Did the underscore character exist before modern computers? [closed]

Yes. The underscore appeared first on mechanical typewriters, and was used as a combining glyph to underline text. You would type your text, then move the carriage back the beginning of the word, and type a series of underscores. It was also used to create horizontal “fill in the blank” lines, such as:

   Name: ________________
Surname: ________________

You can read more on the Wikipedia article.