>So, I now find myself in posession of a maxine.
>
>I'm trying to netboot it using a serial console.

Odd. Worked fine for me on a 5000/50, late in 1.4_BETA..

>Booting the ECOFF NFS-root-based install kernel got a lot further; it
>successfully configures a bunch of devices, and then serial output is
>garbled.  Some experimentation (e.g., typing echo foo>/tmp/bar and
>then looking on the NFS server) shows that serial input is OK, but
>output is completely garbled once autoconf is over.

Does output work all the way through autoconfig, or does it go bad
after printing the line for scc0? Does it go bad before probing for
devices on the SCSI bus, or does that work OK?

(IIRC, the kernel returns to spl0() before it tries to attach
SCSI devices.)