Production of the missile has ceased but updates are always being added to
any of the weapons systems in any branch. I believe the computer has been
updated (although still a basic shell of the original) at least 20 times
since end of production. They still have sites other than Minot but many of
the sites have been closed and imploded after being stripped.
All Minuteman III missiles contain a classic computer
(the Guidance
computer) as production of this missile stopped in 1978.
--Chuck