booting from RQDX3

From: Jerome Fine <jhfine_at_idirect.com>
Date: Thu May 31 13:55:57 2001

>Jonathan Engdahl wrote:

>How does a PDP-11 boot from an RQDX3 controller?

Jerome Fine replies:

Why are you bothering with an old PDP-11/23? There are much faster
systems that are readily available and since you have ONLY four serial
channels (I presume that you are using an M8043/DLV11-J module),
why would you not switch to a faster, more capable system? Unless
you just like the actual hardware in which case you should not mind
the following answer:

Usually from a program stored somewhere in memory. The storage
is almost always on an EPROM, but on occasion it can be on a
sheet of paper. I suppose that for someone who has a photographic
memory, the storage media would be in their brain. In any case, after
the system receives this PRIMARY BOOT program in a form that
it can use, the next step is to read the secondary boot program from
block zero of the media - in your case, the hard disk drive. If you are
willing to spend about 5 minutes typing in a PRIMARY BOOT
program each time you power on the system, them, the RQDX3 can
be used.

If the answer is yes, I will be happy to locate a suitable BOOT program
and type it in for you. I seem to remember it was about 75 words of
code and data, but that could be wrong.

Not that this program would also boot a floppy with XXDP so that
you would be able to format the hard drive.

Please reply if you want me to find it.

Sincerely yours,

Jerome Fine

--------------------------------------------------------------------------------------------------------------------------

I have several 11/23's based on the KDF11-AA CPU, which has no on-board boot ROM. The Andromeda UDC11 disk controller that most of these use
contains the boot ROM. These machines are in a 4-slot dual-wide card cage which is full. There is the CPU, a memory card, the disk
controller, and a serial card.

A couple of these machines are missing the disk controller. RQDX3's seem to be readily available, and there is adequate documentation of the
card on the web (jumpers, cable pinouts, etc). Will the KDF11-AA be able to boot from an RQDX3?

If not, can anyone suggest an good alternative?

--
Jonathan Engdahl             Rockwell Automation
Principal Research Engineer  24800 Tungsten Road
Advanced Technology          Euclid, OH 44117  USA
Euclid Labs                  http://users.safeaccess.com/engdahl
Received on Thu May 31 2001 - 13:55:57 BST

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