Yes, they are 16Kx12. Which means they can fill in 4 of the 8 possible 4K memory fields in the PDP-8/E memory address. There is a 16 pin DIP plastic box in the middle of the top board, near the bottom. It looks like an oversized IC chip. If you tape the 'cover' off of this, you will see the jumper wires. Basically, the 8 connections on the left correspond to the 8 possible 4K memory field addresses, and 4 wires are connected to the middle 4 connections on the right side, which correspond to the actual memory on the DR-118. If you're careful, you can take the top off without pulling the box out of the socket. if you do pull it out, be careful not to bend the pins. If you ever want to trade them for something, just let me know. -Lawrence LeMay lemay(a)cs.umn.edu