Connecting the Palmtop via the serial port to PCs, Printers and Modems

Here is a summary of how to make the three most frequently used Palmtop serial port connections: To a PC or Mac computer for backing up and loading software; to a printer for printing out a hard copy; to a modem for sending and receiving messages and other communications.

Connecting to a PC Directly Via Cables

Hardware needed

The current HP Connectivity Cables work with either Palmtop. They fit directly into the 100LX serial port and HP supplies a small 10-pin-to-4-pin adapter to connect to the HP 95LX. The cable is available in:

Software needed for file transfer

DataComm is the communications program built into the HP Palmtops. Like any PC "communications" program, DataComm can "talk" with another computer in order to transfer files between them. Communications programs use standard file transfer protocols, (such as Text (ASCII), Kermit, Xmodem) to send and receive files.

If you need a communications program on your PC or more capabilities than the Palmtop's BUILT-IN DataComm offers, the following communications programs, which can also transfer files, may be useful:

In addition, there are many programs that are designed specifically to make moving files between PCs and Palmtops easier. You may find one of the following 'file transfer' programs helpful: Designed for laptops and DOS PCs, but reported to work with HP Palmtops Procedure
  1. 1. Connect Palmtop's serial port to the PC's or Mac's serial port using the appropriate HP connectivity cable. PCs with 25-pin serial port will need the 9-pin-to-25 pin adapter from the HP Adapter Kit (HP F1023A).
  2. 2. Run the necessary file transfer or communications software on the Palmtop and on the attached desktop PC. For example: run ZIP.COM on both the Palmtop and the desktop PC; or run DataComm on the Palmtop and Kermit on the PC.
  3. 3. Make sure Baud rate and other settings match the settings on the PC's program and the Palmtop's interface is set to Com1. You can change the settings in FILER, DataComm or the file transfer program you are using:

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  1. 4. Make sure the PC is set to the correct COM port.
  2. 5. Initiate the connection. (The instructions for connecting vary depending on the communications software and protocol used (Kermit, Xmodem, Text). For the Palmtops refer to the detailed instructions for each protocol in the HP 95LX User's Guide, pages 31-13 to 31-17 or in the HP 100LX User's Guide, pages 35-18 to 35-22.)

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Connecting via an external modem

You must correctly connect your modem and the HP Palmtop before you can determine whether or not it will work.

Hardware needed

Since most modems have a female 25-pin connector, a typical connection requires the following parts:

  1. 1. HP Palmtop and another computer with a modem or a fax machine.
  2. 2. Modem compatible with the HP Palmtop. Most external modems will work with the 100LX. Fewer external modems will work with the 95LX. For the 95LX, verify with the manufacturer (Macronix, Telebit, US Robotics, etc.) that the modem supports software handshaking and can get power from its own batteries or an external power supply.
  3. 3. HP PC Connectivity Cable (see above) and Modem Adapter:

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  1. 4. RJ-11 cable to connect modem to phone line or an acoustic coupler to connect modem to phone handset:

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Software Needed

For communications you can use the BUILT-IN DataComm or COMMO.ZIP<ON DISK ICON>, FastCOMM!, or KERM2.ZIP<ON DISK ICON> (communications software mentioned in the previous section). With a modem and the proper software you can send Faxes, access and control remote computers, or access online services:

Procedure
  1. 1. Connect the HP Palmtop to the Connectivity Cable; Connect the 9pin end of the cable to the 9-pin-to-25-pin modem adapter; connect that to the modem; connect the modem to the phone line using RJ-11 cable or an acoustic coupler.
  2. 2. Run the desired communications software on the Palmtop.
  3. 3. Make sure the communications settings (baud rate, parity, data bits, stop bits) on the Palmtop and modem are the same as those on computer and modem to which you're connecting.
  4. 4. Make sure the other system is turned on and running the appropriate software. After connecting, the software will determine what commands and capabilities are available to you.

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Connecting to a Printer

The procedure for connecting an HP Palmtop to a printer is relatively straight-forward, and discussed in the documentation (beginning on page C-1 in the HP 95LX User's Guide and page 36-3 in the HP 100LX User's Guide.) A few other points are worth mentioning:

Printers with Serial Ports

There are few serial port printers available, the portable Kodak Diconix 180si, and the desktop HP LaserJet series. For these use HP's Serial Interface Cable (HP F1015A) with the 9-to-25-pin Printer Adapter from the HP Connector/Adapter kit (HP F1023A) to connect the serial cable to the printer's 25-pin serial port.

Printers with Parallel Ports

Most printers do not have serial ports. To connect the Palmtop to a parallel port printer you need a serial-to-parallel adapter:

Procedure
  1. 1. Connect the Centronix end of the adapter to the printer's parallel port. Connect the Palmtop to the connectivity cable. Connect the 9pin end of the cable to the serial-to-parallel adapters.
  2. 2. We used this procedure to print to a Canon Bubble Jet printer. We had to use an additional Centronix to 25pin-adapter to connect the serial-to-parallel adapter to the Citizen PN48 Printer's non-standard parallel port.
  3. 3. Select the proper printer driver for the printer you are using, Epson FX-80, HP LaserJet, or IBM ProPrinter. Most printers will emulate one of these three. They can be selected in Setup on either Palmtop: on the 95LX press (<Shift>)-(FILER) Printer Config Name; on the 100LX press (CTRL)-(FILER) (MENU) Options Printer (<Tab>) (<Tab>); then use the arrow keys to select the printer.

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