- Cards are in the wrong order.- Bit 3 7-slot chassis must use the IBM bridge chips for both Pro Tools|24 and Pro Tools III compatibility.- Older Bit 3 7-slot chassis' require a modification in order to properly address the 56301 DSP chip used on the d24 card. This modification was rolled into production by Bit 3 on all new 7 slot chassis as of 5/1/97. Users who require this modification or who are unsure if their chassis has been modified should contact Bit 3 Technical Support.- Chassis must be installed on a compatible 6 slot Mac or a G3. If the chassis is installed in a 6 slot Mac, the chassis host card in the CPU must be separated from other PCI bus master cards by a Bridge Chip.- If the chassis is installed in a G3 PowerMac and it uses the IBM352 chips, the Pro Tools|24 cards must be installed in the chassis with the d24 card(s) at the other end of the bus (slots 5-8).