David Sudjiman

My Thinkpad T41 (3273-1FA) does not come with serial port. Indeed IBM choose to use DB25 parallel rather than DB25 Serial. It took me 2 days just to figure out why my RJ45-DB25 connection is not working. Again, it is not a serial DB25!

After googling for several restless hours, I found that we can actually
use USB for serial connection and we need a USB-to-RS232 connector to do it.

I was aiming for this connector but it seems it is quite hard to find and it is expensive too. I was told that this connector would cost me around AUD$ 70.

Luckily I went to this computer store and ask for USB to Serial connector and they gave me this Connectland USB to RS-232.

This connector manufactured by Prolific Technology Inc.. A bit of a search on my kernel configuration, you can find CONFIG_USB_SERIAL_PL2303 option.

To use it, make sure you have this configuration on your kernel (my kernel is 2.6.12.3)

CONFIG_USB_SERIAL=m
CONFIG_USB_SERIAL_PL2303=m


Load the module using command modprobe pl2303 and watch your dmesg. It should see similar like this.


drivers/usb/serial/usb-serial.c: USB Serial Driver core v2.0
drivers/usb/serial/usb-serial.c: USB Serial support registered for PL-2303
pl2303 2-2:1.0: PL-2303 converter detected
usb 2-2: PL-2303 converter now attached to ttyUSB0
usbcore: registered new driver pl2303
drivers/usb/serial/pl2303.c: Prolific PL2303 USB to serial adaptor driver v0.12


Open your minicom and configure it to use /dev/ttyUSB0 or whatever your dmesg tells you. Last thing, don’t forget to use 9600 8N1, no Hardware or Software Flow Control.