DL11 M7800

Noel Chiappa jnc at mercury.lcs.mit.edu
Wed Jun 15 12:51:25 CDT 2016

    > From: William Degnan

    > OMG

Yeah, but look at it this way: their being inverted can be a memory jogger -
'Oh, the DL11, that effed-up interface where the jumper sense is inverted
between address and vector!' Then you only have to look up one of the two.. :-)

    > Yes, so I can use a terminal with the machine, I need a working
    > terminal.

"Terminal" != "console". (Or, rather, the latter is a unitary subset of the
former.) The 'system console' is, by definition, on all PDP-11's, a DL11-type
serial interface at 777560. However, it may have many 'terminals'! :-)

    >> For 777560/60 (standard for the console), you want A7/A3 and V4/V5 'in'.

    > I think you mean 60/64, right?

Sort of (unless you mean 'instead of 777560/60, you meant 60/64, right?').
777560 is the base address, 60 is the base vector.

The receiver registers are 777560-2, and the transmitter are 777564-6, but on
the DL11, one can only set the base of the entire group of 4 registers, one
can't move the transmit and receive around independently. Similarly for the
vector, one can only set the base; the receive (B) and transmit (B+4) are
paired in the hardware.

Hence, "777560/60".


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