I worked with someone who wrote an alternative 'dprintf' (Direct printf()) in assembly - it had a cut-down list of format specifier support,
but also extended it in a few ways, to suit our work. This was for visualisation of a multimedia system. So you could specify a bar graph with a given
screen position and width etc., then feed it a value and it would use the block codes of the IBM character set in (mode 7, was it) to dynamically
show this. There were a lot of other bells and whistles as well. It was c-r-a-z-y fast, even on an 80286... John Goodman, I wonder where you are now...