A comment on the question Why did 8-bit Basic use 40-bit floating point? says the following (emphasis added):
Re, "Nowadays, floating point is usually either 32 or 64 bits." More specifically, floating point is usually IEEE 754 floating point. Pior to the publication of that standard in 1985, it was the Wild West: Pretty much every system had its own internal representation for floating point numbers. I saw a book once that was basically a step-by-step instruction manual for how to construct your own floating point system. It was on the desk of my co-worker who was implementing the floating point arithmetic for a Lisp interpreter.
Some keyword searching turned up only Jean-Michel Muller's Handbook of Floating-Point Arithmetic, which was published in 2009; presumably the comment is discussing something older.
What is this book? It sounds quite interesting.