hard disk questions

Getting ready to add a hard disk. HDM is in the mail.

Question 1: When you attach MPC to PC over USB, my understanding is that it mounts like a mass storage device. Does it mount the CF card only, or can you see the internal HD as well? What happens if both CF and HD are in place?

Question 2: What bus type are the compatible hard disks? ATA-6 or ATA100? Does it matter? I'm confused about this because some google searches on some of the models listed as being compatible say that the drive is ATA-6 and some say, no, the exact same drive is ATA100.

Thanks.

Answer to nr 1 is that it depends on which source you´ve selected in the LOAD / SAVE mode.