My understanding and from what I can tell, the core code only ever uses an integer (long) for the values of coins in tx's; never deals with doubles/floats or scaled floats. This base unit eventually became known as a satoshi or sat.
But when and why did 100 million of these base units become known as a single unit for Bitcoin. I'm interested in both technical and banter of the origin story that became the infamous single unit of a Bitcoin.
A naive assumption I've arrived at is that it may have something to do with the max value of a 32 bit signed integer (2,147,483,647 = [231 – 1]). Probably just a coincidence, but this max value is 100 times (plus some) the 21 million bitcoin limit we always hear about.