Installation boot floppy problem

I tried installing 5.1 from CDs onto a machine at home which is
currently running 4.6-RELEASE (crufty, I know, but it isn't connected
to anything public, it serves files to my other dinosaurs).  This box
is a NexGen Nx586-VL with 64MB of RAM and a 40GB disk.

The NexGen BIOS won't boot from the CD, so I have to boot the install
from floppies.  After inserting mfsroot.flp, I get the following:

Booting [/kernel]
|
int=00000006  err=00000000  efl=00010006  eip=c02096df
eax=00000004  ebx=c0364794  ecx=c0382780  edx=c037e0c0
esi=c03b04d8  edi=c0364788  ebp=c080ed34  esp=c080ed34
cs=0008  ds=0010  es=0010    fs=0018  gs=0010  ss=0010
cs:eip=0f b1 51 1c 0f 94 c0 0f-bb c0 85 c0 74 02 c9 c3
       ff 75 14 ff 75 10 ff 75-0c 51 e8 e0 00 00 00 83
ss:esp=5c ed 80 c0 bf 9c 20 c0-80 27 38 c0 00 00 00 00
       00 00 00 00 00 00 00 00-48 df 37 c0 d7 45 32 c0

That was copied by hand, I hope there aren't any mistakes.  I redid
the floppies a couple times with different floppy disks, with the same
result.  I'm pretty sure the CDs are OK, and the MD5 sums for the
floppies check out.  Any clues?

Thanks in advance,
Ian