-Generally speaking, a window size would be unset only if there were
-some problem obtaining the value from the operating system
-(and \fBsetupterm\fP would still fail).
-For that reason, the \fBLINES\fP and \fBCOLUMNS\fP environment variables
-may be useful for working around window-size problems.
-Those have the drawback that if the window is resized,
-those variables must be recomputed and reassigned.
-To do this more easily, use the \fBresize\fP(1) program.
-.SH ENVIRONMENT
-The \fB@TSET@\fP command uses these environment variables:
-.TP 5
-SHELL
-tells \fB@TSET@\fP whether to initialize \fBTERM\fP using \fBsh\fP(1) or
-\fBcsh\fP(1) syntax.
-.TP 5
-TERM
-Denotes your terminal type.
-Each terminal type is distinct, though many are similar.
-.TP 5
-TERMCAP
-may denote the location of a termcap database.
-If it is not an absolute pathname, e.g., begins with a \*(``/\*('',
-\fB@TSET@\fP removes the variable from the environment before looking
-for the terminal description.
-.SH FILES
-.TP 5
-/etc/ttys
-system port name to terminal type mapping database (BSD versions only).
-.TP
-@TERMINFO@
-terminal capability database
+Generally,
+the window size will remain uninitialized only if there were a problem
+obtaining the value from the operating system
+(and \fB\%setupterm\fP would still fail).
+The \fILINES\fP and \fI\%COLUMNS\fP environment variables
+may thus be useful for working around window-size problems,
+but have the drawback that if the window is resized,
+their values must be recomputed and reassigned.
+The \fI\%resize\fP(1) program distributed with
+\fI\%xterm\fP(1) assists this activity.
+.SH HISTORY
+A \fB\%reset\fP command written by Kurt Shoens appeared in 1BSD
+(March 1978).
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=1BSD/s6/reset.c
+It set the \fIerase\fP and \fIkill\fP characters
+to \fB\*^H\fP (backspace) and \fB@\fP respectively.
+Mark Horton improved this \fB\%reset\fP in 3BSD
+(October 1979),
+adding \fIintr\fP,
+\fIquit\fP,
+\fIstart\fP/\fIstop\fP,
+and \fIeof\fP
+characters as well as changing the program to avoid modifying any user
+settings.
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=3BSD/usr/src/cmd/\
+.\" reset.c
+That version of \fB\%reset\fP did not use \fI\%termcap\fP.
+.PP
+Eric Allman wrote a distinct \fBtset\fP command for 1BSD,
+using a forerunner of \fI\%termcap\fP called \fI\%ttycap\fP.
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=1BSD/s6/tset.c
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=1BSD/man7/ttycap.7
+Allman's comments in the source code indicate
+that he began work in October 1977,
+continuing development over the next few years.
+By late 1979,
+it had migrated to \fI\%termcap\fP and handled the \fI\%TERMCAP\fP
+variable.
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=3BSD/usr/src/cmd/\
+.\" tset/tset.c
+Later comments indicate that \fBtset\fP was modified in September 1980
+to use logic copied from the 3BSD \*(``reset\*('' program when it was
+invoked as \fB\%reset\fP.
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=2.9BSD/usr/src/ucb/\
+.\" tset/tset.c
+This version appeared in 4.1cBSD, \" and backported to 2.9BSD
+late in 1982.
+Other developers such as Keith Bostic and Jim Bloom continued to modify
+\fBtset\fP until 4.4BSD was released in 1993.
+.PP
+The \fI\%ncurses\fP implementation was lightly adapted from the 4.4BSD
+sources to use the \fI\%terminfo\fP API by Eric S.\& Raymond
+<esr@snark.thyrsus.com>.