---
title: ZyXEL Prestige 660HW-67
language: en
layout: default
created: 2009-02-02 20:55:24 +0100
updated: 2009-02-02 20:55:24 +0100
toc: false
tags:
  - know-how
  - hacking
  - hardware
  - zyxel
  - prestige
  - router
---
The 660HW-67 was distributed in Germany as the "WLAN Modem 100" through the Arcor ISP. It came with the firmware `QD.7`
which seems to be originally made for AOL.

To get the router ready for ADSL2+, I needed the `QQ.7` firmware which is the original one.


Firmware crossgrade
===================

**Manual:** [dslrouter-hilfe.de](http://www.dslrouter-hilfe.de/forum/showthread.php?t=16411)

The big problem is that the `rom-0` of the original firmware is 48 KiB whereas that of the AOL firmware is only
*16 KiB*. Usually, you make an upgrade by updating the `rom-0` file (which contains default settings) and then update
the firmware itself which then reads the new default settings upon the next boot. Since the router didn't accept the
new settings, it stuck after the reboot.

This is how it works (using the serial connector on the PCB and a terminal program):

1. upload the new firmware file completely
    * the router will complain that the `rom-0` doesn't match and ask you to upload a new firmware
1. upload the new firmware again but cancel the upload after about 600 KiB (~12 min at 9600 baud)
    * the router will boot into a debug mode
1. upload the new `rom-0` file
1. upload the new firmware file
