You can use BRMS from IBM or RobotSave from Help Systems.  You need the
AS/400 API installed on the AS/400.  We had two as/400 backing up to TSM
both working but one was very slow (640 with 100mb card).  The 830 w/gb
ethernet is as fast as any other client that I have (11.3GB is 30 minutes).
Not sure if this is the processor or the ethernet card since the 640 does
not have a gig card.  I think this just shows that if you through the
hardware at it it will work but if you don't it is very slow.  You  must
configure everything on the AS/400 side and you just register the node in
TSM.