The IBM 1401 mainframe runs "Edith"

I think using characters to make pictures started with teletype machines - maybe even on typewriters! It was common with ham operators in the 60s (RTTY & Teletype machines) and it surely must have been popular before that. On the IBM 1401 (1959) "Edith" is legendary: ▶ this video

Before this, there was line printer art; see "The IBM 1401 mainframe runs 'Edith'": ▶ this video

Here's a fun IBM line printing video I've discovered thanks to your mention of those: The IBM 1401 mainframe runs "Edith" ▶ this video

While much more on the technical side of things, both Ken Shirriff and Curious Marc are great resources for a lot of the historical and technical aspects of things. I'd highly recommend both of them for looking at specific topics of how the computing hardware worked: - Marc's videos on old HP computers, link - Marc's videos on restoring some old IBM hardware, that includes a good bit of the history that went into them, link and ▶ this video - In fact just look at his playlists directly, link For Ken, I'd look at his chip teardowns and explorations, the AM2901 is on HN this very moment, link A lot of his articles dig into why the different chip technologies were made and fell out of favor eventually too. link