The controllers in question, do not support the option of booting to any SCSI device.

These controllers, do not have a BIOS and by design, there is no BIOS option for these controllers.
A BIOS, is an optional ROM (Read Only Memory) feature, that will allow an OS to boot or load from a SCSI device.

The setup option mentioned, in your systems CMOS, is designed for either an IDE bootable CDROM. If you have a system BIOS option to prioritize the SCSI controller as the boot controller, this will only work if your SCSI controller has a BIOS to boot from.

The SCSI controller must have BIOS in it to boot properly. The SCSI controllers in question do not have any BIOS option nor are they capable of BIOS upgrade options.

Note: If you are looking for a SCSI controller that's capable of booting (hard-disk or CDROM), you might want to acquire the AHA-2940AU or higher end controllers like the Adaptec SCSI Card 29160N.

A temporary work around or optional method for booting, would be to create a DOS Bootable diskette with the correct drivers. This would allow the booting to the diskette and then give you access to the specific devices. This method, however, is only a temporary work around and still does not allow the direct booting from a SCSI device attached to one of the above controllers.