CRD-8420B firmware

I am looking for firmware for the CRD-8420B optical CD-ROM drive.

The drive appears to be a rebagged (Compaq) LG CRD-8420B drive.

I have not been able to find a firmware download for CRD-8420B. I have checked The Firmware Page, LG USA and LG Germany websites, and BIOS.ru, but have not found a the firmware update.

Where may firmware for CRD-8420B be acquired?

I have attached an image of current Nero InfoTool information.

The following is a link to a site seems to mention something about CRD-8420B, but I am unable to decipher what (page is not in English):

http://www.tws.ac.th/thoenwit/Library/ruen%20computer/www.ruencom.com/cdp242cd.htm

What information does the page contain?