Booting Unix off Fujitsu Eagles

[Spencer W. Thomas]

There was a bug in pre-4.2 bootstraps for the Fuji.  (Other problem was
you had to throw out other drives to fit the fuji into 512 bytes.)  The
"driver" in the bootstrap program spins on drive ready to decide when a
transfer has completed.  However, the fuji is so fast that this comes up
well before the data has actually made it into memory.  You need to
change that code to spin on controller busy instead (and invert the
sense of the test).  We had the weird situation where it would boot
without the FPA, but not with!  Not having the FPA slowed the CPU down
enough that it was (usually) ok.

=Spencer