These machines were a single floor with the operator sitting at one end.
The operator nodded and sat forward to begin entering a code.
Each had a single seat on which the operator sat, straddling the thing to make it go.
In other words, it is most concentrated to the rear of the computer rather than to the front, where the operator sits.
He found all but two operators sitting behind the large circular radar screens.
It fit into the desk where its operator sat.
The operator sat in front, while two friendly passengers could squeeze into small seats behind him.
"The operator sits here, where he can tell when is the most favorable moment for releasing the bomb."
The operator sat inside and worked the Fat Man's limbs through an electronic control board.
At the large grid, an operator sat at a console.