I just crossflashed my HP DVD Writer 630C to a BenQ DW1620.
The original firmware was AH02 (quite old). I tried to upgrade it to CH16, but the HP flasher wouldn't run for me. HP's flasher requires burning a bootable floppy or CD. It was trying to setup a ram disk, but threw an error saying c: was not formated. As usual, HP support was no help.
So thank you to all who post here for the info I needed!