Yes, the Adaptec 2940UW and 3940UW can be used with the Blue and White G3s with the following system configuration: OS 8.6, Mac ROM update 1.1 (has to be run after installing 8.6), and the Adaptec 5.01 control panel and 4.1 firmware with the cards set to "Fast-SCSI: 10".The new version of the control panel now has 4 SCSI modes: 1. Asynchronous 2. Standard - SCSI:5 3. Fast - SCSI:10 4. Ultra - SCSI:20 The way to disable Ultra is to set each bus to Fast-SCSI: 10, which means 20MB/sec at a clock speed of 10MHz (hence, the "10").- Why do you want to disable ultra-SCSI? It reduces the load on the PCI bus, thus preventing or reducing DAE -6042 errors in Pro Tools. Plus, with single-ended SCSI, it allows greater cable length tolerances.Pro Tools will work just fine at regular, Fast-Wide transfer rates, and currently does not need the higher data transfer capacities.