The Pertec 9 track PE formatter manual that is on loan from Joe is now scanned and on line at www.spies.com/aek/pdf/pertec/101399_F6X9_PEfmtr_Dec71.pdf It isn't going to be directly of use for 7 or 9 track NRZI though, since it appears to be PE only. It does describe the original PERTEC dual 100 pin interface cables, though. I've gotten about 2/3 of the way through scanning the material that arrived from him earlier this week. Things should start trickling onto the web site over the next few weeks.