IBM Bus & Tag channel protocol specs?

[Jay West]

Sridhar wrote....
> But the P/390 does.  And if you need more horsepower than can be provided 
> by a P/390E, then you can set up an emulated mainframe with Hercules 
> addressing the peripherals attached to the P/390 over the network.

I'm confused. I thought the P/390 didn't have any bus & tag connectors on 
it.... in addition, it's a microchannel card right? Making it less likely to 
run in a common PC?

I just skimmed some docs on the P/390 and don't see any way that bus & tag 
devices hook up to it?

Jay