DYSEAC was running in 1954. It was mounted in an Army truck. Not quite a Osborne, but it was the first time a modern, digital computer was specifically designed for mobility.

One has to take everything about missile tech history as if it has a huge red flag on it. The guidance computer from the article is a real oddball, in that it is one of the missile subsystems that somehow managed to get out into the public. Most never did, nor any documentation, and what little is still around is perilously close to being lost. Was there a missile guidance computer before the Minuteman 1 machines? Maybe. Maybe not. Don't take anything as gospel. The same is generally true for submarine tech, and of course crypto tech. -- Will