I wrote, earlier today,

> But those controllers connect to a breakout board which is placed
> outside the usual Q-bus enclosure, in a slot marked "13".

Various people have said that the equivalent of this breakout board is
already included in what I called the "skinny" enclosure (BA23, I
think).  True as this is, it doesn't quite address what I wanted to do.
I want to put the RQDX3 into the home machine, with the breakout board
from the "fat" enclosure (BA123).  I want to do this primarily because
the breakout panel built into the BA23 can't handle more than two
drives.  Obviously, neither can its physical mounting, but for these
purposes I'm happy to run with the drives outside the case, probably on
another power supply in fact.  That's why I was asking about the "slot
13".  Everyone agrees that all it's providing is power - but is the
power on the same pins as an ordinary Q-bus slot?  Will it work to just
slap this board into a spare slot in the BA23?  (Downstream of all
Q-bus devices, to be sure; I do know about daisy-chained signals and
grant continuity!)

Responding to a few specific comments,

> In the worst case, you have to format them.

How would I do that?

> But if they do nothing at the moment, check out, if you have ESDI
> drives connected to a ST506-controller.  If the M8639 is ESDI, you
> might have trashed something now.  The connectors of ESDI and ST506
> are the same, but the signals are very different.

How do I tell which is which?  The drive that works is a Micropolis
1325, marked as an RD53.  The rest are also Micropolis, one marked as
1325, the others as 1325D.

> The problem is that you need to take home a RQDX3 (M7555).

I'm now at home and I just checked - and the controller in the BA23
*is* an M7555.

Interesting.  I've tried the drives again.  Here's how the boot
messages look with no second drive connected:

MicroVAX II
realmem = 9428992
avail mem = 6578176
Using 115 buffers containing 471040 bytes of memory.
mainbus0 (root)
cpu0 at mainbus0: KA630
uba0 at mainbus0: Q22
mtc0 at uba0 csr 174500 vec 774 ipl 17
mscpbus0 at mtc0: version 4 model 3
mscpbus0: DMA burst size set to 4
mt0 at mscpbus0 drive 0: TK50
uda0 at uba0 csr 172150 vec 770 ipl 17
mscpbus1 at uda0: version 2 model 3
mscpbus1: DMA burst size set to 4
ra0 at mscpbus1 drive 0: RD53
qe0 at uba0 csr 174440 vec 764 ipl 17
qe0: deqna, hardware address 08:00:2b:05:10:ba
boot device: ra0
root on ra0a dumps on ra0b
ra0: size 138672 sectors
root file system type: ffs
Enter pathname of shell or RETURN for sh: 

With each of the four disks as the second drive:

Drive 1:
at boot		ra1 at mscpbus1 drive 1: RD51
disklabel ra1	ra1: attempt to bring on line failed:  media format error (unknown subcode) (code 5, subcode 6)

Drive 2:
no ra1 found at boot

Drive 3:
at boot		ra1 at mscpbus1 drive 1: RD51
disklabel ra1	ra1: attempt to bring on line failed:  media format error (unknown subcode) (code 5, subcode 6)

Drive 4:
no ra1 found at boot

There is something very odd going on, though.  I tried moving the
working drive (ra0 above) to the "drive 1" connectors instead of the
"drive 0" connectors.  With nothing, or drive 1 from the above list, on
the "drive 0" connectors, the working drive still shows as UDA0 aka ra0
(when it shows up at all, that is - with drive 4 on the "drive 0"
connectors, I couldn't get anything to boot, but alone, or with drive 1
there, it works as described).

I'll fiddle with it s'more, and if I find anything noteworthy I'll drop
another note here.

					der Mouse

			       mouse@rodents.montreal.qc.ca
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