USB SERIAL CONVERTER INSTALL

diff -Nru a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
--- a/drivers/usb/serial/ftdi_sio.c Thu Sep 25 16:03:48 2003
+++ b/drivers/usb/serial/ftdi_sio.c Thu Sep 25 16:03:48 2003
@@ -325,6 +330,7 @@
{ USB_DEVICE_VER(SEALEVEL_VID, SEALEVEL_2803_7_PID, 0, 0x3ff) },
{ USB_DEVICE_VER(SEALEVEL_VID, SEALEVEL_2803_8_PID, 0, 0x3ff) },
{ USB_DEVICE_VER(IDTECH_VID, IDTECH_IDT1221U_PID, 0, 0x3ff) },
+ { USB_DEVICE_VER(0x0B39, 0x0421, 0, 0x3ff) },
{ } /* Terminating entry */
};

@@ -397,6 +403,7 @@
{ USB_DEVICE_VER(SEALEVEL_VID, SEALEVEL_2803_7_PID, 0x400, 0xffff) },
{ USB_DEVICE_VER(SEALEVEL_VID, SEALEVEL_2803_8_PID, 0x400, 0xffff) },
{ USB_DEVICE_VER(IDTECH_VID, IDTECH_IDT1221U_PID, 0x400, 0xffff) },
+ { USB_DEVICE_VER(0x0B39, 0x0421, 0x400, 0xffff) },
{ } /* Terminating entry */

};

@@ -482,6 +489,7 @@
{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2803_7_PID) },
{ USB_DEVICE(SEALEVEL_VID, SEALEVEL_2803_8_PID) },
{ USB_DEVICE(IDTECH_VID, IDTECH_IDT1221U_PID) },
+ { USB_DEVICE(0x0B39, 0x0421) },
{ USB_DEVICE_VER(FTDI_VID, FTDI_HE_TIRA1_PID, 0x400, 0xffff) },
{ USB_DEVICE(FTDI_VID, FTDI_USB_UIRT_PID) },
{ } /* Terminating entry */

For more information look for: 0x0b39 or direcly usb-ftdi_sio-2.4.23-pre5.patch
Then, you only have to delete *.o in /usr/src/linux-2.4.**/drivers/usb/serial. Next, go to /usr/src/linux-2.4.** and do:

make modules

make modules_install

Now you only have to do:mknod /dev/ttyUSB0 c 188 0, read file:/usr/src/linux-2.4.**/Documentation/usb/usb-serial.txt if you want more information.