PDP-11/45 RSTS/E boot problem

Fritz Mueller fritzm at fritzm.org
Sun Jan 27 17:06:14 CST 2019


> On Jan 27, 2019, at 1:34 PM, Paul Koning <paulkoning at comcast.net> wrote:
> 
> I have the impression that RSTS tries to identify the parity CSRs by forcing wrong parity and seeing which CSR reports the issue.  So if you have a CPU ECO issue that causes trap to 114 not to work, I don't see how you could get RSTS to start at all.
> 
> Can you query the parity information (in defaults->memory->parity) and post the result?

I'm pretty sure my machine can't take a trap to 114, because I have verified that it is missing (at least) the backplane wire that delivers UBCB PE TRAP (L) to the M8100 as well as R17 and the decodes at E7 and E11 on the M8100 that are necessary to deliver constant 114 to the TV input of K1MX.

However, RSTS init defaults->memory->parity reports (correctly):

  0K: 00000000 - 00757777 ( 124K) : 00

I'll keep you posted about what I find out from ANALYS!

	thanks,
          --FritzM.



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