A bit more. I reset the BIOS to its default and restarted. Now I'm getting those disk complaints with bsd.mp. The machine is locked up now but I've typed in the error message below in the spot where the machine chokes.
It seems to be just before the working dmesg notices about dkcsum. (I'm going to run a serial line over and capture the console output for a proper dmesg but here's a start) Here's all that's on the screen now which I hand typed: pckbc0: using irq 1 for kbd slot wskbd0 at pckbd0: console keyboard, using wsdisplay0 pcppi0 at isa0 port 0x61 midi0 at pcppi0: <PC speaker> spkr0 at pcppi0 fdc0 at isa0 port 0x3f0/6 irq 6 drq 2 uhidev0 at uhub1 port 1 configuration 1 interface 0 uhidev0: Chicony USB Keyboard, rev 1.10/3.90, addr 2, iclass 3/1 ukbd0 at uhidev0: 8 modifier keys, 6 key codes wskbd1 at ukbd0 mux 1 wskbd1: connecting to wsdisplay0 uhidev1 at uhub1 port 1 configuration 1 interface 1 uhidev1: Chicony USB Keyboard, rev 1.10/3.90, addr 2, iclass 3/1 uhidev1: 2 report ids uhid0 at uhidev1 reportid 1: input=6, output=0, feature=0 uhid1 at uhidev1 reportid 2: input=1, output=0, feature=0 wd0(pciide0:0:0): timeout type: ata c_bcount: 512 c_skip: 0 wd0(pciide0:0:0): timeout type: ata c_bcount: 512 c_skip: 0 [machine is hung now, here's what was next in the semi-working config] > dkcsum: wd0 matches BIOS drive 0x80 > wd1: no disk label > dkcsum: wd1 matches BIOS drive 0x81 > dkcsum: wd1 matches BIOS drive 0x82 IGNORED > wd2: no disk label > dkcsum: wd2 matches BIOS drive 0x81 IGNORED > dkcsum: wd2 matches BIOS drive 0x82 > root on wd0a > rootdev=0x0 rrootdev=0x300 rawdev=0x302 Gord