When atop the building with sector 2's artillery button, proceed to the north stairs, and turn left (west) and enter the opening between the walls. Following the alley, then climbing the stairs, there is a large machine. A dead Enclave soldier, a Ripper, 2 Psycho, a couple of first aid boxes are all behind the machine, with the holotape on the Enclave soldier's body.
Despite the "#1" in the name of the log, no further entries are found.
Behind the scenes
The Enclave soldier in this holodisk was voiced by Gregory Gorton.
Sometimes the soldier and the holotape will simply not spawn. Loading a save from another cell, then reloading a save from this cell may fix this. [verified]