dterm application is a simple terminal emulator, which doesn't actually emulate any particular terminal. Mainly, it is designed for use with xterm and friends, which already do a perfectly good emulation, and therefore don't need any special help; dterm simply provides a means by which keystrokes are forwarded to the serial line, and data forwarded from the serial line appears on the terminal.

dterm is invoked thusly:
dterm [options|device ...]

dterm attempts to read the file ~/.dtermrc for options; if this doesn't exist, it tries /etc/dtermrc. Then it parses the options passed on the command line.

The options read should include a device name, e.g "ttyS0" or "ttyd0" for the first serial port on a Linux or FreeBSD system respectively.

Once started, dterm can be got into command mode using Ctrl/]. Press enter once from command mode to get back into conversational mode. (The command character can be changed with the esc= option, e.g. esc=p to use Ctrl/P instead of Ctrl/].)

The following options can be used from command mode

300, 1200, 9600 etc: Set speed, default 9600.
5, 6, 7, 8: Set bits per character, default 8.
1, 2: Set number of stop bits, default 1.
e, o, n, m, s: Set parity to even, odd, none, mark or space, default none.
cts, nocts: Enable / disable CTS flow control, default nocts.
xon, noxon: Enable / disable XON/XOFF flow control, default noxon.
modem: Enable / disable modem control (hang up modem on exit, exit if modem hangs up), default nomodem.
bs, nobs: Enable / disable mapping of Delete to Backspace, default nobs.
del, nodel: Enable / disable mapping of Backspace to Delete, default nodel.
maplf, nomaplf: Enable / disable mapping of LF to CR, default nomaplf.
igncr, noigncr: Ignore / output carriage returns, default noigncr.
crlf, nocrlf: Enable / disable sending LF after each CR, default nocrlf.
b: Send a 500 ms break.
dtr, nodtr: Raise / lower DTR, default dtr.
rts, norts: Raise / lower RTS, default rts.
d, r: Toggle DTR / RTS.
esc=: Set command mode character to Ctrl/ (default ']')
@: Read and process configuration from .
!: Execute shell command
show: Display current configuration and modem status.
help, h, ?: Display a summary of commands.
version: Display version, copyright and warranty information.
quit, q: Exit

Connect via ttyS1 to a system running at 2400 bps, 7 bits even parity:

dterm ttyS1 2400 7 e

Send a break in a running session:

^]
dterm> b
dterm>