You mentioned that the TRS-80(s) have hard disks. Perhaps the extra space taken by the
hard disk bios is the culprit. Maybe a floppy-only machine (with floppy only bios) is the
only way to compile it.
Will
Grownups never understand anything by themselves and it is tiresome for children to be
always and forever explaining things to them,
Antoine de Saint-Exupery in The Little Prince