item_register

Significance

item_register is the game code's identifier for Link's item and mask inventory mappings.

Syntax

• zs $filepath -I (char[]) -- Prints the current inventory table for the "Masks" sub-screen, if the case-insensitive string starts with the letter 'M', or for the "Items" sub-screen otherwise.
• zs $filepath -I (char[]) (unsigned int) (unsigned int) (uint8_t) -- Interprets the final extra string parameter as an unsigned hexadecimal integer and stores the result to the relevant bits (as dictated by the two preceding unsigned int coordinate parameters, which correspondingly refer to entry row and column in sub-screen), if said integer falls within the range of values representable by a zero-extended byte in MIPS (0x00 <= x <= 0xFF).

Example Inputs

command	effect
-I items 0 0 0x00	installs the Ocarina of Time to the top-left
-I Items 1 2 0x08	installs Deku Nuts to (row, col) = (1, 2)
-I blah 1 1 0X07	installs Bombchu to (row, col) = (1, 1)
-I m(asks) 0 5 32	installs the Deku Mask to top-right of Masks

Notes

Yet another structure partially similar to that of the SRAM in The Legend of Zelda: Ocarina of Time, the item_register vector is just a table of byte identifiers representing which mask or other item can be selected from which field in the respective sub-screen.

It is perfectly plausible to switch items around from their normal positions: An item like Bombchu can be mapped to a position within the Masks sub-screen, and a mask like the Bunny Hood could be mapped in place of any item on the Items sub-screen. There are only two potential concerns:

• Certain fixed positions within the Items sub-screen are designated an "ammunition" counter of stock for that cell, which can cause the game to show Link as having 0, 1 or even multiple copies of that item. Effectively, the item objects will all behave the same.
• Sometimes the game needs to compare a specific byte in the inventory vector for an exact item ID in order to accurately respond to actions done during the game.

Besides the obvious incompatibility of most of these object ID numbers with that which should correspond with the preceding Zelda game, there is also a conflict between some object identifiers (particularly any of the masks) used to refer to the intended item or mask, based on whether the "modern" or "beta" system of enumerating said objects is used. All USA and PAL releases of the game (including the debug ROM) use the modern method, but the old Japanese releases (not counting the GC version release) use what will be referred to here as the old, "beta" method.

Official Name (in English, if available)	Beta	Modern
Ocarina of Time	00	00
Hero's Bow	01	01
Fire Arrow	02	02
Ice Arrow	03	03
Light Arrow	04	04
妖精のオカリナ	05	05
Bomb	06	06
Bombchu	07	07
Deku Stick	08	08
Deku Nut	09	09
Magic Beans	0A	0A
ロングフック	0B	0B
Powder Keg	0C	0C
Pictograph Box	0D	0D
Lens of Truth	0E	0E
Hookshot	0F	0F
Great Fairy's Sword	10	10
妖精のパチンコ	11	11
Empty Bottle	12	12
Red Potion	13	13
Green Potion	14	14
Blue Potion	15	15
Fairy	16	16
Deku Princess	17	17
Milk	18	18
Milk (1/2)	19	19
Fish	1A	1A
Bug	1B	1B
Blue Fire	1C	1C
Poe	1D	1D
Big Poe	1E	1E
Spring Water	1F	1F
Hot Spring Water	20	20
Zora Egg	21	21
Gold Dust	22	22
Magical Mushroom	23	23
(duplicate of 29h)	24
(duplicate of 29h)	25
Sea Horse	26	24
Chateau Romani	27	25
ハイラルどじょう	28	26
オババのドリンク	29	27
(more reserved bottle duplicates of 29h)	...	N/A
Moon's Tear	30	28
Land Title Deed	31	29
Swamp Title Deed	32	2A
Mountain Title Deed	33	2B
Ocean Title Deed	34	2C
密猟者のコギリ	35
折れたゴロン刀	36
処方せん	37
メダマガエル	38
特製本生目楽	39
Room Key	3A	2D
Special Delivery to Mama	3B	2E
... (duplicate reserved quest items)	...	N/A
Letter to Kafei	44	2F
Pendant of Memories	45	30
... (duplicate reserved quest items)	...	N/A
月の石 (map, possibly the last duplicate)	4D	31
Deku Mask	4E	32
Goron Mask	4F	33
Zora Mask	50	34
Fierce Deity Mask	51	35
Mask of Truth	52	36
Kafei's Mask	53	37
All-Night Mask	54	38
Bunny Hood	55	39
Keaton Mask	56	3A
Garo's Mask	57	3B
Romani's Mask	58	3C
Circus Leader's Mask	59	3D
Postman's Hat	5A	3E
Couple's Mask	5B	3F
Great Fairy's Mask	5C	40
Gibdo Mask	5D	41
Don Gero's Mask	5E	42
Kamaro's Mask	5F	43
Captain's Hat	60	44
Stone Mask	61	45
Bremen Mask	62	46
Blast Mask	63	47
Mask of Scents	64	48
Giant's Mask	65	49
...	...	...
no assignment	FF	FF

It probably is no coincidence that the "items" half of this list corresponds well to the linear positioning of where the game maps those objects into the Items sub-screen.

As can be inferred from the beta object gaps of duplicate, consecutive item objects, the developers probably had just copy-pasted the same instance of a given object over and over to pre-allocate space in the fixed vector for future ideas on items to implement, change or rearrange.

For example, many of the (later removed) bottled items all refer to "Granny's Drink", so it's quite plausible that this placeholder value was repeatedly copied and pasted to fixate space in the SRAM and later edited and replaced with new bottled items introduced with the latter N64 Zelda game as new game design ideas came along.

There appears to be a similar class of objects for the "quest items" as well. All of the unused or reserved items in this space are assigned the text which refers to the "Moon Stone", written in Japanese. One of the quest item slots is given the text "Moon's Tear", instead of "stone", and the icon for the Moon's Tear is a little smaller than the one for the Moon Stone. (This simply implies that the copy-pasta was all done before the item's name, role and likely the acquisition through game play were all changed.) There is also one item, not removed in the USA or PAL releases of the game, which also has this copy-pasta'd "Moon Stone" label in Japanese, but the object and picture itself refers simply to a generic world map texture.

The above table is complete for all in-range inputs to the inventory sub-screen mappings. Other sub-screen and quest status objects (e.g., Link's sword and shield, dungeon map and fairies, rupee wallet icons...) can incorrectly be mapped to the item vector bytes as well by using values beyond those listed in the table above. In doing so, this is probably a memory leak in several of the game's tables, as the actual ID numbers for referencing equipment upgrades and other quest status features are zero-based and much smaller than the identifiers given in the following table. (Although, said IDs are nonetheless legal, of course, so they are at least relevant to a single consolidated texture array of icons for each object so that some sort of picture will be drawn in the Masks and Items sub-screens.)

Official Name (in English, if available)	Beta	Modern
... (continued from the previous table)
風のメダル	66	4A
炎のメダル	67	4B
氷のメダル	68	4C
ゴロン太鼓	69	N/A
ゾーラのギター	6A	N/A
ナッツのラッパ	6B	N/A
Kokiri Sword	6C	4D
Razor Sword	6D	4E
Gilded Sword	6E	4F
折れた巨人のナイフ	6F	50
Hero's Shield	70	51
Mirror Shield	71	52
ミラーシールド	72	N/A
Quiver (holds 30)	73	53
Quiver (holds 40)	74	54
Quiver (holds 50)	75	55
Bomb Bag (holds 20)	76	56
Bomb Bag (holds 30)	77	57
Bomb Bag (holds 40)	78	58
ボス部屋のカギ (99 rupees)	79	59
ボス部屋のカギ (200 rupees)	7A	5A
ボス部屋のカギ (500 rupees)	7B	5B
ボス部屋のカギ (fishing rod)	7C	5C
Odolwa's Remains	7D	5D
Goht's Remains	7E	5C
Gyorg's Remains	7F	5F
Twinmold's Remains	80	60
Sonata of Awakening	81	61
Goron Lullaby	82	62
New Wave Bossa Nova	83	63
Elegy of Emptiness	84	64
Oath to Order	85	65
闇のノクターン	86	66
Song of Time	87	67
Song of Healing	88	68
Epona's Song	89	69
Song of Soaring	8A	6A
Song of Storms	8B	6B
太陽の歌	8C	6C
Bombers' Notebook	8D	6D
黄金のスタルチュラ	8E	6E
Piece of Heart	8F	6F
ハートのかけら	90	70
太陽の歌	91	71
時の歌	92	72
Lullaby Intro	93	73
Big Key	94	74
Compass	95	75
Dungeon Map	96	76
Stray Fairies	97	77
ボス部屋のカギ	98	78
ボス部屋のカギ	99	79
ボス部屋のカギ	9A	7A

Relevant Bits

file[0x0070:0x009F] # 70h:87h items; 88h:9Fh masks

Derived Cheat Codes

GameShark	ROM Version
	JAP (1.0)
	JAP (1.1)
	JAP (GC)
	USA (preview)
	USA
	USA (GC)
	EUR (1.0)
	EUR (1.1)
	EUR (GC)
	EUR (debug)