in which they load in memory).

The heap manipulation setup for getting Zora Mask with chest SRM is
Load room 1
Load room 0
Allocate bomb
Load room 1
Load room 0
Load room 1
Deallocate pot 1 (pick up rupee)
Deallocate pot 2 (pick up rupee)
Load room 0
Allocate bomb
Allocate bomb
Load room 1
Superslide off of pot 2 for SRM (it's okay if pot 1 breaks)
Load room 0 with smoke still loaded
Load room 1 (angle setup for FF86)
Load room 0

When loading room 0 for the second time after the superslide, the angle of the unloaded pot will be writing to the contents of the silver rupee chest.  The setup for angle FF86 (which will give zora mask without having to open the chest) is (see video) target the wall for angle D554, untarget and tap forward to snap to angle D556, ess turn left until you're at angle FF86.

If you do the chest srm setup correctly, the pot's angle should be at 8042AE1E.

After getting zora mask and deathwarping, the heap manipulation for the draw function SRM is

Load room 1
Deallocate pot 0
Allocate smoke (let bomb unload)
Load room 0
Load room 1
Load room 0
Allocate smoke (let bomb unload)
Allocate bomb
Allocate bomb
Load room 1
Allocate bomb
Load room 0
Allocate smoke (let bomb unload)
Allocate bomb
Load room 1
Superslide off of pot 2 for SRM (it's okay if pot 1 breaks)
Load room 0 with smoke still loaded
Load room 1 (angle setup for 9414)
Load room 0

The setup for angle 9414 is (again see video for which is the initial wall)
Target wall for angle 2AAC
ess left to 46CC
snap to 46C1
ess left to 4DC9
snap to 4DC3
ess left to 70EB
snap to 70EC
ess left to 9414

When you superslide off of pot 2, it should be loaded at 80424e40.  After entering and reentering room 0, there should be a pot in that room loaded at 80424dc0, with your unloaded pot writing to its draw function pointer.  As soon as room 0 loads you can drop the unloaded pot, and the draw function pointer should be overwritten to 80419414.  The pot's angle while you're holding it should be writing to 80424EFE.

Before throwing the zora fins you cannot uncull the pot whose draw function was modified, or the game will crash.  Looking in its direction (it is to the right of the balloon from where you're standing) will uncull it, so avoid that.  In order to keep the modified draw function intact, the fin setup has to take place in the hallway with both rooms loaded (keeping room 0 loaded makes sure the fins will spawn in the correct location)

Once the draw function pointer is set, turn zora (here's a demonstration of obtaining the horizontal angle https://www.youtube.com/watch?v=4NQPSGXOWVk)
Target the wall for C000
Ess down to 4001
4 ess right to 23E1
Pull fins
Hold a full left input 4 frames to 31BD
Hold a full right input 6 frames to 1CE7 (this is the horizontal angle we need)
Hold a full down input until your vertical rotation is C950 (this is the value it caps out at)
Hold a full up input until your vertical rotation is 34F7
Switch to a full down input until your vertical rotation is C98E
Switch to a full up input until your vertical rotation is 0F02
Switch to a full down input until your vertical rotation is 0814 (this is the vertical rotation we need)
Your rotations should now read 08142E33
When you let go of B, the left fin will load at 80419400, and its rotation at 80419414 should read 08142CA3

At this point everything is set up -- all that's left to do is play Song of Time while the pot is unculled.  As shown in the video this is possible to do from your current location, if your camera angle is good.  For safety you could move farther into the room before playing SoT; make sure the camera is pointing towards the pot (which is, again, to the right of the balloon from the position where you threw fins).