Two Control Data Cyber 170 mainframe computers, side by side — one online, and one as a spare. (Photograph via Library of Congress)
The year on the photo is listed as 1999, which seems too recent given the feel of the picture. In the high-resolution TIFF, however, the date can be seen on the bulletin board, “21 Oct 99”. The Cyber 170 was produced in the late 1970s, so this unit is at least 20 years old.
The photograph is part of this collection at LOC: Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA