No. Parallel ATA only supports 2 drives per channel, though you can buy additional IDE/PATA, IDE/SATA, or SCSI controllers to add more drives to your system. Keep in mind, hooking up three drives to your PSU will cause significant drain on your wattage. You may need to upgrade your PSU as well.
Thats what I figured, I wanted to add a second hard drive to my xbox because the xbox's hard drive and disk drive share the same ribbon cable. I am doing the chipless xbox modding and installing Linux and I wanted that second hard drive for more space. So I'm pretty much screwed then huh?