.TH VT 1 
.SH NAME
vt \- emulate a VT-100 or VT-220 terminal
.SH SYNOPSIS
.B vt
[
.B -2abcrx
]
[
.B -f
.I font
] [
.B -l
.I log
]
.SH DESCRIPTION
.I Vt
replaces a
.I rio
window with a fresh instance of the shell,
.IR rc (1),
running within an emulation of a DEC VT-100 terminal.
.SS Options
.TF m
.TP
.B 2
.TP
.B a
.TP
.B x
change
.I vt
to emulate a VT-220, ANSI, or XTerm terminal respectively.
.TP
.B b
changes the color scheme to white text on a black background,
but potentially with colors from escape sequences.
.TP
.B c
changes the color scheme to monochrome (no colors).
.TP
.B f
sets the
.IR font .
.TP
.B l
names a
.I log
file for the session.
.TP
.B r
start in raw mode.
.SS Menus
The right button has a menu with the following entries to provide
the sort of character processing expected by non-Plan 9 systems:
.TF cooked
.TP
.B 24x80
Resize the
.I vt
window to hold 24 rows of 80 columns.
.TP
.B crnl
Print a newline (linefeed) character after receiving a carriage return from the host.
.TP
.B cr
Do not print a newline after carriage return.
.TP
.B nlcr
Print a carriage return after receiving a newline from the host.
.TP
.B nl
Do not print a carriage return after newline.
.TP
.B raw
Enter raw (no echo, no interpretation) character mode for input.
.TP
.B cooked
Leave raw mode.
.TP
.B blocksel
Toggle block selection for mode for rio snarf buffer.
.TP
.B exit
Exit
.IR vt .
.PD
.PP
The middle button has a menu with the following entries:
.TF right_key
.TP
.B backup
Move the display back one screenful.
.TP
.B forward
Move the display forward one screenful.
(These are a poor substitute for a scroll bar.)
.TP
.B reset
Display the last screenful; the same as going
.B forward
to the end.
.TP
.B paste
Pastes the contents of the
.B rio
snarf buffer, just as
.B paste
in the
.B rio
menu.
.TP
.B snarf
Copy selection to the
.B rio
snarf buffer.
.TP
.B plumb
Send selection to the plumber.
.TP
.B scroll
Make new lines visible as they appear at the bottom.
.TP
.B page
When the page fills, pause and wait for a character to be typed before proceeding.
The down arrow key advances a page without sending the character to the host.
.PD
.SH SOURCE
.B /sys/src/cmd/vt
.SH BUGS
This program is used only for communicating with foreign systems,
so it is not
as rich an emulation as its equivalent in other environments.
.PP
Use care in setting raw and newline modes when connecting to Unix systems via
.IR con (1).
It may also be necessary to set the emulator into raw mode.