HP 95LX - Using a Modem

Using a Modem
Modems communicate between computers over the telephone lines. The HP 95LX
can work with any modem that can use software handshaking only. During use,
all modems periodically check that a certain wire to the terminal (usually called
DTR) is “on.” Some modems, often the battery-powered ones, also use the DTR to
tell them when to power up and power down. And although AC-powered modems
don’t use the DTR for power decisions, they'll hang up or “stop listening” ifthe DTR
line is off or disconnected. This use of the DTR is called hardware handshaking.
The HP 95LX doesn’t even have a DTR line—just the three lines, RX, TX, and GND
(see discussion, pages 90-91). So, to use the HP 95LX with a modem, you must be
able to tell the modem to ignore its DTR line. Most AC-powered modems have
switches that can be set to “Ignore DTR” (check the modem manual), but you can’t
disable the DTR line on most battery-powered modems without defeating their
power conservation. However, a few battery-powered modems use the RX line
(data signals from the terminal) for instructions as to when to power on and off.
This is software handshaking—the only kind supported by the HP 95LX.
The First Time You Connect with a Modem
1. Set up the modem: Test the cable connection (see pages 90-91) and configure
the modem to ignore the DTR (and any other dedicated handshake) line.
2. Press (<®), (MENU), (Settings, (Clonfig. Find out exactly what the host system’s
communication settings are in each of these areas and change the settings to
match: Baud Rate, Stop Bits, Parity, Bits/Character, Required Terminal
Emulation (if any), Flow control method, Duplex, Access phone number.
3. Choose how the HP 95LX should handle incoming data:
Do you want the data to wrap onto a 40-character screen?
Control characters: Filter them out? Change to other characters? Neither?
What character translation file are you using (if any)?
What logon script file are you using (if any)?
4. Press (Quit, (MENU), (Clonnect. The modem will initiate the connection with the
host and run any logon script file you have included with it.
5. Once you're connected, do whatever you need to do. When you've finished your
work, log off from the host, and press (=EW=NT).
Using a Modem 97