The ISA Bus on this machine doesn't support DMA, and all interrupt lines
are wire-OR'ed together. Mileage may vary if sharing interrupts.
Tested cards:
com: 8250 and 16550 UART's (8 bit)
ec: 3com Etherlink II (8 bit)
we: SMC 8013 Ethernet (16 bit) [work in progress]
Probes, ARP in both directions works, sends clean packets,
tcpdump show correct packets on receive, NDP for IPv6 works,
netstat -s shows nothing strange.. but doesn't talk TCP/IP!