Problem in rescue disk for Sun Ultra 1

[Orion the Hunter <orion@massey.ee.nd.edu>]

I just tried to boot my machine, an Ultra 1, using the
resc1440-sun4u.bin from the debian site, but it gave me the error

	Fast Data Access MMU Miss

Does anybody know what it means and how it can be fixed?  I'm trying to
boot from my floppy drive using the image created on Mar 3, 1999 (the
one in Debian).  Just after starting reading the disk (a couple of
seconds at most) the machine stops loading the image and display the
above message.  I'm trying to install Linux on a second machine, and I
lost the disk I installed Debian the first time.  Any help is greatly
appreciated.  Thanks,

-- 
Hermano Cabral