My scan on highgate is the 8/A version. I didn't know a DEC 16k was available for the 8/E, was this third party?. What are the board numbers? I think I have the 8k prints but they weren't where I though they should so will look further this weekend. Digital numbered the MSB (high) 0 always so EMA 0 is the 0/16k field select bit. On the 4k core when the link is in it selects a 0 for that line. Chapter 9 in the 8/E handbook on highgate documents the omnibus signals and section 4 pg 3-60 of the mantenance manual vol I documents the memory. Section 5 pg 3-93/3-96 documents the front panel. Several front panel schematics are also there. David Gesswein http://www.pdp8.net/ -- Old computers with blinkenlights