I seem to recall reading somewhere that the system was originally designed to be a mobile platform against Soviet missiles in somewhere like west Berlin. Where

I seem to recall reading somewhere that the system was originally designed to be a mobile platform against Soviet missiles in somewhere like west Berlin. Where they needed something that would be moved around every day or two so that the enemy would not know its location. That meant that the system would be reset whenever it was moved, and therefore using a floating point clock was a reasonable design trade off.