2 cards with
512K on them and were labled Disk something.
Well, then, these are your disk controller(s). The "something" that
comes after Disk is very important in identifying them!
The "512K" sounds like a Compupro board etch identifier, but I just
looked over my Compupro Disk 1's, 1A's, Disk 2's, and Disk 3's, and
none of them say 512K. Maybe it's a Disk 1B? Disk 4?
Nope... I suspected RAM disc cards because 512K is the AMOUNT of RAM I
counted (a board covered w/ 4116s). And there were no connectors to the
boards other than the card edge.
There are two of these mystery boards.