> > > >3.  How many scsi drives will the thing actually handle?  It has
> > > 
> > > As many as your controller card can handle - probably seven.
> > 
> > I could not get it to recognize a pair of added in RZ56's.
> 
> What I'm surprised at here is the fact that noone seems to have mentioned
> that the VAX really don't see this as a SCSI controller.
> Anything you might have read about SCSI controllers just don't apply to
> what you have.

But, in the end it seems to work fine as scsi on the hardware via mscp.
The joke is that none (read zilch) of my DEC drives will work correctly
on the silly thing.  But, by the graces, NON-DEC drives work fine after
I fiddled with the controller nvram settings.  What is it with these
silly DEC RZ56/57ish things?  Motor spinup is what it seems to be.
The Fuji's from the Sun scrap, worked fine, and now the critter has
3 1 giggers on it with NetBSD-1.4.1 (don't have any tapes rolled for
anything later, and with no ethernet....(:+{{.....).

> This is a MSCP controller, using the SCSI interface to hook up the
> drives. So the limits are defined by the MSCP protocol, as far as the OS
> is concerned, and by the mapping between MSCP and SCSI for the controller.
> 
> If this controller handles both tape a disks, it will actually look like
> two controllers to the VAX, since tapes are handled by TMSCP controllers,
> which are slightly different from MSCP.

OK, for the sake of discussion, I am having fits of problems with my scsi
TK50's trying to write tars for the MV2 TK70.  The Ultrix VS3100M38 box is
just not liking my available TK50 drives very well.  I did run across a two
buck expansion chassis with a TKZ10 (Tandberg) tape drive in it.  I dunno
what the actual tape capacity is on it, since it is unmarked on the tape
door as to density (most Tandbergs are marked).  It could be 60mb or
maybe 150/250/525mb, dunno for sure.  CAN this silly TKZ10 thing be used
on a MV2 off the scsi bus?  IFF so, what should it be ID'd to to work
with the NetBSD drivers (4 or 5?), and what if any funky DEC termination
or jumpering needs to be twiddled?  When I tried a TKZ10 on my Sun 4/110
it fried the scsi ports due to termination power getting into the Sun
board in not quite a standared way.  I DONT EVEN want that to happen to
the MV2 crate since it is a fun toy.  Getting standard 9 or 18 track 1/4
inch cartridge capability into the MV2 would be a great boost over the
TK50 as a second drive.  I am beginning to dislike TK50 drives.  Sneeze
sideways at them and they stop loading tapes.  There must be something
delicate or critical in the way tapes are first read after being loaded.
Three of my TK50's are not working and I only have one usable one left.

Continuing the sakes of discussion...., can an RRD42A cdrom drive be used
in a MV2 off the scsi bus?  I would think so, but dunno for sure, in case
any DEC funzies arise.  That might help porting things into the box as
opposed to writing TK50 tapes or kermitting things into it (gotta build
up kermit still).  I am expecting it should work, since I use the RRD42
on all my DEC scsi things and on my Sun scsi things.

> > Is there something strange like special formatting or such that
> > I need to do to get it to recognize more drives?
> 
> It probably requires the disks to be formatted specifically for them to be
> visible from MSCP. The MSCP protocol assumes there are more intelligence
> than what a SCSI drive have. Thus, the controller adds more intelligence
> to the disk. This requires that the controller sets up some extra
> information on the disk.

Yes, it did.  The easiest approach was to move the console connector from
the CPU to the HD controller and let it boot the controller directly.
Setting the controller to port 7 and then matching the controller ID
ports of 0-5 to drive ID nodes of 0-5 each at lun 0, and writing it back
to the controller nvram, was what it took.  A bit illogical in the way
the thing worked, but after two or three passes I finally got it right.

I do gotta find another ram board of some kind, even 4 megs, since 5
megs is not enough to load Ultrix later than 4.0 and just barely
enough to load NetBSD-1.4.1.

Thanks for the insights, though, since the collective wisdom is most
welcome....

Bob