Fixed

misc-fixed is a collection of monospace bitmap fonts that is distributed with the X Window System. It is a set of independent bitmap fonts which—apart from all being sans-serif fonts—cannot be described as belonging to a single font family. The misc-fixed fonts were the first fonts available for the X Window System. Their individual origin is not attributed, but it is likely that many of them were created in the early or mid 1980s as part of MIT's Project Athena, or at its industrial partner, DEC. The misc-fixed fonts are in the public domain. The individual fonts in the collection have a short name that matches their respective pixel dimensions, plus a letter that indicates a bold or oblique variant.

From the Wikipedia article “Fixed (typeface)”, licensed under CC BY-SA 4.0.

Monospaced faces suit code listings, typewriter effects and technical material; their even spacing is less comfortable for continuous reading.

Commercial typefaces require a licence that covers embedding in PDFs and ebooks; check the foundry's licence before you publish.