I just cloned my original hard drive to a new drive. Each drive is set to cable select and is connected at the end of individual 80 wire cables to the two ports of a Promise ATA66 controller card. The middle cable connectors are unused. When I did the copy, the old drive was detected by the BIOS as channel D0 and the new drive as D3. When I finished the clone operation, I hid the O/S partition of the old drive and simply swapped cables at the controller end. I expected that the new drive would become D0 and the old, D3. However, what I found was that the new Drive became D1 and the old became D2. The system and both drives are working fine, there are no apparent problems, but I am totally puzzled as to why I got D1/D2 instead of the original D0/D3. I thought the channels were simply a function of controller port and cable position. Can anyone explain this unexpected result?