Make sure you have the right kind of cable. A null modem cable bought at a computer store will do it. But it must be a null modem cable! Make sure you are using your serial port, and not your parallel port.
At a minimum, you should have (for a DB25 connector):
RxD Receive Data 2 - 3 TxD Transmit Data
TxD Transmit Data 3 - 2 RxD Receive Data
GND Signal Ground 7 - 7 GND Signal Ground
If you want to have flow control and hardware handshaking, you must have a full null modem cable:
Frame Ground 1 - 1 Frame Ground
RxD Receive Data 2 - 3 TxD Transmit Data
TxD Transmit Data 3 - 2 RxD Receive Data
RTS Request To Send 4 - 5 CTS Clear To Send
CTS Clear To Send 5 - 4 RTS Request To Send
DSR Data Set Ready 6 - 20 DTR Data Terminal Ready
GND Signal Ground 7 - 7 GND Signal Ground
DCD Carrier Detect 8 - 20 DTR Data Terminal Ready
DTR Data Terminal Ready 20 - 6 DSR Data Set Ready
DTR Data Terminal Ready 20 - 8 DCD Carrier Detect
If you have a DB9 connector on your port, try the following:
DB9 DB25
RxD Receive Data 2 - 2 TxD Transmit Data
TxD Transmit Data 3 - 3 RxD Receive Data
GND Signal Ground 5 - 7 GND Signal Ground
Alternatively, a DB9-DB25 null modem cable:
DB9 DB25
DCD Carrier Detect 1 - 20 DTR Data Terminal Ready
RxD Receive Data 2 - 2 TxD Transmit Data
TxD Transmit Data 3 - 3 RxD Receive Data
DTR Data Terminal Ready 4 - 6 DSR Data Set Ready
DTR Data Terminal Ready 4 - 8 DCD Carrier Detect
GND Signal Ground 5 - 7 GND Signal Ground
DSR Data Set Ready 6 - 20 DTR Data Terminal Ready
RTS Request To Send 7 - 5 CTS Clear To Send
CTS Clear To Send 8 - 4 RTS Request To Send
(RI Ring Indicator 9 not needed)
If you are not using a full null modem cable, you might have to do the following trick: on your computer side of the connector, connect RTS and CTS together, and also connect DSR, DCD and DTR together. This way, when the computer wants a certain handshaking signal, it will get it (from itself).
Now that you have the right kind of cable, connect your terminal to your computer. If you can, tell you terminal to ignore modem control signals. Try using 9600 bps, 8 data bits, 1 stop bit, no parity bits for the terminal's setup.
getty Replace the stock getty with getty_ps as described in section
What is getty_ps?
. Add an entry
for getty to use for your terminal in /etc/gettydefs:
# 38400 bps Dumb Terminal entry
DT38400# B38400 CS8 CLOCAL # B38400 SANE -ISTRIP CLOCAL #S @L login: #DT38400
# 19200 bps Dumb Terminal entry
DT19200# B19200 CS8 CLOCAL # B19200 SANE -ISTRIP CLOCAL #S @L login: #DT19200
# 9600 bps Dumb Terminal entry
DT9600# B9600 CS8 CLOCAL # B9600 SANE -ISTRIP CLOCAL #S @L login: #DT9600
You can add HUPCL so the login is killed whenever you switch of
the terminal (provided you use a proper null modem cable).
If you want, you can make getty print interesting things in the
login banner. In my examples, I have the system name and the serial
line printed. You can add other things:
@B The current (evaluated at the time the @B is seen) bps rate.
@D The current date, in MM/DD/YY.
@L The serial line to which getty is attached.
@S The system name.
@T The current time, in HH:MM:SS (24-hour).
@U The number of currently signed-on users. This is a
count of the number of entries in the /etc/utmp file
that have a non-null ut_name field.
@V The value of VERSION, as given in the defaults file.
To display a single '@' character, use either '\@' or '@@'.
Edit your /etc/inittab file to run getty on the serial
port (substituting in the correct information for your environment -
port, speed, and terminal type):
S1:456:respawn:/sbin/getty ttyS1 DT9600 vt100
Restart init:
linux# init q
At this point, you should see a login prompt on your terminal. You
may have to hit return a couple of times to get the terminal's
attention. Rejoice. Party. Log in on your terminal and PC.
talk to yourself from accross the room.
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