Just sharing this document list I spotted on an eBay listing as I was perusing things: https://i.ebayimg.com/images/g/HIcAAOSwnoZjoSNA/s-l1600.jpg The manual in the auction[1] is interesting in that it features the Bell Logo scratched off, presumably as this was sold/shipped right around that magic flip of the switch. I keep seeing variation upon variation of these covers, some 5.0 with the bell, some 5.0 without, some System V with, some System V without. The oddest I've seen recently is actually another active eBay auction[2] as of this typing in which the typical grid-pattern cover is seen but the title is given as "UNIX operating system" rather than just "UNIX system". Anywho, going to describe the document here so the text is in the archive somewhere. After the above link is a document titled "Section 3 - Available Documentation" with a handwritten note indicating this is a section of DC-001 which is in turn listed as the "3B20S Documentation Catalog". The contents of the document are (all listed documents are Issue/Version 1): Table A - 3B20S Processor System Predelivery Documents 3B20S Technical Data Sheets - TDS-01 3B20S Site Preparation Manual - SPM-01 3B20S Documentation Catalog - DC-001 Table B - 3B20S Processor Applications Documents OAS User's Guide - 302-920 OAS Administrator's Guide - 302-921 OAS Electronic Messaging Reference Card - 302-922 OAS Editor-Formatter Reference Card - 302-923 OAS Document Editing and Formatting Workbook - 302-924 Table C - 3B20S Processor System Basic Documentation 3B20S System Index - 301-901 3B20S System Description - 301-911 UNIX System User's Guide - 301-921 UNIX Operating System Error Message Manual - 301-922 UNIX System User's Manual - 301-925 UNIX System Administrator's Manual - 301-926 UNIX System Administrator's Guide - 301-931 UNIX System Operator's Guide - 301-941 3B20S System Maintenance Guide - 301-951 Looks like there is another page stapled behind that one. I've reached out to the seller to see if they're willing to share the rest info on the pieces of paper. Looks like the OAS card I happened upon recently has friends, and what I wouldn't give for some of that 3B20 stuff. I think that's going to be one of my next documentation goals, to track down some more 3B20 documents, there seems to actually be a surprising lack of 3B20 documentation that has been scanned. - Matt G. [1] - https://www.ebay.com/itm/125672373414?mkcid=16&mkevt=1&mkrid=711-12… [2] - https://www.ebay.com/itm/385464959716?mkcid=16&mkevt=1&mkrid=711-12…