The machines I've seen allow you to set the IDE as boot but the slave would be the second IDE drive. There are some machines where the SATA drive would land on the virtual or emulated second IDE channel but that is not what you asked for.
Why not try the various setups?
I am upgrading my computer (first build Athelon socket 939) in preparation to istall W7. I would like to make my current boot drive (EIDE) a slave to a new clean HD (SATA).
The are plugs for both. Will the updated computer (intel i5, asus P7P55D Evo, 4gigs DDR3 1600) recognize the SATA as "C" and the EIDE as slave. Do I just set the EIDE HD jumpers to slave or cable select? Set the boot sequence in the BIOS? Any other hoops may I have to jump thru? Gracias