"michael@camaronet.de"  worte:

>On Wed, 2 Feb 2000, Dave McGuire wrote:
>> >But both are very fine boxes, if you like the QBus, you really should get a
>> >4000-300. 4000-500 port might take some while, the CPU is a bit difficult.
>> 
>>   Any thoughts on the 4000-400?  I've got two of them here, currently running
>> VMS.  Pretty zippy machines.  Anybody working on support for them?
>
>Never saw the "internals" of them. What CPU does it use ? My 4000-300 port is
>based on the VS 3100m76 port, so maybe it should be not that big job. If it
>is NVAX based, it's a bit harter, but should go with my plans for the 4000-500
>and 4000-105A

The VAX 4000-400 is based on the KA675 (L4002-CA) which is an NVAX running at
16ns. I'm moderately sure that it has the VIC turned off but my manuals are not
to hand right now.

Basically VAX 4000-400 and upwards all live in the same box, use the same
peripherals etc. and are all NVAX based. They just differ in the CPU module
used. The VAX 4000-400 is the slowest of the bunch at 16VUPs and the VAX
4000-705A is the fastest at 45VUPs. If you can support one you can probably
support them all (the only wrinkle is the VAX 4000-400 has no VIC). IIRC the
last CPU tech doc produced for the VAX 4000-705A (KA694) is just an update of
the VAX 4000-500 manual but with the slight differences highlighted.

Anyway, what's hard about NVAX compared to Rigel? 

Antonio