ATA66 controller/cable question

[Ben Bullock <brb@meadvillelibrary.org>]

I'm getting ready to install 2.8 on an ATA66 hard drive that is
connected to a Promise ATA66 controller card using one of the newer
80-conductor cables required for the ATA66 drives.  Just out of
curiosity, would there be any risk of damaging the drive(s) and/or
controller if I connected a second, older IDE drive to this controller
as a slave using this cable?  My guess is that the answer is "no," but I
have no documentation for the Promise controller, so I'm not sure it
will work at all with older drives.

Thanks for your help.

-Ben