Subject: Re: VAX 4000/200 issue resolved!
To: Jon Lindgren <>
From: Chuck McManis <>
List: port-vax
Date: 09/26/2000 10:16:54
At 05:54 AM 9/26/00 -0400, Jon Lindgren wrote:
>It does?  Does that mean that the C/D connectors on my 4000/200 has DSSI
>running down it?  How would that work?  Where would it terminate?

Yup. The signals go both to the connector next to the memory connector and 
to the C/D connectors. When the CPU is installed in the BA215 or BA213 the 
DSSI drives connect via a cable to the CPU, when the CPU is in a BA440 the 
C/D slots connect up through the backplane into the top of the chassis. 
Since there is a paddle board in there, and it is clearly designed to hook 
up the DSSI drives, my only guess is that it gets used if you use the KA640 
CPU in the BA440 chassis (was there ever a MicroVAX 3400 in the BA440?) The 
bottom line is that is isn't used for the KA660.

>Don't the memory boards use the C/D connectors for additional lines, using
>the 50 pin berg for actual data transfer?  How is this possible?

Most of the memory traffic goes over the 50 pin cable on the top. However, 
I did notice that some third party MS650 memory would not work with the 
KA660 installed, but with other memory cards it worked fine (these same 
memory cards worked with the KA640 CPU)