Hi Antonio,

At 12:08 PM 4/16/2001 -0700, Carlini, Antonio wrote:
>         You're right - everything beyond the VAX 4000-300 is NVAX.
>         The boards are largely similar and the only differences should
>         be the occasional crystal and a few parts at different speeds.
>
>         The VAX 4000-300 was a Mariah-based CPU (KA670). It used
>         the MS670 memory modules (L4001).
>
>         The later NVAX systems used the MS690 modules and a
>         slightly revised backplane. The later VAX 4000-300 systems
>         also had that same backplane. The part number is 54-19354-01,
>         which you appear to have. (In fact, since your VAX 4000-400
>         works, you already have the necessary backplane and memory).


The KA675 (aka VAX 4000/400) is NVAX ? I was under the impression from what 
information I can glean that the KA675 was a "souped up" Rigel and that the 
KA680 (aka 4000/500) was NVAX based. Oh well, if/when I get one for the 
collection it will be obvious :-) The KA680 is clearly NVAX but there was 
some confusion in some DEC documentation about whether or not the 4000/400 
needed MS670 modules for memory or not, given that NVAX used a different 
memory timing it adds confusion.

Was there a VAX 4000/300A ?

--Chuck