Probably JSR $FFD2 followed by PLA

$FFD2 is a publicly listed API of the C64 KERNAL that prints a character.
It corrupts the contents of the A register. Thus is it totally expected to restore the A register
from the stack after calling $FFD2.  That this happens several times in the C64 KERNAL itself
is evidence of this being boilerplate and not copyrightable on that basis, as well as it simply
being too short and lacking any creativity etc.