These files were pared from a 1995 snapshot of the source code for post-Tenth-Edition Research UNIX, as used in the Computing Science Research Center at Bell Labs. It is in no sense a formal distribution, and it is unlikely that it can be made into a working system without a fair amount of hand-waving, not to mention obsolete hardware; rather it is meant as a piece of the historic record. It has been trimmed in several ways: - It was habit at the time to put a copy of all source code that seemed interesting in /usr/src, even if it came from outside and required little or no surgery to make work, and in some cases even if it was never used or even consistently installed. None of these seem an important part of the history of this system; most cases, especially large ones, have been expunged. - Some programs were in some sense part of the system, but encumbered in one way or another so that it is (even more) unclear whether it is fair to redistribute them. They have been set aside as well. Some marginal cases that are key to the system (e.g. the pcc2 C compiler, modified by Research from code that came from the System III/System V developers) remain. There remain parts that ought to be thought of as encumbered, especially the documentation (which was published as a copyrighted book); and the overall system was never released save under single-target letter agreements. As of this writing (March 2003) it is not obvious that it is covered by extant Ancient Systems license agreements. The files are stored in three GNU-compressed tar archives: secombe.gz (the heavy one) Source code for UNIX proper, including commands, libraries, and OS kernel. Originally rooted at /usr/src. milligan.gz (the eclectic high-flying one) Source and perhaps some binaries for the AT&T 5620 (jerq) code. Originally rooted at /usr, i.e. directory jerq in the archive was /usr/jerq. sellers.gz (the well-dressed one) Documentation; originally rooted in /usr/src, but it would make as much sense in /usr. Subdirectory man is Volume 1 of the manual, with some additional tools used to produce the printed version; subdirectory vol2 is Volume 2.