@jef It's amazing to me that DEC went with such a user-hostile data entry system, when the PDP-11 came out years and years after the FADAC.

The FADAC uses a data-entry system that looks fairly modern and easy, and an output system that could be mistaken for a modern monitor.

https://youtu.be/d_I_4CqZxoI?t=26

Compare that to the PDP-11:

https://youtu.be/0n3UFtiyxwA?t=282

Don't get me wrong, the industrial designer did a fantastic job. But, really, entering octal data by flipping a series of binary switches?