in cardmgr/probe.c:tcic_probe_at() the function first attempts to
determine if any device is in the slot ... and loops checking first
8 words and aborts if ANY are 0xfffff.

This is incorrect, since some un-initialized devices may have one or
more ports returning 0xffff ... in particular Aironet PC4800 do, and
are unusable in slots managed by tcic controllers (like Databook chips).

The correct choice would be to check for ALL ports returning 0xffff:

    /* Anything there? /*
    for (i = 0; i < 0x10; i+=2)
        if (tcic_getw(base, i) != 0xffff)
            break;
    /* if all registers/ports are floating do an error return - JBass */
    if(i == 0x10)
        return -1;