[red-beard]

Originally Posted by winders

Look at the caption for the main photograph:

Blackbird Diaries | Flight Today | Air & Space Magazine

Computers were in use by most designers by the late 1950's. Skunk works was no exception. Not like today. A lot was by hand, and for engineers that meant slide rules.

Here is a really big (equal to 41 feet long) slide rule.



Our High school had one of these bad boys chained to a wall in 1979 in the Science department. I expect it was more than 10 years old.



Close up of the display - not LED, each number was a separate filament in the tube.