VAX 4000-200 in BA215 chassis. Can I install a KFQSA card and connect the cabinet disks to it?
2 Jan
2024
2 Jan
'24
11:29 a.m.
I have a couple of VAX 4000-200 boxen running OpenVMS. I want to try out NetBSD on them
but NetBSD does not support the SHAC DSSI controller on the KA660 CPU card. However
NetBSD *DOES* support the KFQSA DSSI controller which I have a few of in my VAX 3800s.
Can I install the KFQSA card in my 4000-200, disconnect the internal disks from the SHAC
and connect the disks to the KFQSA thereby allowing NetBSD to run?
Has anyone done anything like that?
Happy 2024 everyone!
Thomas Dzubin
Calgary, Vancouver, or Saskatoon CANADA
2 Jan
2 Jan
11:42 a.m.
On Tuesday, January 2, 2024 at 11:29:36 AM PST, thomasdzubin--- via cctalk
<cctalk(a)classiccmp.org> wrote:
Can I install the KFQSA card in my 4000-200,
disconnect the internal disks from the SHAC and connect the disks to the KFQSA thereby
allowing NetBSD >to run?
Ive read (here?) that he BA430 has special magic which connects the KA660's SHAC to
the internal DSSI bus, via the Q22 fingers.
The KA660 ROM has built-in machinery to configure DSSI, both the onboard SHAC and a
KFQSA.
So in theory, you could use the KA660 boot-rom to configure the KFQSA.to a different DSSI
node number (not already in use).
Connect the KFQSA to the "end" of the internal DSSI bus, via the DSSI
bulkhead.
NetBSD won't recognise the SHAC, so you shouldn't need to disconnect the internal
DSSI bus, at least for manually booting from the KFQSA rather than the SHAC. I have not
yet tried this myself, though -- my BA430 has a KN220.
11:51 a.m.
On Tuesday, January 2, 2024 at 11:29:36 AM PST, thomasdzubin--- via cctalk
<cctalk(a)classiccmp.org> wrote:
Can I install the KFQSA card in my 4000-200,
disconnect the internal disks from the SHAC and connect the disks to the KFQSA thereby
allowing NetBSD >to run?
Oh wait, your "Vax 4000-200" is a KA660 in a BA215? Then the internal DSSI is
connected via the 50-pin connector piggybacked on the KA660.
Not via the BA430 backplane. Connecting the KFQSA's external DSSI connector to the
other end of the DSSI bus, via an external DSSI cable, should still work.
The possible problem with just disconnecting the DSSi internal cable from the CPU and
leaving it hanging, is no longer terminating that end of the DSSI bus.
12:31 p.m.
When you get it working maybe post some pictures or a brief description of
the setup. I have a 4000-700 that I believe was used in some sort of dual
mode like you describe, but it's still on my to be explored list
On Tue, Jan 2, 2024, 2:51 PM Jonathan Stone via cctalk <
cctalk(a)classiccmp.org> wrote:
On Tuesday, January 2, 2024 at 11:29:36 AM PST, thomasdzubin--- via cctalk
<cctalk(a)classiccmp.org> wrote:
Can I install the KFQSA card in my 4000-200,
disconnect the internal
disks from the SHAC and connect the disks to the KFQSA thereby allowing
NetBSD >to run?
Oh wait, your "Vax 4000-200" is a KA660 in a BA215? Then the internal DSSI
is connected via the 50-pin connector piggybacked on the KA660.
Not via the BA430 backplane. Connecting the KFQSA's external DSSI
connector to the other end of the DSSI bus, via an external DSSI cable,
should still work.
The possible problem with just disconnecting the DSSi internal cable from
the CPU and leaving it hanging, is no longer terminating that end of the
DSSI bus.
12:56 p.m.
On Tue, Jan 2, 2024 at 11:51 AM Jonathan Stone via cctalk
<cctalk(a)classiccmp.org> wrote:
On Tuesday, January 2, 2024 at 11:29:36 AM PST, thomasdzubin--- via cctalk
<cctalk(a)classiccmp.org> wrote:
The BA215 internal DSSI cable wouldn't be left hanging when it is
disconnected from the KA660 DSSI connector, it would be connected to
the KFQSA instead. So there would be no DSSI bus termination issues.
I have a BA215 that I sometimes alternate between a KA660, and an
M7554 KDJ11-D/S PDP-11/53 (which was originally a DECserver 550 CPU
board). When the M7554 KDJ11-D/S is installed I either use a QBus SCSI
controller, or a KFQSA attached to the internal DSSI bus.
Can I install the KFQSA card in my 4000-200,
disconnect the internal disks from the SHAC and connect the disks to the KFQSA thereby
allowing NetBSD >to run?
Oh wait, your "Vax 4000-200" is a KA660 in a BA215? Then the internal DSSI is
connected via the 50-pin connector piggybacked on the KA660.
Not via the BA430 backplane. Connecting the KFQSA's external DSSI connector to the
other end of the DSSI bus, via an external DSSI cable, should still work.
The possible problem with just disconnecting the DSSi internal cable from the CPU and
leaving it hanging, is no longer terminating that end of the DSSI bus.
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