14 Jun
2010
14 Jun
'10
10:35 p.m.
On Tue, Jun 15, 2010 at 4:16 AM, Johnny Billquist <bqt at softjar.se> wrote:
The RQZX1 can be configured as disk-tape or disk-disk.
In the disk-disk
case, one of the disks will use SCSI units 0-3, while the other will use
units 4-6. That would totally explain why your SCSI id 4 maps to MSCP lun 0.
You're on the "second" disk controller. And that also explains why you
cannot use any tapes.
Ok, that helps me understand the unusual addressing behavior I was
seeing. When I added the tape drive, the autoconfigure option on the
RQZX1 did not find the hard disk that was also attached.
Just SCSI as far as I know. The only other connection
is for a floppy,
unless I remember wrong.
More searching and I came across these notes from Terry Kennedy
(buried deeply on DECUS, now Encompass) writing on 4-JUN-1993:
The 50-pin connector is the SCSI bus, the 60-pin connector is for a logic
analyzer for design testing, and the 34-pin connector is for the floppy.
The jumper by the 50-pin connector (JU1) is the termination power enable
jumper. The jumper by the 60-pin connector (JU2) is a reset signal to the
on-board 80186 (jumpering this is a bad idea 8-).
The two switch packs define the 2 logical halves of the controller. There
are two halves, each of which can be set to MSCP or TMSCP.
1 2 3 4 5
OFF OFF OFF OFF OFF MSCP at 17772150 (normal)
OFF OFF OFF OFF ON MSCP at 17760334 (1st alternate)
ON OFF OFF OFF OFF TMSCP at 17774500 (normal)
ON OFF OFF OFF ON TMSCP at 17760404 (1st alternate)
If you need another setting, tell me what it is and I'll post it.
Note that if you change these, you'll need to go into the on-board menu
(get there by booting DU253 or MU253) and do an auto-configure to redefine
the new units.
...and in a followup message Terry Kennedy wrote:
The RQZX1 is the replacement for the RQDXn series controllers. It attaches
SCSI disks and/or tapes to Q-bus PDP-11 systems.
I supposed the big differences between it and the non-DEC competition is:
1) Supports the RX33 floppy via normal floppy interface for backward compat-
ibility with the RQDX3.
2) Provides both disk and tape in the base product - no extra cost.
3) Provided and supported by DEC.
It does not "officially support" bigger disks than the RZ2-something, nor
any tape except the TZ30. Other things do work, however. It's somewhere in
between the KZQSA (I believe that's the model) which only supports tapes and
is kind of lame, and the non-DEC competition. I don't believe it's supported
under VMS. I'm not sure if it works under VMS. It also doesn't "support"
ex-
ternal devices, although there is an external connector and terminator on the
BA23 back panel.
It has a few programming "quirks", which is why the various PDP-11 oper-
ating systems had to have new releases to support it. [I did the driver sup-
port for 2.11BSD Unix]
It's not a bad board. If I were buying a board in this market space to-
day, I'd probably look at the CMD products, just because they don't limit
"support" to a subset of the disk drives, or to only the PDP-11 architecture.
end of quote
Posting here since information about the RQZX1 M5977-AA is difficult to find.