Greetings, I'm trying to find the predecessor to "Writing a UNIX Device Driver, J. Egan & T. Teixeira, 1st ed, 1988". In the preface, it says: "This book is based on a MASSCOMP manual, Guide to Writing a Unix Device Driver. The first version that MASSCOMP published as part of the documentation set for the MC-500 was based on preliminary drafts prepared for MASSCOMP by Cliff Cary and Tom Albough of Creare R&D." I checked bit keepers and found nothing. I was wondering if people on this list know of this manual, have a copy, etc. In general, I'm looking for pre-SysV driver manuals. I can find all kinds of SysV driver books (some of which cover 4.2BSD or 4.3BSD as well), but nothing for System III or V7 unix. There were a lot of early systems that were based on ports of V7 to different architectures that were then updated to System III or System V (at least according to the big chart of unix history and some wikipedia entries, which may be just repeating marketing schlock and not reflect actual reality). As part of a talk I'm putting together on the 40th anniversary of V7, I wanted to have a bit of history for things we still have in unix today (like strategy) and things that successors to unix have added or left behind (like the packet mux in V7 that was tossed aside for either STREAMS or netinet from BSD, though packet muxing to userland is back with DPDK). Warner