On May 25, 2021, at 11:54 AM, Glen Slick via cctalk <cctalk at classiccmp.org>
On Tue, May 25, 2021 at 10:54 AM Zane Healy via cctalk
<cctalk at classiccmp.org> wrote:
One odd thing is that the KA640-A seems to plug into another board, before the DSSI
drives. I?m getting ready to dig into that, and find out what that board is.
Is that an M9715 board plugged into the backplane between the CPU
board slot and the power supply, or something else?
Or is there a cable plugged into the DSSI connector on the M7624 KA640
adjacent to the memory bus connector that plugs into a some board and
stops there, and then another cable from that board to the DSSI
drives? Do the DSSI drives plug into the backplane, or do they have
cables connecting to them?
It turns out that the oddness was the CPU Board, and a 16MB Clearpoint RAM board. What I
thought was the CPU, is really the header panel over the RAM and TK70 controller. There
is also a M9715 between the CPU and the powersupply that I?d missed seeing. The cables to
get to the DSSI connector by the Powersupply are hanging out the front. Basically it?s a
cable going from the KA640 to a ribbon cable to a cab kit, then DSSI cable from that to
the connector next to the power supply.
I disconnected the DSSI cable from the KA640 (M7624), and got the same errors.
The more I play with this, the more I like the chassis, and the more I want to get it
going. This chassis is definitely better than the 3rd party rack-mount chassis that my
MicroVAX 3 lives in. If it was working, it would simply need my RLV12 moved to it to be
At this point, I?m suspecting an issue with the KA640 board.