Final Fantasy IV Information
Yes64 Item Warps Guide

Jason Lynch <jason@calindora.com> (Aexoden)

This guide is a work in progress. It probably doesn't flow very well. The information is probably mostly correct, however.

Introduction

A key feature of the current 64-floor glitch routes is the use of item warps. The exact technical description of these warps and why they come about is probably beyond the scope of this document, but the short version is something like the following: Certain tiles are trigger tiles, and the game searches a particular area of memory for the trigger tile data. If a given trigger tile doesn't have any data, it starts searching memory almost endlessly. These searches can happen to pass through areas of memory we can modify, like our inventory. As far as I can tell, every trigger tile on a normal map in the game either has an associated trigger or is inaccessible. However, on certain glitch maps, there are trigger tiles that are completely manipulable.

Warp Description Anatomy

When searching for data regarding a trigger tile, the game is searching for five bytes of the following pattern:

Trigger X
The X-coordinate of the trigger tile
Trigger Y
The Y-coordinate of the triggler tile
Target Map
The ID number of the target map
Target X
The target X-coordinate
Target Y
The target Y-coordinate

Thus, the game searches five bytes at a time until it finds an entry matching the X and Y coordinates of the trigger tile you are stepping on. Now, warp descriptions are five bytes but inventory entries are two bytes (one byte for the item and one for the count), so each warp description actually only takes 2.5 inventory slots. This isn't particularly useful for us, however, as the trigger tiles we use in the mage room have an X-coordinate of 13, and the item with that ID number is the Stardust Rod. Therefore, the easiest way to make use of item warps is to actually use a six byte sequence where the first byte can be anything we want (as it's ignored). We can then insert a new item warp every 10 bytes (or every five inventory entries).

Keeping this in mind, we'll review exactly how we will structure our item warps:

ByteTypeWarp Component
0Item<padding> (therefore anything)
1CountTrigger X
2ItemTrigger Y
3CountTarget Map
4ItemTarget X
5CountTarget Y

To summarize, we are going to set our Trigger Y-coordinate and Target X-coordinate with items, and our Trigger X-coordinate, target map, and target Y-coordinate with item counts.

Claws

A common element to all of these warps is the use of either a FireClaw or IceClaw. Looking at the table above, you can see that this item corresponds to the trigger Y-coordinate. The FireClaw is 1 and the IceClaw is 2, so by choosing a particular claw here, you are doing nothing more than setting which trigger tile will activate this warp.

Warps

The following warps are presented in the order we use them, not necessarily the order they are in the inventory. The first active warp in your inventory is the one that will be used. The warps themselves are based on how they are used in the 12-item route, but much of the information is the same or similar for the 9-item route.

The target map for each warp is basically non-negotiable. We need to access each of these rooms (through item warps or otherwise, such as RGB). However, the target coordinates are often very flexible so if you screw something up, you may have some easy (and some difficult) alternatives available to you.

Mage Room

Items

Bytes

(16) 13 2 57 15 1

Description

This sets up a warp for the trigger at coordinates 13, 2 to travel to map 57 (the mage room) at coordinates 15, 1. The purpose of this warp is to help in setting the mage room as floor 0.

Alternatives for Last Item

There are a large number of acceptable coordinates to land in this room, so there are actually numerous alternates, but ones you are most likely to have are Cure (staff) x1 or Shadow x1.

Sealed Cave

Items

Bytes

(16) 13 1 68 3 8

Description

This sets up a warp for the trigger at coordinates 13, 1 to travel to map 68 (the Sealed Cave entrance) at coordinates 3, 8.

Alternatives for Last Item

I'll have to fill this section in later, because I don't know the safe coordinates, but a quick look suggests some number of Rods is a possibility.

FuSoYa

Items

Bytes

(16) 13 2 96 16 20

Description

This sets up a warp for the trigger at coordinates 13, 2 to travel to map 96 (the Lunarian Palace) at coordinates 16, 20.

Alternatives for Last Item

The range of possible values for the Cure (staff) or any other item is actually quite large. 20 is optimal, of course. Other potential items are other staves or rods, but again, I'll have to verify to be sure.

Zeromus

Items

Bytes

(16) 13 1 114 16 13

Description

This sets up a warp for the trigger at coordinates 13, 1 to travel to map 114 (Zeromus) at coordinates 16, 13.

Alternatives for Last Item

Same basic idea as previous warps. We'll fill in all the acceptable answers later.