Old Sun diags questions (4/300 and 3/200)

[Dave McGuire]

On Nov 12, 2007, at 1:18 AM, Scott Quinn wrote:
>> > Couple of questions on old Sun machines (well, parts).
>> >
>> > On a Sun 4300 CPU board, I'm getting the
>> > "EEPROM Write-Write-Read-Read test
>> > error PA=0xF2000000 VA=0X00FF8000 Exp=0x0000005a Obs=0x00000000
>> > (looping)"
>> > error. Looking on the Web and Usenet seems to show that this has
>> > happened a couple of times, with some reference to possibly being
>> > the NVRAM (although the most comprehensive posing set was in
>> > German :(). This seems a bit odd, though - on my other Suns it
>> > calls the NVRAM the NVRAM, so I'm wondering if this is something  
>> else.
>>
>>    It's just a terminological difference.  Most of those machines (if
>> I recall correctly) used 2816 NVRAM chips, which are also correctly
>> referred to as EEPROMs.
>
> Oh, so the Mostek unit isn't what this is talking about. Hmm- have  
> to go over the board again.
>
> I saw the Mostek and assumed that it was the same as the 4c/m/u  
> NVRAM setup .

   Duh, I was talking about the 3/200, which (again, if I recall  
correctly) used a 2816, like with most older Sun processor boards.   
If the 4/300 has a Mostek NVRAM chip on it, then the proof is in the  
pudding...I don't have one here anymore.  (sniff)

   At any rate, though, at some point in the late-Sun3 to early-Sun4  
timeframe, they switched from 2816 EEPROMs to the Mostek SRAM chips  
with battery backup tophats on them.

             -Dave

-- 
Dave McGuire
Port Charlotte, FL
Farewell Ophelia, 9/22/1991 - 7/25/2007