added examples to many routines, small change to avoid similarity

c64/basic/math/e09a.interop

@@ -1,5 +1,5 @@
 This is an important floating point math routine, see:
-
 - https://www.atarimagazines.com/compute/issue72/random_numbers.php
 
-XXX - try to find real-life example
+Example code utilizing the routine:
+- https://stackoverflow.com/questions/44937759/getting-random-number-from-6502-assembler/44937995