    The IRQ and interface-select jumpers are pretty straightforward, but I
    don't grok the settings of W10-W18 (also labelled A15 through A18).
    Could somebody tell me which settings of these four jumpers correspond
    to what I/O addresses?
    
The U-B PCNIC (also OEMed by IBM for a while) is the only Ethernet card I
know of that doesn't use I/O addresses.  It only has interrupts and shared
memory.  The jumpers you see control bits 15-18 in the base address of the
shared memory.  I can't recall which is 1 and which 0, but that's easy
to determine with DEBUG.