Travel kit cable USB to serial conversion

What's that? Why?

Some people have troubles with the USB cradle or cable, because of software incompatibility (ex. with Windows NT 4.0 or Windows 95 lack of USB support) or hardware limitations (no USB port on an old computer), or simply want to connect external devices like a GPS to the Clie. Sony isn't currently selling serial cable, only a serial cradle for the PEG-S300 / PEG-S500C, and if you don't want to carry a cradle with you all the time, or if you've got a PEG-N700C / PEG-N710C, you have no choice but build your own cable. Fortunately, this is a simple task, although maybe a bit expensive...

What you need:

  1. You need to buy Sony's Travel kit (ref. PEGA-TK500). You can buy it at about US$60 (70 €), it comes with an AC adapter (100/240V, usefull if you travel or need a second recharging place) and a USB hotsync cable which we'll convert to serial.
  2. You'll need a small screwdriver, a soldering iron, a 9 wires cable (actually 6 wires are enough), a female RS232 DB9 connector (I suggest buying a straight serial cable with molded connectors, and cutting one of the connector, reducing the cable to the desired lenght) and a small 51 kohms resistor. Oh, yes, you'll also need basic soldering skills, a good sight and agile fingers, but nothing really hard involved here.

The detailed instructions:

Caution! Use these instructions at your own risks. I did this myself and encountered no problem whatsoever, but be aware that you can potentially damage / destroy your Clie and / or your cable (and possibly your computer or any device you connect the Clie to). YOU take the responsibility of the cable modification, not I... ;-)

Step 1: Disassembling the USB cable
First unscrew the two small screws to open the Clie-side connector (not the USB-side one).
The connector case is kept closed by additional plastic tabs on each side of the connector. (see picture of the opened connector)
In order to unlock those plastic tabs, you need to press gently on the connector sides (lower par of the case) as shown on picture, and pull slightly outward the lateral sides of the upper part of the case. You can then lift the upper cover upward to open it.
Once the connector case is opened, separate the case from the connector and its attached cable.  
Step 2: The actual cable modification
You can now use the soldering iron to disconnect all the wires from the USB cable, and remove the small resistor as well, leaving the connector empty.
Connect now the wires from your serial cable to the connector using the following table (if you're using a cable with molded connectors, you'll have first to find out which wire goes to which pin on the DB9 connector):
Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13
Serial DB9
Pin # NC NC 6 3 8 2 7 NC NC NC NC NC 5
Signal     DSR TXD CTS RXD RTS           GND

(NC = not connected)
The 51 kohm resistor is to be soldered between the #12 and #13 pins of the Clie connector, as showm on picture. Be carefull to connect the ground wire to the correct side of the resistor:
Step 3: closing the connector case again
Now that the hardest part is finished, take a breath and proceed to the final part.
Put the connector in the lower case, ensure that everything fits correctly inside the case (you'll certainly need to bend carefully the resistor so that you can put everything in the case). Depending on the serial cable diameter, you might need to adapt it so that the cable is tightly locked into position when the connector case is closed again, otherwise you'll tear the connections away if you pull the cable... Put the upper half cover into position. It should lock with the plastic tabs
Step 4: test your cable
If the tests are sucessful, put the 2 screws back, relax and enjoy your new serial cable! ;-)