The Atlantic has a story about The Never-Before-Told Story of the World’s First Computer Art (It’s a Sexy Dame). The image (see above) was apparently created by an IBM programmer for the SAGE system and was used as a diagnostic.
According to Tipton, the program that displayed the pin-up image was a diagnostic that tested data flow between the two SAGE computers on site (referred to as the A and B computers). At the end of every shift, as one computer was about to go offline and switch over to the other, the active machine would begin transferring flight and intercept data to the standby machine so there could be a seamless switch over.
Two switching consoles on site were used to handle this process. After running the diagnostic, Tipton describes, if the pin-up displayed correctly on the screen, then data was being transferred between the A and B computers correctly. If the image displayed improperly, then the technicians immediately knew there was a problem.
This reminds me of the story of Lena and the use of her image. Why were so many early images drawn from porn? Does this say something about the male culture of computing in those years that it was cool/acceptable to use pin up pictures when you needed a graphic image?
Thanks to @manovich for this.