Fire in Pocket Edition is certainly an odd case, given its history: initially invisible and the perpetrator of a game-breaking bug, it was removed until v0.7.0 alpha, at which point its texture generation was bugged (#20) to either appear solid black or white in most regions. It was later changed again in v0.7.1 alpha to fix this, with those changes being currently unknown.
As the being on fire animation also used the placeholder texture up to v0.7.0 alpha, it seems reasonable to expect this to be another lava case - the animation code may have been there, and if it was, was simply not being executed. Overall, fire in early Pocket Edition is pretty mysterious, and much more research is needed into this matter.
Again, as with water and lava, the C++-based Pocket Edition used MT19937 for random numbers, meaning that an identical starting seed will still generate different results from the same seed for the LCG-using Java Edition. It seems that other differences are mentioned in the fire generation code, which may need looked at.
I also do not know if "Fire 1" existed in the edition at all at this time.
Split from #2.
Fire in Pocket Edition is certainly an odd case, given its history: initially invisible and the perpetrator of a game-breaking bug, it was removed until v0.7.0 alpha, at which point its texture generation was bugged (#20) to either appear solid black or white in most regions. It was later changed again in v0.7.1 alpha to fix this, with those changes being currently unknown.
As the being on fire animation also used the placeholder texture up to v0.7.0 alpha, it seems reasonable to expect this to be another lava case - the animation code may have been there, and if it was, was simply not being executed. Overall, fire in early Pocket Edition is pretty mysterious, and much more research is needed into this matter.
Again, as with water and lava, the C++-based Pocket Edition used MT19937 for random numbers, meaning that an identical starting seed will still generate different results from the same seed for the LCG-using Java Edition. It seems that other differences are mentioned in the fire generation code, which may need looked at.
I also do not know if "Fire 1" existed in the edition at all at this time.