Information: you get icy water to walk on - works only in 16x16 screens
Rom: ALTTP (US), without header
Screenshot:



Zip File: http://bszelda.zeldalegends.net/stuff/Con/icelink.zip
Mirror: https://mega.nz/file/ugNGnIZI#rBgbCNHDwiG0JDzMcrqSD9PDzqJJrgyBXuBrGWYuEZc

Code Addresses: 0x77ba0 - 0x77d8f (after pot with sword destroy above)
Uses free ram 7F/5010 (0xF)

Update: was possible to freeze water with sword when full energy. Fixed this.

Inside above zip file you'll find 3 versions:

1) Icerod freezing water final:



This is the normal code for freezing deep water!
The effect was implemented in the overworlds only (simply to many unfixable bugs if indoors), and even here you might have a lot of trouble to avoid game paradoxes (this is also described in one of the included files).
All files are packed in the zip file (hex, asm, smc etc). The fastest way to insert the effect is using the Ips patch.

2) Variants of Icerod ASM:



List:
1 Ground rod
2 Ground rod (lava variant)
3 Shallow water rod
4 Water rock
5 Lava rock
6 Lava ground
No image: Freeze bushes, Broken bridge

We are dealing with the same code, but the icerod affects different things: from making ground and shallow water, to freeze new objects, such as water rocks, lava rocks and freezing lava ground.

Most recomended (because of zero possibility of bugs and zero possibility for game paradoxes):

Water rock, Freeze bushes, Lava rock, Lava ground.

With these 4 variants almost no bugs or paradoxes are possible, since you affect certain objects only.

If you however freeze all water, you can come to some paradoxes (original icerod effect, ground rod, shallow water rod, broken bridge).

3) Dungeon Incomplete:



This is a try to get ice in dungeons, but I gave up on it due to several bugs:
- Link swims through ice
- Link jumps from ice into walls
- Makes Water Dungeon riddle to pull lever in light world obsolete since you must place a water layer on bg1 next to the transludent bg2 water layer!