DEC RQZX1 and KDJ11-E boot problem?

Zane H. Healy healyzh at
Tue Jun 15 09:46:50 CDT 2010

At 3:35 PM +1000 6/15/10, Nigel Williams wrote:
>...and in a followup message Terry Kennedy wrote:
>   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


>   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

I think these two bits of info are the key ones...

Also, from the RSTS/E 10.1 SPD:
SCSI Support:

o  There is no SCSI device handler. The SCSI disk devices are treated
    as MSCP disks using DUDVR.

o  RQZX1 SCSI adapter-Provides two ports that can be configured (via
    a hardware switch on the RQZX1 board itself) as the following:

    -  2 disk ports

Each port has it's own CSR and is considered to be a separate controller.

Each disk port can support up to 4 disks (i.e. RX33, RZ23L, RZ24L).

Since the RQZX1 supports RX33 floppy disks, these disks must be counted
in this maximum number of four. For example, one RX33 floppy attached
to the RQZX1 disk port will allow up to three additional SCSI disks
to be attached to that port.

The maximum number of RQZX1 adapters supported per system is one.

RSTS/E does not support any SCSI devices attached outside of the sys-
tem box.

Note: HARDWARE RESTRICTION: Support for the RQZX1 adapter is limited
to microcode version 2.1 or later.

Terry's comments seem to indicate you need DEC HD's.   You're 
definitely good up to a RZ24 based on the SPD, though it would be 
good to know how high you can go.  I've used the equivalent of an 
RZ28 (a 2GB Seagate Barracuda on my Viking QDT board).  What is 
interesting is that the SPD doesn't mention supporting the TZ30, yet 
Terry mentions the board supports it, and he ran RSTS/E.

All this seems to support my suspicion that you need DEC branded hard 
drives.  The more interesting question is, can you use DEC branded 
tape drives.

I sent a dealer I know that specializes in PDP-11's a few questions, 
I'll let you know if find out anything.


| Zane H. Healy                    | UNIX Systems Administrator |
| healyzh at              | OpenVMS Enthusiast         |
|                                  | Classic Computer Collector |
|     Empire of the Petal Throne and Traveller Role Playing,    |
|          PDP-10 Emulation and Zane's Computer Museum.         |
|                     |

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