Ok, I still can't get my 10 running correctly. I still get the ethernet
problems (dma errors), and I still get random core dumps.

The dma errors seem to be triggered by disk access, like fsck.

My machine is a SS10, FRU: 501-2365, ROM 2.25. Rev 4.50? -4.50?
It has an SM51 in it. Four 16Mb SIMMS, part no 501-2273

We tried: 
1) Swapping motherboards
2) Swapping processor modules
3) Swapping RAM.
4) Various combinations of SCSI cabling. 
5) Changing every jumper that might be useful.
6) Swapped out the power supply.

What else can we try? 

Here is info from a pair of Sun employees:

>From Eric Melvin:
>> The #501-2273 is a 80ns memory SIMM that is supported
>> on the SPARC 10.  Maybe you have a bad SIMM?  I've
>> attached the reference in the Sun FE handbook.
>>
>> The SPARC 10 can also take 60ns SIMMs.  Not sure about 70ns.

>From Michael Garvin:
>	The Sparc 10 takes either 80 or 60ns SIMMs; the following parts are
>supported:
>
>	501-1785	16MB	80ns
>	501-2273	16MB	80ns
>	501-2479	16MB	60ns
>	501-1930	64MB	80ns
>	501-2480	64MB	60ns
>
>With 80ns parts the controller provides 100ns data access.  The 60ns parts were
>added when the Sparc 20 was introduced, probably so they only had to ship one
>part for both lines.  You might get a performance increase going to the faster
>parts, but I wouldn't worry about it.  70ns parts were not supported by Sun.

Michael's headers had this in it on the From line:
>(Michael Garvin - Sun SE -  Cary NC)

Guys, this information is about as capital-Official as it gets.

Anyway, thanks to all who have tried to help. If I'm not running by this
weekend, we're gonna hang it up.
--
XCOMM Kevin P. Neal, Junior, Comp. Sci.     -   House of Retrocomputing
XCOMM  mailto:kpneal@pobox.com              -   http://www.pobox.com/~kpn/
XCOMM  kpneal@eos.ncsu.edu         " *** StarDOS makes great coffee! ***"
XCOMM From a mid-80's advertisement in "Compute's GAZETTE", a C64/C128 mag