So... after setting the "keep agent running after boot" option
as suggested by Manuel, and various other fixes suggested by
Wolfgang offlist, (thanks Joel, Manuel, Wojciech, & Wolfgang)
I finally get the install floppies to come up.

So now I can't talk to the disk drives.  :-(

The kernel is able to get the model number and such:

wd0 at atabus2 drive 0viaide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
: <ST3250823AS>
wd0: drive supports 16-sector PIO transfers, LBA48 addressing
wd0: 232 GB, 484521 cyl, 16 head, 63 sec, 512 bytes/sect x 488397168 sectors
viaide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
viaide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
wd0: 32-bit data port
viaide1:0:0: lost interrupt
        type: ata tc_bcount: 0 tc_skip: 0
wd0: drive supports PIO mode 4viaide1:0:0: lost interrupt
        type: ata tc_bcount: 0 tc_skip: 0
, DMA mode 2viaide1:0:0: lost interrupt
        type: ata tc_bcount: 0 tc_skip: 0
, Ultra-DMA mode 6 (Ultra/133)
wd0(viaide1:0:0): using PIO mode 4, Ultra-DMA mode 6 (Ultra/133) (using DMA)


But even a simple 1 sector read fails:

# dd if=/dev/rwd0d of=foo bs=512 count=1
viaide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
viaide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
viaide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
viaide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
viaide1:0:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
1+0 records out
512 bytes transferred in 10.020 secs (51 bytes/sec)
viaide1:0:0: lost interrupt
        type: ata tc_bcount: 0 tc_skip: 0
#  


I tried both 2.0.2 and -current.  Messages above are from:
ftp://ftp.netbsd.org/pub/NetBSD-daily/HEAD/200508240000Z/
amd64/installation/floppy/boot-com1.fs

According to http://mail-index.netbsd.org/port-amd64/2005/07/31/0000.html

	The mailing list mail says nforce4 works without MPBIOS
	(but that was -current as of 6 months or so ago)

So is this fix going to appear in current someday soon?
Kinda hard to install NetBSD when you can't talk to the disk drives.