.if \nv .rm CM
.af % i
.TL
PREFACE
.LP
These manuals describe the Version 7
.UX
system for the \s-1PDP\s0-11\(dd,
.FS
\(dd \s-1PDP\s0, \s-1VAX\s0 and \s-1DEC\s0
are trademarks of Digital Equipment Corporation.
.FE
with additions and changes made at the University of California,
Berkeley, over the last several years.
Many of the enhancements originated elsewhere and were integrated
here.
In particular, much is owed to the Fourth Berkeley Software Distribution
(the Berkeley VAX release) and to Bill Joy and the many others who
have contributed to it.
Job control was first added by Jim Kulp of IIASA.
This release includes contributions by
Carl Smith, Bill Jolitz, Michael Toy, George Mattinger,
Thomas Ferrin, Lou Salkind,
the \s-1DEC\s0 \s-1UNIX\s0 Engineering Group,
and many others at Berkeley and elsewhere.
.sp
.in 4i
Michael Karels
.in 0
.sp 2
.ce
\fIPreface to the Seventh Edition\fP
.sp
.LP
Although this Seventh Edition no longer bears their byline,
Ken Thompson and Dennis Ritchie remain the fathers
and preceptors of the
.UX
time-sharing system.
Many of the improvements here described bear their mark.
Among many, many other people who have contributed to
the further flowering of
\s-2UNIX\s0,
we wish especially to
acknowledge the contributions of
A. V. Aho,
S. R. Bourne,
L. L. Cherry,
G. L. Chesson,
S. I. Feldman,
C. B. Haley,
R. C. Haight,
S. C. Johnson,
M. E. Lesk,
T. L. Lyon,
L. E. McMahon,
R. Morris,
R. Muha,
D. A. Nowitz,
L. Wehr,
and
P. J. Weinberger.
We appreciate also 
the effective advice and criticism of
T. A. Dolotta,
A. G. Fraser,
J. F. Maranzano,
and
J. R. Mashey;
and we remember the important work of
the late Joseph F. Ossanna.
.sp 2
.in 4i
B. W. Kernighan
.br
M. D. McIlroy
.in 0