sym driver failure - what to do?

[hostis outis]

On a DECpc XL590 that has for years happily run NeXTSTEP 3.3pl1,
Windoze 95, and Linux kernel 2.0.35 (Slackware 3.6), attempted
installation of FreeBSD 4.8 (as replacement for all three of the above
OSs) fails. The machine has 48 MB of 70 nanosecond memory,
NCR PCI v3.04.02, and all other standard equipment in working
order.

   The attempted installation has been by kern.flp + mfsroot.flp
on freshly formatted diskettes dd-written on another FreeBSD
4.8 machine; I've written 4 of each floppy to be sure they are
not at fault.

   One of two things happens. First scenario: the machine locks
up after driver configuration (makes no difference  how or
whether the superfluous ISA device probes are disabled) with
the floppy drive light on and the following message on screen
from the very beginning of the probes:

   pcibios: No call  entry point
   ...
   ...
   ...
   sym0: <810> port 0xd100-0xd1ff mem 0x20000000-0x200000ff\
            irq 11 at device 1.0 on pci0
   [25 instances of ASCII char 177 alternating  with ASCII char 255]
  sym0: PCI BUS clock seems too high: 4444160 KHz

LOCK UP

Second scenario (randomly alternating with the first on any
given further attempt after a cold reboot): after save-and-quit
from the kernel configuration screen, probing dumps
incoherent gibberish to standard out, then

LOCK UP

   Does anyone have any suggestions? What should I do,
go back to Linux (ugh!) ? Will that even do any good?
Apparently, the same guy who wrote the sym driver
for present-day FreeBSD seems to be the author of
the corresponding Linux driver too, and Linux  has
run happily on this machine for years. So why isn't
FBSD 4.8 installing his driver correctly on this
NCR PCI bus?

   Admittedly, FreeBSD installations (of which I've done
some dozen) go better on machines I've built myself,
even with such problems as misreported disk
geometry; but still, I'd hate to think version 4.8 has
met its match on nothing more exotic than this
elderly DEC.
                                         Hosed Installer