Maintenance ease took a leading part in the design of a digital fire-control computer for use in nuclear submarines, built by Librascope Div., General Precision, Inc., Glendale, Calif.
Critical equipment in nuclear subs must be designed so that shipboard repairs can be made without the aid of shore-based technicians. This consideration led to a cookbook method of maintenance, using only standard test equipment such as the vtvm, oscilloscope, or multitester.
A maintenance panel on one of the four computer cabinets permits a technician to trace a malfunction down to a particular register, and even to a flip-flop in that register, without opening the cabinet. Individual circuit cards are interconnected within a module by a printed circuit mother board which covers one side of the vertical pullout drawers. (Electronic Design, Sept. 28, 1960, p. 8)
One thing about the old computers—you could get right down to the flip-flop level in troubleshooting.