PDP-8 signed overflow detection - Apollo guidace computer

[Noel Chiappa]

    > From: Ben Bfranchuk

    > Now they seem to have have found a SCRAPPED Apollo guidance
    > computer and am rebuilding the missing pieces.

Wow. What a great site (and that guy has mad skills, everything from
repairing old Teletypes, through designing boards, to repairing analog
stuff). Just 'wasted' a good chunk of the morning reading back through
it; tons of really neat things (including recovery of the very first
FORTH, along with a lot of Diablo drive - from the Alto - repairs).

As a shortcut, here:

  http://rescue1130.blogspot.com/2018/11/

is the backstory on the AGC; about 1/3 of the way down, in "Restoring an
Apollo Guidance Computer, part V".

	Noel