I'm finally back to my scan pile and have a few to share: https://archive.org/details/unix-system-document-processing-guide First is the UNIX System Document Processing Guide. This is the version of the TROFF et. al. documentation distributed for Release 5.0 as well as the initial release of System V. This contains the expected papers on NROFF/TROFF, MM, Eqn, Tbl, and other bits and pieces like viewgraph macros. These documents appear to be revisions of the various technical memoranda distributed as UNIX papers over time. I think this just leaves the Support Tools Guide as far as unscanned initial System V documents. I have this so just need to get it on my scanner and then the initial System V documentation run should be completely preserved out there on the net. https://archive.org/details/we-november-december-1981 Second is a copy of WE Magazine from November-December 1981. Distributed to Western Electric employees, this issue of the magazine has a cover story on the installation of the very first central office 5ESS in Seneca, Illinois on July 1st, 1981. The piece goes into some local reactions to installation day, some technical details of 5ESS, and has some nice pictures of the unit being unloaded and moved into place. There are additional articles concerning Nassau Metals, ISSMs, and some goings on around the company. https://archive.org/details/attached-processor-interface-3b-1a Finally is the "Attached Processor Interface", a small Western Electric pamphlet detailing an interface for incorporating 3B processors into existing 1A offices such as 4ESS and 1AESS. As with other applications of the 3B to telephony, DMERT features as the operating system, although the pamphlet is mostly concerned with the installation and diagnostic aspects of working with the interface. By the way, the original text is all green, but I scanned all but the covers in B/W. The last one is interesting in that it's an integration of the 3B into a telephone central office that isn't a 5ESS, rather, you wind up with something more like a 4.5ESS, a 4ESS with a 3B up in it somewhere. However, given the date of November 1981, this postdates the installation of that first 5ESS, making it less likely that this was some embryonic step before the 5ESS and more likely a retrofit designed to get more 3Bs into service in older offices. That this was 1A general was interesting too, that is why a 1AESS could absorb it, meaning there very well could've been frankenstein central offices out there with a 1ESS that got retrofitted with a 1A and then got retrofitted further with an API and a 3B, making one of the monstrosities this pamphlet suggests installing. It's too bad there's a snowball's chance in hell of one of these "API" units popping up out there, much less still mated to its 1A and 3B...but a guy can dream. Anywho, going to start a slow trickle of scans again now that I've got my office all settled. I'm foraying further and further into telephones so my document hunting these days lands closer to ESS and 1A2 KTS than UNIX, but I'm still keeping an eye out for whatever I can manage to preserve. That all said, that also means my "accepted for scan" circle has gotten larger, as I'm now seeking other 70s-early 80s Bell System stuff generally, not strictly UNIX things, so if you've got some obscure Dimension PBX manual collecting dust I'll happily scan it for ya! - Matt G.