On 5/29/2013 1:20 PM, dwight elvey wrote: http://www.flickr.com/photos/8024729 at N07/sets/72157633559116849/ The one card is almost certainly core memory. I've never pulled any cards out of the Varian I've had access to, but I do have one of the core memory boards I picked up very long ago, in the late 70's which had its edge clipped. That was a normal thing to do for RMA'ed material as well as the possible gold scrap value, though then it was more to destroy the card from being reused. I only have the core stack and always wondered why it was the way it was, and seeing the photo in this set of pictures explains it. The drivers and what not were on another board shoved in the slot ahead of the core stack board. The other systems I had always had the drivers and other logic all on the base board, but this one did not. In the late 60's and early 70's there were a lot of companies trying to make the memory business a good business model, but it obviously didn't last, nor did it ever develop into any generic business as many tried and failed at. thanks jim