French astrophysicist Jean-Pierre Luminet created the first-ever simulation of a black hole, published in Astronomy and Astrophysics. Using an IBM 7040 computer and hand-plotting techniques with India ink, he calculated how light from an accretion disk would be distorted by gravity, producing a “distorted eye” image remarkably similar to modern direct imaging
I was skeptical, but the source checks out.
Luminet, J.-P. (1979). “Image of a spherical black hole with thin accretion disk”. Astronomy & Astrophysics. 75: 228–235. Bibcode:1979A&A…75…228L