UniBone: Linux-to-DEC-UNIBUS-bridge, year #1

Noel Chiappa jnc at mercury.lcs.mit.edu
Fri Nov 22 07:38:57 CST 2019

    > Although, with the 3 SPC slots - although they are on UNIBUS A, and only
    > UNIBUS B has the 18-bit capability

Duhhhh. My brain finally turned on.

It is of course perfectly possible to run UNIBUS _A_ (where the SPC slots are)
in 18-bit mode too - although the _RH11_ can't use it that way. But you won't
be using the RH11 anyway, so who cares?

Also, I took another look at the KS10 tech manual, and they do in fact use use
an M9200 'thin' jumper (although it's mis-labelled "M9300" in the diagram -
that diagram has a number of errors, including the "M8014" in the UNIBUS 'A'
In slot - they must mean an M9014 [UNIBUS to 3 flat cables] instead) to link
the two UNIBI together. Which answers the question of how the KS10 CPU gained
access to UNIBUS A (where the device registers, interrupts, etc are) when it
also had to be connected to UNIBUS B (for 18-bit data transfers).

So I think all our questions are answerered (except for the -AB/-C difference


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