Following from off-list:
The P1-C6 is an IOP/IOA slot. The 5737 is considered a Smart IOA and when
used with V5R4 doesn’t require a 2844/2843 IOP card. If you were wanting to
try the 5737 with the use of a IOP, I would put the 5737 in slot P1-C5 and
the 2844 in P1-C6. P1-C5 has a bridge address of 7,8 vs P1-C6’s 1,2. If an
IOP is placed on the same multi-adapter bridge number and at a lower
address number, then this adapter is under IOP control and does not
function as an IOP-less adapter.
I see that you’re running V7R1 which supports using the 5737 as an IOP-less
slot. P1-C4 is an IOP-less only slot. So that should work just fine to run
that configuration as well. I would advise using this placement vs having
the 5737 in P1-C5 and a 2844 in P1-C6.