S.U.P.E.R. HP 200LX Archive
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Sending files to your palmtop over serial

How to connect an HP 200LX or 100LX to your computer and receive files straight from this site, with no software to install on either end.

The palmtop must be waiting before you press the button, or the transfer will fail. It is the palmtop that announces it is ready, not the other way round.

On the palmtop

  1. Connect the serial cable between the palmtop and the computer.
  2. Open Data Comm and go to Menu → Connect → Settings. Set: 9600 baud, 8 data bits, parity None, 1 stop bit.
  3. Go back to the menu and enter Menu → File → Receive, with the Zmodem protocol. The palmtop now waits: leave it like that.

On the computer

  1. Use Chrome (or Edge / Opera). Firefox and Safari cannot open the serial port, and no mobile browser can either.
  2. Find out which port is yours — it is explained below.
  3. Press the button and pick it in the window Chrome opens.

How do I know which port is mine?

Linux — your USB-serial adapter will be /dev/ttyUSB0 or /dev/ttyACM0. The /dev/ttyS0…ttyS31 are legacy motherboard ports: the kernel lists them even when none exist, so they are almost never yours. To be sure:

ls -l /dev/serial/by-id/

It shows the manufacturer and model, and which ttyUSB* it points to. If nothing appears, unplug and replug the cable and check dmesg | tail: you will see a line like «ch341-uart converter now attached to ttyUSB0».

Permissions: on Debian and derivatives your user must be in the dialout group or the port will not open. Check with groups, and if it is missing:

sudo usermod -aG dialout $USER

You must log out and back in for it to take effect.

Windows — Device Manager → Ports (COM & LPT). Your adapter shows up as COM3, COM4… If it has a yellow triangle, you are missing the chip driver (FTDI, Prolific or CH340 depending on the cable).

macOS — ls /dev/cu.*; your adapter will be something like /dev/cu.usbserial-A50285BI. Always use the cu. one, not tty..

The 200LX has no standard serial connector: you need HP's connectivity cable (the F1015A or an equivalent) and, unless your computer has a real serial port, a USB-serial adapter behind it.

Once the palmtop is waiting, the button is on every program's page. Browse the catalogue.