Zelda1 damage properties

[ChaosPrime8]

I have been hex editing Zelda1 and I have been trouble finding the main address that can lengthen the duration of invincibility frames when taking damage from an enemy.  Whenever I edit a byte that was listed on the address, either Link loses the i-frames or downright ignores collision with the enemies. Also, when it comes to bounce velocity when receiving a hit, I presume that would require many addresses. Now my question is mainly for the i-frames, do I need to exit the entire asm or would it take only one byte. In ALttP, I was able to edit the i-frame duration with just one byte.