Custom 7x0 ROM
Instructions to Update/Flash
Note - you can see an english translated listing of the boot menu (service menu) here - 
Flash to new Custom 7x0 ROM
- Make sure you have the updater.sh and initrd.bin files in the root of your cf/sd card.
(Yes, you can use either cf or sd to flash now!)
- Make sure the Zaurus isn't plugged into AC power.
- Remove battery for at least 5 seconds.
- Replace battery (replace battery cover, lock cover), plug in AC power.
- Press and hold the "OK" button on the keyboard.
- Turn the power on, you should see the Japanese service menu:
- Now Plug in the Power Cord.
(You will get an error if it isn't plugged in!)
- Select option 4 (flash/update).
- You then have four options (1. USB, 2. CF, 3. SD, 4. ?? it's in Japanese!)
- Choose either option 2 or 3, depending on which media you put the files on.
I don't know what it would take to use option 1 as I don't use the USB connector at all with my Zs.
- Select Yes in the confirmation window (left option with the "Y").
( If you don't get a Yes/No choice you don't have the Power Plugged in!)
- Screen will go black for a couple seconds, you'll then get the Sharp
splash screen (Sharp logo in red, Japanese characters below).
Then the screen will go black, and display
"--- Zaurus CF updater ---" and you can monitor the progress.
- It will finish, and reboot your Z automatically.
- After reboot, turn off your Z and proceed with the Format Internal Flash instructions.
Format Internal Flash
- Perform steps 1 - 7 above (to get to the service menu):
- Select option 3 (Erase all / Format (all data will be lost!))
- You should then get a confirmation message (in Japanese) with a Yes/No
option (left one is Yes). Click the Yes button to confirm.
(If you don't get this, then you don't have the AC power plugged in.)
- Wait, get some coffee/tea, watch the pretty screen.
- Send Sash lots of money to say "Thanks!" for building this nice custom ROM...