Booting an IBM MP 3000 S/390 System

Jay Jaeger cube1 at
Thu Aug 6 20:22:48 CDT 2015

Four, I expect:

CPU, Memory, VAX Interface, Floppy Controller.

I have one in pieces floating around here somewhere.

One of those puppies (probably the one I have) held our VAX hostage for
DAYS while the service folks from the OEM (Intergraph) tried to figure
out what was wrong - they kept blaming the console processor which was
not the problem.  Turned out to be a recently added power supply - which
I had pointed out to them was something that changed, and something we
could do without as a test.  Sigh.

On 8/6/2015 7:13 PM, Jon Elson wrote:
> On 08/06/2015 04:01 PM, Jay Jaeger wrote:
>> Until that console processor fails with no backups.  I seem to recall
>> having 4 or 5 "backups" (aka operators).  ;)
> Well, the idea is that the console or diagnostic processor is WAY
> simpler than the mainframe CPU.  So, if the console computer dies, you
> can troubleshoot it and be sure it is running in just a few minutes, and
> then get on to the real problem.
> The VAX 11/780 had an LSI-11 with a floppy controller and an interface
> board to the VAX, so I think it was down to 3 boards or something.
> Jon

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