Here's a puzzler.
One of the two memory boards from my PDP-11/35 is short four ICs. See:
It looks like it was an 8KW board that was user-expanded to 16KW, and if
I'm reading the switches correctly it was configured for starting
address 000000. (The other 16KW board I have is configured to start at
Those four missing ICs seem weird, though. The other board is is fully
populated. Were they just pulled before the PDP was trashed? Or is that
a valid configuration?