Hi!

Thanks for your hints! I managed to add a 10 GB 2,5" Harddrive to my WL500g Deluxe

56k warning: all images ~500k

I used the IDE-USB-adapter from an external USB-HD-case, which I got from ebay for 10 EUR.
HD with IDE-USB-adaptor
All other parts can be found in the heaps of computer junk any geek has lying around.
But I also heard rumors of shops were you actually by that stuff.

I had to remove the connector from the board and solder the USB cable directly onto it to fit it in the case of the router.
USB-adapter with soldered USB-cable
I did not solder the +5V (red cable) and shielding directly to the board, but instead used a strip. I had to bend the pins a little bit, to be able to push them in.
Strip for +5V and shielding (sorry, a little bit blurry)

Attaching the connectors to the USB-cable took me years.
The two pin connector is from a computer power switch, the 8 pin connector is from a PS/2 port.
+5V/Shielding Connector (Warning: the USB pinout is wrong)
USB Connector (right pinout)
WARNING: make sure you don't mess up the polarity!

A test run. YES! It works!
Code:
$ ssh root@192.168.0.25
root@192.168.0.25's password:


BusyBox v1.00 (2005.06.25-07:50+0000) Built-in shell (ash)
Enter 'help' for a list of built-in commands.

  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 WHITE RUSSIAN (RC1) -------------------------------
  * 2 oz Vodka   Mix the Vodka and Kahlua together
  * 1 oz Kahlua  over ice, then float the cream or
  * 1/2oz cream  milk on the top.
 ---------------------------------------------------
root@OpenWrt:~# cat /proc/partitions
major minor  #blocks  name

   8     0    9820440 scsi/host0/bus0/target0/lun0/disc
   8     1    9820144 scsi/host0/bus0/target0/lun0/part1
root@OpenWrt:~# insmod ext2
Using /lib/modules/2.4.30/ext2.o
root@OpenWrt:~# insmod jbd
Using /lib/modules/2.4.30/jbd.o
root@OpenWrt:~# insmod ext3
Using /lib/modules/2.4.30/ext3.o
root@OpenWrt:~# mount -t ext3 /dev/scsi/host0/bus0/target0/lun0/part1  /mnt/
root@OpenWrt:~# df -h
Filesystem                Size      Used Available Use% Mounted on
/dev/root                 3.2M      2.2M      1.0M  68% /
none                     14.9M     16.0k     14.9M   0% /tmp
/dev/scsi/host0/bus0/target0/lun0/part1     9.2G     34.6M      8.7G   0% /mnt
Ok, but I wanted it nice and clean => closed case
A test fit
Well, it didn't work this way. The harddrive touched the tall IC next to the switch.
I used the cover of a cable duct to mount the harddisk.
Mounting 1
Mounting 2
And some hot glue art...
As you can see, I've cut out a window to improve ventilation.
Fits like a second skin.

Case closed, without bezels:
Back 1
Back 2
Front 1
Front 2
Hope you can recognize anything.


Finished!
I have not installed the rear bezel for better ventilation. I think I will make one from a piece of mesh or something like that.