[beerandt]

Y'all are overthinking it- true lat long "coordinates" would be meaningless to this computer. What was fed into the computer (ahead of time) was a series of firing instructions (per target for 3 targets), calculated to take into account the launch site of each missile. (Core memory values persist long term, even through power outages, hence the need to manually erase values before maintenance.)

So even two missiles/warheads launched from different sites at the same target would have different guidance instructions.

You'd need to do some major reverse engineering and geodetic calculations even after decoding targeting punchcards to figure out what the actual targets were.

The punchcards used to select the target during launch are simply instructions to execute "target stored in memory 2" or something similar. The minutemen would not have had the ability to change the set of targeting options programmed in the missile, only select one of the pre-programmed options.