Sun 3/4 updates

[Scott Quinn]

Al was right about the Sun 3/200 - it was the PROM - more specifically 
the complete absence of the PROM - that left the diag lights on all the 
time. That board's been shelved for a while.

The 4300 is up though - it was the NVRAM (someone had put it in 
backwards at some point during the board's lifetime). Fortunately I had 
another 4300 board (suffering from the "all lights on" plague) that I 
grabbed the NVRAM from and it now works fine (but 200+MB of memory 
makes the diag boot excruciatingly slow).