TDM Mix plus 3, I can't see the 24 I/Os only shows 16

[soundblaster]

Greetings,
I just upgraded to PT6.4 on OSX10.3.9 on a G4 and I am using 1 core and 2 farm cards that individually connect to 3x 888/24.
When I look at the Audio Core set up PT only sees 16 I/Os when it should recognize 24 I/Os with this system.
The DigiTest shows that the Core and 2 farm cards are working fine.
By process of elimination and many hours wasted I found that the 3 888s are working fine and the cables are OK. I can swop the modules back and forth but I only get 16 outs, in combination of module A B or A C or B C, but not ABC at the same time.
I am getting very frustrated.
Please help.
Thank you.

Here is more info....days later
I checked the Show System Usage and card #1 and #2 show Mix Engine 100% but card #3 does not show any mix engine. Card #3 does show Stereo Mixer 24

[crizdee]

When I look at the Audio Core set up PT only sees 16 I/Os when it should recognize 24 I/Os with this system.

Hi,

Are you trying to use the core audio setup for Pro Tools? You should be using the Hardware setup page, under setup from within Pro Tools!

Each interface will have its own page under the H/W setup page, where you set the various inputs and outputs, then you have to go the the i/o setup page and create your 24 inputs and outputs and assign them to the 3 interfaces, inputs/outputs 1-8 for interface 1. inputs/outputs 9-16 for interface 2 and inputs/outputs 17-24 for interface 3.

Chris

[soundblaster]

Thanks for your suggestion.
This is the first thing I tried.
PT will see the three 888s under Hardware setup. (even more if I specify more).
In the I/Os I can set it up for 24 I/Os. All the grid is set up for the three modules but when I hit play I can only play back 16 at a time. By setting different order of the 888s in the hardware set-up I can get A and C to play or A and B or even B and C but not all three (A,B,C) at the same time.

Any other suggestion will be greatly appreciated.
Thanks!