Thanks for all the help in dealing with my problem so far. I have been able
to boot from floppy and mount the harddisc so I can access it. The
permissions on the rc file looked fine, but I changed them to world write
with chmod to make sure. Unfortunately this did not have any effect. I have
noted down in more detail the display that I get, and I have typed it below
in the hope that someone can tell me more about how to solve it.

I can boot RiscBSD fine up to this point:

# Clock has gained....
#
# /etc/rc : Can't open /etc/rc
# Enter pathname of shell or return for sh:         [I press return]
# getcwd() failed
# /etc/rc : Can't open /etc/rc

and so it goes on...round and round until I have to press reset :)

Any further help in this matter would be appreciated.

Thanks,
  Richard