I first saw ASCII art in an issue of Creative Computing, Vol. 2, 1976. It was an image of Starship Enterprise:
Can it get much nerdier? :P
Also read about people doing ASCII art on a PDP-8, in 1969 I believe. Can't find where I read it right now.
These are printouts we're talking about here, since many computers back then had no CRT. Would be cool to know who did the first screen ASCII Art 8)
I'm sure someone did the usual Snoopy characters before 1969 even. And before that, X's and spaces on typewriters, lol. But that's getting silly. Had a discussion of what 'Oldskool' is in #scene.se yesterday. I went all the way, back to programmable looms in the 1700s or so