I had written about how to expand the backplanes of an 11/40. Basically I am upgrading the system I have had for a while. I completed the work and I now have the system running with core memory rather than MOS memory. Just seems more authentic that way. I learned a ton about UNIBUS in the past two days if anyone wants to talk shop about them. I hope soon to boot RT11, still working on that, but closer now...closer... I got a lot of help, could not have done it without CCTECH DEC Heads. Very knowledgeable. b -- @ BillDeg: Web: vintagecomputer.net Twitter: @billdeg <https://twitter.com/billdeg> Youtube: @billdeg <https://www.youtube.com/user/billdeg> Unauthorized Bio <http://www.vintagecomputer.net/readme.cfm>