SCSI working under 10.4.8/9
Hi - at least one HBA from the LSI U320 range works to some extent. The driver used = "LSIUltra320.kext" which appears to be for those adaptors using the LSI 53C1030 IC & the 'Fusion-MPT" driver in other OS'
The HBA I used is a (hacked) Dell OEM version of the 21320-R: the 53C1030 SCSI controller is often integrated into modern server-class motherboards. Apple have supplied versions of these U320 HBAs with XServes.
HDD device function only, as far as I can see - I had issues with the optical Ultra/Narrow device shown in this external link [had to link to thread elsewhere since file upload not working here]. It might be possible that such devices might work if the sync & width parameters are forced in the MPT BIOS.
Have not tried to install direct to a SCSI HDD not tried the firmware 'RAID' function of this HBA.
Interestingly, there is an EFI firmware d/l for these HBAs. Again, have not tried this since my HBA is a hacked version with a mixture of LSI & Dell-specific firmware.