[TUHS] Unix on an 11/23 (Was: Work I've done with a PDP-11 simulator)

Noel Chiappa jnc at mercury.lcs.mit.edu
Fri May 16 06:56:59 AEST 2014

    > From: SPC <spedraja at gmail.com>

    > I'll keep a reference of this message and try it as soon as possible...

No rush! Take your time...

    > the disruptive fact (in terms of time) here is to put up-to-date both
    > the PDP-11/23-PLUS and RL02. 

My apologies, I just now noticed that you have an 11/23-PLUS (it is slightly
different from a plain 11/23).

I am not very familiar with the 11/23-PLUS (I never worked with one), but from
documentation I just dug out, it seems that they normally come with the MMU
chip, so we don't need to worry about that. However, the FPP is not standard,
so that is still an issue for bringing up Unix.

In fact, there are two different FPP options for the 11/23-PLUS (and,
actually, for the 11/23 as well): one is the KEF-11AA chip which goes on the
CPU card (on the 11/23-PLUS, in the middle large DIP holder), and the other is
something called the FPF-11 card, which is basically hardware floating point
(the KEF-11A is just microcode), for people who are doing serious number
crunching. It's a quad-size card which has a cable with a DIP header on the
end which plugs into the same DIP holder on the CPU card as the KEF-11A. They
look the same to software; one is just faster than the other.

Anyway, if you don't have either one, we'll have to produce a new Unix
load for you (not a big problem, if it is needed).


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