I don't know what TRS-80 you used, but I do know that the Microsoft BASIC in the Color Computer had a re-number command (RENUM newline, startline, increment). It was actually a very sophisticated version of BASIC:
As a kid (and I still own them) I had a Color Computer 2 and 3 - I programmed a ton of things on them, which ultimately led me to where I am today as a software engineer.
http://www.colorcomputerarchive.com/coco/Documents/Manuals/H...
As a kid (and I still own them) I had a Color Computer 2 and 3 - I programmed a ton of things on them, which ultimately led me to where I am today as a software engineer.