Hello Lsdmeasap,
actually the problem is just that: everything works correctly, if the SATA CTRL is configured in IDE mode. The DVD drives make booting and all devices are seen in standard CMOS page. If I select AHCI mode, all devices disappear from the Standard CMOS page, and the SATA DVD drives does not run on boot. The same thing happens if I select RAID modes or EXTENDED.
My system is also equipped with an Adaptec 29160N SCSI Controller, which manages a DVD drive and a hard disk with the operating system. The problem with the SATA units on the motherboard's BIOS also has an impact on the boot from the SCSI DVD: in fact, in the other mode it does not work, and the boot from the SCSI DVD is done only if the SATA CTRL is in IDE mode.
Another little curiosity: I connected 3 hard drives to SATA ports, but if I try to use some bootable CD to manage partitions, the software will see only two, while Windows sees them all three. I saw that the first four SATA ports are divided into MASTER-SLAVE, is there any limitation on the visibility of disks in DOS?!?
Thank you again...