Epson Multi-mode Data Controller MFJ-1278B - Manual (Page 214)

MFJ-1278B MULTI-MODE OPERATIONAL COMMANDS
DELETE ON/OFF Mode: Packet Default: OFF
Parameters:
ON
The delete character input editing character is <DELETE> ($7F).
OFF
The delete character input editing character is <BACKSPACE> ($08).
This command is used to change the input editing command for character deletion. When
this character is typed, the last character from the input line is deleted. How the TNC
indicates the deletion is controlled by the BKONDEL command.
You can not use this character to delete past the beginning of a line, although you can delete
<CR> characters that have been entered in the text with the pass character.
To see a corrected display of the current line after you have deleted characters, type the
redisplay-line character, which is set by the REDISPLA command.
DEFLTDLC
Mode: Host Default: 254
Parameters:
Effective only when non-0 MYDLCNUM, this parm tells the TNC what the DLC address is
of the host (ex, MTHOST). Default is 254.
DIDDLE ON/OFF
Mode: ASCII/RTTY Default: ON
During ASCII/RTTY transmit, the MFJ-1278B sends a non-printing synchronization
character, DIDDLE, whenever the transmitter is keyed but not sending anything else.
The DIDDLE characters for ASCII and RTTY are NUL and LTRS, respectively.
Diddling while the transmitter is keyed makes it much easier for persons receiving to tune
and remain tuned to your transmitted signal.
Some stations running mechanical teletype equipment may ask you not to "Diddle" while you
are talking to them since it may cause their older equipment to make a lot of noise, but do
nothing. It should be noted that NO damage can occur should mechanical teletypes receive
"Diddles", and it is not considered bad practice to leave it ON unless sked otherwise by the
other station in the QSO.