Topic: HDSP9652 with Powermac G5

Is Mac software version 1.5 the latest version which will work with the Powermac G5 (IBM processors) for this card. I currently run the last version of OS X which runs on this platform: OSX 10.5.8. Software version 1.6 was on the system. When I used the Flash utilty to update the card [which was successful] it reverted to version 1.5

I also note that when using SubMix that I don't see greyed out channels underneath as seen on YouTube video demonstrations (or is this an intel thing).

Thank you in advance for anyone who can shed any light on this.