I have a RS3000 based DecStation 5000/200.  I can't seem to boot the 
thing yet.  I have Ultrix v4.4 on a disk that worked fine on a 2000/3100. 
 I want to put NetBSD on it but got to boot first.

I'm lacking a hardware manual so please excuse the inane questions (I 
bought it for $400).

1. What's the rationale for memory slots?  Seems slot 0 has to occupied.  
Any rules regarding the other slots, especially when mixing different 
sized memory modules?

2. I've got revision 5.6 of the ROM's, anyway to get a newer version?  
The 2000/3100's I built the ultrix distribution on had 6.2 or so ROMS 
with a bit more functionality.

3. The boot hangs when trying to exec the kernel.
[input]
>> boot 5/rz0/vmunix
[output]
Loading 5/rz0/vmunix ... (disk light flashes)

Sizes:
text = 1292144
data = 205552
bss = 402400
Starting at 0x80030000
[goes into never never land]

4. Is there a architecture difference between the 2000/3100's and the 
5000 that makes my boot disk worthless?

I realize the digital help forum would be the best place for it (will 
cross post later) but I'd like to pick your collective brains...