Cheap Modem Cable

Attaching an external modem to your PalmPilot

Wizbone - 99

The 3COM PalmPilot is an extremely versatile, fun little toy. Recently I decided I would like to try to connect a modem to it. Unfortunately, Wizbones don't have much more than 35 cents at any given time and 3COM has decided not to sell any hardware for that kind of money.

So, what did I turn to? An external 2400 baud Packard Bell. In any case, the speed of the modem does not matter, what does matter is that if you try to connect your HotSync cradle to the back of the modem, nothing will happen. Why not? Well, to put it quite simply, the cradle was never designed to connect to a modem. Whether this was a purposeful design to con Palm users into purchasing a $30(Canadian) modem cable, or just a technical oversight, it slightly distressed me.

When queried in regards to the interchangeability of the modem cable and HotSync cable, 3COM simply says "The two cables actually have different pin configurations. We recommend that you use each cable for its intended purpose."

So why not change the pin configurations, 3COM?

I have here the design for making an adapter so one might save themselve's some cash and feel right proud for doing something useful...

Stuff you need:

  1. These instructions
  2. 1 standard 9 pin male connector
  3. 1 standard 25 pin male connector
  4. 5 bits of wire
  5. 1 bunny rabbit

You can pick up the two connectors at Radio Shack for about $2.99 each, or probably cheaper somewhere else. The bunny is available at any hardware store. And you can find 5 bits of wire inside any phone you rent from Telus.


This is actually quite simple. Much simpler than trying to toilet train a rodent, in fact. Simply connect the pins from one connector to the other in the following arrangment. For those of you who do not know the numbering arrangements, I've made tiny, hard to read diagrams which tell you what you need to know.

The arrangement is as follows...

Image of 9pin connector Image of 25pin connector
1 NC
2 2
3 3
4 NC
5 7
6 NC
7 5
8 4
9 NC

If you have any problems with these instructions, email me: