In the 1960s, Eduardo Joselevich and Fanny Fingerman developed a technique to represent images with only four symbols. Full blocks or circles, in either black or white. They called it Fototrama and it was used at Olivetti and Philips for example.
Text graphics by Manfred Schroeder at Bell Labs in 1968. For the cover of the exhibition catalogue for Some More Beginnings organised by Experiments in Art and Technology (E.A.T.) at the Brooklyn Museum. h/t: Tim Koch
Mona By The Numbers
Probably the earliest example of computer-generated text art, put together in 1964 by H. Philip Peterson:
In 1964, H. Philip Peterson of Control Data Corporation (CDC) used a CDC 3200 computer and a “flying-spot” scanner to create a digital representation of the Mona Lisa. The image contained 100,000 pixels that were plotted using numerals, sometimes overprinted, to approximate the required density and took 14 hours to complete.
Similar digital images of popular art, cartoon characters, and even nudes adorned the walls of corporate offices, labs, and computer centers throughout the 1960s.