J. Buck Caldwell wrote:

>What memory modules are compatible with what processors?

>In other words, can I take memory from a KA650 and attach it to a KA660?

The KA630 uses the MS630 series

The KA650 can use MS650-A and MS650-B
The KA655 can use only the faster MS650-B
The KA660 can use only MS650-B

I don't recall whether the KA640 can use
the MS650-A as well as the MS650-B.

>I know that the KA630 and KA640/65x style memory boards are different,
>but are the KA650 memory boards compatible with 4000-series CPUs?

Yes and no; but only for suitable values of 4000 :-)

The KA660 (VAX 4000-200) is described above.

The KA670 (VAX 4000-300) uses the MS670 memory.

The KA680 (VAX 4000-500) onwards use MS690 memory
(and an enahanced backplane). 

The KA660 is the only VAX 4000-xxx that has memory
that plugs into the Q-bus (albeit only for power).
The rest use a different chassis and a
local bus for memory.

>Also, perhaps important in the near future, if nobody outbids me - can
>memory in a 4000/200 be used by a 4000/500?

No.


Antonio