As part of my dissertation I’m working with the Southern California Edison Photographs and Negatives collection at the Huntington Library. The photographic collection is now available online at the Huntington Digital Library. A few years ago when I first came across this collection, it was only available in-person on a single computer.
The two photos below are from “People working in computer room with 1″ tape drives”. These before and after photos taken in 1966 at SCE appear to show how people would fit alongside and interact with the mainframe computer.
Photographs such as these often show many people in the room, mostly trying to look busy, with a few of them staring at equipment or pretending to use the machine. These staged photographs for internal use are similar to those used for marketing. In both cases the images are designed to show how people and computers would work together.
The mainframe in these photographs is a Control Data Corporation mainframe, and it appears to be a CDC 3200 system.
The Computer History Museum in Silicon Valley has a brochure for the CDC 3200 mainframe (PDF) available online as well.