Help configuring a Breece Hill Q7

[jlm17]

How do I configure amanda to handle a Breece Hill Q7 tape changer? It 
has two disks and 28 tape slots. I am guessing that I need to set 
tpchanger to "chg-scsi" but how do I tell it what the tape changer 
device is, and about both of the drives and the number of tapes etc.?

Either help or some pointers to documentation that I may have missed 
would be appreciated.

Thanks.