MicroVAX 3300/3400

[Glen Slick]

On Wed, May 26, 2021 at 2:35 PM Zane Healy <healyzh at avanthar.com> wrote:
>
> One question, do I need to worry about the batteries on the H3602-SA panel?  I can’t imagine that this would be causing any issue.
>

Yes, you do need to worry about the Ni-Cad battery pack on the
H3602-SA panel. Remove it and throw it away. If it hasn't started
leaking and causing corrosion yet it is only a matter of time before
it does. I have removed all of the Ni-Cad battery packs from all of
the VAX systems I have.

> An interesting thing about the BA430 backplane is that in addition to
> the M7626 KA660 CPU DSSI bus being present on the 50-pin connector, it
> is also present on the C/D connectors, and the BA430 backplane routes
> the DSSI bus on slot 1 C/D connectors to the DSSI storage device bays
> without the need for a DSSI cable.
>
> I finally found that, in the “KA660 CPU System Maintenance” manual.  What’s interesting is that there is also a 50-pin header on the KA660, and I’m not yet clear on why. :-)
>

The M7626 KA660 VAX 4000-200 was available in BA430 and BA215 enclosures.

VAX 4000 Model 200 (BA215) Installation, Order Number EK-432AB-IN-002
https://manx-docs.org/collections/antonio/dec/MDS-2000-01/cd1/VAX/432ABIN2.PDF

In the BA430 enclosure the KA660 DSSI bus is connected to the DSSI bus
on the backplane through the KA660 C/D connectors, and nothing is
connected to the 50-pin DSSI connector on the front of the KA660
module.

In the BA215 enclosure the DSSI bus is cable based and connects to the
50-pin DSSI connector on the front of the KA660 module.