Building a PDP-11 for the first time

[Megan]

>From what I understand, the 11/73 and 11/83 are both J-11 cpus, the only 
>difference being that the /73 runs at 15MHz and the /83 runs at 18MHz.  
>The issue is that there's NO SUCH THING as an 11/84 cpu card, since 
>11/84 systems use an 11/83 (ie qbus) cpu with a Qniverter to convert to 
>UNIBUS.

Back when we were working on the changes to RESORC to correctly report
the various types of KDJ-based machines, it was explained to us (in
RT-11 development) that a dual-high KDJ11-A was simply reported as an
11/73.  The KDJ11-B (running at either 15Mhz or 18Mhz) using normal
memory was to be referred to as an 11/73B.  A KDJ11-B (running at
either 15Mhz or 18Mhz) using PMI memory was to be referred to as an
11/83.

It was my understanding that the standard KDJ11-B was also the heart
of the 11/84 machine (and could be distinguished from the QBus
*system* due to a UNIBUS bit in one of the registers).  I have heard,
though, that only specific revisions of the KDJ11-B board could be
used in the 11/84 system.

I am willing to be corrected, however... though my experience tells
me different.

Since I scavanged one from parts in the hallways of the Mill back when
the RT group was on ML5-5, I simply grabbed parts and put an 11/84
together and it worked fine with what I had (and in fact we used that
machine to do the unibus map support for the RT-11 device handlers
back when we put that support in -- I remember specifically working
on the DEUNA/DELUA handler)

                                        Megan Gentry
                                        Former RT-11 Developer

+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL   | email: mbg at world.std.com         |
| Member of Technical Staff      |        megan at savaje.com          |
| SavaJe Technologies, Inc.      |             (s/ at /@/)             |
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