Trying to get my RLV11 working

Noel Chiappa jnc at
Tue Oct 27 16:11:59 CDT 2015

    > From: Ben Sinclair

    > I'm trying to get my RLV11 working

Oh, I was going to mention this about the RLV11 - it's a Q18 device. So it
_probably_ won't work in a system with more than 256KB of memory (which you
don't, at this point, have, though). It would all depend on the OS, whether
it understood that it couldn't DMA to anywhere above 256KB. (The controller
should work OK in a Q22 system - it just won't drive the high address lines,
so they will go to 0 - but it just won't be able to DMA to high memory.)

    > I have a PDP-11/23 in an H9273 backplane. I just got it working
    > reliably without the RLV11 boards installed ...
    > Here's my configuration:
    > Down the left side: M8186, M8044, M8044, M8043, M8013, M8014, and
    > M8012 (the BDV11) on the bottom.

Here's something to try (to make sure the 8013 is passing grants OK); put the
M8013/14 _before_ the M8043, and see if a test which uses interrupts on the
DLV11J works.

    > I also looked at  myself and get 005737, though I'm not sure what
    > it should be.

I take it "17440" is a typo for '174400'? Anyway, neither would work: in
11/23 ODT, '174400' is the address of a word of memory, up near the 64K
boundary. To get to the device registers, you need to type '774400'. If that
doesn't work, the addressing on the RL11 board-set is wrong somehow.


PS: Speaking of typing addresses to ODT - My favourite pet 11/23 peeve: there
is no way, from ODT, to read/write memory above 256KB! That can only by done
by a program! (The 11/73 does not suffer this issue.)

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