bit slice chips (was Re: Harris H800 Computer)

Noel Chiappa jnc at
Sat Apr 23 13:16:18 CDT 2016

    > AFAIK, the only non-FPP board in the CPU which is interchangeable
    > between the two machines is the M8132 (instruction register decode &
    > condition codes)

So it seems like there's an(other) error in the DEC documentation.

If one looks at 11/70 Maintenance Manual (EK-11070-MM-002), it says (pg. 1-3)
that the KB11-C (11/70 later CPU) contains an M8133 ROM and ROM Control
board, the same as the KB11-B (earlier CPU, pg. 1-4), _but_ ...

The KB11-C prints include the drawings for the M8123 (also used by the
KB11-D, the later /45 CPU). Other manuals confirm that the KB11-C uses the
M8123 (see, e.g., the KB11-A,D Maintainence Manual, EK-KB11A-MM-004, pg 1-1).

I _thought_ the KB11-D used two of the same boards as the KB11-C, but then,
when I went to check, to be sure I had the correct info (before sending out
my email intended to "just want to be accurate", sigh), I relied on the DEC
manual... :-(

Oh well, that's what I get for relying on DEC manuals! :-)


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