If I'm not mistaken the 9121 on Ebay right now
would run it, at least if
the 9191 will do 370 mode. I believe that it has XA mode and probably
ESA mode capability and the 3725 might not be operable on it, since you
probably would not have access to an OS due to license costs, on anything
but the 370 arch.
At least the 9121 guy has some new pictures. Same price, however.
Anyway, not all 3725s are channel attached. Some were made for remote
sites and talk to the mainframe over leased modem lines (probably should
be called "far end processor").
William Donzelli
aw288 at
osfn.org