I did find a one wire Ace key at chipzone.com that claims to boot dvdr. This is the dvd boot method it has posted.PS2 DVD Backup Games With (AR2/GS2 v2.0x):
Note: The first thing you have to do before playing a DVD backup with AR2 (GS2) V2) is the following:
Please make sure the cheat code of "...BMX" exists in your AR2 (GS2) cheat list.
Set the cheat code of "Dave Mirra Freestyle BMX2" as default cheat code. (Just enter "select cheat code" and select the "Dave Mirra Freestyle BMX2" code, then return to Main Menu).
Insert AR2(GS2) Disc into PS2. ( v2.0X )
Boot on PS2 and after a while, the Main Menu will appear on screen, at this time press the Eject button TWICE. The cd tray will come out automatically. (The Reset and Eject lights will flash for about 5 seconds).
Swap the DVD Original in place of the AR2(GS2) disc within 5 seconds. After 5 seconds the cd tray will close automatically, and the Reset light will turn RED.
Wait apx. 10 seconds, and Reset light will turn GREEN. Then select "START GAME", and "WITH CODE", then press the "X" button of the controller. An Error message, "Too many codes....", will appear on screen. Press the "O" button on the controller twice to return to the Main Menu Page.
Press "START GAME", and "WITHOUT CODE", then press and hold the Eject button for one second, the cd tray will open automatically. Swap the DVD backup for DVD Original within 5 seconds. (The Reset and Eject lights will flash for about 5 seconds and the cd tray will close after 5 seconds)
Press the "X" button on the controller, and then the game will start up.This info is posted at
www.chipzone.com if interested. Hope this helps.