This is the library in Z80 form based on the work of Herb Johnson;
http://retrotechnology.com/herbs_stuff/float.html
I have added a basic menu to show how to use the library, using the emulated 6850 terminal provided by ASM80.(asm80.com)
Paste this URL into ASM80's "Import Repo from Github" option, "compile" the file Build.z80 and then "emulate".